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The relationship between buccofacial and limb apraxia

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The relationship between buccofacial and limb apraxia
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Raade, Adele S., 1956-
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1990
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English

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University of Florida
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University of Florida
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Copyright Adele S. Raade. Permission granted to the University of Florida to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
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Full Text
THE RELATIONSHIP BETWEEN BUCODFACIAL AND
LIMB A1RAXIA
By
ADELE S. RAADE

A DISSERTATION PRESENTED TO ME GRADUATE SCHOOL OF THE UNIVERSITY OF FIDRIIDA IN PARTIAL FULFIIMENT
OF THE REQUIREMENIS FOR THE DEGREE OF
DOCIOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
1990

UNRIV'Sill U 1 j 7-




ACNOMLEDGEENTS
This dissertation would not have been possible without the assistance of a number of individuals. I am deeply indebted to Dr. Leslie Gonzalez-Rothi for her persevering support and her belief in me. I am grateful to Dr. Ken Heilman for the creative spark he infused into the project. I thank my other ccumittee members, Drs. Thomas Abbott, Russ Bauer and Mike Crary, for their support and understanding when deadlines were tight. I appreciate Dr. Ken Gerhardt, who very graciously and willingly agreed to serve as a substitute committee member.
Other individuals were also instrumental in the completion of this dissertation. I thank Janice Howell, who assisted me with the grueling task of scoring of the videotapes. I appreciate Joy Davey, who was always there when I needed her. I thank my parents and family, who continue to support me in my endeavors. And last but not least, I am deeply indebted to Dave Steels for his patience, love and unquestioning support.




TABLE OF CONTENTS
LIST OF TABLES .................................................... v
ABSTRACT .......................................................... vi
CHAPTERS
1 BUCCOFACIAL AND LIMB APRAXA ............................ 1
Buccofacial Apraxia ......................................... 1
Incidence .......................................... 2
Clinical Relevance ................................. 3
Nature of the Disorder ............................. 3
Limb Apraxia ............................................ 11
Incidence .......................................... i
Transitivity Factor ................................ 12
Error Type Analysis ................................ 13
Mechanisms of Limb Apraxia ......................... 16
Relationship Between Buccofacial and Limb Apraxia ....... 24
Possible Constructs ................................ 25
Clinical Relevance ................................. 26
Transitivity Factor ................................ 27
Error Type Analyses ................................ 28
Statement of the Problem ................................ 30
2 METHODO aY............................................. 34
Subjects ................................................ 34
Procedures and Testing Materials ........................ 35
Screening Tests .................................... 38
Experimental Tests ................................. 40
Apraxia Scoring Reliability ........................ 42
Localization of the Lesion .............................. 44
3 RESULTS ................................................. 45
WCaTarisons Between Groups .............................. 45
Behavioral Test Results ................................. 45
Screening Tests .................................... 45
Experimental Tests ................................. 47
iii




Research Questions ......................................
Research Question #1 ...............................
Research Question #1a ..............................
Research Question #1b ..............................
Research Question #1c ..............................
Research Question #2 ..............................
Research Question #3 ..............................
4 DISCUSSION .............................................
Research Questions ......................................
Implications for Future Research ........................
Clinical Implications ...................................
APPENDICES
A ERROR TYPE CATEGORIES AND DEFINITIONS FOR LIMB
MOVEMENTS. .... .....................................
B LIST OF JBUCCOFACIAL AND LIMB STIMUIIJS ITEMS .............
C ERROR TYPE CATEGORIES AND DEFINITIONS FOR JBUCCFACIAL
AND LIMB VEMENTS..................................
D INTERRATER RELIABILITY MEASURES FOR THE ACCURACY
JUDGEMENT FOR EACH BUCOOFACIAL AND LIMB MOVEMENT AS EXPRESSED BY A EAPPA STATISTIC.....................
E INTERRATER RELIABILITY MEASURES FOR THE MAIN TYPE OF
ERROR JUDGEMENT FOR EACH MOVEMENT AS EXPRESSED BY
PERCENTAGE AGREEMENT (P.A.) ........................
F BANK CHECKLIST OF SPECIFIC NEIUROANAIOMIC STRUCITRES ....
G COMPLETED CHECKLIST OF INVOLVEMENT OF SPECIFIC
NEUROIANATCMIC STRUCIURES FOR EACH EXPERIMENTAL
SUBJECT............................................
BIBLIOGRAPHY. .....................................................
BIOGRAPHICAL SKETCH ...............................................




LIST OF TABLES

Table Paq
2-1 Descriptive demographic data for the experimental and control groups ....................................... 36
2-2 Detailed descriptive data on each of the experimental subjects ............................................. 37
3-1 The relationship between the production of buccofacial
and limb movements ................................... 50
3-2 The means and standard deviations for each of the four types of movements for the experimental and control
groups ............................................... 51
3-3 The observed and expected frequencies of each type of
error for buccofacial and limb movements ............. 55
3-4 The relationship between the comprehension and
production of buccofacial movements .................. 57
3-5 The relationship between the comprehension of
buccofacial movements and the integrity of the
inferior parietal lobule (IPL) ...................... 59
3-6 The relationship between the comprehension of
buccofacial movements and the involvement of specific
neuroanatomic structures for each experimental
subject .............................................. 61
3-7 The presence of buccofacial apraxia and the involvement
of specific neuroanatomic structures for each
experimental subject ................................. 62




Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy
THE RELATIONSHIP BETWEEN JUOOOFACIAL AND LIMB APRAXIA
By
ADELE S. RAADE
May 1990
Chairman: Leslie J. Gonzalez-Rothi, Ph.D. Major Department: Communication Processes and Disorders
There are at least two possible constructs depicting the nature of the relationship between buccofacial and limb apraxia. In the first construct, apraxia is viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb output. A high degree of concordance and similarity between the two types of apraxia would support this model. The second construct would postulate that the relationship between buccofacial and limb apraxia is not unitary. The presence of quantitative and qualitative differences between buccofacial and limb performance would support this construct. The purpose of this study was to determine if buccofacial and limb apraxia are manifestations of a unitary disorder or a non-unitary disorder. In addition, the possible presence of two types of buccofacial apraxia was examined, as well as the neuroanatomy of the disorder.




The experimental group was ccmprised of fifteen subjects who had experienced a single, unilateral, left-hemisphere cerebrovascular ac-ident. The control group was ccorised of eight neurologically intact adults matched for age, sex and education.
Results indicated that there were a significant number of double dissociations, that the transitivity factor was manifested in a dissimilar manner, and that the proportion of error types was dissimilar between the two disorders. These results support a nonunitary construct for buccofacial and limb apraxia. In addition, results indicated that two different types of buccofacial apraxia were exhibited: one type characterized by impaired production and comprehension, and the second type characterized by impaired production but preserved comprehension. This is similar to the pattern that has been reported previously for limb apraxia. Regarding the neuroanatomy of the disorders, previous research has suggested that the inferior parietal lobule (IPL) is a critical neuroanatomic structure for the coprehension and production of limb movements. In contrast, the results of this study suggest that the IPL is not a critical structure for the comprehension and production of buccofacial movements. Instead, it appears that structures anterior to the IPL are the crucial areas for buccofacial performance. These results suggest that the buccofacial and limb praxis system are, at least in part, functionally and anatomically independent systems.

vii




C(APIER 1
BUCCOFACIAL AND LIMB APRAXIA
Steinthal (1871) was the first to use the term apraxia to describe impaired performance of skilled movement in the absence of weakness or discoordination. More recently, Geschwind (1965) and Heilman and Rothi (1985) have provided an exclusionary definition of apraxia as "a disorder of skilled movement not caused by weakness, akinesia, deafferentation, abnormal tone or posture, movement disorders (e.g., tremors or chorea), intellectual deterioration, poor comprehension, or uncooperativeness" (p. 131). In addition, Rothi, Mack, Verfaellie, Brown and Heilman (1988) defined the nature of errors associated with ideamotor apraxia of the limbs. Numerous other forms of apraxia have been described including dressing, constructional, truncal, gait, verbal, ideational, limb-kinetic, verbo-motor, and buccofacial. However, this dissertation will deal exclusively with the buccofacial and limb ideamotor apraxias.
Buccofacial Apraxia
Buccofacial apraxia is a form of apraxia (as described above)
specific to oral/facial structures. It was first described by Jackson (1878/1932), who described a patient with spared comprehension who was unable to stick out his tongue on command, but was able to use his




tongue to remove a bread crumb from his lip. However, buccofacial apraxia is not limited to the tongue and is characteri,.d by the inability to also correctly perform skilled movements with the muscles of the larynx, pharynx, lips and cheeks (Heilman & Rothi, 1985). For example, when asked to pantamle blowing out a match, a patient with buccofacial apraxia may be unable to perform this action correctly. He may incorrectly place his lips or may actually say the word "blow." However, he may improve if a lit match is placed in front of his mouth. Incidence
The incidence of buccofacial apraxia is variable and influenced by task and subject selection. Mintz, Raade and Kertesz (1989) performed a retrospective study on the incidence of buccofacial apraxia in righthanded subjects subsequent to a single lesion of their left hemisphere. From a series spanning a 10-year period of 314 patients who were evaluated for the possible presence of aphasia, 112 were selected as meeting the criteria of right-handedness and the presence of a single lesion, 108 of whcm were aphasic. In order to determine the presence of buccofacial apraxia, the five-item buccofacial subcamponent of the apraxia subtest of the Western Aphasia Battery (Kertesz, 1982) was administered in the initial 7 to 45 days post onset. The control group's average buccofacial score minus two standard deviations was utilized as the cut-off score between normal and apraxic performance. Seventy-three of the 112 subjects (65%) demonstrated a buccofacial apraxia. These results suggest that buccofacial apraxia is frequently associated with left-hemisphere damage.




Clinical Relevance
Beca, se this disorder is frequently associated with left-hemisphere lesions, it frequently co-occurs with language ard/or speech disorders. A speech-language pathologist may choose to use verbal prompting to facilitate the patient's compensation for articulatory deficits, such as "close your lips," or "put your tongue up" (Square-Storer, 1989). The presence of a moderate or severe case of buccofacial apraxia would create a significant barrier to this type of treatment. In order to effectively treat a neuropsychological disorder, it is important to understand the neuropsychological mechanism underlying the disorder, and to use that information to direct treatment task selection. Unfortunately, there have not been many reports elucidating the brain mechanism(s) underlying buccofacial apraxia. Nature of the Disorder
An analysis of factors that influence buccofacial praxis
performance may provide clues to its underlying mechanism. There have been anecdotal reports that the performance of "emotional" movements with the same sets of facial muscles used in practic behaviors may not be impaired (Critchley, 1953; Kertesz, 1979). "Emotional" movements are behaviors that may be produced spontaneously (e.g., blowing a kiss in response to a departure), or may be produced upon verbal request (e.g., demonstrating how to blow a kiss to scueone). Borod, Lorch, Koff, and Nicholas (1987) examined subjects with left- and right-hemisphere cerebrovascular pathology for two forms of facial behavior, one in response to a neutral or nonemotional command, and the other in response to an emotion-associated commaid. For example, one of the neutral




commands was "lower your eyebrows," whereas the emotional analog was "lower your eyebrows like a frown." Each buccofacial movement was assessed for accuracy and motor execution. They found that lefthemisphere-damaged subjects were significantly more impaired in these buccofacial tasks relative to right-hemisphere-damaged and normal control subjects for both accuracy and motor execution. The emotional cues appeared to facilitate performance for all subjects. However, the performance of the left-hemisphere-damaged patients improved the most. In summary, the literature cited suggests that an emotional context can facilitate the facial motor performance of left-brain-damaged patients with buccofacial apraxia. It was suggested that the right hemisphere may be mediating the "emotional" performance.
Error Type Analysis. An analysis of error types may also provide clues to the underlying mechanism of buccofacial apraxia because the nature of the error performance may elucidate the nature of the mechanism(s) that are deficient. Unfortunately, few studies have attempted to capture the quality of buccofacial apraxic errors. Typically, researchers utilized pass/fail scores or multi-point scales which reflected a continuum of degree of deficit. For example, Kertesz
and Ferro (1984) utilized a three-point system with the lowest score classified as incorrect and the highest score classified as totally correct.
However, Poeck and his colleagues (Poeck & Kerschensteiner, 1975; Iehmkuhl, Poeck & Willmes, 1983) have provided a system for qualitatively analyzing buccofacial apraxic movements. This system was modified (laehmkuhl, Poeck & Willmes, 1983) to include the following five




response categories: correct, fragmentary (production of only part of the required movements), augmentative (production of additional movements or noises), perseveratory (production of perseveratory elements within a movement), and other errors. The subjects included 88 aphasic patients, with an equal number dmonstratinr one of the four following types of aphasia: global, Wernicke's, Broca 's and amnesic (anciic) aphasia. They attempted to ascertain whether there were apractic syndrcmes which were related to the standard aphasic syndromes or were characterized by certain patterns of error types. The findings were negative for both questions. Specifically, they reported that the performance of oral movements was poorer than the performance of arm, leg or bimanual movements for all types of aphasia. In addition, the most prominent error type was perseveration, with a relatively low frequency of the other error types.
Unfortunately, based in their analyses, these researchers did not speculate as to the mechanism(s) underlying buccofacial apraxia. It is possible that their error analyses did not provide them with sufficient information because their scoring system were not structured to capture the nature of the errors induced by left-hemisphere dysfunction.
R. While observations of recovery may also provide clues asto the mehanism(s) underlying buccofacial apraxia, little has been written about the recovery of this disorder. Kertesz (1979) evaluated the course of recovery from apraxia by testing aphasic patients at the following post-onset intervals: one week, three months, six months, and one year. He utilized a praxis test that combined praxis performance of oral, limb intransitive, limb transitive, and complex (an act that




requires a series of actions utilizing both hands, such as "pretend to drive a car") action ccmands. Unfortunately, Kertesz (1979) combined the performance of each of these tasks into a single praxis score. Therefore, little is known about the specific recovery pattern of buccofacial apraxia.
Ochipa and Rothi (1989) reported a right-handed male with a righthemisphere frontotemporoparietal lesion who exhibited a severe buccofacial apraxia, in addition to severe limb apraxia and nonfluent aphasia. Ochipa and Rothi (1989) evaluated buccofacial and limb praxis at two, three and six weeks post-onset. The patient's severe buccofacial apraxia improved only minimally by three weeks post onset, and remained unchanged at six weeks post onset. In addition, the quality of the buccofacial errors remained the same throughout the serial testing. The patient also continued to demonstrate a severe limb apraxia across the three testing sessions. However, in contrast to buccofacial praxis, there was a significant change in the quality of the limb errors as a function of time post-onset. Limb praxis error types evolved from predominantly perseverative errors to predominantly spatial and body-part-as-object errors. Therefore, because of the dissociation in the qualitative recovery patterns for buccofacial and limb praxis, Ochipa and Rothi (1989) suggested that the mechanisms underlying each type of apraxia is distinct.
In summary, little is known about the recovery pattern of
buccofacial apraxia. However, the qualitative recovery of buccofacial and limb praxis may dissociate.




Localization. Buccofacial apraxia in right-handed patients is
usually the result of a left-hemisphere lesion (eiiran, 1979; Heilman & Rothi, 1985). However, isolated cases of this disorder following righthemisphere damage have been reported (Kramer, Delis & Nakada, 1985; Rapcsak, Rothi & Heilman, 1987).
Unlike the laterality, the intrahemispheric localization of this disorder remains controversial. Like the different forms of aphasia which may be associated with different lesion loci, buccofacial apraxia can be associated with a variety of different types of aphasia as well. DeRenzi, Pieczuro and Vignolo (1966) report buccofacial apraxia in Broca' s, phonemic jargon aphasia (a subtype of Wernicke's aphasia), and
conduction aphasia; Kertesz (1979 & 1985) reports buccofacial apraxia in global, Broca's and isolation aphasia; and Benson et al. (1973) report buccofacial apraxia in conduction aphasia. In studies which specifically compared the incidence of buccofacial apraxia in a variety of aphasia types (DeRenzi et al., 1966; Kertesz, 1979 & 1985), buccofacial apraxia was most frequently associated with Broca's aphasia. However, the presence of buccofacial apraxia was also noted with posterior, fluent syndromes such as conduction, Wernicke's or jargon aphasias. DeRenzi et al. (1966) reported the percentage of each aphasic type which demonstrated an associated buccofacial apraxia as follows: 90% of the Broca's aphasics; 33% of the conduction aphasics; less than 6% of the Wernicke's aphasics; and 83% of the phonemic jargon aphasics. In summary, buccofacial apraxia most frequently co-occurs with aphasic types associated with anterior peri-Sylvian lesions. However, it is also reported with posterior types of aphasia.




Very specific intrahemispheric localization of the lesions
associated with buccofacial apraxia was supplied by Benson and his colleagues (1973) in their clinicopathological study of three conduction aphasics. In fact, this study provides evidence of the association between posterior lesions and this disorder. The postmortem examinations completed in this study clearly defined the extent and location of the lesions. Two of the three cases demonstrated a buccofacial apraxia. One of the two cases with buccofacial apraxia exhibited a lesion which affected the supramarginal gyrus extending in depth from the convexity of the hemisphere to within one centimeter of the ventricular wall. Further posteriorly, the subcortical white matter underneath parts of the angular gyrus and the superior parietal gyrus were also infarcted. The second case with buccofacial apraxia presented
with softening of the cortex over the left supranimarginal and angular gyri. An irregular cavitated infarction was noted in the white matter deep to these areas, which extended to the left lateral ventricle and interrupted the arcuate fasciculus.
Heilman, Rothi and Kertesz (1983) reported that they have seen cases of buccofacial apraxia in which the lesion was located in the supramarginal and angular gyri, and did not involve frontal cortical structures.
Analysis of these results reveals that the posteriorly situated IPL, specifically the supramarginal and angular gyri and the white matter deep to these areas, may play a critical role in buccofacial praxis. The importance of this site was especially evident when the buccofacial movements were elicited with verbal commands.




However, there is also evidence that anterior peri-Sylvian
structures are associated with buccofacial apraxia. Tognola and Vignolo (1980) conducted a clinico-neuroradiological investigation of the brain lesions associated with buccofacial apraxia. Included as subjects in the study were 44 right-handed patients who had sustained a lefthemisphere cerebrovascular accident and had a CT scan performed more than 21 days post-stroke. The subjects' performance on the imitation of ten simple buccofacial gestures was evaluated using a two-point scoring system. The researchers compared the CT scan findings for patients with and without buccofacial apraxia, and found the critical cortical areas to include the following left hemisphere structures: the frontal and central (Rolandic) opercula, the adjacent portion of the first temporal convolution, and the anterior portion of the insula. Their results also suggested that posterior cortical structures, such as the parietal operculum and the supramarginal gyrus, were not crucial in the performance of buccofacial gestures.
Haaland, Rubens and Harrington (1989) evaluated 43 left-hemisphere stroke patients for both buccofacial and limb apraxia employing the elicitation methods of verbal command and imitation. In the subset of patients with small- and medium-sized lesions, damage to the left parietal cortex, specifically the supramarginal gyrus, was more associated with limb rather than buccofacial apraxia.
Finally, Mintz, Raade and Kertesz (1989) conducted a retrospective study on the relationship between the occurrence of buccofacial apraxia and lesion localization with 112 left-hemisphere ischemic stroke




10
patients, as discussed previously. The five buccofacial stimulus items on the Western Aphasia Battery apraxia subtest (Kertesz, 1^82) were administered during the initial 7 to 45 days post onset. The performance scores on imitation were utilized. Lesion localization, using a check listing procedure, was characterized by eight broadly defined lesion localization sites, and also by 26 specific neuroanatamic structures. The multiple regression analysis results revealed that size and two broadly defined sites were significant predictors of the occurrence of buccofacial apraxia: the central site and the anterior subcortical site. The central site was composed of the precentral gyrus, the postcentral gyrus, the insula and the centrum semiovale, whereas the anterior subcortical site was composed of the putamen, the anterior capsule and the caudate nucleus. In addition, the regression analysis revealed that four specific neuroanatamic structures were also significant predictors: the insula, the centrum semiovale, the putamen and the inferior frontal gyrus. These results confirm the strong associations between anterior cortical and/or subcortical structures and buccofacial apraxia. In contrast, the inferior parietal site, which included the structures of the supramarginal and angular gyri, was not a significant predictor of the occurrence of buccofacial apraxia.
In summary, buccofacial apraxia is usually the result of left hemisphere lesions. However, there is controversy regarding the specific areas within the left hemisphere that are critical for normal buccofacial praxis. The importance of frontal cortical and/or subcortical structures is clearly supported, whereas the importance of




posterior areas, such as the inferior parietal lobe (IPL), remains controversiJl.
Limb Apraxia
While little is known about the neuropsychological mechanism
underlying buccofacial apraxia, there has been a significant amount of research directed at understanding the underlying mechanism of limb apraxia; a cammonly co-occurrixng left-hemisphere disorder. Therefore, it may be that mechanisms elucidated for limb apraxia can have application to understanding buccofacial apraxia.
Limb apraxia refers to the inability to correctly perform skilled movements with the limbs. As discussed previously, this inability can not be related to weakness, akinesia, deafferentation, abnormal tone or posture, movement disorders, intellectual deterioration, poor comprehension, or lack of cooperation (Heilman & Rothi, 1985). Incidence
Similar to buccofacial apraxia, the incidence of limb apraxia is variable and influenced by task and subject selection. In the retrospective study by Mintz, Raade and Kertesz (1989) described previously, the five-item limb transitive subcomponent of the Western Aphasia Battery (Kertesz, 1982) was used to confirm the presence of limb apraxia. The control group's average limb score minus two standard deviations was utilized as the cut-off score between normal and apraxic performance. Eighty percent (90) of the 112 left-brain-damaged subjects demonstrated a limb apraxia. As with buccofacial apraxia, these results suggest that limb apraxia is frequently associated with left-hemisphere damage.




Transitivity Factor
Previous research has suggested tht there is a difference in
performance between transitive and intransitive movements in patients with left hemisphere damage. Transitive movements are movements made in relation to an object or instrument, such as using a screwdriver, whereas intransitive movements are not related to object use, such as waving goodbye.
Liepmann (1905/1980a) was the first to note a difference in
performance between limb transitive and intransitive movements. He reported patients who demonstrated defective performance in both types of movements, as well as patients who demonstrated defective limb transitive movements, but spared limb intransitive movements. Liepmann (1905/1980a) suggested that these differences in performance reflected differences in degree of impairment, rather than differences in the quality or nature of the movements.
Goodglass and Kaplan (1963) also noted a difference in performance between transitive and intransitive limb movements. In their evaluation of 20 aphasic adults, they noted that the subjects' average performance of limb intransitive movements was better than their average performance of limb transitive movements.
Haaland and Flaherty (1984) evaluated 41 left-hxmisphiere-damaged and 18 right-hemisphere-damaged stroke patients in the imitation of nonrepresentative (meaningless), representative/intransitive, and pretended-object-use/transitive movements. Of particular importance for this study, they reported that the limb transitive movements were more impaired in the left-hemisphere- than the right-hemispher-damaged




subjects. In contrast, the intransitive and the nonrepresentative movements were equally impaired after lesions of either hemispheree. They suggested that the neural control IwIanisns for the nonrepresentative and representative/intransitive movements may be quite different than the control mecharni for transitive movements.
In addition to the group studies cited, two case-study reports also support the limb transitivity distinction. Heilman, Pothi and Kertesz (1983) reported two cases with limb apraxia who exhibited relatively spared performance of limb intransitive movements, but very defective performance of limb transitive movements. In the second case study, Watson, Fleet, Rothi and Heilman (1986) reported two cases with supplementary motor area damage who were spared for limb intransitive movements, but who were apraxic for limb transitive movements.
In summary, the processing of transitive and intransitive movements fractionate implying that these movements have at least partially differing underlying mechanisms. In left-hemisphere patients, most typically the limb transitive movements are more impaired than limb intransitive movements. The reverse pattern has not been reported for any type of patient, i.e., that the limb intransitive movements are more impaired than the limb transitive movements. Error Type Analysis
Similar to buccofacial apraxia, few studies have attempted to capture the quality of limb apraxic errors and/or to utilize this information to speculate about the underlying mechanism(s). Typically, researchers utilized the pass/fail scores or the multi-point measures of severity discussed previously (Krtesz & Ferro, 1984).




14
However, several studies have provided a qualitative error analysis of limb movements. LIe.nk1M l, Poeck and Willmes (1983) examined arm and leg movements, in addition to the oral movements discussed previously. The same five response categories were utilized: correct, fragmentary, augmentative, perseveratory and other errors. And similar to the previous results, they did not find limb apractic syndromes which were related to the standard aphasic syndrames or were characterized by certain patterns of errors. Similarly, the most prominent error type was perseveration, with a relatively low frequency of the other error types. They did not speculate what implications these results had regarding underlying mechanisms that have been proposed for limb apraxia.
In another qualitative study of limb praxis, Haaland and Flaherty (1984) utilized a seven-category scoring system that included the following error types: hand or arm position errors, hand-to-arm orientation errors, target errors, partial errors, and two forms of body-part-as-object (BPO) errors. The first BPO error, as traditionally defined, is characterized by utilization of the hand or fingers as the imagined object. In contrast, the second BPO error is characterized by correctly positioning the hand to hold the imagined object but
positioning the hand "such that the length of the object was not considered." Their results revealed that both the left- and rightbrain-damaged patients demonstrated similar errors on nonrepresentative
and representative/ intransitive movements. In contrast, the left- and right-brain-damaged patients demonstrated a different pattern of errors on pretended-object-use movements (transitive movements). For these




movements, the left-brain-damaged group made more arm position errors and more traditional BPO-l errors. In contrast, the right-brain-damaged group made more BPO-2 errors than the left-brain-damaged group. Haaland and Flaherty noted the importance of the left hemisphere for the production of limb transitive movements and attempted to explain the underlying mechanism. They suggested that the symbolic value of the limb transitive movements could not account for the differences because the limb intransitive movements were also symbolic but were less impaired. However, the complexity of the transitive and intransitive movements did vary in their use of intrapersonal and extrapersonal space. The representative/intransitive movements are strictly intrapersonal in that the patient places the hand and annrm in a particular relationship to the body. In contrast, the pretended-objectuse/transitive movements are both intrapersonal and extrapersonal in that the patient must have same "representation" of extrapersonal space by pretending to hold and manipulate an object. They suggested therefore, that when intrapersonal movements have to be integrated with a "representation" of extrapersonal space, the left hemisphere is more important than the right hemisphere.
Finally, Rothi, Mack, Verfaellie, Brown and Heilman (1988)
developed a categorical scoring system for limb praxis which was a modification of a system used by Klima and Bellugi (1979) (based on the work of Stokoe [1960]) to describe the structure of American Sign Language of the deaf. Rothi et al. (1988) particularly wanted to capture the spatial and temporal characteristics of the performance of limb apraxic patients. This apraxia scoring system has four main error




16
categories of content, temporal, spatial and other errors. Two to five subx-ategories of errors are defined under each of these main categories (Appendix A). Rothi et al. (1988) found that apraxic patients with left hemisphere cortical lesions characteristically produced six error types. Under the main category of spatial errors, the patients demonstrated a significant number of body-part-as--cbject, internal configuration, external configuration-orientation, and movement errors. Additionally, under the category of content, there were related content errors, and under the category of temporal, there were occurrence errors. Rothi et al. (1988) suggested that this confirms the vulnerability of spatial aspects in the limb performance of limb apraxic patients. Although only one type of temporal error was significant, it is possible that this type of error is difficult to ascertain with only a perceptual analysis of the patient's productions.
In sunary, analyses of limb apraxic errors may provide researchers with a window to the underlying mechanism(s) of limb apraxia. Several studies have attempted to hypothesize about the underlying mechanisms. The integration of intrapersonal and extrapersonal representations of space and the spatial representation of limb movements appear to be especially important roles of the left hemisphere. Mechanisms of Limb Apraxia
There have been several models proposed to explain the mechanism
underlying limb apraxia including a symbolic deficit (Finkelnburg, 1870, in Duffy & Liles, 1979), a disconnection syndrome (Liepmann, 1905/1980b; Geschwind, 1965, 1975), and a representational deficit (Heilman & Rothi, 1985).




Apraxia as a symbolic deficit. In 1870, Finkelnburg (Duffy &
Liles, 1979) was one of the firzt to propose that apraxia was part of a more general disorder called asymbolia, that is, an inability to understand and express both verbal and nonverbal symbols. In this construct, aphasia involves a disturbance of verbal symbolization, whereas apraxia involves a disturbance of nonverbal symbolization.
One approach to use if apraxia is a symbolic disorder is to
investigate the co-occurrence of the two disorders. The incidence of
apraxia should strongly correlate with the incidence of aphasia if they are both symbolic disorders. Goldstein (1942) noted that apraxia and aphasia frequently co-occur, and that both result from left-hemisphere damage, providing support for the symbolic hypothesis. Several other researchers (DeRenzi, Pieczuro & Vignolo, 1968; Kertesz, 1979) have also
reported a relationship between the severity of the two disorders. However, others (Liepmann, 1905/1980b; Goodglass & Kaplan, 1963) have documented dissociations between the two disorders. Liepmann (1905/1980b) reported dissociations in both directions, in that one of his apraxic patients was not aphasic, and not all of his aphasic patients were apraxic. In addition, Goodglass and Kaplan (1963) reported that the severity of the two disorders correlated poorly.
A second approach to the investigation of apraxia as a symbolic disorder involves the supposition that apraxic patients should perform symbolic movements more poorly than nonsymbolic movements. However, Kimura (1977) reported that apraxic subjects performed poorly on both types of movements, which would not support the asymbolia construct.




A third approach is to analyze the overall patterns of deficit observed with limb apraxia. As discussed previously, reseaihers (Goodglass & Kaplan, 1963; Haaland & Flaherty, 1984) have reported that, in left-hemisphere-damaged patients, limb transitive movements are more impaired than limb intransitive movements. It does not follow that limb intransitive movements, such as "signaling OK," are less symbolic than limb transitive movements, such as "1%almering." Therefore, the asymbolia construct fails to explain why the transitivity distinction is observed in patients with limb apraxia.
A fourth and final approach is to analyze the types of errors
produced by apraxic subjects. If the disorder is symbolically based,
the apraxic patients should primarily produce content errors, i.e., substitution of one gesture for another or lack of content altogether. However, the majority of errors do not appear content based. Liepmann (1905/1980b) described the movement errors as recognizable, but a
distortion of the required production. In addition, Rothi, Mack, Verfaellie, Brown and Heilman (1988) documented that the majority of limb apraxic errors were spatial distortions and movement aberrations, and only a small percentage were classified as related content errors.
In summary, the notion that apraxia is a symbolic disorder is only weakly supported. However, there are other hypotheses that may account for apraxia.
Apraxia as a disconnection syndrome. Liepmann (1905/1980b) was the first to propose that the underlying mechanism for apraxia was a disconnection between control centers within the cerebral cortex. He believed that the left hemisphere, specifically the parietal lobe, was




dominant for praxis, that is, it guided both the left- and right-sided skilled movements. Projections from this area to the premotor region of the left frontal area, which project to the left motor hand area is what guided the right hand. Callosal connections from the left motor hand area to the hcmologous areas in the right hemisphere is what guided the left hand. A lesion anywhere along this pathway would result in a disconnection of the control centers, and therefore in an apraxia.
Geschwind (1965, 1975) elaborated and modified this disconnection view of apraxia. Unlike Liepmann, he emphasized the importance of verbal commands in eliciting apraxic performance, and therefore the importance of Wernicke's area. Geschwind (1965, 1975) based this idea
on studies with split-brain patients who were apraxic with their left hand to verbal command, but were not apraxic on imitation or in actual use of the object. According to this disconnection model, a lesion of the supramarginal gyrus or arcuate fasciculus would result in an apraxia because of a disconnection of the posterior language areas from the anterior motor association area. Based on this model, apraxic patients should be able to imitate gestures. However, knowing this was not the case, and knowing that fibers passing from the visual association cortex to the premotor cortex pass through the arcuate fasciculus, Geschwind suggested that the left-hemisphere arcuate fasciculus was dominant for these visucmotor connections. Therefore, with an appropriately placed lesion, the patient would demonstrate apraxic performance to verbal command and imitation. While Geschwind thought performance with the actual object was normal, recent studies have demonstrated that actual




object use is impaired. Unfortunately, Geschwind's disconnection hypothesis cannot totally account for thi observation.
In summary, two variations of a disconnection view of apraxia were discussed. The major limitations appear to be in the prediction and adequate explanation of poor performance on imitation and actual object use, and in the failure to explain possible subtypes of apraxia. However, this does not preclude that disconnection can account for certain subtypes of apraxia.
Apraxia as a representational deficit. Heilman, Rothi and
colleagues (Heilman, 1979; Heilman, Rothi & Kertesz, 1983; and Heilman & Rothi, 1985) propose that one of the underlying mechanisms for apraxia is a representational deficit. The model elaborates upon Liepmann's concept of "'movement formulas." Heilman, Rothi and colleagues postulate that the visuokinesthetic engrams for skilled limb movements are located in the inferior aspect of the dominant parietal lobule, specifically in the areas of the supramarginal and angular gyri. These motor engrams guide the sequencing and timing of limb movements and direct the movement of the limb within space. The model further specifies that once the engrams for a particular limb movement are elicited by stimulation in one or more modalities, this information is further processed by the motor association cortex into a motor plan which is carried out by the primary motor cortex.
Heilman and Rothi hypothesized that the integrity of these
visuokinesthetic engranms would be crucial for the production of skilled limb movements, as well as crucial for receptive tasks, such as the
discrimination or comprehension of skilled movements. In addition, they




suggested that there should exist at least two distinguishable behavioral profiles, depending on whether the actual engrams were destroyed or whether the engrams were disconnected from the frontal, motor association cortex. In order to test these hypotheses, Heilman, Rothi and Valenstein (1982) evaluated anterior- and posterior-lesioned patients in their ability to discriminate well-performed from poorly performed limb movements, as well as their ability to comprehend the meaning of the pantomime. In the discrimination testing, the patients were asked to distinguish well-performed from poorly performed gestures. The results of this testing revealed that apraxic patients with posterior infarctions that included the parietal lobe demonstrated a pantomime discrimination deficit, whereas the anterior apraxic patients did not. In the comprehension testing, the patients were shown the target pantamime and two foil pantomimes and were given the verbal stimulus for the target pantamime. The results of this testing revealed that the performance of the apraxic patients with posterior lesions was poorer than the patients with anterior lesions.
Therefore, the notion of at least two forms of idecmotor limb
apraxia was supported. The first type was induced by posterior lesions (which may have included the inferior parietal lobule) and produced destruction of the actual engrams. This type was characterized by poor performance of limb movements to verbal command, as well as decreased discrimination and comprehension of limb pantomimes. The second type of ideamotor limb apraxia was induced by lesions anterior to the supramarginal gyrus, up to and including the premotor association area. These lesions produced a disconnection between the visuokinesthetic




engrams in the parietal lobe, and the premntor and motor areas in the frontal lobe. The second type of ideamotor limb apraxia was characterized by poor performance of limb movements to verbal command, but preserved discrimination and comprehension.
The gestural comprehension deficits noted in this study could
possibly be explained by alternative mechanisms. Because the testing involved a verbal stimulus and the subjects were aphasic, an auditory comprehension deficit may have accounted for the results. In addition,
because the testing involved three consecutive gestural presentations, proactive or retroactive interference may have contaminated the subject's performance. Therefore, in order to rule out these alternative possible explanations, Rothi, Heilman and Watson (1985) completed a second gesture comprehension study which employed a
nonverbal pantomimne-to-picture matching paradigm. The subjects viewed one pantcamime and were asked which one of four drawings '%"went with the gesture." The results revealed that the apraxic-aphasic subjects with lesions that included posterior areas made significantly more comprehension errors than the nonapraxic-aphasic subjects or the normal subjects. These results confirm the importance of the visuokinesthetic engrams in the comprehension of limb pantcmimes and are consistent with the localization of these engrams in the left parietal lobule.
Further support of the concept of visuokinesthetic engrams as an integral component of the functional limb praxis system was supplied by a gestural memory study completed by Rothi and Heilman (1984). Using a modified Buschke and Fuld (1974) paradigm, the subjects were asked to learn a list of gestures. The patients with left parietal lobe lesions




demonstrated a deficit in secondary memory which was characterized by poor consolidation of the information. This finding could be explained by the mechanism of a deficit in the visuokinesthetic engrams.
In summary, these studies support the hypothesis that the visuokinesthetic engrams are crucial for the production of limb movements, as well as for the discrimination, comprehension and learning of limb pantamimes. These studies further suggest that posterior structures, specifically the inferior parietal labule (IPL), appear crucial to the limb praxis processing system.
Additional intrahemispheric localization of limb apraxia was
provided by Watson, Fleet, Rothi and Heilman (1986). They reported two patients with mesial left hemisphere infarctions that included the supplementary motor area (SMA). These patients demonstrated bilateral limb apraxia for transitive movements without buccofacial apraxia. As previously discussed, it has been proposed that the left inferior parietal lobe plays a crucial role in the spatial and temporal representations of limb transitive movements (Heilman, Rothi & Valenstein, 1982). Watson et al. (1986) suggested that the lefthemisphere SMA translates these representations into motor plans. Therefore, the left SMA lesions may induce only limb apraxia, whereas lesions of the convexity premotor area of the face may induce only buccofacial apraxia. They further suggested that patients with apraxia from parietal lesions may demonstrate both limb and buccofacial apraxia. In summary, lesions of crucial posterior structures may induce both buccofacial and limb apraxia, whereas critically placed lesions in anterior structures may induce only limb or buccofacial apraxia.




Relationship Between Buccofacial and Limb Apraxia
FEavcofacial and limb apraxia most frequently co-occur within the same patients. DeRenzi, Pieczuro and Vignolo (1966) were the first to examine the c-o rrence of buccofacial apraxia, limb apraxia and "phonemic-articulatory" disorders. Of particular interest in this study was that the co-occurrence of buccofacial and limb apraxia was significantly greater than chance. Out of the total population of 134 subjects, 28 (21%) demonstrated both apraxias and 68 (51%) demonstrated normal praxis ability in both. However, 38 subjects (28%) demonstrated dissociations between the two disorders. Double dissociations characterized 30 subjects who exhibited normal buccofacial praxis in the context of limb apraxia, and eight subjects who exhibited normal limb praxis in the context of buccofacial apraxia.
Mohr et al. (1978) described 20 patients with minor Broca's
aphasia; 19 of wham demonstrated both buccofacial and limb apraxia. The lesions involved the following areas: the premotor areas for both the face and arm, and/or the arcuate fasciculus.
Marquardt and Sussman (1984) studied 15 Broca's aphasics with documented left-hemisphere lesions. All 15 patients demonstrated a buccofacial apraxia, but only five demonstrated a limb apraxia. They reported a significant positive correlation between buccofacial and limb apraxia. The lesions involved the frontal and/or temporal labes and/or subcortical structures including the internal capsule, the thalamus and the basal ganglia.




25
Basso, Capitani, Della Sala, laiacona and Spinnler (1987) conducted a study primarily focusing on the recovery of idecmotor limb apraxia. In the first examination session for each patient, 20 out of 26 subjects demonstrated both buccofacial and limb apraxia, while six demonstrated only limb apraxia. The number of limb/buccofacial apraxia dissociations increased at subsequent examinations, suggesting that one disorder exhibited more recovery than the other. The additional recovery dissociations were characterized by six patients continuing to demonstrate buccofacial but not limb apraxia, and by one patient exhibiting the reverse dissociation. Therefore, with this group of patients, the limb apraxia appeared to recover more than the buccofacial apraxia.
Finally, Hogg, Square-Storer and Roy (1988) found that 20 out of 23 left-hemisphere-damaged subjects demonstrated both disorders. In summary, while many studies showed a high incidence of co-occurrence of buccofacial and limb apraxia, a significant number of patients in these groups also showed a dissociation of these disorders in both directions. These dissociations call into question the possibility that buccofacial and limb apraxia are different manifestations of the same disorder. Possible Constructs
There are at least two possible constructs depicting the
relationship between buccofacial and limb apraxia. In the first construct, apraxia is viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb praxis (Square-Storer & Roy, 1989; Roy & Square, 1985; Hogg, Square-Storer & Roy, 1988; and Poeck, 1985). In fact, Poeck (1985) explicitly stated




26
that "the traditional distinction between oral and limb apraxia appears quite artificial" (p. 103). This "unitary motor disorder" construct would predict a high degree of concordance and similarity between the two types of apraxia. An alternative construct would postulate that the relationship between buccofacial and limb apraxia is not unitary. This alternative construct could be expressed in at least two different models. In the first alternative, there would be two totally separable praxis systems: one for planning and controlling buccofacial movements and another one for planning and controlling limb movements. This "totally separable praxis systems" construct would predict quantitative and qualitative differences to be noted in all factors between buccofacial and limb performance. In the second alternative model, the two praxis systems would be at least partially separable. This "partially separable model" would predict areas of concordance as well as areas of discordance between buccofacial and limb praxis. Additional research is needed to determine which construct best describes the relationship between buccofacial and limb apraxia. Clinical Relevance
These possible constructs have an impact upon clinical decisions regarding patients with buccofacial and limb apraxia. If the "unitary motor disorder" construct is valid, it would be predicted that treatment of one disorder would generalize to the other disorder. Therefore, the second disorder would demonstrate improvement, even though it was not directly targeted in treatment. In addition, if the underlying mechanisms were similar, a treatment task effective for one disorder would be likely to be effective for the second disorder as well.




However, if buccofacial and limb apraxia are not a unitary motor disorder, treatMent generalization may not occur. If the "separable praxis system" construct is valid, it would be predicted that treatment of one disorder would not necessarily generalize to the other disorder. Therefore, each disorder would need to be treated separately in order to assure improvement in each. In addition, if the underlying mechanisms were dissimilar, a treatment task effective for one disorder may not be effective for the second disorder. More specifically, if the "partially separable" model is valid, clinicians would need to know what mechanisms are shared and what mechanisms are separable. In summary, in order to optimize the utilization of treatment time for patients, clinicians need to know which construct best describes the relationship between buccofacial and limb apraxia.
Transitivity Factor
One approach to exploring the relationship between buccofacial and limb apraxia is to study a factor which influences the performance in one type of apraxia, in order to determine if it influences the performance in the other type of apraxia in a similar manner. One such factor could be transitivity. As previously discussed, several studies have suggested that left-hemispere-damaged subjects are more impaired in the performance of limb transitive than limb intransitive novements (LiePann, 1905/1980a; Goodglass & Kaplan, 1963; Haaland & Flaherty, 1984; Heilman, Rothi & Kertesz, 1983; and Watson, Fleet, Rothi & Heilman, 1986). It was suggested by several researchers that this
difference in performance may be explained by a difference in the manner in which these two types of limb movements are represented in the brain.




However, the transitivity factor has not been investigated for buccofacial movements.
Error Type Analyses
A second approach to exploring the relationship between buccofacial
and limb apraxia is to analyze the quality of the errors produced in each disorder. Patterns of error types may give researchers insights into the similarity or dissimilarity of the underlying mechanism(s) of the two disorders.
Retrospectively, Square-Storer and Roy (1989) and Roy and Square
(1985) have reviewed previous research to analyze the common types of errors reported for buccofacial and limb apraxia. In their review, they noted the following categories of error types common to both buccofacial and limb apraxia: delayed initiation of movement, deficits in spatial targeting, deficits in temporal coordination of motor subsystemssubcomponents, decreased rate of movement, additive or augmentative motor behavior, emitted behaviors, disturbances of sequencing, and perseverative behaviors. They suggested that the presence of these common error types supported the concept of a unitary motor disorder for both buccofacial and limb apraxia. However, they did not make inferences regarding the mechanisms underlying buccofacial and limb apraxia. As an additional limitation, almost all of the studies reviewed involved only buccofacial apraxia or only limb apraxia. Therefore, comparisons between buccofacial and limb praxis were made across different subjects, rather than within the same subjects.
As discussed previously, Lehmkuhl, Poeck and Willmes (1983)
completed the only prospective study which analyzed the error types for




29
both buccofacial and limb movements within the same left-brain-damaged subjects. As stated previously, their scoring system included the following five response categories: correct, fragmentary, augmentative, perseveratory and other errors. The results of the cluster analysis revealed that the types of errors examined did not yield any characteristic patterns for certain parts of the body (e.g., oral or arm or leg). Therefore, as Poeck (1985) explicitly stated, "The traditional distinction between oral and limb apraxia appears quite artificial" (p. 103). However, the most prominent type of error for both buccofacial and limb movements was perseveration, with a relatively low frequency of the other types of errors. The low frequency of the other types of errors might make a meaningful differentiation of subtypes of
apraxia quite unlikely, for body part or otherwise. It is interesting to note that other researchers who have completed error analyses for limb movements do not report a high incidence of perseveration errors (Rothi, Mack, Verfaellie, Brown & Heilman, 1988). A major limitation of the study completed by Lehmnkuhl et al. (1983) is the specific scoring system employed. The system appears to be characterized by too few categories to capture the nature of the errors induced by lefthemisphere dysfunction. For example, the scoring system does not
include body-part-as-object errors, which have been emphasized as characteristic of limb apraxia (Goodglass & Kaplan, 1963; Geschwind, 1965). In addition, the lehmkuhl et al. (1983) scoring system fails to capture the spatial or temporal aspects of movements.
As noted previously, Rothi, Mack, Verfaellie, Brown and Heilman
(1988) developed a categorical scoring system specifically designed for




30
depicting the adequacy of limb praxis in three-dimensional space. Based upon Liepnann's (1905/1980b) proposal that the left hemisphere contained the "space-time" engrams that controlled skilled movement for each hand, this scoring system is the only one specifically designed and modified to reflect the temporal and spatial aspects of limb movement. This system also reflected the occurrence of body-part-as-object errors, as previously reported by Goodglass and Kaplan (1963) and Geschwind (1965). Currently, however, this scoring system has not been extended to depict buccofacial apraxic movements.
Additional research is needed in the form of a prospective study which applies the same error analysis system to both buccofacial and limb movements within the same subjects. The scoring system developed by Rothi, Mack, Verfaellie, Brown and Heilman (1988) for limb movements could be extended to apply to buccofacial movements.
Statement of the Problem
The literature suggests that buccofacial and limb apraxia
frequently co-occur, leading some to speculate that they share a common underlying mechanism. However, patients have been described who display buccofacial apraxia and no limb apraxia, while others are described who display limb apraxia with no buccofacial apraxia. This double dissociation calls into question the concept of a unitary mechanism for both buccofacial apraxia and limb apraxia. Therefore, the specific intent of the present study was to investigate the relationship between buccofacial and limb apraxia. The nature of this relationship has theoretical as well as clinical implications.




There are at least two possible constructs depicting the
relationship between buccofacial and limb apraxia. Ln the first construct, apraxia is viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb output. A high degree of concordance and similarity between the two types of apraxia would support this construct. An alternative construct would postulate that the relationship between buccofacial and limb apraxia is not unitary. The presence of quantitative and qualitative differences between buccofacial and limb performance would support this construct. For example, a high incidence of co-occurrence of buccofacial and limb apraxia would support a unitary motor disorder construct, whereas a low incidence of co-occurrence of these disorders would support a nonunitary construct.
Based upon the preceding discussion, several studies suggested that left-hemisphere-damaged subjects are more impaired in the performance of limb transitive than limb intransitive movements. It was further
suggested that this difference in performance may be explained by a difference in the manner in which these two types of limb movements are represented in the brain. However, the transitivity factor has not been investigated for buccofacial movements. The unitary motor disorder construct would predict that the neural control mechanisms for both buccofacial and limb praxis would be similar and, therefore, that the transitivity factor would be manifested in a similar manner for both disorders. Thus, this construct would predict that, in patients with buccofacial apraxia (as with limb apraxia), the degree of impairment of buccofacial transitive movements would be impaired compared to the




impairment of the buccofacial intransitive movements. In contrast, a non-unitary construct would predict that the transitivity factor would be manifested in a dissimilar manner for buccofacial and limb movements.
Additionally, it is suggested that an analysis of the error types of both buccofacial and limb praxis within the same subjects may give researchers insights into the similarity or dissimilarity of the underlying mechanism(s). This would be particularly true if the scoring system employed captured the nature of apractic dysfunction after a left-hemisphere lesion, based upon previous literature. A similar proportion of error types for both buccofacial and limb movements would support the concept of a unitary motor disorder. Whereas, a dissimilar proportion of error types would support the concept of non-unitary motor disorders.
As with the two types of ideamotor limb apraxia, it would logically follow that there may also be two types of buccofacial apraxia. Specifically, one type of buccofacial apraxia would be characterized by impaired production and comprehension of buccofacial movements, and a second type would be characterized by impaired production but preserved comprehension.
Based upon the discussion of the neuroanatamic distinctions for limb apraxia which outlined the importance of the inferior parietal lobule (IPL) for the disorder, if the unitary mechanism for buccofacial and limb praxis is accepted, it would logically follow that the IPL would also be a critical structure for buccofacial praxis. Specifically, if it is a structure critical for the functioning of the visuokinesthetic buccofacial engrams, it is predicted that it would be a




critical neuroanatamic structure for both the comprehension and production of buccofacial movements.
Based upon the aforementioned discussion, this investigation attempted to address the following research questions:
1. Are buccofacial and limb apraxia manifestations of a unitary
motor disorder?
a. What is the nature of the co-occurrence or
dissociation of buccofacial and limb apraxia?
b. Is the transitivity factor manifested similarly in
the production of buccofacial and limb movements?
c. Is the proportion of error types similar for both
buccofacial and limb movements?
2. Are there at least two different types of ideamotor
buccofacial apraxia: the first type characterized by impaired
production and comprehension, and the second type by impaired
production, but preserved comprehension?
3. If two types of buccofacial apraxia exist, is the inferior
parietal lobule (IPL) a critical neuroanatcmic structure for
both the comprehension and production of buccofacial
movements?




CNAPTER 2
METHODOIDGY
This study was designed to determine the nature of the relationship between buccofacial and limb apraxia. Specifically, are buccofacial and limb apraxia manifestations of a unitary motor disorder or are they at least partially separable? In addition, the possible presence of two types of buccofacial apraxia was examined, as well as the neuroanatomy of the disorder.
Subjects
Twenty-three subjects were included in this study. All subjects were right-handed and participated in this study after informed consent was obtained. Subjects were excluded frim the study if they had any history of alcohol abuse. The experimental subject group included fifteen patients who had experienced a single, unilateral, lefthemisphere cerebrovascular accident (CVA). The control subject group included eight subjects who had no history of a central nervous system disorder. Subjects were also excluded from the experimental group if they had any history of multiple strokes or a history of a central nervous system disorder other than the unilateral stroke. All of the experimental patients had either computerized tomography (CT) or magnetic resonance imaging (MRI) scan documentation of the lesion localization.




Age, gender and the number of years of education for the
experimental and control groups are reported in Table 2-1. Detailed
descriptive information on each of the experimental subjects is provided in Table 2-2. As noted in this table, the time post-onset of the CVA ranged between 27 and 2253 days. The types of syndromes demonstrated included Broca's aphasia, anemic aphasia, conduction aphasia, and no aphasia. The overall severity of the linguistic deficit included moderate, mild and minimal impairments, as indicated by an Aphasia Quotient range between 40.8 and 97.2, out of a possible 100. All of the patients had relatively spared auditory comprehension, as indicated by the range of 8.2-10.0 out of a possible 10 in the comprehension section of the Western Aphasia Battery (Kertesz, 1982).
Procedures and Testing Materials
All of the subjects were tested individually in a quiet roam by the same examiner. The testing was completed in one or two sessions, depending on the fatiguability of the subject. All subjects used their left arm to perform the limb movements, which for the experimental patients, was nonhemiplegic and ipsilateral to the lesion.
The behavioral tests utilized in this study included one auditory and three visual subtests, hereafter referred to as the screening subtests. The screening tests were included in order to rule out auditory comprehension or visual processing deficits as the source of
defective performance. The behavioral tests also included a buccofacial movement caiprehension subtest, and a limb and buccofacial movement production subtest, hereafter referred to as the experimental tests.




Groups Age Education Gender
(years) (years) M F
Control 52.5 (16.8) 12.0 (4) 4 4
Experimental 58.9 (13.0) 11.4 (3) 8 7
Note. Group means with standard deviations in parentheses.

Table 2-1.

Descriptive demographic data for the experimental and control groups.




Table 2-2. Detailed descriptive data on each of the experimental
subjects.
Time
Post- Type Type
Subject Education CVA of of WAB WAB
Number Age Sex (years) (days) CVA Aphasia AQ Comp
1 66 F 14 52 0 B 79.6 9.6
2 58 M 9 95 0 A 78.6 8.9
3 61 M 13 154 0 B 69.6 8.6
4 78 F 11 67 0 C 75.2 8.9
5 64 M 13 271 0 A 92.6 9.2
6 43 F 9 358 0 A 90.2 10.0
7 52 F 12 128 0 A 88.2 9.3
8 32 F 14 85 0 NA 97.2 10.0
9 67 M 8 357 0 C 70.8 9.9
10 37 M 17 473 H B 76.8 9.5
11 62 M 5 358 0 B 42.6 8.6
12 74 F 10 44 H NA 96.8 10.0
13 66 M 10 58 0 A 76.0 9.0
14 56 F 13 2253 0 B 72.2 8.5
15 67 M 13 27 0 B 40.8 8.2
Note. CVA = cerebrovascular accident; 0 = occlusive stroke; H =
hemorrhagic stroke; B = Broca's aphasia; A = anomic aphasia;
C = conduction aphasia; NA = non-aphasic; WAB = Western
Aphasia Battery; AQ = aphasia quotient; Comp =
Comprehension.




38
These screening and experimental subtests were administered in the same order for each subject.- The order was as follows: the comprehension of buccofacial movements, the production of buccofacial and limb movements to verbal command, the three visual screening subtests, and finally the auditory screening subtest. The production testing followed the movement comprehension testing in order to avoid providing verbal labels to the movements prior to comprehension testing.
The last test given to each experimental subject, but not
administered to the control subjects, was the Western Aphasia Battery (Kertesz, 1982). It was administered according to its published instructions. The aphasia quotient and the auditory comprehension score were calculated for each experimental subject. The type of aphasic syndrome demonstrated, if present, was also determined using the standard taxonomy suggested by Kertesz (1982). Screening Tests
There were four screening subtests altogether, three were visual
and one was auditory. The procedures for all of the screening subtests will be discussed first, followed by a description of each of the subtests separately. The responses were scored as correct/incorrect at the time of testing by the examiner for the four screening subtests. Percent correct was calculated for each subtest. Each subject was required to achieve at least 50% correct on each screening subtest.
The three visual screening subtests were designed to assess the integrity of processing visual information. These three subtests included the same stimulus items which were composed of three training trials and ten randomized scored trials. The first visual screening




subtest was a tool-to-object matching task. A tool is defined as an iplement for performing or facilitating physical opeictions performed with the arm, hand and fingers, or with the oral mechanism. An object is defined as a thing to which physical action is directed. Specifically, the stiruli in this first visual subtest were pictures of tools, sud as a screwdriver, and the target responses were pictures of objects, such as several screws. The second visual screening subtest
was a tool-to-picture matching task. The stimuli were the actual tools and the target responses were pictures of the same tools. The third
visual screening subtest was a picture-to-picture matching task. The stimuli were pictures of tools and the target responses were identical pictures of the same tools. All three subtests included four pictures on the response page which included the target response, a visually similar tool, a visually similar nontool, and an object semantically related to the target response.
In addition, one auditory screening subtest was included to assess the integrity of auditory ccanprehension. The stimuli included three training trials and 20 rardmized scored trials of action line drawings. The examiner instructed the subject to point to one of the action pictures, such as, "Show me shaving," for example. There were four pictures on the response page which included the target action picture, a semantically related foil, a visually similar foil, and a pbonologically similar foil, i.e., an action word sharing more than 50% of its phonemes with the target response.




Experimental Tests
Camprehension of buccofacial movements. Buccofacial movement
caCmprehension was assessed with a pantacmime-to-picture pointing task. A videotape of an actress performing buccofacial transitive movements was utilized. During this testing, the subject was seated approximately 4 to 6 feet away frcm a television monitor. Each movement stimulus was shown one time and the subject was given up to 10 seconds to respond. The subject's first response, pointing to one of four pictures, was recorded and scored immediately by the examiner as correct or incorrect.
The stimulus items were comprised of three training trials and ten randomized buccofacial transitive movements (Appendix B). Each response page was composed of four pictures which included the target response (which was a picture of the tool being pantacmimed on the videotape), and three foil pictures. One foil was a picture semantically related to the target response. A second foil was a picture of a tool with an
associated movement which was similar to the target pantomime. The third foil was a picture of a nonrelated tool.
The percentage correct was calculated for each subject. The lowest score achieved by a normal subject was used as the cut-off score between normal and impaired performance.
Production of movements. The production of movements to verbal
caTand was also assessed. This subtest was comprised of three training trials and 40 randcmized buccofacial and limb movements. There were 10 of each type of stimulus, i.e., buocofacial transitive and intransitive, and limb transitive and intransitive movements (Appendix B).




41
During the movement production testing, each subject's performance was videotaped by a camera placed approximately 6 feet away frcm th-c subject. The camera was focused on the subject's upper body to include his left arm and facial area. The subject was instructed to perform the limb or buccofacial movement as carefully and accurately as possible. During the three training trials, the instructions and feedback enhasized acoczmudating the manipulation of the pretended object, if one was involved.
The accuracy and the error type scoring of the movement production subtest was accomplished using the videotapes of each subject's performance. All of the videotapes were scored during the same time period after the testing of all of the subjects had been completed. For the accuracy scoring, the subject's first response for each trial was scored as correct or incorrect by two trained judges. The percent correct was calculated for each of the following types of movements: buccofacial intransitive, buccofacial transitive, limb intransitive, limb transitive, bucxofacial combined, and limb combined movements. The lowest scores achieved by a normal subject for the buccofacial combined and the limb combined stimulus items were used as the cut-off scores between normal and apraxic performance.
In addition to the accuracy scoring, a qualitative error typing was completed on the buccofacial and limb movement productions. The qualitative scoring system developed by Rothi et al. (1988) for depicting limb apraxic movements was extended and applied to buccofacial apraxic movements as well. In this scoring system, there are four major error categories which are labeled content, temporal, spatial or other




errors. These four major categories are further subdivided into three to seven subcategoricz, as defined in Appendix C. Three subcategories of errors not contained in the system used for limb praxis were added to the system for buccofacial praxis. These consisted of extraneous, place of articulation, and verbalization errors. Each of the error types
could be applied to both buccofacial and limb movements except for four subcategories under spatial errors which could only occur for one type of movement. Specifically, internal configuration, external configuration, and body-part-as-object errors could only occur for limb movements and place of articulation errors could only occur for buccofacial movements.
The error typing was completed only for movements judged to be defective. One movement could exhibit more than one subcategory of error, as well as more than one main type of error. Apraxia Scoring Reliability
Interrater reliability measures were obtained for the accuracy and error type scoring of the buccofacial and limb movement production subtest. A third rater, who was trained in the procedure, independently scored all of the experimental subjects' movement productions for accuracy and error type. The third rater's judgements were compared with the combined judgements of the first two raters.
Accuracy of movement. Kappa statistics (Kramer & Feinstein, 1981) were calculated as interrater reliability measures for the accuracy judgement for each movement (Appendix D). The kappa statistic for the limb intransitive movement "pinching your nose" could not be calculated because all of the ratings were within one column. The range for the




kappa statistics was fram 0.444 to 1.000. Landis and Koch (1977) have suggested the following guidelines, in part, for the values of kappa and the strength of the agreement: .41-.60, moderate agreement; .61-.80, substantial agreement; and .81-1.00, almost perfect agreement. According to these guidelines, there were six kappas of moderate strength, seven kappas of substantial strength, and 26 kappas of almost perfect strength.
In addition to the reliability measures for each individual
movement, intraclass correlations (ICC) employing a one-way analysis of variance of the ratings (Shrout & Fleiss, 1979) were computed to measure the interrater reliability of the percent accuracy for each of the four types of movements. The results were as follows: for limb intransitive movements, ICC=0.9873; for limb transitive movements, IC=0.8162; for buccofacial intransitive movements, I(C=0.8949; and for buccofacial transitive movements, ICC=0.9917.
In smmary, the interrater reliability results reveal that
independent raters could reliably judge the accuracy of buccofacial and limb movement productions. This reliability was demonstrated when the ratings were analyzed individually, as well as when the ratings were analyzed by type of movement.
Error type scoring. Percentage agreement was calculated to measure the interrater reliability of the error type judgement for the main type(s) of errors for each of the 40 movements (Appeidix E). The main error types observed were content, temporal, spatial, other, and the combinations of content and temporal, and spatial and temporal. The range for percentage agreement was frcm 70 to 100%. The mean




percentages for each of the movement types were as follows: limb intr-ansitive, 94.3; limb transitive, 86.0; buccofacial intransitive, 90.0; and buccofacial transitive, 91.0. In summary, the interrater reliability results reveal that independent raters could reliably judge the types of errors demonstrated for buccofacial and limb movements.
Localization of the Lesion
The computerized ta~mgraphy (CT) or magnetic resonance imaging
(MRI) scan of each of the experimental subjects was utilized to document the location of infarcted area(s) in the brain. A checklist of specific neuroanatamic structures was developed (Appendix F). A neurologist, blinded to the behavioral test results, analyzed the CT or MRI scan of each of the patients and marked a plus sign on the checklist for each neuroanatamic structure that was more than 50% involved by the lesion and marked a minus sign for each structure that was involved less than 50% by the lesion. All neuroanatamic structures that were totally spared were left blank on the checklist. Anatomic localization was aided by reference to Matsui and Hirano (1978) for the Cr scans and to Schnitzlein and Murtagh (1985) for the MRI scans. Idiosyncratic areas of low density less than one centimeter in diameter or slight periventricular lucencies were noted, but not included as part of the lesion site.




CAPIER 3
RESULTS
The purpose of this study was to determine the nature of the
relationship between buccofacial and limb apraxia. Specifically, are buccofacial and limb apraxia manifestations of a unitary motor disorder or are they at least partially separable? In addition, the possible presence of two types of buccofacial apraxia was examined as well as the neuroanatmy of the disorder. The experimental group was comprised of fifteen patients who had experienced a single, unilateral, lefthemisphere cerebrovascular accident (CVA). The control group was cmprised of eight subjects who had no history of a central nervous system disorder.
Comparisons Between Groups
There were no significant differences between the control and
experimental groups in age (t = 1.01, df = 21, p = .324) or educational level (t = -0.39, df = 21, p = .702).
Behavioral Test Results
Screening Tests
The experimental group performed significantly worse than the control group in the auditory comprehension screening subtest (t = -3.50, df [corrected for heterogenous variances] = 17.31, p = .003). Specifically, the control group demonstrated a mean of 98.8 45




(SD = 2.31) and the experimental group demonstrated a mean of 90.3
(SD = 8.76). Although there was a significant difference between the experimental and control groups, it was determined that the control group's auditory comprehension was adequate for the apraxia testing, in that it was preserved for following one-stage ccmmands. This relative sparing of auditory comprehension was documented by the carprehension scores on the Western Aphasia Battery (Kertesz, 1982). The range for the experimental subjects was from 8.2 to 10.0 out of a possible 10 (Table 2-2).
In addition, processing of visual stimuli by the experimental subjects was relatively spared as documented by the subjects' performance on the visual screening subtests. In the first visual subtest, a tool-to-object matching task, the experimental group did not significantly differ fran the control group (t = -1.55, df [corrected for heterogenous variances] = 18.72, p = .139). Specifically, the control group achieved a mean of 97.5 (SD = 4.63) and the experimental group a mean of 91.3 (SD = 14.07). In the second visual subtest, the tool-to-picture matching task, the experimental group did not significantly differ from the control group (t = .68, df = 21, p = .504). Specifically, the control group demonstrated a mean of 97.5 (SD = 4.63) and the experimental group demonstrated a mean of 98.7 (SD = 3.52). Finally in the third visual subtest, the picture-topicture matching task, it was not possible to apply a t-test because the experimental group demonstrated no variance. Specifically, the control group achieved a mean of 98.7 (SD = 3.54) and the experimental group achieved a mean of 100.0 (SD = 0.00). In summary, the experimental




group did not significantly differ from the control group in the processing of visual information.
Exerimental Tests
COmprehension of buccofacial movements. The experimental group performed significantly worse than the control group in the comprehension of buccofacial movements (t = -2.31, df [corrected for
heterogenous variances] = 20.79, p = .031). Specifically, the control group achieved a range of scores between 80 and 100% accuracy, with a mean of 88.8 (SD = 8.35). The lowest score (80%) achieved by a control subject was used as the cut-off score between spared arndi impaired buccofacial movement comprehension. The experimental subjects achieved a range of scores between 30 and 100% accuracy, with a mean score of 76.0 (SD = 18.05). Utilizing the above cut-off score, eight experimental subjects demonstrated spared buccofacial comprehension, while seven demonstrated impaired buccofacial comprehension.
Production of movements. The experimental group performed significantly worse than the control group in the production of buccofacial movements (t = -4.67, df [corrected for heterogenous variances] = 14.31, p = .000). Specifically, the control group achieved a range of scores between 95 and 100% accuracy, with a mean of 98.8 (SD = 2.31). Again, the lowest score (95%) achieved by a control subject was used as the cut-off score between spared praxis and apraxia. The experimental group achieved a range of scores between 5 and 100% accuracy, with a mean of 62.3 (SD = 30.05). Utilizing the above cutoff score, four experimental subjects demonstrated spared buccofacial praxis, while 11 experimental subjects demonstrated buccofacial apraxia.




Similarly, the experimental group performed significantly worse that the control group in the production' of limb movements (t = -5.29, df [corrected for heterogenous variances] = 16.87, p = .000). Specifically, the control group achieved a range of scores between 80 and 95% accuracy, with a mean of 88.8 (SD = 5.82). The experimental group achieved a range of scores between 15 and 90% accuracy, with a mean of 54.3 (SD = 23.89). Again, utilizing the lowest normal score (80%) as the cut-off score, four of the experimental subjects demonstrated spared limb praxis, while 11 experimental subjects demonstrated limb apraxia.
Research Questions
The statistical analysis relevant to each question will be discussed separately.
Research Question #1
Are buccofacial and limb apraxia manifestations of a unitary
motor disorder?
To determine the nature of the relationship between buccofacial and limb apraxia, the following three subquestions on the co-occurrence of the two disorders, the transitivity factor and the proportion of error types were addressed.
Research Question #1a
What is the nature of the co-occurrence or dissociation of
buccofacial and limb apraxia?
To determine the nature of the co-occurrence or dissociation of the two disorders, the following null hypothesis was tested:
Ho: There is an association between the co-occurrence of
buccofacial and limb apraxia.




There was a nonsignificant association between buccofacial and limb apraxia (Fisher's exact test, df = [1,1], p = 0.7253). in addition, Table 3-1 descriptively presents the relationship between the production of buccofacial and limb movements to verbal ccmund. As noted, there was a co-occurrence of buccofacial and limb praxis ability for nine patients, spared for both types in one subject and impaired for both types in eight subjects. However, there were six patients (40%) who demonstrated a double dissociation between the two types, three subjects
with spared limb praxis and buccofacial apraxia, and three subjects with spared buccofacial praxis and limb apraxia. In sunnary, buccofacial and limb apraxia can be dissociated within the same subjects. Research Question #Ib
Is the transitivity factor manifested similarly in the
production of buccofacial and limb movements?
To determine the effect of the transitivity factor in the production of buccofacial and limb movements, the following null hypothesis was tested:
Ho: The transitivity factor is manifested in a similar manner
for both buccofacial and limb movements.
For example for both types of movements, the transitive and intransitive movements may be equally impaired, or the transitive movements may be more impaired than the intransitive movements, or the intransitive movements may be more impaired than the transitive movements. Table 3-2 presents the means and standard deviations for each type of movement for the experimental and control groups. A two-way analysis of variance with repeated measures was conducted with the within-subject factors of transitivity and body part. As illustrated in Figure 3-1, the




Table 3-1.

The relationship between the production of buccofacial and limb movements.

Buccofacial Movements
Spared Impaired
Spared Limb
Movements 8 3, 6, 10
Impaired Limb 5, 7, 12 1, 2, 4, 9, 11,
Movements 13, 14, 15
Note. The numbers in the table represent subject identification
numbers.




Table 3-2.

The means and standard deviations for each of the four types of movements for the experimental and control groups.

Type of Movement
Limb Limb Buccofacial Buccofacial
Group Intransitive Transitive Intransitive Transitive
Experimental 74.0 (22.93) 34.7 (29.00) 64.7 (32.04) 60.7 (29.63) Control 95.0 ( 7.56) 82.5 (11.65) 98.8 ( 3.54) 98.8 ( 3.54)
Note. Numbers in parentheses are the standard deviations.




100
90 80 70 60 50
40 30
20 10
0

Intrans Trans
Limb Movements

Figure 3-1.

Intrans Trans
Buccofacial Movements

The performance of transitive and intransitive buccofacial and limb movements by the experimental and control groups.

Note. Intrans = Intransitive; Trans = Transitive.




interaction between the two factors was significant (F = 23.89, df = [1, 14], p = .0002). Because ths interaction was significant, a follow-up analysis of the transitivity effect was completed by applying the Bonferroni statistic. The limb transitive movements were significantly more impaired than the limb intransitive movements (t = 8.62, df = [2, 14], with a 95% confidence interval between 2.79 and
5.08). In contrast, the buccofacial transitive movements were not significantly more impaired than the buccofacial intransitive movements (t = 0.88, df = [2, 14], with a 95% confidence interval between -0.74 and 1.54). In summary, the transitivity factor was manifested in a significantly dissimilar manner in the production of buccofacial and limb movements.
As part of the follow-up analysis, a comparison was made between the experimental and control groups for each type of movement. The experimental group performed significantly worse than the control group for each type of movement (degrees of freedon was corrected for heterogenous variances for each comparison): limb intransitive (t = -3.23, df = 18.73, p = .004); limb transitive (t = -5.60, df = 20.08, p = .000); buccofacial intransitive (t = -4.10, df = 14.61, p = .001); and buccofacial transitive (t = -4.91, df = 14.74, p = .000).
In summary, the experimental group was significantly more impaired than the control group regardless of the type of movement. Research Question #1c
Is the proportion of error types similar for both buccofacial
and limb movements?
To determine the nature of the relationship between error types for buccofacial and limb apraxia, the following null hypothesis was tested:




Ho: The proportion of error types is similar for both
buccofacial and limb movements.
Table 3-3 delineates the contingency table which contrasts body part (buccofacial or limb) with the four main types of errors (content, teporal, spatial and other). There was a significant relationship between the proportion of error types and body part (chi-square = 34.20, df = 3, p < .005). That is, the proportion of error types was significantly dissimilar for bucxofacial and limb movements.
Because a significant relationship was found between the proportion of error types and body part, a follow-up analysis was completed in order to determine what specific types of errors exhibited dissimilar proportions for buccofacial and limb movements. In four follow-up chisquare tests, each error type was contrasted with the average of the other three error types in 2 X 2 contingency tables. There was a significant relationship between the proportion of content errors and body part (chi-square = 16.02, df = 1, p < .005). Specifically, there was a disproportionately large number of content errors for buccofacial movements. There was a nonsignificant relationship between the proportion of temporal errors and body part (chi-square = 0.61, df = 1, p > .100). There was a significant relationship between the proportion of spatial errors and body part (chi-square = 8.69, df = 1, p < .005). Specifically, there was a disproportionately large number of spatial errors for limb movements. And finally, there was a significant relationship between the proportion of other errors and body part (chi-square = 7.27, df = 1, p < .010). Specifically, there was a disproportionately large number of other errors for buccofacial movements.




55
Table 3-3. The observed and expected frequencies of each type of error
for buccofacial and limb movements.
Type of Error
Type of
Movement Content Temporal Spatial Other
Limb 8 (20.74) 35 (31.95) 109 (91.37) 10 (17.94)
Buccofacial 29 (16.26) 22 (25.05) 54 (71.63) 22 (14.06)

Note. Numbers

in parentheses are the expected cell frequencies.




In summary, there was a dissimilar proportion of error types for
buccofacial and limb movements. The follow-up cid-squares revealed that the proportion of temporal errors was similar for both buccofacial and limb movements. However, the proportions of content, spatial and other error types were dissimilar for buccofacial and limb movements, and therefore accounted for the overall dissimilarity found in the initial analysis. Specifically, buccofacial movements exhibited a
disproportionately large number of content and other errors, whereas limb movements exhibited a disproportionately large number of spatial errors.
Research Question #2
Are there at least two different types of idecamotor
buccofacial apraxia: the first type characterized by impaired production and comprehension, and the second type by impaired
production but preserved camiprehension?
To determine the possible types of buccofacial apraxia demonstrated, the following null hypothesis was tested:
Ho: There is only one type of buccofacial apraxia.
Table 3-4 delineates the relationship between the comprehension and production of buccofacial movements. The proportion of subjects who demonstrated an association between buccofacial comprehension and production (11/15) was evaluated by applying a binomial statistic. The proportion of subjects with an association between the comprehension and production of buccofacial movements just failed to reach significance (p = .0592). As noted in Table 3-4, the comprehension and production were frequently associated, spared for both in four subjects and impaired for both in seven subjects. However, there were four patients who dwnstrated spared comprehension but impaired production. There




Table 3-4. The relationship between the comprehension and production
of buccofacial movements.
Buccofacial Comprehension
Spared Impaired
Spared
Buccofacial 5, 7, 8, 12
Movements
Impaired
Buccofacial 6, 10, 11, 15 1, 2, 3, 4, 9, 13, 14
Movements
Note. The numbers in the table represent subject identification
numbers.




were no subjects who demonstrated spared movement production with impaired comprehension. In su~nary, two different types of buccofacial apraxia were exhibited, one type characterized by impaired production and comprehension, and the second type characterized by impaired production but preserved comprehension. Specifically, buccofacial comprehension and production may dissociate within an individual subject.
Research Ouestion #3
If two types of buccofacial apraxia exist, is the inferior parietal lobe (IPL) a critical neuroanatomic structure for
both the comprehension and production of buccofacial
movements?
To determine the importance of the IPL for the comprehension and production of buccofacial movements, the following null hypothesis was tested:
Ho: The IPL is a crucial neuroanatcmic structure for both the
comprehension and production of buccofacial movements. Appendix G documents the involvement of specific neuroanatomic structures in the lesion for each experimental subject. A plus sign designates more than 50% damage to the specific structure and a minus sign designates less than 50% damage to the specific structure. A blank space designates that the structure is spared.
There was a nonsignificant relationship between the comprehension of buccofacial movements and the integrity of the IPL (Fisher's exact test, df = [1,1], p = .3776). As delineated in Table 3-5, buccofacial movement comprehension and the integrity of the IPL are associated for only six subjects, that is, both are spared for four subjects and both are impaired for two subjects. In contrast, buccofacial movement




Table 3-5.

The relationship between the comprehension of buccofacial movements and the integrity of the inferior parietal lobule (IPL).

Buccofacial Comprehension Spared Impaired
IPL Spared 6, 8, 10, 15 1, 2, 4, 9, 13
IPL Involved 5, 7, 11, 12 3, 14
Note. The numbers in the table represent subject identification
numbers.




comprehension and the integrity of the IPL are dissociated for nine subject. Specifically, four subjects demonstrated spared buccofacial movement comprehension and involvement of the IPL, and five subjects demonstrated impaired buccofacial movement comprehension and spared IPL. In summary, the integrity of the IPL does not appear to be a critical neuroanatcmic structure for the comprehension of buccofacial movements.
As part of the post hoc analysis, Table 3-6 provides additional
descriptive data regarding the relationship between the comprehension of bucxcofacial movements and the involvement of specific neuroanatamic structures. The specific neuroanatamic structures which were included in this table, excluding the IPL, have previously been reported to be associated with the presence of buccofacial apraxia (Tognola & Vignolo, 1980; Mintz, Raade & Kertesz, 1989). Fisher's exact tests were applied to evaluate the relationship between each neuroanatcmic structure and the comprehension of buccofacial movements. The inferior frontal gyrus (p = .0317) and the peri-Sylvian central area (p = .0317) were significantly related to the comprehension of buccofacial movements. The insula (p = .0513) just failed to reach significance. The remaining neuroanatamic structures were not significantly related to the comprehension of buccofacial movements: the superior temporal gyrus
(p = .1818), the striatum (p = .0839), and the corona radiata (p = .3776). In summary, the frontal cortical areas appeared to be crucial for the comprehension of buccofacial movements.
Table 3-7 provides descriptive data regarding the relationship
between the production of buccofacial movements and the involvement of specific neuroanatamic structures. Again, the specific neuroanatomic




Table 3-6. The relationship between the comprehension of buccofacial movements and the involvement of
specific neuroanatomic structures for each
experimental subject.
IPL Corona
Subject AG SMG PSC Insula IFG STG Striatum Radiata
Impaired Buccofacial Comprehension
1 + + + +
2 + + + + + +
3 + + + + +
4 + +
9 + + + + + +
13 + + + + +
14 + + + + + +
Spared Buccofacial Comprehension
5 + +
6 + + + + + +
7 + + + +
8
10 + + +
11 + + + + + + +
12 +
15
Note. IPL = inferior parietal lobule; AG = angular gyrus;
SMG = supramarginal gyrus; PSC = peri-sylvian central; IFG = inferior frontal gyrus; STG = superior temporal
gyrus. + = more than 50% involvement of the
structure; = less than 50% involvement of the
structure.




Table 3-7.

The presence of buccofacial apraxia and the involvement of specific neuroanatomic structures for each experimental subject.

IPL Corona
Subject AG SMG PSC Insula IFG STG Striatum Radiata
Buccofacial Apraxia
1 + + + +
2 + + + + + +
3 + + + + +
4 + +
6 + + + + + +
9 + + + + + +
10 + + +
11 + + + + + + +
13 + + + + +
14 + + + + + +
15
Spared Buccofacial Praxis
5 + +
7 + + + +
8
12 +
Note. IPL = inferior parietal lobule; AG = angular gyrus;
SMG = supramarginal gyrus; PSC = peri-sylvian central; IFG = inferior frontal gyrus; STG = superior temporal
gyrus. + = more than 50% involvement of the structure;
- = less than 50% involvement of the structure.




structures which were included in this table, excluding the IPL, have previously been reported to be associated with the presence of buccofacial apraxia (Tognola & Vignolo, 1980; Mintz, Raade & Kertesz, 1989). There was a nonsignificant relationship between the production of buccofacial movements and the integrity of the IPL (Fisher's exact test, df = [1,1], p = .1428). As delineated in Table 3-6, buccofacial movement production and the integrity of the IPL are associated for only four subjects, that is, both are spared for one subject and both are impaired for three subjects. In contrast, buccofacial movement production and the integrity of the IPL are dissociated for 11 subjects. Specifically, three subjects demonstrated spared buccofacial production and involvement of the IPL, and eight subjects demonstrated impaired buccofacial production and spared IPL. In summary, these data do not provide support for the hypothesis that the IPL is a critical neuroanatmic structure for the production of buccofacial movements.
As part of the post hoc analysis, Fisher's exact tests were applied to test the relationship between each of the remaining neuroanatomic structures listed in Table 3-7 and the production of buccofacial movements. The following neuroanatomic structures were significantly related to the presence of buccofacial apraxia: the inferior frontal gyrus (p = .0256), the peri-Sylvian central area (p = .0256), the insula (p = .0329), and the striatum (p = .0110). In contrast, the superior temporal gyrus (p = .4066) and the corona radiata (p = .1428) were not related to the production of buccofacial movements. In summary, the frontal cortical structures, with the addition of the striatum, appeared to be crucial for the production of buccofacial movements.




In summary, the results for each question are reviewed as they relate to the specific null hypothesis tested. Null hypothesis la, "There is an association between the co-occurrence of buccofacial arnd limb apraxia," was rejected. Null hypothesis lb, "The transitivity factor is manifested in a similar mariner for both buccofacial and limb movements," was rejected. Null hypothesis ic, "The proportion of error types is similar for both buccofacial and limb movements," was rejected. Null hypothesis 2, "There is only one type of buccofacial apraxia," was rejected. And finally null hypothesis 3, "The inferior parietal lobule (IPL) is a crucial neuroanatomic structure for both the comprehension and production of buccofacial movements," was rejected for both the comprehension and production aspects of the question.




CHAPTER 4
DISCUSSION
The literature suggests that buccofacial and limb apraxia
frequently co-occur, leading same to speculate that they share a camnon underlying mechanism. However, double dissociations have been reported, which would call into question the concept of a unitary mechanism for both buccofacial and limb apraxia. The nature of the relationship between these two disorders has theoretical, as well as clinical implications.
There are at least two possible constructs depicting the
relationship between buccofacial and limb apraxia. In the first construct, apraxia is viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb output. This "unitary disorder" construct would predict a high degree of concordance and similarity between the two types of apraxia. An alternative construct would postulate that the relationship between buccofacial and limb apraxia is not unitary. This non-unitary construct would predict quantitative and qualitative differences to be noted between buccofacial and limb performance.
The present study was designed to determine the nature of the relationship between buccofacial and limb apraxia. The experimental group was cmprised of fifteen patients who had experienced a single, unilateral, left-hemisphere cerebrovascular accident (CVA). The control 65




group was comprised of eight subjects who had no history of a central nervous system disorder. An analysis 'us -xmpleted on the following factors for both buccofacial and limb apraxia in these groups: their cooccurrence, the transitivity factor, and the proportion of error types. The predictions that each model would make for each factor and the actual results are presented.
Research Questions
In terms of the co-occurrence of the two disorders, a hig
incidence of co-occurrence would support the unitary motor disorder construct, whereas a low incidence of co-occurrence would support a nonunitary construct. The results of this study indicated that there were a significant number of dissociations between buccofacial and limb apraxia within the same subjects. These results would support a nonunitary construct.
In terms of the transitivity factor, several studies have suggested that left-hemisphere-damaged subjects are more impaired in the performance of limb transitive than limb intransitive movements. It was further suggested that this difference in performance may be explained by a difference in the manner in which these two types of limb movements are represented in the brain. However, the transitivity factor has not been investigated for buccofacial movements. The unitary motor disorder construct would predict that the neural control mechanisms for both buccofacial and limb praxis would be similar andI, therefore, that the transitivity factor would be manifested in a similar manner for both disorders. In contrast, a non-unitary construct would predict that the neural control mechanisms for buccofacial and limb praxis would be




separable arid, therefore, that the transitivity factor would be manifested in a dissimilar manner for each disorder.
The results of this study revealed that the transitivity factor was manifested in a significantly dis imilar manner in the production of buccofacial and limb movements. The limb transitive movements were significantly more impaired than the limb intransitive movements. In contrast, the buccofacial transitive movements were not significantly more impaired than the buccofacial intransitive movements. One explanation for the nonsignificant buccofacial transitivity result could be that the buccofacial movements were not impaired and so would not demonstrate the transitivity difference. However, a follow-up analysis revealed that the experimental group was significantly more impaired than the control group for each type of movement, including the two types of buccofacial movements. Therefore, a lack of buccofacial impairment could not explain the nonsignificant buccofacial transitivity results. A second explanation for these results would suggest that buccofacial and limb apraxia are not manifestations of a unitary underlying mechanism. The transitivity factor is important for the limb movements but not for the buccofacial movements. In conclusion, these results would support a non-unitary construct and would suggest that the underlying mechanism(s) of these two disorders are, at least in part, functionally independent.
Additionally, it is suggested that an analysis of the error types of both buccofacial and limb movements may give researchers insights into the similarity or dissimilarity of the underlying mechanism(s). The unitary motor disorder construct would predict a similar proportion




68
of error types for both buccofacial and limb movements. In contrast, a non-unitary construct would predict a dissimilar proportion of error types for both disorders. The results of this study revealed that the proportion of error types was significantly dissimilar for buccofacial and limb movements. In addition, the follow-up analysis suggested that the proportion of temporal errors was similar for both buccofacial and limb movements. Therefore, temporal errors did not account for the differences found. However, the follo-up analysis also indicated that the proportions of content, spatial and other error types were significantly dissimilar for buccofacial and limb movements. Specifically, buccofacial movements exhibited a disproportionately large number of content and other errors, whereas limb movements exhibited a disproportionately large number of spatial errors. These results would support a non-unitary construct and would suggest that the underlying mechanism(s) of these two disorders are, at least in part, functionally independent. In addition, these results would suggest that the spatial and semantic aspects of movement production may account for the differences found.
In sunary, the results frum these three questions supported a nonunitary construct for buccofacial and limb apraxia. Specifically, double dissociations between buccofacial and limb apraxia were noted, the transitivity factor was manifested in a dissimilar manner between the two disorders, and the proportion of error types was dissimilar between the two disorders.
Additional analyses were completed in order to further elucidate
the nature of the relationship between buccofacial and limb apraxia. As




69
with the two types of idecmotor limb apraxia, it would logically follow that there may also be two types of buccofacial apraxia. Specifically, one type would be characterized by impaired production and comprehension of buccofacial movements, and a second type would be characterized by impaired production but preserved cacuprehension.
The results of this study indicated that there was a nonsignificant association between the comprehension and production of buccofacial movements. Specifically, buccofacial ccmprehension and production may dissociate within an individual subject. Therefore, two different types of buccofacial apraxia were exhibited: one type characterized by impaired production and comprehension, and the second type characterized by impaired production but preserved comprehension. This is similar to the pattern that has been previously reported for limb apraxia (Heilman, Rothi & Valenstein, 1982).
The neuroanatomy of each disorder may also elucidate the nature of the relationship between buccofacial and limb apraxia. The previous discussion of the neuroanatanmic distinctions for limb apraxia outlined the importance of the inferior parietal lobule (IPL) for the disorder. If a unitary mechanism for buccofacial and limb praxis is accepted, it would logically follow that the IPL would also be a critical structure for buccofacial praxis. Specifically, it was predicted that the IPL would be a critical neuroanatnmic structure for both the comprehension and production of buccofacial movements.
The results of this study revealed a nonsignificant relationship between the comprehension of buccofacial movements and the integrity of the IPL. Although the two factors were associated for six subjects,




they were dissociated for nine subjects. Therefore, the integrity of theb IPL does not appear to be a critical neuroanatcmic structure for the camprehension of buccofacial movements. In contrast, previous research has suggested that the IPL is a critical neuroanatamic structure for the comprehension of limb movements (Heilman, Rothi & Valenstein, 1982).
In addition, the results of this study revealed a nonsignificant relationship between the production of buccofacial movements and the integrity of the IPL. Although the two factors were associated for four subjects, they were dissociated for 11 subjects. Therefore, the integrity of the IPL does not appear to be a critical neuroanatamic structure for the production of buccofacial movements. In contrast, previous research has suggested that the IPL is a critical neuroanatomic structure for the production of limb movements.
Because the results indicated that the IPL was not a critical
neuroanatcmic structure for either the comprehension or production of
buccofacial movements, additional analyses were completed in order to determine what specific structures were associated with these impairments. Regarding the ccmprehension of buccofacial movements, anterior cortical areas, primarily frontal lobe structures, appeared to be critical. Specifically, the inferior frontal gyrus and the periSylvian central area were significantly related to the comprehension of
buccofacial movements. The insula just approached reaching significance. Regarding the production of buccofacial movements, anterior cortical areas and several deeper structures appeared to be critical. Specifically, the inferior frontal gyrus, the peri-Sylvian central area, the insula and the striatum were significantly related to




the production of buccofacial movements. A comparison between the two impairments revealed that ths anterior surface structures appeared critical for the comprehension of buccofacial movements, whereas the same anterior surface structures and several deeper anterior structures appeared critical for the production of buccofacial movements.
In summary, buccofacial and limb apraxia are similar in the fact that both disorders are manifested as two types. Specifically, the comprehension and production of movements may be dissociated. Hcever, bucoofacial and limb apraxia are dissimilar in the fact that the IPL is a critical neuroanatomic structure for the comprehension and production of limb movements, but apparently is not a critical structure for the comprehension and production of buccofacial movements. In contrast, it appears that anterior structures are the crucial areas for buccofacial praxis performance.
Are there alternative explanations of these results? In this
study, the presence of impairments in the production of buccofacial or limb movements could not be explained by age or educational level, as
there were no significant differences between the experimental and control groups for either of these factors. Although the experimental group performed significantly worse than the control group in the auditory comprehension subtest, the experimental group did demonstrate relatively preserved performance on this test. It is unlikely that the relatively mild deficits in auditory comprehension could account for the significant deficits exhibited during the movement production testing. As additional evidence of relatively spared auditory comprehension, the comprehension scores on the Western Apasia Battery (Kertesz, 1982) were




relatively preserved. Additionally, the presence of impairments in the ccmprehension of buocofacial movements could not be explained by poor visuoperceptual skills as there were no significant differences between the experimental and control groups for the visual subtests.
The results of this study clearly support a non-unitary construct for the relationship between the production of buccofacial and limb movements. What could account for the non-unitary patterns observed? There was a disproportionately large number of spatial errors for the limb movements. Previous researchers have reported dissociations in behavior and dissociations in lesion localization in the representation of space surrounding the body. Rizzolatti and his colleagues (Rizzolatti, Matelli & Pavesi, 1983; Rizzolatti & Camarda, 1987) have defined the space surrounding the body in the following way. Peripersonal space is the space immediately around the body, including actual touching of the body, whereas distant peripersonal space is the space outside of the preceding area but within the reach of the arm. Rizzolatti and his colleagues made unilateral, left-hemisphere surgical ablations of specific frontal areas in macaque monkeys. The subsequent behavioral testing was accomplished by moving a piece of food held by a pair of forceps at different distances from the animal. After surgical ablation of the left-hemisphere postarcuate cortex, which is a premotor frontal area, the monkeys demonstrated a failure to grasp food with the mouth when presented contralaterally to the lesion and a severe hemiinattention of visual stimuli which was limited to peripersonal space. Specifically, when the food was presented in the contralateral peripersonal space, the monkey ignored the stimulus and did not produce




the normal mouth-grasping response. Likewise, when a threatening stimulus w as presented to the contralateral hemiface, the normal blink response was absent. In contrast, when a threatening stimulus was presented in distant contralateral peripersonal space, the monkey demonstrated facial movements and a rich emotional response. In contrast to these mouth deficits, the motor disturbances of the arm were markedly less severe and quite different in quality. The mild arm deficits consisted of a reluctance to use the contralateral arm and of mild clumsiness of finger movements. As part of the control experiment, Rizzolatti and his colleagues also made surgical ablations of a second area in the frontal cortex (the frontal eye fields) with a separate set of monkeys. These monkeys demonstrated a neglect of the contralateral hemispace which was more prominent for distant peripersonal space than peripersonal space. In summary, these results demonstrate that lesions of one area (postarcuate cortex) produce peripersonal neglect, whereas lesions of another area (frontal eye fields) produce distant peripersonal neglect. In addition, there is a close relationship
between the spatial properties of the neglect and the type of motor disturbance. Specifically, peripersonal neglect is associated with a disturbance of mouth movements, whereas distant peripersonal neglect is associated with a disturbance of arm movements. These results would suggest that areas of the brain that organize complex motor acts also have attention functions that are specific for the space in which the movements occur.
Employing Rizzolatti's definitions of peripersonal and distant
peripersonal space, an analysis of the specific stimulus items utilized




in the present study was canpleted. All of the buccofacial movements would be classified as occurring in peripersonal space, whereas 70% of the limb movements would be classified as occurring in distant peripersonal space, with the remaining 30% classified as occurring in peripersonal space. The peripersonal-distant personal distinction could possibly explain the patterns of dissociations noted between buccofacial and limb movements. For example, there was a disproportionately large number of spatial errors for the limb movements. This might suggest that the distant peripersonal representation was severely affected, but the peripersonal representation was not. In addition, previous research has outlined the importance of the inferior parietal lobe (IPL) for both the ccmprehension and production of limb movements. In contrast, the results of the present study suggested that IPL is not a critical structure for either the comprehension or production of buccofacial movements. Instead, the present study suggests that structures anterior to the IPL are crucial areas for buccofacial performance. The localizations of the present study do not match the localizations that Rizzolatti proposed. However, localizations alternative to those proposed by Rizzolatti have been presented. Grusser (1983) suggested an anterior to posterior gradient for the localization of the representations of space. Specifically, he proposed the following neuronal networks for the perceptual and motor operations: oral grasping by the prefrontal neuronal networks, manual grasping by the "central" parietal mechanisms, the near distant action space by the posterior




parietal regions, and the far-distant action space by occipital cortex. These data would approximate an anterior to posterior gradient.
Implications for Future Research
The results of this study clearly support a non-unitary construct for the relationship between buccofacial and limb apraxia. However, there are at least two alternative versions of the non-unitary construct. In the first alternative, there would be two totally separable praxis systems: one for planning and controlling buccofacial movements and another one for planning and controlling limb movements. This "totally separable" model would predict quantitative and qualitative differences to be noted in all factors between buccofacial and limb performance. In the second alternative model, the two praxis systems would be partially separable. This "partially separable" model would predict areas of concordance as well as areas of discordance between buccofacial and limb praxis.
Given the results of this study, it is not possible to
differentiate between these two alternatives of the non-unitary model. Although the results appeared to support the complete separation of buccofacial and limb praxis, which is consistent with the "totally separable" model, it is possible that additional factor(s) that were not tested would not support this model. Specifically, these additional factors may be associated for buccofacial and limb praxis and, therefore, would support the "partially separable" model.
Additional research is needed to determine which non-unitary model best describes the relationship between buccofacial and limb apraxia. This additional research may take the form of recovery studies. In this




type of study, the evolution of qualitative aspects of buccofacial and limb apraxia would be analyzed over a period of time post-onset. There are several possible patterns of results that might be observed. In the first alternative, all types of errors may evolve at dissimilar rates for buccofacial and limb apraxia. This pattern of results would suggest that buccofacial and limb praxis emanate from entirely separable mechanism(s). In the second alternative, same types of errors may evolve at similar rates for buccofacial and limb apraxia, whereas other types of errors may evolve at dissimilar rates. This pattern of results would suggest that, for the former type of errors, buccofacial and limb praxis share that mechanism, whereas for the latter type of errors, buccofacial and limb praxis emanate from different mechanism(s). In summary, detailed recovery studies may allow researchers to differentiate between the "totally separable" model and the "partially separable" model of buccofacial and limb praxis.
Clinical Implications
As discussed previously, buccofacial apraxia is frequently
associated with left-hemisphere damage. And because this disorder is associated with left-hemisphere lesions, it frequently co-occurs with language and/or speech disorders. A speech-language pathologist may choose to use verbal prompting to facilitate the patient's compensation for articulatory deficits, such as, "close your lips," or "put your tongue up" (Square-Storer, 1989). The presence of a moderate or severe case of buccofacial apraxia would create a significant barrier to this type of treatment. Additionally, buccofacial apraxia may co-occur with a swallowing disorder. The assessment or treatment of a dysphagic




patient may also involve verbal ccmimands to, "cough now," or "move the bolus of food with your tongue." Again, the pr--nce of a moderate or severe buccofacial apraxia would have a significant impact on the management of this type of patient.
In order to treat a neuropsychological disorder, it is important to understand the neuropsychological medansm(s) underlying the disorder. This study attempted to elucidate the underlying mechanism(s) of buccofacial and limb apraxia. The results suggested that buccofacial and limb apraxia are at least partially separable motor disorders. This would imply that a clinician should assess each disorder separately. Because a patient demonstrates a deficit in one disorder does not necessarily imply that the patient will demonstrate a deficit in the second disorder.
In addition, the results of this study have implications for
treatment decisions regarding buccofacial or limb apraxia. Because a non-unitary model was supported, treatment of one disorder may not generalize to the other disorder. Therefore, each disorder would need to be treated separately in order to assure improvement in each. In addition, because the underlying mechanisms are at least partially separable, a specific treatment task which is effective for one disorder may not be effective for the second disorder.
Finally, the proportion of error types demonstrated may have
clinical implications. Specifically, the proportion of spatial errors was significantly dissimilar between buccofacial and limb movements. The follow-up analysis revealed that the number of spatial errors for limb movements appeared disproportionately high. This would suggest




that, if a clinician was choosing to treat limb praxis, the list of initial gestures targeted should be very distinct from each other spatially. Similarly, the proportion of content errors was significantly dissimilar between buccofacial and limb movements. The follow-up analysis revealed that the number of content errors for buocofacial movements appeared disproportionately high. This would suggest that, if a clinician was choosing to treat buccofacial praxis, the list of initial gestures targeted should be very distinct from each other semantically.
In summary, the results of this study suggest that buccofacial and limb apraxia are at least partially separable, which would imply that a
clinician should assess and treat each disorder separately.




APPENDIX A
ERROR TYPE CATEGORIES AND DEFINITIONS FOR LIMB MOVEMENTS
CONTENT
P Perseverative = the subject produces a response that includes all
or part of a previously produced pantomime.
R Related = the pantomime is an accurately produced pantomime
associated in content to the target. For example, the subject
might pantomime playing a trombone for a target of a bugle.
N Non-Related = the pantomime is an accurately produced pantomime
not associated in content to the target. For example, the subject might pantomime playing a trombone for a target of
shaving.
TEMPORAL
S Sequencing = some pantomimes require multiple positionings that
are performed in a characteristic sequence. Sequencing errors
involve any perturbation of this sequence including addition,
deletion, or transposition of movement elements as long as the
overall movement structure remains recognizable.
T Timing = this error reflects any alterations from the typical
timing or speed of a pantomime and may include abnormally
increased, decreased, or irregular rate of production.
0 Occurrence = pantomimes may involve either single (i.e. unlocking
a door with a key) or repetitive (i.e. screwing in a screw with a
screwdriver) movement cycles. This error type reflects any
multiplication of single cycles or reduction of a repetitive
cycle to a single event.
D Delay = delay in the initiation of a movement.




APPENDIX A (CONTINUED)
SPATIAL
A Amplitude = any amplification, reduction, or irregularity of the
characteristic amplitude of a target pantomime.
IC Internal Configuration = when pantomiming, the fingers and hand
must be in a specific spatial relation to one another to reflect recognition and respect for the imagined tool. This error type
reflects any abnormality of the required finger/hand posture and its relationship to the target tool. For example, when asked to
pretend to brush teeth, the subject's hand may close tightly into
a fist with no space allowed for the imagined toothbrush handle.
BPO Body-Part-as-Object = the subject uses his/her finger, hand, or
arm as the imagined tool of the pantomime. For example, when
asked to smoke a cigarette, the subject might puff on his index
finger.
ECO External Configuration Orientation = when pantomiming, the fingers/hand/arm and the imagined tool must be in a specific relationship to the "object" receiving the action. Errors of
this type involve difficulties orienting to the "object" or in
placing the "object" in space. For example, the subject might
pantomime brushing teeth by holding his hand next to his mouth
without reflecting the distance necessary to accommodate an imagined toothbrush. Another example would be when asked to
hammer a nail, the subject might hammer in differing locations in space reflecting difficulty placing the imagined nail in a stable
orientation.
M Movement = when acting on an object with a tool, a movement
characteristic of the action and necessary to accomplishing the
goal is required. Any disturbance of the characteristic movement reflects a movement error. For example, a subject, when asked to
pantomime using a screwdriver, may orient the imagined
screwdriver correctly to the imagined screw but instead of
stabilizing the shoulder and wrist and twisting at the elbow, the subject stabilizes the elbow and twists at the wrist or shoulder.
OTHER
NR No Response.
UR Unrecognizable Response = a response that is not recognizable and
shares no temporal or spatial features of the target.
Note. Adapted from Rothi, Mack, Verfaellie, Brown and Heilman (1988).




APPENDIX B
LIST OF BUCCOFACIAL AND LIMB STIMULUS ITEMS

Buccofacial Intransitive

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

whistle
cough
puff out your cheeks click your tongue make a 'be quiet' sound lick your lips open your mouth smack your lips clear your throat hold your breath

Buccofacial Transitive

suck from a straw kiss a baby lick a lollipop sniff a flower blow out a match bite an apple sneeze with a kleenex blow up a balloon chew gum use a toothpick

Limb Intransitive

hichhike snap your fingers wave goodbye salute
scratch your head make a fist signal 'OK' make a victory sign pinch your nose cross your fingers

Limb Transitive

cut with scissors use a hammer lock a door brush your teeth comb your hair use a screwdriver write with a pencil flip a coin eat with a fork use a razor




APPENDIX C
ERROR TYPE CATEGORIES AND DEFINITIONS FOR BUCCOFACIAL AND LIMB MOVEMENTS
CONTENT
P Perseverative = the subject produces a response that includes all
or part of a previously produced movement.
R Related = the movement is an accurately produced movement
associated in content to the target.
N Non-Related =the movement is an accurately produced movement
which is not associated in content to the target.
TEMPORAL
S Sequencing = some movements require multiple positionings which
are performed in a characteristic sequence. Sequencing errors
involve any perturbation of this sequence including addition,
deletion, or transposition of movement elements as long as the
overall movement structure remains recognizable.
T Timing = this error reflects any alterations from the typical
timing or speed of a movement and may include abnormally
increased, decreased, or irregular rate of production.
0 Occurrence = movements may involve either single or repetitive
movement cycles. This error type reflects any multiplication of
single cycles or reduction of a repetitive cycle to a single
event.
D Delay = delay in the initiation of a movement with no intervening
facilitative movement.
SPATIAL
IC Internal Configuration (limb only) = when performing a movement,
the fingers and hand must be in a specific spatial relation to one another to reflect recognition and respect for the imagined tool. This error type reflects any abnormality of the required
finger/hand posture and its relationship to the target tool.




APPENDIX C (CONTINUED)
SPATIAL (continued)
A Amplitude = any amplification, reduction, or irregularity of the
characteristic amplitude of a target movement.
ECO External Configuration/Orientation (limb only) = when performing a movement, the fingers/hand/arm and the imagined tool must be in
a specific relationship to the "object" receiving the action.
Errors of this type involve difficulties orienting to the
"object" or in placing the "object" in space.
BPO Body-Part-as-Object (limb only) = the subject used the finger/hand/arm as the imagined tool of the movement.
M Movement = when acting on an object with a tool, a movement
characteristic of the action and necessary to accomplishing the
goal is required. Any disturbance of the characteristic movement
reflects a movement error.
E Extraneous = recognizable production of a movement with
additional or extra movement(s) involved of non-target
articulators or body parts.
P Place of Articulation (buccofacial only) = an inappropriate point
or place of articulation was employed in production of the
movement.
OTHER
NR No Response = subject may conclude his response with a
verbalization such as, "I can't" or "No."
UR Unrecognizable Response = a response which is not recognizable and shares no temporal or spatial features of the target.
V Verbalization = the subject produces a verbalization or written
output instead of a movement. It should be recognizable and
semantically related.




APPENDIX D
INTERRATER RELIABILITY MEASURES FOR THE ACCURACY JUDGEMENT FOR EACH BUCCOFACIAL AND LIMB MOVEMENT AS EXPRESSED BY A KAPPA STATISTIC

Movement

Kappa

Movement

Kappa

Limb Intransitive
1. crossing fingers
2. victory sign
3. hitchhiking
4. waving good bye
5. signaling 'OK' 6. pinching nose
7. scratching head
8. saluting
9. snapping fingers 10. making a fist
Limb Transitive
1. eating
2. locking a door
3. flipping a coin
4. using a screwdriver
5. cutting with scissors
6. shaving 7. combing 8. writing
9. hammering 10. brushing teeth

Buccofacial Intransitive
1.000 1. whistling
1.000 2. 'be quiet' sound
0.595 3. clearing throat 1.000 4. holding breath
1.000 5. licking lips
--- 6. puffing cheeks
1.000 7. smacking lips 0.737 8. opening mouth
1.000 9. clicking tongue
1.000 10. coughing
Buccofacial Transitive

0.500 1.000 0.659
0.444 1.000 1.000 0.471 0.706 0.865
1.000

sniffing a flower sneezing chewing gum picking teeth blowing a balloon sucking a straw kissing a baby biting an apple blowing out a match licking a lollipop

1.000 1.000 0.587 0.842 0.842 0.762 1.000 0.634 0.857 0.583

1.000 1.000 1.000 0.762 0.857 0.732 1.000 0.737 1.000 0.867




APPENDIX E
INTERRATER RELIABILITY MEASURES FOR THE MAIN TYPE OF ERROR JUDGEMENT
FOR EACH MOVEMENT AS EXPRESSED BY PERCENTAGE AGREEMENT (P. A.)
Movement P.A. Movement P.A.

Limb Intransitive
1. crossing fingers
2. victory sign
3. hitchhiking
4. waving good bye
5. signaling 'OKI 6. pinching nose
7. scratching head
8. saluting
9. snapping fingers 10. making a fist

Limb Transitive
1. eating
2. locking a door
3. flipping a coin
4. using a screwdriver
5. cutting with scissors
6. shaving 7. combing 8. writing
9. hammering 10. brushing teeth

100.0 100.0 86.7 100.0 83.3 93.3 100.0 83.3 96.7 100.0 M= 94. 3

73.3 90.0 70.0 80.0 96.7 93.3 76.7 86.7 93.3 100.0 M=86. 0

Buccofacial Intransitive
1. whistling
2. 'be quiet' sound
3. clearing throat 4. holding breath
5. licking lips
6. puffing cheeks
7. smacking lips 8. opening mouth
9. clicking tongue 10. coughing

Buccotacial Transitive
1. sniffing a flower
2. sneezing
3. chewing gum
4. picking teeth
5. blowing a balloon
6. sucking a straw
7. kissing a baby
8. biting an apple
9. blowing out a match 10. licking a lollipop

100.0 100.0 73.3 93.3 93.3 86.7 90.0 93.3 83.3 86.7 M=90. 0

86.7 100.0 100.0 93.3 93.3 76.7 90.0 83.3 100.0 86.7 M=91.0




APPENDIX F
BLANK CHECKLIST OF SPECIFIC NEUROANATOMIC STURCTURES

Neuroanatomic Structures

Subject Numbers
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Parietal
1. inferior parietal
a) angular gyrus
b) supramarginal gyrus
2. superior parietal
Central (Sensorimotor Cortex)
1. Peri-Sylvian 2. Supra-Sylvian
3. Mesial 4. Insula
Frontal
1. inferior gyrus(Broca's) a) anterior b) posterior
2. middle
3. superior
4. mesial (SMA and Cingulate)

Temporal
1. superior
a) anterior b) posterior
2. middle
a) anterior b) posterior
3. inferior a) anterior b) posterior
4. mesial a) anterior b) posterior




APPENDIX F (CONTINUED)
Neuroanatomic Structures Subject Numbers
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Occipital
1. inferior 2. superior
3. mesial
Deep Gray Matter Structures
1. thalamus
a) medial
b) lateral 2. striatum
Subcortical White Matter
1. internal capsule
a) anterior
b) posterior
2. corona radiata
3. arcuate fasiculus
4. temporal isthmus
5. anterior periventricular
6. posterior periventricular
7. corpus callosum
a) genu b) body
c) splenium
Enlarged Ventricles
Cortical Atrophy
No Readable Lesion
Note. SMA = supplementary motor area.




APPENDIX G
COMPLETED CHECKLIST OF INVOLVEMENT OF
SPECIFIC NEUROANATOMIC STURCTURES FOR EACH EXPERIMENTAL SUBJECT

Neuroanatomic Structures

Subject Numbers
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Parietal

1. inferior parietal
a) angular gyrus
b) supramarginal gyrus
2. superior parietal
Central (Sensorimotor Cortex)

Peri-Sylvian Supra-Sylvian Mesial Insula

+ + +
+

+ + +
+ +

+ + + + + + + + + +

Frontal

1. inferior gyrus(Broca's) a) anterior b) posterior
2. middle
3. superior
4. mesial (SMA and Cingulate)

+

+ + +
+

Temporal

1. superior a) anterior b) posterior
2. middle a) anterior b) posterior
3. inferior a) anterior b) posterior
4. mesial a) anterior b) posterior

+ +
- +

+ +
+

+ +
+




APPENDIX G (CONTINUED)

Neuroanatomic Structures

Subject Numbers
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Occipital

inferior superior mesial

Deep Gray Matter Structures

1. thalamus a) medial b) lateral 2. striatum

Subcortical White Matter
1. internal capsule
a) anterior
b) posterior
2. corona radiata
3. arcuate fasiculus 4. temporal isthmus
5. anterior periventricular 6. posterior periventricular
7. corpus callosum a) genu
b) body
c) splenium


- + + + +

+ +
+
+ + +
+

+ + +

+ + +
+

+ + + +
+ + +

Enlarged Ventricles

Cortical Atrophy +
No Readable Lesion +
Note. SMA = supplementary motor area. + = more than 50% involvement of
the structure; = less than 50% involvement of the structure;
+ = periventricular lucency also noted in the right hemisphere.




BIBLIOGRAPHY

Basso, A., Capitani, E., Della Sala, S., Laiacona, M. & Spinnler, H.
(1987). Recovery from idecmotor apraxia: A study on acute stroke
patients. Brain, 110, 747-760.
Benson, F., Sheremata, W., Bouchard, R., Segarra, J., Price, D. & Geschwind, N. (1973). Conduction aphasia: A clinicopathological
study. Archives of Neuroloy, 28, 339-346.
Borod, J.C., Lorch, M.P., Koff, E. & Nicholas, M. (1987). Effect of
emotional context on bucco-facial apraxia. Journal of Clinical and
Experimental Neuropsychology, 9, 155-161.
Buschke, H. & Fuld, P.A. (1974). Evaluating storage, retention, and retrieval in disordered memory and learning. Neurology, 24,
1019-1025.
Critchley, M. (1953). The parietal lobes. New York: Hafner Publishing
Company.
DeRenzi, E., Pieczuro, A. & Vignolo, L.A. (1966). Oral apraxia and
aphasia. Cortex, 2, 50-73.
DeRenzi, E., Pieczuro, A. & Vignolo, L.A. (1968). Ideational apraxia: A
quantitative study. Neuropsychologia, 6, 41-52.
Duffy, R.J. & Liles, B.Z. (1979). A translation of Finkelnburg's (1870)
lecture on aphasia as "asymbolia" with commentary. Journal of Speech
and Hearinq Disorders, 44, 156-168.
Geschwind, N. (1965). Disconexion syndratmes in animals and man. Brain,
8, 237-294, 585-644.
Geschwind, N. (1975). The apraxias: Neural mechanisms of disorder of
learned movement. American Scientist, 63, 188-195.
Goldstein, K. (1942). Aftereffects of brain injuries in war. New York:
Grune and Stratton.
Goodglass, H. & Kaplan, E. (1963). Disturbance of gesture and pantomime
in aphasia. Brain, 86, 703-720.




Grusser, O.-J. (1983). Multimodal structure of the extrapersonal space.
In A. Hein & M. Jeannerod (Eds.), Spatially oriented behavior
(pp. 327-352). New York: Springer-Verlag.
Haaland, K.Y. & Flaherty, D. (1984). The different types of limb apraxia errors made by patients with left vs. right hemisphere damage. Brain
& Cognition, 3, 370-384.
Haaland, K.Y., Rubens, A. & Harrington, D.L. (1989). Anatomical correlates of limb and buccofacial apraxia. Journal of Clinical and
Experimental Neuropsychology, II, 42.
Heilman, K.M. (1979). Apraxia. In K.M. Heilman & E. Valenstein (Eds.),
Clinical neuropsychology (pp. 159-185). New York: Oxford University
Press.
Heilman, K.M. & Rothi, L.J.G. (1985). Apraxia. In K.M. Heilman &
E. Valenstein (Eds.), Clinical neuropsychology (2nd ed.,
pp. 131-150). New York: Oxford University Press.
Heilman, K.M., Rothi, L.J.G. & Kertesz, A. (1983). Localization of
apraxia-producing lesions. In A. Kertesz (Ed.), Localization in
neuropsycholoy (pp. 371-392). New York: Academic Press.
Heilman, K.M., Rothi, L.J.G. & Valenstein, E. (1982). Two forms of
idecimotor apraxia. Neurology (NY), 32, 342-346.
Hogg, S.C., Square-Storer, P.A. & Roy, E.A. (1988, December).
Co-occurrence of limb, orofacial and verbal apraxia in left
hemisphere damaged subjects. Paper presented at Neuropsychology
Rounds, St. Joseph Health Centre, London, Ontario.
Jackson, H. (1932). Remarks on non-protrusion of the tongue in some
cases of aphasia. In J. Taylor (Ed.), Selected writings (Vol. II).
London: Hodder & Stoughton. (Original work published 1878).
Kertesz, A. (1979). Apraxia, aphasia and associated disorders. New York:
Grune & Stratton.
Kertesz, A. (1982). The Western Aphasia Battery. London, Ontario:
University of Western Ontario.
Kertesz, A. (1985). Apraxia and aphasia: Anatomical and clinical
relationship. In E.A. Roy (Ed.), Neuropsycholoqical studies of
apraxia and related disorders (pp. 163-178). Amsterdam: Elsevier
Science Publishers.
Kertesz, A. & Ferro, J.M. (1984). Lesion size and location in ideomotor
apraxia. Brain, 107, 921-933.
Kimura, D. (1977). Acquisition of a motor skill after left-hemisphere
damage. Brain, 100, 527-542.




Klima, E. & Bellugi, U. (1979). The signs of language. Cambridge, MA: Harvard University Press.
Kramer, J.H. Delis, D.C. & Nakada, T. (1985). Buccofacial apraxia without aphasia due to a right parietal lesion. Annals of Neurology,
18, 512-514.
Kramer, M.S. & Feintein, A.R. (1981). Clinical biostatistics: LIV. The biostatistics of concordance. Clinical Pharmacology and Therapeutics,
29, 111-123.
Landis, R.J. & Koch, G.G. (1977). The measurement of observer agreement for categorical data. Biometrics, 33, 159-174.
Lehmkuhl, G., Poeck, K. & Willmes, K. (1983). Ideamotor apraxia and
aphasia: An examination of types and manifestations of apraxic
symptoms. Neuropsychologia, 21, 199-212.
Liepmann, H. (1980a). Small helpful hints in the examination of the
brain damaged. In D. Kimura (Trans.) Translations from Liepmann's
essays on apraxia (Research Bulletin #506, pp. 4-16). London,
Ontario: The University of Western Ontario. (Original work published
1905).
Liepmann, H. (1980b). The left hemisphere and action. In D. Kimura
(Trans.) Translations from Liepmann's essays on apraxia (Research
Bulletin #506, pp. 17-50). London, Ontario: The University of Western
Ontario. (Orignal work published 1905).
Marquardt, T.P. & Sussman, H. (1984). The elusive lesion: Apraxia of
speech link in Broca's aphasia. In J.C. Rosenbek, M.R. McNeil & A.E.
Aronson (Eds.), Apraxia of speech: Physiology, acoustics,
linqgustics, management (pp. 91-112). San Diego: College Hill Press.
Matsui, T. & Hirano, A. (1978). An atlas of the human brain for
computerized tomography. New York: Igaku-Shoin.
Mintz, T., Raade, A.S. & Kertesz, A. (1989, May). Lesion size and
localization in buccofacial apraxia: A retrospective analysis.
Presentation at the annual convention of the Canadian Association of
Speech-Language Pathologists and Audiologists (CASLPA), Toronto,
Ontario.
Mohr, J.P., Pessin, M.S., Finkelstein, S., Funkenstein, H.H., Duncan,
G.W. & Davis, K.R. (1978). Broca aphasia: Pathological and clinical.
Neurol o, 28, 311-324.
Ochipa, C. & Rothi, L.J.G. (1989). Buccofacial apraxia recovery in a
patient with atypical cerebral dominance. ASHA, 31, 73.




Poeck, K. (1985). Clues to the nature of disruptions to limb praxis. In E.A. Roy (Ed.), Neuropsychological studies of apraxia and related
disorders (pp. 99-109). Amsterdam: Elsevier Science Publishers.
Poeck, K. & Kerschensteiner, M. (1975). Analysis of the sequential motor events in oral apraxia. In K. Zulch, O. Kreutzfeld &
G. Galbraith (Eds.), Otfried Foerster Symposium (pp. 98-111). Berlin:
Springer.
Rapcsak, S.Z., Rothi, L.J.G. & Heilman, K.M. (1987). Apraxia in a patient with atypical cerebral dcminance. Brain and Coqnition, 6,
450-463.
Rizzolatti, G. & Camarda, R. (1987). Neural circuits for spatial attention and unilateral neglect. In M. Jeannerod (Ed.),
Neurophysiological and neuropsychological aspects of spatial neglect
(pp. 289-313). North-Holland: Elsevier Science Publishers.
Rizzolatti, G., Matelli, M. & Pavesi, G. (1983). Deficits in attention
and movement following the removal of postarcuate (area 6) and
prearcuate (area 8) cortex in macaque monkeys. Brain, 106, 655-673.
Rothi, L.J.G. & Heilman, K.M. (1984). Acquisition and retention of
gestures by apraxic patients. Brain & Coqnition, 3, 426-437.
Rothi, L.J.G., Heilman K.M. & Watson, R.T. (1985). Pantomime
comprehension and ideamotor apraxia. Journal of Neurology,
Neurosurgery, & Psychiatry, 48, 207-210.
Rothi, L.J.G., Mack, L., Verfaellie, M., Brown, P. & Heilman, K.M.
(1988). Ideomotor apraxia: Error pattern analysis. Aphasioloqy, 2,
381-388.
Roy, E.A. & Square, P.A. (1985). Ccmon considerations in the study of
limb, verbal and oral apraxia. In E.A. Roy (Ed.), Neuropsychological
studies of apraxia and related disorders
(pp. 111-162). Amsterdam: Elsevier Science Publishers.
Schnitzlein, H.N. & Murtagh, F.R. (1985). Imaging anatomy of the head
and spine. Baltimore, MD: Urban and Scharzenberg.
Shrout, P.E. & Fleiss, J.L. (1979). Intraclass correlations: Uses in
assessing rater reliability. Psychological Bulletin, 86, 420-428.
Square-Storer, P. (1989). Traditional therapies for apraxia of speech
reviewed and rationalized. In P. Square-Storer (Ed.) Acquired apraxia
of speech in aphasic adults (pp. 145-161). London: Taylor & Francis.
Square-Storer, P. & Roy, E.A. (1989). The apraxias: Commonalities and
distinctions. In P. Square-Storer (Ed.) Acquired apraxia of speech in
aphasic adults (pp. 20-63). London: Taylor & Francis.




Full Text

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THE RELATIONSHIP BETWEEN BUCOOFACIAL AND LIMB APPAXIA By ADELE S. RAADE A DISSERTATTON PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 1990 UN!V3Si7Y OF FLCrliDA LiZR^IES

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ACKNOWLEDGEMENTS This dissertation would not have been possible without the assistance of a number of individuals. I am deeply indebted to Dr. Leslie Gonzalez -Rothi for her persevering support and her belief in me. I am grateful to Dr. Ken Heilman for the creative spark he infused into the project. I thank my other committee members, Drs. Thomas Abbott, Russ Bauer and Mike Crary, for their support and understanding when deadlines were tight. I appreciate Dr. Ken Gerhardt, who very graciously and willingly agreed to serve as a substitute committee member. Other individuals were also instrumental in the completion of this dissertation. I thank Janice Howell, who assisted me with the grueling task of scoring of the videotapes. I appreciate Joy Davey, who was always there when I needed her. I thank my parents and family, who continue to support ire in my endeavors. And last but not least, I am deeply indebted to Dave Steels for his patience, love and unquestioning support.

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TABTE OF CONTENTS ACKNOWLEDGEMENTS. LIST OF TABLES. Page 11 v ABSTRACT. VI CHAPTERS 1 BUCCOFACIAL AND T.TMR APRAXIA i Buccofacial Apraxia 1 Incidence 2 Clinical Relevance 3 Nature of the Disorder 3 Limb Apraxia n Incidence n Transitivity Factor 12 Error Type Analysis 13 Mechanisms of Limb Apraxia 16 Relationship Between Buccofacial and Limb Apraxia 24 Possible Constructs 25 Clinical Relevance 26 Transitivity Factor 27 Error Type Analyses 28 Statement of the Problem 30 2 METHODOLOGY 34 Subjects 34 Procedures and Testing Materials 35 Screening Tests 38 Experimental Tests 40 Apraxia Scoring Reliability 42 Localization of the Lesion 44 3 RESULTS 45 Comparisons Between Groups 45 Behavioral Test Results 45 Screening Tests 45 Experimental Tests 47

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Research Questions 48 Research Question #1 48 Research Question #la 48 Research Question #lb 49 Research Question #lc 53 Research Question #2 56 Research Question #3 58 4 DISCUSSION 65 Research Questions 66 Implications for Future Research 75 Clinical Implications 76 APPENDICES A ERROR TYPE CATEGORIES AND DEFINITIONS FOR LIMB MOVEMENTS 79 B LIST OF BUCCOFACIAL AND LIMB STIMULUS ITEMS 81 C ERROR TYPE CATEGORIES AND DEFINITIONS FOR BUCCOFACIAL AND LIMB MOVEMENTS 82 D INTERRATER RELIA BILITY MEASURES FOR THE ACCURACY JUDGEMENT FOR EACH BUCCOFACIAL AND LIMB MOVEMENT AS EXPRESSED BY A KAPPA STATISTIC 84 E INTERRATER RELIABILITY MEASURES FOR THE MAIN TYPE OF ERROR JUDGEMENT FOR EACH MOVEMENT AS EXPRESSED BY PERCENTAGE AGREEMENT (P.A. ) 85 F BLANK CHECKLIST OF SPECIFIC NEUROANATOMIC STRUCTURES 86 G COMPLETED CHECKLIST OF INVOLVEMENT OF SPECIFIC NEUROANATOMIC STRUCTURES FOR EACH EXPERIMENTAL SUBJECT 88 BIBLIOGRAPHY 90 BIOGRAPHICAL SKETCH 95

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LIST OF TABLES Table Page 2-1 Descriptive demographic data for the experimental and control groups 36 2-2 Detailed descriptive data on each of the experimental subjects 37 3-1 The relationship between the production of buccofacial and limb movements 50 3-2 The means and standard deviations for each of the four types of movements for the experimental and control groups 51 3-3 The observed and expected frequencies of each type of error for buccofacial and limb movements 55 3-4 The relationship between the comprehension and production of buccofacial movements 57 3-5 The relationship between the comprehension of buccofacial movements and the integrity of the inferior parietal lobule (IPL) 59 3-6 The relationship between the comprehension of buccofacial movements and the involvement of specific neuroanatomic structures for each experimental subject 61 3-7 The presence of buccofacial apraxia and the involvement of specific neuroanatomic structures for each experimental subject 62

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Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy THE RELATIONSHIP BETWEEN BUCCOFACIAL AND LIMB APRAXIA By ADELE S. RAADE May 1990 Chairman: Leslie J. Gonzalez -Rothi Ph.D. Major Department: Communication Processes and Disorders There are at least two possible constructs depicting the nature of the relationship between buccofacial and limb apraxia. In the first construct, apraxia is viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb output. A high degree of concordance and similarity between the two types of apraxia would support this model. The second construct would postulate that the relationship between buccofacial and limb apraxia is not unitary. The presence of quantitative and qualitative differences between buccofacial and limb performance would support this construct. The purpose of this study was to determine if buccofacial and limb apraxia are manifestations of a unitary disorder or a non-unitary disorder. In addition, the possible presence of two types of buccofacial apraxia was examined, as well as the neuroanatomy of the disorder. VI

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The experimental group was comprised of fifteen subjects who had experienced a single, unilateral, left-hemisphere cerebrovascular accident. The control group was comprised of eight neurologically intact adults matched for age, sex and education. Results indicated that there were a significant number of double dissociations, that the transitivity factor was manifested in a dissimilar manner, and that the proportion of error types was dissimilar between the two disorders. These results support a nonunitary construct for buccofacial and limb apraxia. In addition, results indicated that two different types of buccofacial apraxia were exhibited: one type characterized by impaired production and comprehension, and the second type characterized by impaired production but preserved comprehension. This is similar to the pattern that has been reported previously for limb apraxia. Regarding the neuroanatomy of the disorders, previous research has suggested that the inferior parietal lobule (IPL) is a critical neuroanatomic structure for the comprehension and production of limb movements. In contrast, the results of this study suggest that the IPL is not a critical structure for the comprehension and production of buccofacial movements. Instead, it appears that structures anterior to the IPL are the crucial areas for buccofacial performance. These results suggest that the buccofacial and limb praxis systems are, at least in part, functionally and anatomically independent systems. vn

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CHAPTER 1 BUCCOFACIAL AND LIMB APRAXIA Steinthal (1871) was the first to use the term apraxia to describe impaired performance of skilled movement in the absence of weakness or discoordination. More recently, Geschwind (1965) and Heilman and Rothi (1985) have provided an exclusionary definition of apraxia as "a disorder of skilled movement not caused by weakness, akinesia, deaf ferentat ion, abnormal tone or posture, movement disorders (e.g. tremors or chorea) intellectual deterioration, poor comprehension, or uncooperativeness" (p. 131) In addition, Rothi, Mack, Verfaellie, Brown and Heilman (1988) defined the nature of errors associated with ideomotor apraxia of the limbs. Numerous other forms of apraxia have been described including dressing, constructional, truncal, gait, verbal, ideational, limb-kinetic, verbo-motor, and buccofacial. However, this dissertation will deal exclusively with the buccofacial and limb ideomotor apraxias. Buccofacial Apraxia Buccofacial apraxia is a form of apraxia (as described above) specific to oral/ facial structures. It was first described by Jackson (1878/1932) who described a patient with spared comprehension who was unable to stick out his tongue on command, but was able to use his

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2 tongue to remove a bread crumb from his lip. However, buccofacial apraxia is not limited to the tongue and is characterised by the inability to also correctly perform skilled movements with the muscles of the larynx, pharynx, lips and cheeks (Heilman & Rothi, 1985) For example, when asked to pantomime blowing out a match, a patient with buccofacial apraxia may be unable to perform this action correctly. He may incorrectly place his lips or may actually say the word "blow. However, he may improve if a lit match is placed in front of his mouth. Incidence The incidence of buccofacial apraxia is variable and influenced by task and subject selection. Mintz, Raade and Kertesz (1989) performed a retrospective study on the incidence of buccofacial apraxia in righthanded subjects subsequent to a single lesion of their left hemisphere. From a series spanning a 10-year period of 314 patients who were evaluated for the possible presence of aphasia, 112 were selected as meeting the criteria of right-handedness and the presence of a single lesion, 108 of whom were aphasic. In order to determine the presence of buccofacial apraxia, the five-item buccofacial subcomponent of the apraxia subtest of the Western Aphasia Battery (Kertesz, 1982) was administered in the initial 7 to 45 days post onset. The control group's average buccofacial score minus two standard deviations was utilized as the cut-off score between normal and apraxic performance. Seventy-three of the 112 subjects (65%) demonstrated a buccofacial apraxia. These results suggest that buccofacial apraxia is frequently associated with left-hemisphere damage.

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3 Clinical Relevance Because this disorder is frequently associated with left-hemisphere lesions, it frequently co-occurs with language and/or speech disorders. A speech-language pathologist may choose to use verbal prompting to facilitate the patient's compensation for articulatory deficits, such as "close your lips," or "put your tongue up" (Square-Storer, 1989) The presence of a moderate or severe case of buccofacial apraxia would create a significant barrier to this type of treatment. In order to effectively treat a neuropsychological disorder, it is important to understand the neuropsychological mechanism underlying the disorder, and to use that information to direct treatment task selection. Unfortunately, there have not been many reports elucidating the brain mechanism (s) underlying buccofacial apraxia. Nature of the Disorder An analysis of factors that influence buccofacial praxis performance may provide clues to its underlying mechanism. There have been anecdotal reports that the performance of "emotional" movements with the same sets of facial muscles used in practic behaviors may not be impaired (Critchley, 1953; Kertesz, 1979). "Emotional" movements are behaviors that may be produced spontaneously (e.g., blowing a kiss in response to a departure) or may be produced upon verbal request (e.g. demonstrating how to blow a kiss to someone) Bored, Lorch, Koff and Nicholas (1987) examined subjects with leftand right-hemisphere cerebrovascular pathology for two forms of facial behavior, one in response to a neutral or nonemotional command, and the other in response to an emotion-associated command. For example, one of the neutral

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4 commands was "lower your eyebrows," whereas the emotional analog was "lower your eyebrows like a frown." Each buccofacial movement was assessed for accuracy and motor execution. They found that lefthemisphere-damaged subjects were significantly more impaired in these buccofacial tasks relative to right-hemisphere-damaged and normal control subjects for both accuracy and motor execution. The emotional cues appeared to facilitate performance for all subjects. However, the performance of the left-hemisphere-damaged patients improved the most. In summary, the literature cited suggests that an emotional context can facilitate the facial motor performance of left-brain-damaged patients with buccofacial apraxia. It was suggested that the right hemisphere may be mediating the "emotional" performance. Error Type Analysis An analysis of error types may also provide clues to the underlying mechanism of buccofacial apraxia because the nature of the error performance may elucidate the nature of the mechanism (s) that are deficient. Unfortunately, few studies have attempted to capture the quality of buccofacial apraxic errors. Typically, researchers utilized pass/fail scores or multi-point scales which reflected a continuum of degree of deficit. For example, Kertesz and Ferro (1984) utilized a three-point system with the lowest score classified as incorrect and the highest score classified as totally correct. However, Poeck and his colleagues (Poeck & Kerschensteiner, 1975; lehmkuhl, Poeck & Willmes, 1983) have provided a system for qualitatively analyzing buccofacial apraxic movements. This system was modified (Lehmkuhl, Poeck & Willmes, 1983) to include the following five

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5 response categories: correct, fragmentary (production of only part of the required movements) augmentative (production of additional movements or noises) perseveratory (production of perseveratory elements within a movement) and other errors. The subjects included 88 aphasic patients, with an equal number demonstrating one of the four following types of aphasia: global, Wernicke's, Broca's and amnesic (anemic) aphasia. They attempted to ascertain whether there were apractic syndromes which were related to the standard aphasic syndromes or were characterized by certain patterns of error types. The findings were negative for both questions. Specifically, they reported that the performance of oral movements was poorer than the performance of arm, leg or bimanual movements for all types of aphasia. In addition, the most prominent error type was perseveration, with a relatively low frequency of the other error types. unfortunately, based in their analyses, these researchers did not speculate as to the mechanism (s) underlying buccofacial apraxia. It is possible that their error analyses did not provide them with sufficient information because their scoring systems were not structured to capture the nature of the errors induced by left-hemisphere dysfunction. Recovery. While observations of recovery may also provide clues asto the mechanism (s) underlying buccofacial apraxia, little has been written about the recovery of this disorder. Kertesz (1979) evaluated the course of recovery from apraxia by testing aphasic patients at the following post-onset intervals: one week, three months, six months, and one year. He utilized a praxis test that combined praxis performance of oral, limb intransitive, limb transitive, and complex (an act that

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6 requires a series of actions utilizing both hands, such as "pretend to drive a car") action corarands. Unfortunately, Kertesz (1979) combined the performance of each of these tasks into a single praxis score. Therefore, little is known about the specific recovery pattern of buccofacial apraxia. Ochipa and Rothi (1989) reported a right-handed male with a righthemisphere frontotemporoparietal lesion who exhibited a severe buccofacial apraxia, in addition to severe limb apraxia and nonfluent aphasia. Ochipa and Rothi (1989) evaluated buccofacial and limb praxis at two, three and six weeks post-onset. The patient's severe buccofacial apraxia improved only minimally by three weeks post onset, and remained unchanged at six weeks post onset. In addition, the quality of the buccofacial errors remained the same throughout the serial testing. The patient also continued to demonstrate a severe limb apraxia across the three testing sessions. However, in contrast to buccofacial praxis, there was a significant change in the quality of the limb errors as a function of time post-onset. Limb praxis error types evolved from predominantly perseverative errors to predominantly spatial and body-part-as-object errors. Therefore, because of the dissociation in the qualitative recovery patterns for buccofacial and limb praxis, Ochipa and Rothi (1989) suggested that the mechanisms underlying each type of apraxia is distinct. In summary, little is known about the recovery pattern of buccofacial apraxia. However, the qualitative recovery of buccofacial and limb praxis may dissociate.

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7 Localization Buccofacial apraxia in right-handed patients is usually the result of a left-hemisphere lesion (Heilman, 1979; Heilman & Rothi, 1985) However, isolated cases of this disorder following righthemisphere damage have been reported (Kramer, Delis & Nakada, 1985; Rapcsak, Rothi & Heilman, 1987) Unlike the laterality, the intrahemi spheric localization of this disorder remains controversial. Like the different forms of aphasia which may be associated with different lesion loci, buccofacial apraxia can be associated with a variety of different types of aphasia as well. DeRenzi, Pieczuro and Vignolo (1966) report buccofacial apraxia in Broca's, phonemic jargon aphasia (a subtype of Wernicke's aphasia) and conduction aphasia; Kertesz (1979 & 1985) reports buccofacial apraxia in global, Broca's and isolation aphasia; and Benson et al. (1973) report buccofacial apraxia in conduction aphasia. In studies which specifically compared the incidence of buccofacial apraxia in a variety of aphasia types (DeRenzi et al., 1966; Kertesz, 1979 & 1985), buccofacial apraxia was most frequently associated with Broca's aphasia. However, the presence of buccofacial apraxia was also noted with posterior, fluent syndromes such as conduction, Wernicke's or jargon aphasias. DeRenzi et al. (1966) reported the percentage of each aphasic type which demonstrated an associated buccofacial apraxia as follows: 90% of the Broca's aphasics; 33% of the conduction aphasics; less than 6% of the Wernicke's aphasics; and 83% of the phonemic jargon aphasics. In summary, buccofacial apraxia most frequently co-occurs with aphasic types associated with anterior peri-Sylvian lesions. However, it is also reported with posterior types of aphasia.

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8 Very specific intrahemispheric localization of the lesions associated with buccofacial apraxia was supplied by Benson and his colleagues (1973) in their clinicopathological study of three conduction aphasics. In fact, this study provides evidence of the association between posterior lesions and this disorder. The postmortem examinations completed in this study clearly defined the extent and location of the lesions. Two of the three cases demonstrated a buccofacial apraxia. One of the two cases with buccofacial apraxia exhibited a lesion which affected the supramarginal gyrus extending in depth from the convexity of the hemisphere to within one centimeter of the ventricular wall. Further posteriorly, the subcortical white matter underneath parts of the angular gyrus and the superior parietal gyrus were also infarcted. The second case with buccofacial apraxia presented with softening of the cortex over the left supramarginal and angular gyri. An irregular cavitated infarction was noted in the white matter deep to these areas, which extended to the left lateral ventricle and interrupted the arcuate fasciculus. Heilman, Rothi and Kertesz (1983) reported that they have seen cases of buccofacial apraxia in which the lesion was located in the supramarginal and angular gyri, and did not involve frontal cortical structures. Analysis of these results reveals that the posteriorly situated IPL, specifically the supramarginal and angular gyri and the white matter deep to these areas, may play a critical role in buccofacial praxis. The importance of this site was especially evident when the buccofacial movements were elicited with verbal commands.

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9 However, there is also evidence that anterior peri-Sylvian structures are associated with buccofacial apraxia. Tognola and Vignolo (1980) conducted a clinico-neuroradiological investigation of the brain lesions associated with buccofacial apraxia. Included as subjects in the study were 44 right-handed patients who had sustained a lefthemisphere cerebrovascular accident and had a CI scan performed more than 21 days post-stroke. The subjects' performance on the imitation of ten simple buccofacial gestures was evaluated using a two-point scoring system. The researchers compared the CT scan findings for patients with and without buccofacial apraxia, and found the critical cortical areas to include the following left hemisphere structures: the frontal and central (Rolandic) opercula, the adjacent portion of the first temporal convolution, and the anterior portion of the insula. Their results also suggested that posterior cortical structures, such as the parietal operculum and the supramarginal gyrus, were not crucial in the performance of buccofacial gestures. Haaland, Rubens and Harrington (1989) evaluated 43 left-hemisphere stroke patients for both buccofacial and limb apraxia employing the elicitation methods of verbal command and imitation. In the subset of patients with smalland medium-sized lesions, damage to the left parietal cortex, specifically the supramarginal gyrus, was more associated with limb rather than buccofacial apraxia. Finally, Mintz, Raade and Kertesz (1989) conducted a retrospective study on the relationship between the occurrence of buccofacial apraxia and lesion localization with 112 left-hemisphere ischemic stroke

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10 patients, as discussed previously. The five buccofacial stimulus items on the Western Aphasia Battery apraxia subtest (Kertesz, 19S2) were a
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11 posterior areas, such as the inferior parietal lobe (IPL) remains controvers i?l Limb Apraxia While little is known about the neuropsychological mechanism underlying buccofacial apraxia, there has been a significant amount of research directed at understanding the underlying mechanism of limb apraxia; a commonly co-occurring left-hemisphere disorder. Therefore, it may be that mechanisms elucidated for limb apraxia can have application to understanding buccofacial apraxia. Limb apraxia refers to the inability to correctly perform skilled movements with the limbs. As discussed previously, this inability can not be related to weakness, akinesia, deafferentation, abnormal tone or posture, movement disorders, intellectual deterioration, poor comprehension, or lack of cooperation (Heilman & Ftothi, 1985) Incidence Similar to buccofacial apraxia, the incidence of limb apraxia is variable and influenced by task and subject selection. In the retrospective study by Mintz, Raade and Kertesz (1989) described previously, the five-item limb transitive subcomponent of the Western Aphasia Battery (Kertesz, 1982) was used to confirm the presence of limb apraxia. The control group's average limb score minus two standard deviations was utilized as the cut-off score between normal and apraxic performance. Eighty percent (90) of the 112 left-brain-damaged subjects demonstrated a limb apraxia. As with buccofacial apraxia, these results suggest that limb apraxia is frequently associated with left-hemisphere damage.

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12 Transitivity Factor Previous research has suggested th^t there is a difference in performance between transitive and intransitive movements in patients with left hemisphere damage. Transitive movements are movements made in relation to an object or instrument, such as using a screwdriver, whereas intransitive movements are not related to object use, such as waving goodbye. Liepmann (1905/1980a) was the first to note a difference in performance between limb transitive and intransitive movements. He reported patients who demonstrated defective performance in both types of movements, as well as patients who demonstrated defective limb transitive movements, but spared limb intransitive movements. Liepmann (1905/1980a) suggested that these differences in performance reflected differences in degree of impairment, rather than differences in the quality or nature of the movements. Goodglass and Kaplan (1963) also noted a difference in performance between transitive and intransitive limb movements. In their evaluation of 20 aphasic adults, they noted that the subjects' average performance of limb intransitive movements was better than their average performance of limb transitive movements. Haaland and Flaherty (1984) evaluated 41 left-hemisphere-damaged and 18 right-hemisphere-damaged stroke patients in the imitation of nonrepresentative (meaningless) representative/intransitive, and pretended-object-use/transitive movements. Of particular importance for this study, they reported that the limb transitive movements were more impaired in the left-hemispherethan the right-hemisphere-damaged

PAGE 20

13 subjects. In contrast, the intransitive and the nonrepresentative movements were equally impaired after lesions of either hemisphere. They suggested that the neural control mechanisms for the nonrepresentative and representative/ intransitive movements may be quite different than the control mechanisms for transitive movements. In addition to the group studies cited, two case-study reports also support the limb transitivity distinction. Heilman, Rothi and Kertesz (1983) reported two cases with limb apraxia who exhibited relatively spared performance of limb intransitive movements, but very defective performance of limb transitive movements. In the second case study, Watson, Fleet, Rothi and Heilman (1986) reported two cases with supplementary motor area damage who were spared for limb intransitive movements, but who were apraxic for limb transitive movements. In summary, the processing of transitive and intransitive movements fractionate implying that these movements have at least partially differing underlying mechanisms. In left-hemisphere patients, most typically the limb transitive movements are more impaired than limb intransitive movements. The reverse pattern has not been reported for any type of patient, i.e., that the limb intransitive movements are more impaired than the limb transitive movements. Error Type Analysis Similar to buccofacial apraxia, few studies have attempted to capture the quality of limb apraxic errors and/or to utilize this information to speculate about the underlying mechanism (s) Typically, researchers utilized the pass/fail scores or the multi-point measures of severity discussed previously (Kertesz & Ferro, 1984)

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14 However, several studies have provided a qualitative error analysis of limb movements. Letankuhl, Poeck and Willmes (1983) examined arm and leg movements, in addition to the oral movements discussed previously. The same five response categories were utilized: correct, fragmentary, augmentative, perseveratory and other errors. And similar to the previous results, they did not find limb apractic syndromes which were related to the standard aphasic syndromes or were characterized by certain patterns of errors. Similarly, the most prominent error type was perseveration, with a relatively low frequency of the other error types. They did not speculate what implications these results had regarding underlying mechanisms that have been proposed for limb apraxia. In another qualitative study of limb praxis, Haaland and Flaherty (1984) utilized a seven-category scoring system that included the following error types: hand or arm position errors, hand-to-arm orientation errors, target errors, partial errors, and two forms of bcdy-part-as-object (BPO) errors. The first EPO error, as traditionally defined, is characterized by utilization of the hand or fingers as the imagined object. In contrast, the second BPO error is characterized by correctly positioning the hand to hold the imagined object but positioning the hand "such that the length of the object was not considered." Their results revealed that both the leftand rightbrain-damaged patients demonstrated similar errors on nonrepresentative and representative/ intransitive movements. In contrast, the leftand right-brain-damaged patients demonstrated a different pattern of errors on pretended-object-use movements (transitive movements) For these

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15 movements, the left-brain-damaged group made more arm position errors and more traditional BPO-1 errors. In contrast, the right-brain-damaged group made more BPO-2 errors than the left-brain-damaged group. Haaland and Flaherty noted the importance of the left hemisphere for the production of limb transitive movements and attempted to explain the underlying mechanism. They suggested that the symbolic value of the limb transitive movements could not account for the differences because the limb intransitive movements were also symbolic but were less impaired. However, the complexity of the transitive and intransitive movements did vary in their use of intrapersonal and extrapersonal space. The representative/ intransitive movements are strictly intrapersonal in that the patient places the hand and arm in a particular relationship to the body. In contrast, the pretended-objectuse/transitive movements are both intrapersonal and extrapersonal in that the patient must have some "representation" of extrapersonal space by pretending to hold and manipulate an object. They suggested therefore, that when intrapersonal movements have to be integrated with a "representation" of extrapersonal space, the left hemisphere is more important than the right hemisphere. Finally, Rothi, Mack, Verfaellie, Brown and Heilman (1988) developed a categorical scoring system for limb praxis which was a modification of a system used by KLima and Bellugi (1979) (based on the work of Stokoe [I960]) to describe the structure of American Sign Language of the deaf. Rothi et al. (1988) particularly wanted to capture the spatial and temporal characteristics of the performance of limb apraxic patients. This apraxia scoring system has four main error

PAGE 23

16 categories of content, teirporal, spatial and other errors. Two to five subcategories of errors are defined under each of these main categories (Appendix A) Rothi et al. (1988) found that apraxic patients with left hemisphere cortical lesions characteristically produced six error types. Under the main category of spatial errors, the patients demonstrated a significant number of body-part-as-object, internal configuration, external configuration-orientation, and movement errors. Additionally, under the category of content, there were related content errors, and under the category of temporal, there were occurrence errors. Rothi et al. (1988) suggested that this confirms the vulnerability of spatial aspects in the limb performance of limb apraxic patients. Although only one type of temporal error was significant, it is possible that this type of error is difficult to ascertain with only a perceptual analysis of the patient's productions. In summary, analyses of limb apraxic errors may provide researchers with a window to the underlying mechanism (s) of limb apraxia. Several studies have attempted to hypothesize about the underlying mechanisms. The integration of intrapersonal and extrapersonal representations of space and the spatial representation of limb movements appear to be especially important roles of the left hemisphere. Mechani sms of T,i mb Apraxia There have been several models proposed to explain the mechanism underlying limb apraxia including a symbolic deficit (Finkelnburg, 1870, in EXiffy & Liles, 1979), a disconnection syndrome (Liepmann, 1905/1980b; Geschwird, 1965, 1975) and a representational deficit (Heilman & Rothi, 1985)

PAGE 24

17 Apraxia as a symbolic deficit In 1870, Finkelnburg (Duffy & Liles, 1979) was one of the first to propose that apraxia was part of a more general disorder called asymbolia, that is, an inability to understand and express both verbal and nonverbal symbols. In this construct, aphasia involves a disturbance of verbal symbolization, whereas apraxia involves a disturbance of nonverbal symbolization. One approach to use if apraxia is a symbolic disorder is to investigate the co-occurrence of the two disorders. The incidence of apraxia should strongly correlate with the incidence of aphasia if they are both symbolic disorders. Goldstein (1942) noted that apraxia and aphasia frequently co-occur, and that both result from left-hemisphere damage, providing support for the symbolic hypothesis. Several other researchers (DeRenzi, Pieczuro & Vignolo, 1968; Kertesz, 1979) have also reported a relationship between the severity of the two disorders. However, others (Liepmann, 1905/1980b; Gcodglass & Kaplan, 1963) have documented dissociations between the two disorders. Liepmann (1905/1980b) reported dissociations in both directions, in that one of his apraxic patients was not aphasic, and not all of his aphasic patients were apraxic. In addition, Goodglass and Kaplan (1963) reported that the severity of the two disorders correlated poorly. A second approach to the investigation of apraxia as a symbolic disorder involves the supposition that apraxic patients should perform symbolic movements more poorly than nonsymbolic movements. However, Kimura (1977) reported that apraxic subjects performed poorly on both types of movements, which would not support the asymbolia construct.

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18 A third approach is to analyze the overall patterns of deficit observed with limb apraxia. As discussed previously, researchers (Goodglass & Kaplan, 1963; Haaland & Flaherty/ 1984) have reported that, in left-hemisphere-dainaged patients, limb transitive movements are more impaired than limb intransitive movements. It does not follow that limb intransitive movements, such as "signaling OK," are less symbolic than limb transitive movements, such as "hammering." Therefore, the asymbolia construct fails to explain why the transitivity distinction is observed in patients with limb apraxia. A fourth and final approach is to analyze the types of errors produced by apraxic subjects. If the disorder is symbolically based, the apraxic patients should primarily produce content errors, i.e., substitution of one gesture for another or lack of content altogether. However, the majority of errors do not appear content based. Liepmann (1905/1980b) described the movement errors as recognizable, but a distortion of the required production. In addition, Rothi, Mack, Verfaellie, Brown and Heilman (1988) documented that the majority of limb apraxic errors were spatial distortions and movement aberrations, and only a small percentage were classified as related content errors. In summary, the notion that apraxia is a symbolic disorder is only weakly supported. However, there are other hypotheses that may account for apraxia. Apraxia as a disconnection syndrome Liepmann (1905/1980b) was the first to propose that the underlying mechanism for apraxia was a disconnection between control centers within the cerebral cortex. He believed that the left hemisphere, specifically the parietal lobe, was

PAGE 26

19 dominant for praxis, that is, it guided both the leftand right-sided skilled movements. Projections from this area to the premotor region of the left frontal area, which project to the left motor hand area is what guided the right hand. Callosal connections from the left motor hand area to the homologous areas in the right hemisphere is what guided the left hand. A lesion anywhere along this pathway would result in a disconnection of the control centers, and therefore in an apraxia. Geschwind (1965, 1975) elaborated and modified this disconnection view of apraxia. Unlike Liepmann, he emphasized the importance of verbal commands in eliciting apraxic performance, and therefore the importance of Wernicke's area. Geschwind (1965, 1975) based this idea on studies with split-brain patients who were apraxic with their left hand to verbal command, but were not apraxic on imitation or in actual use of the object. According to this disconnection model, a lesion of the supramarginal gyrus or arcuate fasciculus would result in an apraxia because of a disconnection of the posterior language areas from the anterior motor association area. Based on this model, apraxic patients should be able to imitate gestures. However, knowing this was not the case, and knowing that fibers passing from the visual association cortex to the premotor cortex pass through the arcuate fasciculus, Geschwind suggested that the left-hemisphere arcuate fasciculus was dominant for these visuomotor connections. Therefore, with an appropriately placed lesion, the patient would demonstrate apraxic performance to verbal command and imitation. While Geschwind thought performance with the actual object was normal, recent studies have demonstrated that actual

PAGE 27

20 abject use is impaired. Unfortunately, Geschwind's disconnection hypothesis cannot totally account for this observation. In summary, two variations of a disconnection view of apraxia were discussed. The major Imitations appear to be in the prediction and adequate explanation of poor performance on imitation and actual object use, and in the failure to explain possible subtypes of apraxia. However, this does not preclude that disconnection can account for certain subtypes of apraxia. Apraxia as a representational deficit Heilman, Rothi and colleagues (Heilman, 1979; Heilman, Rothi & Kertesz, 1983; and Heilman & Rothi, 1985) propose that one of the underlying mechanisms for apraxia is a representational deficit. The model elaborates upon Liepmann's concept of "movement formulas. Heilman, Rothi and colleagues postulate that the visuokinesthetic engrams for skilled limb movements are located in the inferior aspect of the dominant parietal lobule, specifically in the areas of the supramarginal and angular gyri. These motor engrams guide the sequencing and timing of limb movements and direct the movement of the limb within space. The model further specifies that once the engrams for a particular limb movement are elicited by stimulation in one or more modalities, this information is further processed by the motor association cortex into a motor plan which is carried out by the primary motor cortex. Heilman and Rothi hypothesized that the integrity of these visuokinesthetic engrams would be crucial for the production of skilled limb movements, as well as crucial for receptive tasks, such as the discrimination or comprehension of skilled movements. In addition, they

PAGE 28

21 suggested that there should exist at least two distinguishable behavioral profiles, depending on whether the actual engrains were destroyed or whether the engrams were disconnected from the frontal, motor association cortex. In order to test these hypotheses, Heilman, Rothi and Valenstein (1982) evaluated anteriorand posterior-lesioned patients in their ability to discriminate well-performed from poorly performed limb movements, as well as their ability to comprehend the meaning of the pantomime. In the discrimination testing, the patients were asked to distinguish well-performed from poorly performed gestures. The results of this testing revealed that apraxic patients with posterior infarctions that included the parietal lobe demonstrated a pantomime discrimination deficit, whereas the anterior apraxic patients did not. In the comprehension testing, the patients were shown the target pantomime and two foil pantomimes and were given the verbal stimulus for the target pantomime. The results of this testing revealed that the performance of the apraxic patients with posterior lesions was poorer than the patients with anterior lesions. Therefore, the notion of at least two forms of ideomotor limb apraxia was supported. The first type was induced by posterior lesions (which may have included the inferior parietal lobule) and produced destruction of the actual engrams. Ihis type was characterized by poor performance of limb movements to verbal command, as well as decreased discrimination and comprehension of limb pantomimes. The second type of ideomotor limb apraxia was induced by lesions anterior to the supramarginal gyrus, up to and including the premotor association area. These lesions produced a disconnection between the visuokinesthetic

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22 engrams in the parietal lobe, and the premotor and motor areas in the frontal lobe. The second type of ideomotor limb apraxia was characterized by poor performance of limb movements to verbal command, but preserved discrimination and comprehension. The gestural comprehension deficits noted in this study could possibly be explained by alternative mechanisms. Because the testing involved a verbal stimulus and the subjects were aphasic, an auditory comprehension deficit may have accounted for the results. In addition, because the testing involved three consecutive gestural presentations, proactive or retroactive interference may have contaminated the subject's performance. Therefore, in order to rule out these alternative possible explanations, Rothi, Heilman and Watson (1985) completed a second gesture comprehension study which employed a nonverbal pantomime-to-picture matching paradigm. The subjects viewed one pantomime and were asked which one of four drawings "went with the gesture." Ihe results revealed that the apraxic-aphasic subjects with lesions that included posterior areas made significantly more comprehension errors than the nonapraxic-aphasic subjects or the normal subjects. These results confirm the importance of the visuokinesthetic engrams in the comprehension of limb pantomimes and are consistent with the localization of these engrams in the left parietal lobule. Further support of the concept of visuokinesthetic engrams as an integral component of the functional limb praxis system was supplied by a gestural memory study completed by Rothi and Heilman (1984) Using a modified Buschke and Fuld (1974) paradigm, the subjects were asked to learn a list of gestures. The patients with left parietal lobe lesions

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23 demonstrated a deficit in secondary memory which was characterized by poor consolidation of the information. This finding could be explained by the mechanism of a deficit in the visuokinesthetic engrams. In summary, these studies support the hypothesis that the visuokinesthetic engrams are crucial for the production of limb movements, as well as for the discrimination comprehension and learning of limb pantomimes. These studies further suggest that posterior structures, specifically the inferior parietal lobule (IPL) appear crucial to the limb praxis processing system. Additional intrahemispheric localization of limb apraxia was provided by Watson, Fleet, Rothi and Heilman (1986) They reported two patients with mesial left hemisphere infarctions that included the supplementary motor area (SMA) These patients demonstrated bilateral limb apraxia for transitive movements without buccofacial apraxia. As previously discussed, it has been proposed that the left inferior parietal lobe plays a crucial role in the spatial and temporal representations of limb transitive movements (Heilman, Rothi & Valenstein, 1982). Watson et al. (1986) suggested that the lefthemisphere SMA translates these representations into motor plans. Therefore, the left SMA lesions may induce only limb apraxia, whereas lesions of the convexity premotor area of the face may induce only buccofacial apraxia. They further suggested that patients with apraxia from parietal lesions may demonstrate both limb and buccofacial apraxia. In summary, lesions of crucial posterior structures may induce both buccofacial and limb apraxia, whereas critically placed lesions in anterior structures may induce only limb or buccofacial apraxia.

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24 Relationship Between Buccofacial and T.imh Apravia P"Kxxfacial and limb apraxia most frequently co-occur within the same patients. DeRenzi, Pieczuro and Vignolo (1966) were the first to examine the co-occurrence of buccofacial apraxia, limb apraxia and "phonemic-articulatory M disorders. Of particular interest in this study was that the CG>-occurrence of buccofacial and limb apraxia was significantly greater than chance. Out of the total population of 134 subjects, 28 (21%) demonstrated both apraxias and 68 (51%) demonstrated normal praxis ability in both. However, 38 subjects (28%) demonstrated dissociations between the two disorders. Double dissociations characterized 30 subjects who exhibited normal buccofacial praxis in the context of limb apraxia, and eight subjects who exhibited normal limb praxis in the context of buccofacial apraxia. Mohr et al. (1978) described 20 patients with minor Broca's aphasia; 19 of whom demonstrated both buccofacial and limb apraxia. The lesions involved the following areas: the premotor areas for both the face and arm, and/or the arcuate fasciculus. Marquardt and Sussman (1984) studied 15 Broca's aphasics with documented left-hemisphere lesions. All 15 patients demonstrated a buccofacial apraxia, but only five demonstrated a limb apraxia. They reported a significant positive correlation between buccofacial and limb apraxia. The lesions involved the frontal and/or temporal lobes and/or subcortical structures including the internal capsule, the thalamus and the basal ganglia.

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25 Basso, Capitani, Delia Sala, Laiacona and Spinnler (1987) conducted a study primarily focusing on the. recovery of idecmotor limb apraxia. In the first examination session for each patient, 20 out of 26 subjects demonstrated both buccofacial and limb apraxia, while six demonstrated only limb apraxia. The number of limb/buccofacial apraxia dissociations increased at subsequent examinations, suggesting that one disorder exhibited more recovery than the other. The additional recovery dissociations were characterized by six patients continuing to demonstrate buccofacial but not limb apraxia, and by one patient exhibiting the reverse dissociation. Therefore, with this group of patients, the limb apraxia appeared to recover more than the buccofacial apraxia. Finally, Hogg, Square-Storer and Roy (1988) found that 20 out of 23 left-hemisphere-damaged subjects demonstrated both disorders. In summary, while many studies showed a high incidence of cc>-occurrence of buccofacial and limb apraxia, a significant number of patients in these groups also showed a dissociation of these disorders in both directions. These dissociations call into question the possibility that buccofacial and limb apraxia are different manifestations of the same disorder. Possible Constructs There are at least two possible constructs depicting the relationship between buccofacial and limb apraxia. In the first construct, apraxia is viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb praxis (Square-Storer & Roy, 1989; Roy & Square, 1985; Hogg, Square-Storer & Roy, 1988; and Poeck, 1985). In fact, Poeck (1985) explicitly stated

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26 that "the traditional distinction between oral and limb apraxia appears quite artificial" (p. 103) This "unitary motor disorder" coiistruct would predict a high degree of concordance and similarity between the two types of apraxia. An alternative construct would postulate that the relationship between buccofacial and limb apraxia is not unitary. This alternative construct could be expressed in at least two different models. In the first alternative, there would be two totally separable praxis systems: one for planning and controlling buccofacial movements and another one for planning and controlling limb movements. This "totally separable praxis systems" construct would predict quantitative and qualitative differences to be noted in all factors between buccofacial and limb performance. In the second alternative model, the two praxis systems would be at least partially separable. This "partially separable model" would predict areas of concordance as well as areas of discordance between buccofacial and limb praxis. Additional research is needed to determine which construct best describes the relationship between buccofacial and limb apraxia. Clinical Relevance These possible constructs have an impact upon clinical decisions regarding patients with buccofacial and limb apraxia. If the "unitary motor disorder" construct is valid, it would be predicted that treatment of one disorder would generalize to the other disorder. Therefore, the second disorder would demonstrate improvement, even though it was not directly targeted in treatment. In addition, if the underlying mechanisms were similar, a treatment task effective for one disorder would be likely to be effective for the second disorder as well.

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27 However, if buccofacial and limb apraxia are not a unitary motor disorder, treatment generalization may not occur. If the "separable praxis system" construct is valid, it would be predicted that treatment of one disorder would not necessarily generalize to the other disorder. Therefore, each disorder would need to be treated separately in order to assure improvement in each. In addition, if the underlying mechanisms were dissimilar, a treatment task effective for one disorder may not be effective for the second disorder. More specifically, if the "partially separable" model is valid, clinicians would need to know what mechanisms are shared and what mechanisms are separable. In summary, in order to optimize the utilization of treatment time for patients, clinicians need to know which construct best describes the relationship between buccofacial and limb apraxia. Transitivity Factor One approach to exploring the relationship between buccofacial and limb apraxia is to study a factor which influences the performance in one type of apraxia, in order to determine if it influences the performance in the other type of apraxia in a similar manner. One such factor could be transitivity. As previously discussed, several studies have suggested that left-hemisphere-damaged subjects are more impaired in the performance of limb transitive than limb intransitive movements (Liepmann, 1905/1980a; Goodglass & Kaplan, 1963; Haaland & Flaherty, 1984; Heilman, Rothi & Kertesz, 1983; and Watson, Fleet, Rothi & Heilman, 1986) It was suggested by several researchers that this difference in performance may be explained by a difference in the manner in which these two types of limb movements are represented in the brain.

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28 However, the transitivity factor has not been investigated for buccofacial movements. Error Type Analyses A second approach to exploring the relationship between buccofacial and limb apraxia is to analyze the quality of the errors produced in each disorder. Patterns of error types may give researchers insights into the similarity or dissimilarity of the underlying mechanism (s) of the two disorders. Retrospectively, Square-Storer and Roy (1989) and Roy and Square (1985) have reviewed previous research to analyze the common types of errors reported for buccofacial and limb apraxia. In their review, they noted the following categories of error types common to both buccofacial and limb apraxia: delayed initiation of movement, deficits in spatial targeting, deficits in temporal coordination of motor subsystemssubcomponents, decreased rate of movement, additive or augmentative motor behavior, omitted behaviors, disturbances of sequencing, and perseverative behaviors. They suggested that the presence of these common error types supported the concept of a unitary motor disorder for both buccofacial and limb apraxia. However, they did not make inferences regarding the mechanisms underlying buccofacial and limb apraxia. As an additional limitation, almost all of the studies reviewed involved only buccofacial apraxia or only limb apraxia. Therefore, comparisons between buccofacial and limb praxis were made across different subjects, rather than within the same subjects. As discussed previously, Lehmkuhl, Poeck and Willmes (1983) completed the only prospective study which analyzed the error types for

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29 both buccofacial and limb movements within the same left-brain-damaged subjects. As stated previously, their scoring system included the following five response categories: correct, fragmentary, augmentative, perseveratory and other errors. The results of the cluster analysis revealed that the types of errors examined did not yield any characteristic patterns for certain parts of the body (e.g. oral or arm or leg) Therefore, as Poeck (1985) explicitly stated, "The traditional distinction between oral and limb apraxia appears quite artificial" (p. 103) However, the most prominent type of error for both buccofacial and limb movements was perseveration, with a relatively low frequency of the other types of errors. The low frequency of the other types of errors might make a meaningful differentiation of subtypes of apraxia quite unlikely, for body part or otherwise. It is interesting to note that other researchers who have completed error analyses for limb movements do not report a high incidence of perseveration errors (Rothi, Mack, Verfaellie, Brown & Heilman, 1988) A major limitation of the study completed by l£hmkuhl et al. (1983) is the specific scoring system employed. The system appears to be characterized by too few categories to capture the nature of the errors induced by lefthemisphere dysfunction. For example, the scoring system does not include body-part-as-object errors, which have been emphasized as characteristic of limb apraxia (Goodglass & Kaplan, 1963; Geschwind, 1965). In addition, the Lehmkuhl et al. (1983) scoring system fails to capture the spatial or temporal aspects of movements. As noted previously, Rothi, Mack, Verfaellie, Brown and Heilman (1988) developed a categorical scoring system specifically designed for

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30 depicting the adequacy of limb praxis in three-diinensional space. Based upon Hermann' s (1905/19GCL) proposal that the left hemisphere contained the "space-time" engrams that controlled skilled movement for each hand, this scoring system is the only one specifically designed and modified to reflect the temporal and spatial aspects of limb movement. This system also reflected the oocurrence of body-part-as-object errors, as previously reported by Goodglass and Kaplan (1963) and Geschwind (1965) Currently, however, this scoring system has not been extended to depict buccofacial apraxic movements. Additional research is needed in the form of a prospective study which applies the same error analysis system to both buccofacial and limb movements within the same subjects. The scoring system developed by Rothi, Mack, Verfaellie, Brown and Heilman (1988) for limb movements could be extended to apply to buccofacial movements. Statement of the Problem The literature suggests that buccofacial and limb apraxia frequently co-occur, leading some to speculate that they share a common underlying mechanism. However, patients have been described who display buccofacial apraxia and no limb apraxia, while others are described who display limb apraxia with no buccofacial apraxia. This double dissociation calls into question the concept of a unitary mechanism for both buccofacial apraxia and limb apraxia. Therefore, the specific intent of the present study was to investigate the relationship between buccofacial and limb apraxia. The nature of this relationship has theoretical as well as clinical implications.

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31 There are at least two possible constructs depicting the relationship between buccofacial and limb apraxia. In the first construct, apraxia is viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb output. A high degree of concordance and similarity between the two types of apraxia would support this construct. An alternative construct would postulate that the relationship between buccofacial and limb apraxia is not unitary. The presence of quantitative and qualitative differences between buccofacial and limb performance would support this construct. For example, a high incidence of co-occurrence of buccofacial and limb apraxia would support a unitary motor disorder construct, whereas a low incidence of cx>-occurrence of these disorders would support a nonunitary construct. Based upon the preceding discussion, several studies suggested that left-hemisphere-damaged subjects are more impaired in the performance of limb transitive than limb intransitive movements. It was further suggested that this difference in performance may be explained by a difference in the manner in which these two types of limb movements are represented in the brain. However, the transitivity factor has not been investigated for buccofacial movements. The unitary motor disorder construct would predict that the neural control mechanisms for both buccofacial and limb praxis would be similar and, therefore, that the transitivity factor would be manifested in a similar manner for both disorders. Thus, this construct would predict that, in patients with buccofacial apraxia (as with limb apraxia) the degree of impairment of buccofacial transitive movements would be impaired compared to the

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32 impairment of the buccofacial intransitive movements. In contrast, a non-unj-t-^.ry construct would predict that the transitivity factor would be manifested in a dissimilar manner for buccofacial and limb movements. Additionally, it is suggested that an analysis of the error types of both buccofacial and limb praxis within the same subjects may give researchers insights into the similarity or dissimilarity of the underlying mechanism (s) This would be particularly true if the scoring system employed captured the nature of apractic dysfunction after a left-hemisphere lesion, based upon previous literature. A similar proportion of error types for both buccofacial and limb movements would support the concept of a unitary motor disorder. Whereas, a dissimilar proportion of error types would support the concept of non-unitary motor disorders. As with the two types of ideomotor limb apraxia, it would logically follow that there may also be two types of buccofacial apraxia. Specifically, one type of buccofacial apraxia would be characterized by impaired production and comprehension of buccofacial movements, and a second type would be characterized by impaired production but preserved comprehension Based upon the discussion of the neuroanatcmic distinctions for limb apraxia which outlined the importance of the inferior parietal lobule (IPL) for the disorder, if the unitary mechanism for buccofacial and limb praxis is accepted, it would logically follow that the IPL would also be a critical structure for buccofacial praxis. Specifically, if it is a structure critical for the functioning of the visuokinesthetic buccofacial engrams, it is predicted that it would be a

PAGE 40

33 critical neuroanatcmic structure for both the comprehension and production of buccofacial movements. Based upon the aforementioned discussion, this investigation attempted to address the following research questions: 1. Are buccofacial and limb apraxia manifestations of a unitary motor disorder? a. What is the nature of the co-occurrence or dissociation of buccofacial and limb apraxia? b. Is the transitivity factor manifested similarly in the production of buccofacial and limb movements? c. Is the proportion of error types similar for both buccofacial and limb movements? 2. Are there at least two different types of ideomotor buccofacial apraxia: the first type characterized by impaired production and comprehension, and the second type by impaired production, but preserved comprehension? 3. If two types of buccofacial apraxia exist, is the inferior parietal lobule (IPL) a critical rjeuroanatomic structure for both the comprehension and production of buccofacial movements?

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CHAPTER 2 MBIHODODDGY This study was designed to determine the nature of the relationship between buccofacial and limb apraxia. Specifically, are buccofacial and limb apraxia manifestations of a unitary motor disorder or are they at least partially separable? In addition, the possible presence of two types of buccofacial apraxia was examined, as well as the neuroanatomy of the disorder. Subjects Twenty-three subjects were included in this study. All subjects were right-handed and participated in this study after informed consent was obtained. Subjects were excluded from the study if they had any history of alcohol abuse. The experimental subject group included fifteen patients who had experienced a single, unilateral, lefthemisphere cerebrovascular accident (CVA) The control subject group included eight subjects who had no history of a central nervous system disorder. Subjects were also excluded from the experimental group if they had any history of multiple strokes or a history of a central nervous system disorder other than the unilateral stroke. All of the experimental patients had either computerized tomography (CT) or magnetic resonance imaging (MRI) scan documentation of the lesion localization. 34

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35 Age, gender and the number of years of education for the experimental and control groups are reported in Table 2-1. Detailed descriptive information on each of the experimental subjects is provided in Table 2-2. As noted in this table, the time post-onset of the CVA ranged between 27 and 2253 days. The types of syndromes demonstrated included Broca's aphasia, anemic aphasia, conduction aphasia, and no aphasia. The overall severity of the linguistic deficit included moderate, mild and minimal impairments, as indicated by an Aphasia Quotient range between 40.8 and 97.2, out of a possible 100. All of the patients had relatively spared auditory comprehension, as indicated by the range of 8.2-10.0 out of a possible 10 in the comprehension section of the Western Aphasia Battery (Kertesz, 1982) Procedures and Testing Materials All of the subjects were tested individually in a quiet room by the same examiner. The testing was completed in one or two sessions, depending on the fatiguability of the subject. All subjects used their left arm to perform the limb movements, which for the experimental patients, was nonhemiplegic and ipsilateral to the lesion. The behavioral tests utilized in this study included one auditory and three visual subtests, hereafter referred to as the screening subtests. The screening tests were included in order to rule out auditory comprehension or visual processing deficits as the source of defective performance. The behavioral tests also included a buccofacial movement comprehension subtest, and a limb and buccofacial movement production subtest, hereafter referred to as the experimental tests.

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36 Table 2-1. Descriptive demographic data for the experimental and control groups. Groups Age (years) Education (years) Gender M F Control Experimental 52.5 (16.8) 58.9 (13.0) 12.0 (4) 11.4 (3) 4 4 8 7 Note Group means with standard deviations in parentheses.

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37 Table 2-2. Detailed descriptive data on each of the experimental subjects Time PostType Type Subject Education CVA of of WAB WAB Number Age Sex (years) (days) CVA Aphasia AQ Comp 1 66 F 14 2 58 M 9 3 61 M 13 4 78 F 11 5 64 M 13 6 43 F 9 7 52 F 12 8 32 F 14 9 67 M 8 10 37 M 17 11 62 M 5 12 74 F 10 13 66 M 10 14 56 F 13 15 67 M 13 Note CVA = cerebrovascular accident; = occlusive stroke; H = hemorrhagic stroke; B = Broca's aphasia; A = anomic aphasia; C = conduction aphasia; NA = non-aphasic; WAB = Western Aphasia Battery; AQ = aphasia quotient; Comp = Comprehension. 52

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38 These screening and experimental subtests were administered in the same order for each subject. The order was as follows: the comprehension of buccofacial movements, the production of buccofacial and limb movements to verbal command, the three visual screening subtests, and finally the auditory screening subtest. The production testing followed the movement comprehension testing in order to avoid providing verbal labels to the movements prior to comprehension testing. The last test given to each experimental subject, but not administered to the control subjects, was the Western Aphasia Battery (Kertesz, 1982) It was administered according to its published instructions. The aphasia quotient and the auditory comprehension score were calculated for each experimental subject. The type of aphasic syndrome demonstrated, if present, was also determined using the standard taxonomy suggested by Kertesz (1982) Screening Tests There were four screening subtests altogether, three were visual and one was auditory. The procedures for all of the screening subtests will be discussed first, followed by a description of each of the subtests separately. The responses were scored as correct/ incorrect at the time of testing by the examiner for the four screening subtests. Percent correct was calculated for each subtest. Each subject was required to achieve at least 50% correct on each screening subtest. The three visual screening subtests were designed to assess the integrity of processing visual information. These three subtests included the same stimulus items which were composed of three training trials and ten randomized scored trials. The first visual screening

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39 subtest was a tool-to-object matching task. A tool is defined as an implement for performing or facilitating physical operat-ions performed with the arm, hand and fingers, or with the oral mechanism. An object is defined as a thing to which physical action is directed. Specifically, the stimuli in this first visual subtest were pictures of tools, such as a screwdriver, and the target responses were pictures of objects, such as several screws. The second visual screening subtest was a tool-to-picture matching task. The stimuli were the actual tools and the target responses were pictures of the same tools. The third visual screening subtest was a picture-to-picture matching task. The stimuli were pictures of tools and the target responses were identical pictures of the same tools. All three subtests included four pictures on the response page which included the target response, a visually similar tool, a visually similar nontool, and an object semantically related to the target response. In addition, one auditory screening subtest was included to assess the integrity of auditory comprehension. The stimuli included three training trials and 20 randomized scored trials of action line drawings. The examiner instructed the subject to point to one of the action pictures, such as, "Show me shaving," for example. There were four pictures on the response page which included the target action picture, a semantically related foil, a visually similar foil, and a phonologically similar foil, i.e., an action word sharing more than 50% of its phonemes with the target response.

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40 Experimental Tests Ccanprahe nsion of buccofacial movements Buccofacial movement comprehension was assessed with a pantanime-to-^iicture pointing task. A videotape of an actress performing buccofacial transitive movements was utilized. IXiring this testing, the subject was seated approximately 4 to 6 feet away from a television monitor. Each movement stimulus was shown one time and the subject was given up to 10 seconds to respond. The subject's first response, pointing to one of four pictures, was recorded and scored immediately by the examiner as correct or incorrect. The stimulus items were comprised of three training trials and ten randomized buccofacial transitive movements (Appendix B) Each response page was composed of four pictures which included the target response (which was a picture of the tool being pantomimed on the videotape) and three foil pictures. One foil was a picture semantically related to the target response. A second foil was a picture of a tool with an associated movement which was similar to the target pantomime. The third foil was a picture of a nonrelated tool. The percentage correct was calculated for each subject. The lowest score achieved by a normal subject was used as the cut-off score between normal and impaired performance. Producti on of movements The production of movements to verbal command was also assessed. This subtest was comprised of three training trials and 40 randomized buccofacial and limb movements. There were 10 of each type of stimulus, i.e., buccofacial transitive and intransitive, and limb transitive and intransitive movements (Appendix B)

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41 Curing the movement production testing, each subject's performance was videotaped by a camera placed approximately 6 feet away from the subject. The camera was focused on the subject's upper body to include his left arm and facial area. The subject was instructed to perform the limb or buccofacial movement as carefully and accurately as possible. Curing the three training trials, the instructions and feedback emphasized accommodating the manipulation of the pretended object, if one was involved. The accuracy and the error type scoring of the movement production subtest was accomplished using the videotapes of each subject's performance. All of the videotapes were scored during the same time period after the testing of all of the subjects had been completed. For the accuracy scoring, the subject's first response for each trial was scored as correct or incorrect by two trained judges. The percent correct was calculated for each of the following types of movements: buccofacial intransitive, buccofacial transitive, limb intransitive, limb transitive, buccofacial combined, and limb combined movements. The lowest scores achieved by a normal subject for the buccofacial combined and the limb combined stimulus items were used as the cut-off scores between normal and apraxic performance. In addition to the accuracy scoring, a qualitative error typing was completed on the buccofacial and limb movement productions. The qualitative scoring system developed by Rothi et al. (1988) for depicting limb apraxic movements was extended and applied to buccofacial apraxic movements as well, in this scoring system, there are four major error categories which are labeled content, temporal, spatial or other

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42 errors. These four major categories are further subdivided into three to seven subcategories, as defined in Appendix C. Three subcategories of errors not contained in the system used for limb praxis were added to the system for buccofacial praxis. These consisted of extraneous, place of articulation, and verbalization errors. Each of the error types could be applied to both buccofacial and limb movements except for four subcategories under spatial errors which could only occur for one type of movement. Specifically, internal configuration, external configuration, and body-part-as-object errors could only occur for limb movements and place of articulation errors could only occur for buccofacial movements. The error typing was completed only for movements judged to be defective. One movement could exhibit more than one subcategory of error, as well as more than one main type of error. Apraxia Scoring Reliability Interrater reliability measures were obtained for the accuracy and error type scoring of the buccofacial and limb movement production subtest. A third rater, who was trained in the procedure, independently scored all of the experimental subjects' movement productions for accuracy and error type. The third rater's judgements were compared with the combined judgements of the first two raters. Accuracy of movement Kappa statistics (Kramer & Feinstein, 1981) were calculated as interrater reliability measures for the accuracy judgement for each movement (Appendix D) The kappa statistic for the limb intransitive movement ''pinching your nose" could not be calculated because all of the ratings were within one column. The range for the

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43 kappa statistics was from 0.444 to 1.000. Tanciis and Koch (1977) have suggested the following guidelines, in part, for the values of kappa and the strength of the agreement: .41-. 60, moderate agreement; .61-. 80, substantial agreement; and .81-1.00, almost perfect agreement. According to these guidelines, there were six kappas of moderate strength, seven kappas of substantial strength, and 26 kappas of almost perfect strength. In addition to the reliability measures for each individual movement, intraclass correlations (IOC) employing a one-way analysis of variance of the ratings (Shrout & Fleiss, 1979) were computed to measure the interrater reliability of the percent accuracy for each of the four types of movements. The results were as follows: for limb intransitive movements, ICO0.9873; for limb transitive movements, 100=0.8162; for buccofacial intransitive movements, 100=0.8949; and for buccofacial transitive movements, 100=0.9917. In summary, the interrater reliability results reveal that independent raters could reliably judge the accuracy of buccofacial and limb movement productions. This reliability was demonstrated when the ratings were analyzed individually, as well as when the ratings were analyzed by type of movement. Error type scoring Percentage agreement was calculated to measure the interrater reliability of the error type judgement for the main type(s) of errors for each of the 40 movements (Appendix E) The main error types observed were content, temporal, spatial, other, and the combinations of content and temporal, and spatial and temporal. The range for percentage agreement was from 70 to 100%. The mean

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44 percentages for each of the movement types were as follows: limb intransitive, 94.3; limb transitive, 86.0; buccofacial intransitive, 90.0; and buccofacial transitive, 91.0. In summary, the interrater reliability results reveal that independent raters could reliably judge the types of errors demonstrated for buccofacial and limb movements. Localization of the Lesion The computerized tomography (CI) or magnetic resonance imaging (MRI) scan of each of the experimental subjects was utilized to document the location of infarcted area(s) in the brain. A checklist of specific neuroanatomic structures was developed (Appendix F) A neurologist, blinded to the behavioral test results, analyzed the CI or MRI scan of each of the patients and marked a plus sign on the checklist for each neuroanatomic structure that was more than 50% involved by the lesion and marked a minus sign for each structure that was involved less than 50% by the lesion. All neuroanatomic structures that were totally spared were left blank on the checklist. Anatomic localization was aided by reference to Matsui and Hirano (1978) for the CI scans and to Schnitzlein and Murtagh (1985) for the MRI scans. Idiosyncratic areas of low density less than one centimeter in diameter or slight periventricular lucencies were noted, but not included as part of the lesion site.

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CHAPTER 3 RESUIUS The purpose of this study was to determine the nature of the relationship between buccofacial and limb apraxia. Specifically, are buccofacial and limb apraxia manifestations of a unitary motor disorder or are they at least partially separable? In addition, the possible presence of two types of buccofacial apraxia was examined as well as the neuroanatoiny of the disorder. The experimental group was comprised of fifteen patients who had experienced a single, unilateral, lefthemisphere cerebrovascular accident (CVA) The control group was comprised of eight subjects who had no history of a central nervous system disorder. Comparisons Between Groups There were no significant differences between the control and experimental groups in age (t = 1.01, df = 21, p = .324) or educational level (t = -0.39, df = 21, p = .702). Behavioral Test Results Screening Tests The experimental group performed significantly worse than the control group in the auditory comprehension screening subtest (t = -3.50, df [corrected for heterogenous variances] = 17.31, p = .003) Specifically, the control group demonstrated a mean of 98.8 45

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46 (SD = 2.31) and the experimental group demonstrated a mean of 90.3 (SD = 8.76). Although there was a significant difference between the experimental and control groups, it was determined that the control group's auditory comprehension was adequate for the apraxia testing, in that it was preserved for following one-stage commands. This relative sparing of auditory comprehension was documented by the comprehension scores on the Western Aphasia Battery (Kertesz, 1982) The range for the experimental subjects was from 8.2 to 10.0 out of a possible 10 (Table 2-2) In addition, processing of visual stimuli by the experimental subjects was relatively spared as documented by the subjects' performance on the visual screening subtests. In the first visual subtest, a tcol-to-object matching task, the experimental group did not significantly differ from the control group (t = -1.55, df [corrected for heterogenous variances] = 18.72, p = .139). Specifically, the control group achieved a mean of 97.5 (SD = 4.63) and the experimental group a mean of 91.3 (SD = 14.07) In the second visual subtest, the tool-to-picture matching task, the experimental group did not significantly differ from the control group (t = .68, df = 21, p = .504) Specifically, the control group demonstrated a mean of 97.5 (SD = 4.63) and the experimental group demonstrated a mean of 98.7 (SD = 3.52) Finally in the third visual subtest, the picture-topicture matching task, it was not possible to apply a t-test because the experimental group demonstrated no variance. Specifically, the control group achieved a mean of 98.7 (SD = 3.54) and the experimental group achieved a mean of 100.0 (SD = 0.00) In summary, the experimental

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47 grot?) did not significantly differ from the control group in the processing of visual information. Experimental Tests Comprehension of buccofacial movements The experimental group performed significantly worse than the control group in the comprehension of buccofacial movements (t = -2.31, df [corrected for heterogenous variances] =20.79, p = .031). Specifically, the control group achieved a range of scores between 80 and 100% accuracy, with a mean of 88.8 (SD = 8.35) The lowest score (80%) achieved by a control subject was used as the cut-off score between spared and impaired buccofacial movement comprehension. The experimental subjects achieved a range of scores between 30 and 100% accuracy, with a mean score of 76.0 (SD = 18.05) Utilizing the above cut-off score, eight experimental subjects demonstrated spared buccofacial comprehension, while seven demonstrated impaired buccofacial comprehension. Production of movements The experimental group performed significantly worse than the control group in the production of buccofacial movements (t = -4.67, df [corrected for heterogenous variances] = 14.31, p = .000). Specifically, the control group achieved a range of scores between 95 and 100% accuracy, with a mean of 98.8 (SD = 2.31) Again, the lowest score (95%) achieved by a control subject was used as the cut-off score between spared praxis and apraxia. The experimental group achieved a range of scores between 5 and 100% accuracy, with a mean of 62.3 (SD = 30.05) Utilizing the above cutoff score, four experimental subjects demonstrated spared buccofacial praxis, while 11 experimental subjects demonstrated buccofacial apraxia.

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48 Similarly, the experimental group performed significantly worse that the control group in the production of limb movements (t = -5.29, df [corrected for heterogenous variances] = 16.87, p = .000) Specifically, the control group achieved a range of scores between 80 and 95% accuracy, with a mean of 88.8 (SD = 5.82) The experimental group achieved a range of scores between 15 and 90% accuracy, with a mean of 54.3 (SD = 23.89) Again, utilizing the lowest normal score (80%) as the cut-off score, four of the experimental subjects demonstrated spared limb praxis, while 11 experimental subjects demonstrated limb apraxia. Research Questions The statistical analysis relevant to each question will be discussed separately. Research Question #1 Are buccofacial and limb apraxia manifestations of a unitary motor disorder? To determine the nature of the relationship between buccofacial and limb apraxia, the following three subquestions on the co-occurrence of the two disorders, the transitivity factor and the proportion of error types were addressed. Research Question ftla What is the nature of the co-occurrence or dissociation of buccofacial and limb apraxia? To determine the nature of the co-occurrence or dissociation of the two disorders, the following null hypothesis was tested: Hq: There is an association between the co-occurrence of buccofacial and limb apraxia.

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49 There was a nonsignificant association between buccofacial and limb apraxia (Fisher's exact test, df = [1,1], p = 0.7253). In addition, Table 3-1 descriptively presents the relationship between the production of buccofacial and limb movements to verbal command. As noted, there was a c-cccurrence of buccofacial and limb praxis ability for nine patients, spared for both types in one subject and impaired for both types in eight subjects. However, there were six patients (40%) who demonstrated a double dissociation between the two types, three subjects with spared limb praxis and buccofacial apraxia, and three subjects with spared buccofacial praxis and limb apraxia. In summary, buccofacial and limb apraxia can be dissociated within the same subjects. Research Question #lb Is the transitivity factor manifested similarly in the production of buccofacial and limb movements? To determine the effect of the transitivity factor in the production of buccofacial and limb movements, the following null hypothesis was tested: H,-,: The transitivity factor is manifested in a similar manner for both buccofacial and limb movements. For example for both types of movements, the transitive and intransitive movements may be equally impaired, or the transitive movements may be more impaired than the intransitive movements, or the intransitive movements may be more impaired than the transitive movements. Table 3-2 presents the means and standard deviations for each type of movement for the experimental and control groups. A two-way analysis of variance with repeated measures was conducted with the within-subject factors of transitivity and body part. As illustrated in Figure 3-1, the

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50 Table 3-1. The relationship between the production of buccofacial and limb movements. Buccofacial Movements Spared Impaired Spared Limb Movements 8 3, 6, 10 Impaired Limb 5, 7, 12 1, 2, 4, 9, 11, Movements 13, 14, 15 Note The numbers in the table represent subject identification numbers.

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51 Table 3-2. The means and standard deviations for each of the four types of movements for the experimental and control groups Type of Movement Limb Limb Buccofacial Buccofacial Group Intransitive Transitive Intransitive Transitive Experimental 74.0 (22.93) 34.7 (29.00) 64.7 (32.04) 60.7 (29.63) Control 95.0 ( 7.56) 82.5 (11.65) 98.8 ( 3.54) 98.8 ( 3.54) Note. Numbers in parentheses are the standard deviations.

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52 Intrans Trans Intrans Trans Limb Movements Buccofacial Movements Figure 3-1. The performance of transitive and intransitive buccofacial and limb movements by the experimental and control groups. Note Intrans = Intransitive; Trans = Transitive.

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53 interaction between the two factors was significant (F = 23.89, df = [1, 14], p = .0002). Becaucc the interaction was significant, a follow-up analysis of the transitivity effect was completed by applying the Bonferroni statistic. The limb transitive movements were significantly more impaired than the limb intransitive movements (t = 8.62, df = [2, 14], with a 95% confidence interval between 2.79 and 5.08) In contrast, the buccofacial transitive movements were not significantly more impaired than the buccofacial intransitive movements (t = 0.88, df = [2, 14], with a 95% confidence interval between -0.74 and 1.54) In summary, the transitivity factor was manifested in a significantly dissimilar manner in the production of buccofacial and limb movements. As part of the follow-up analysis, a comparison was made between the experimental and control groups for each type of movement. Ihe experimental group performed significantly worse than the control group for each type of movement (degrees of freedom was corrected for heterogenous variances for each comparison) : limb intransitive (t = -3.23, df = 18.73, p = .004); limb transitive (t = -5.60, df = 20.08, p = .000); buccofacial intransitive (t = -4.10, df = 14.61, p = .001) ; and buccofacial transitive (t = -4.91, df = 14.74, p = .000) In summary, the experimental group was significantly more impaired than the control group regardless of the type of movement. Research Question ila Is the proportion of error types similar for both buccofacial and limb movements? To determine the nature of the relationship between error types for buccofacial and limb apraxia, the following null hypothesis was tested:

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54 Hq: The proportion of error types is similar for both buocofacial and limb movements. Table 3-3 delineates the contingency table which contrasts body part (buccofacial or limb) with the four main types of errors (content, temporal, spatial and other) There was a significant relationship between the proportion of error types and body part (chi-square = 34.20, df = 3, p < .005) That is, the proportion of error types was significantly dissimilar for buccofacial and limb movements. Because a significant relationship was found between the proportion of error types and body part, a follow-up analysis was completed in order to determine what specific types of errors exhibited dissimilar proportions for buccofacial and limb movements. In four follow-up chisquare tests, each error type was contrasted with the average of the other three error types in 2 X 2 contingency tables. There was a significant relationship between the proportion of content errors and body part (chi-square = 16.02, df = 1, p < .005). Specifically, there was a disproportionately large number of content errors for buccofacial movements. There was a nonsignificant relationship between the proportion of temporal errors and body part (chi-square = 0.61, df = 1, p > .100) There was a significant relationship between the proportion of spatial errors and body part (chi-square = 8.69, df = 1, p < .005) Specifically, there was a disproportionately large number of spatial errors for limb movements. And finally, there was a significant relationship between the proportion of other errors and body part (chi-square = 7.27, df = 1, p < .010) Specifically, there was a disproportionately large number of other errors for buccofacial movements.

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55 Table 3-3. The observed and expected frequencies of each type of error for buccofacial and limb movements. Type of Error Type of Movement Content Temporal Spatial Other Limb 8 (20.74) 35 (31.95) 109 (91.37) 10 (17.94) Buccofacial 29 (16.26) 22 (25.05) 54 (71.63) 22 (14.06) Note Numbers in parentheses are the expected cell frequencies.

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56 In summary, there was a dissimilar proportion of error types for buccofacial and limb movements. The follow -up chi-squares revealed that the proportion of temporal errors was similar for both buccofacial and limb movements. However, the proportions of content, spatial and other error types were dissimilar for buccofacial and limb movements, and therefore accounted for the overall dissimilarity found in the initial analysis. Specifically, buccofacial movements exhibited a disproportionately large number of content and other errors, whereas limb movements exhibited a disproportionately large number of spatial errors. Research Question #2 Are there at least two different types of idecmotor buccofacial apraxia: the first type characterized by impaired production and comprehension, and the second type by impaired production but preserved comprehension? To determine the possible types of buccofacial apraxia demonstrated, the following null hypothesis was tested: Hq: There is only one type of buccofacial apraxia. Table 3-4 delineates the relationship between the comprehension and production of buccofacial movements. The proportion of subjects who demonstrated an association between buccofacial comprehension and production (11/15) was evaluated by applying a binomial statistic. The proportion of subjects with an association between the comprehension and production of buccofacial movements just failed to reach significance (p = .0592) As noted in Table 3-4, the comprehension and production were frequently associated, spared for both in four subjects and impaired for both in seven subjects. However, there were four patients who demonstrated spared comprehension but impaired production. There

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57 Table 3-4. The relationship between the comprehension and production of buccofacial movements. Buccofacial Comprehension Spared Impaired Spared Buccofacial 5, 7, 8, 12 Movements Impaired Buccofacial 6, 10, 11, 15 1, 2, 3, 4, 9, 13, 14 Movements Note The numbers in the table represent subject identification numbers

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58 were no subjects who demonstrated spared movement production with impaired comprehension. In summary, two different types of buccofacial apraxia were exhibited, one type characterized by impaired production and comprehension, and the second type characterized by impaired production but preserved comprehension. Specifically, buccofacial comprehension and production may dissociate within an individual subject. Research Question #3 If two types of buccofacial apraxia exist, is the inferior parietal lobe (IPL) a critical neuroanatomic structure for both the comprehension and production of buccofacial movements? To determine the importance of the IPL for the comprehension and production of buccofacial movements, the following null hypothesis was tested: Hq: The IPL is a crucial neuroanatomic structure for both the comprehension and production of buccofacial movements. Appendix G documents the involvement of specific neuroanatomic structures in the lesion for each experimental subject. A plus sign designates more than 50% damage to the specific structure and a minus sign designates less than 50% damage to the specific structure. A blank space designates that the structure is spared. There was a nonsignificant relationship between the comprehension of buccofacial movements and the integrity of the IPL (Fisher's exact test, df = [1,1], p = .3776). As delineated in Table 3-5, buccofacial movement comprehension and the integrity of the IPL are associated for only six subjects, that is, both are spared for four subjects and both are impaired for two subjects. In contrast, buccofacial movement

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59 Table 3-5. The relationship between the comprehension of buccofacial movements and the integrity of the inferior parietal lobule (IPL). Buccofacial Comprehension Spared Impaired IPL Spared 6, 8, 10, 15 1, 2, 4, 9, 13 IPL Involved 5, 7, 11, 12 3, 14 Note. The numbers in the table represent subject identification numbers

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60 comprehension and the integrity of the IPL are dissociated for nine subjects. Specifically, four subjects demonstrated spared buccofacial movement comprehension and involvement of the IPL, and five subjects demonstrated impaired buccofacial movement comprehension and spared IPL. In summary, the integrity of the IPL does not appear to be a critical neuroanatomic structure for the comprehension of buccofacial movements. As part of the post hoc analysis, Table 3-6 provides additional descriptive data regarding the relationship between the comprehension of buccofacial movements and the involvement of specific neuroanatomic structures. The specific neuroanatomic structures which were included in this table, excluding the IPL, have previously been reported to be associated with the presence of buccofacial apraxia (Tognola & Vignolo, 1980; Mintz, Raade & Kertesz, 1989). Fisher's exact tests were applied to evaluate the relationship between each neuroanatomic structure and the comprehension of buccofacial movements. The inferior frontal gyrus (p = .0317) and the peri-Sylvian central area (p = .0317) were significantly related to the comprehension of buccofacial movements. The insula (p = .0513) just failed to reach significance. The remaining rieuroanatomic structures were not significantly related to the comprehension of buccofacial movements: the superior temporal gyrus (p = .1818), the striatum (p = .0839), and the corona radiata (P = -3776) In summary, the frontal cortical areas appeared to be crucial for the comprehension of buccofacial movements. Table 3-7 provides descriptive data regarding the relationship between the production of buccofacial movements and the involvement of specific neuroanatomic structures. Again, the specific neuroanatomic

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61 Table 3-6. The relationship between the comprehension of buccofacial movements and the involvement of specific neuroanatomic structures for each experimental subject. IPL Corona Subject AG SMG PSC Insula IFG STG Striatum Radiata Impaired Buccofacial Comprehension 1 + + 2 + + 3 + + + 4 + 9 + + 13 + + 14 + + + Spared Buccofacial Comprehension 5 + 6 + + 7 + + 8 10 + 11 + + + 12 + 15 Note IPL = inferior parietal lobule; AG = angular gyrus; SMG = supramarginal gyrus; PSC = peri-sylvian central; IFG = inferior frontal gyrus; STG = superior temporal gyrus. + = more than 50% involvement of the structure; = less than 50% involvement of the structure.

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62 Table 3-7. The presence of buccofacial apraxia and the involvement of specific neuroanatomic structures for each experimental subject. IPL Corona Subject AG SMG PSC Insula IFG STG Striatum Radiata Buccofacial Apraxia 1 + + + + 2 + + + + + + 3 + + + + + 4 + + 6 + + + + + + 9 + + + + + + 10 + + + 11 ++++++ + 13 + + + + + 14 + + + + + + 15 Spared Buccofacial Praxis 12 + Note. IPL = inferior parietal lobule; AG = angular gyrus; SMG = supramarginal gyrus; PSC = peri-sylvian central; IFG = inferior frontal gyrus; STG = superior temporal gyrus. + = more than 50% involvement of the structure; = less than 50% involvement of the structure.

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63 structures which were included in this table, excluding the IPL, have previously been reported to be associated with the presence of buccofacial apraxia (Tognola & Vignolo, 1980; Mintz, Raade & Kertesz, 1989) There was a nonsignificant relationship between the production of buccofacial movements and the integrity of the IPL (Fisher's exact test, df = [1,1], p = .1428) As delineated in Table 3-6, buccofacial movement production and the integrity of the IPL are associated for only four subjects, that is, both are spared for one subject and both are unpaired for three subjects. In contrast, buccofacial movement production and the integrity of the IPL are dissociated for 11 subjects. Specifically, three subjects demonstrated spared buccofacial production and involvement of the IPL, and eight subjects demonstrated inpaired buccofacial production and spared IPL. In summary, these data do not provide support for the hypothesis that the IPL is a critical neuroanatomic structure for the production of buccofacial movements. As part of the post hoc analysis, Fisher's exact tests were applied to test the relationship between each of the remaining neuroanatomic structures listed in Table 3-7 and the production of buccofacial movements. The following neuroanatomic structures were significantly related to the presence of buccofacial apraxia: the inferior frontal gyrus (p = .0256), the peri-Sylvian central area (p = .0256), the insula (p = .0329), and the striatum (p = .0110). In contrast, the superior temporal gyrus (p = .4066) and the corona radiata (p = .1428) were not related to the production of buccofacial movements. In summary, the frontal cortical structures, with the addition of the striatum, appeared to be crucial for the production of buccofacial movements.

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64 In summary, the results for each question are reviewed as they relate to the specific null hypothesis tested. Null hypothesis la, "There is an association between the cx>-
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CHAPTER 4 DISCUSSION The literature suggests that buccofacial and limb apraxia frequently co-occur, leading some to speculate that they share a common underlying mechanism. However, double dissociations have been reported, which would call into question the concept of a unitary mechanism for both buccofacial and limb apraxia. The nature of the relationship between these two disorders has theoretical, as well as clinical implications. There are at least two possible constructs depicting the relationship between buccofacial and limb apraxia. In the first construct, apraxia is viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb output. This "unitary disorder" construct would predict a high degree of concordance and similarity between the two types of apraxia. An alternative construct would postulate that the relationship between buccofacial and limb apraxia is not unitary. This non-unitary construct would predict quantitative and qualitative differences to be noted between buccofacial and limb performance. The present study was designed to determine the nature of the relationship between buccofacial and limb apraxia. The experimental group was comprised of fifteen patients who had experienced a single, unilateral, left-hemisphere cerebrovascular accident (CVA) The control 65

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66 group was comprised of eight subjects who had no history of a central nervous system disorder. An analysis was completed on the following factors for both buccofacial and limb apraxia in these groups: their cooccurrence, the transitivity factor, and the proportion of error types. The predictions that each model would make for each factor and the actual results are presented. Research Questions In terms of the co-occurrence of the two disorders, a high incidence of co-occurrence would support the unitary motor disorder construct, whereas a low incidence of co-occorrence would support a nonunitary construct. The results of this study indicated that there were a significant number of dissociations between buccofacial and limb apraxia within the same subjects. These results would support a nonunitary construct. In terms of the transitivity factor, several studies have suggested that left-hemisphere-damaged subjects are more impaired in the performance of limb transitive than limb intransitive movements. It was further suggested that this difference in performance may be explained by a difference in the manner in which these two types of limb movements are represented in the brain. However, the transitivity factor has not been investigated for buccofacial movements. The unitary motor disorder construct would predict that the neural control mechanisms for both buccofacial and limb praxis would be similar and, therefore, that the transitivity factor would be manifested in a similar manner for both disorders. In contrast, a non-unitary construct would predict that the neural control mechanisms for buccofacial and limb praxis would be

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67 separable and, therefore, that the transitivity factor would be manifested in a dissimilar manner for each disorder. The results of this study revealed that the transitivity factor was manifested in a significantly dissimilar manner in the production of buccofacial and limb movements. The limb transitive movements were significantly more impaired than the limb intransitive movements. In contrast, the buccofacial transitive movements were not significantly more impaired than the buccofacial intransitive movements. One explanation for the nonsignificant buccofacial transitivity result could be that the buccofacial movements were not impaired and so would not demonstrate the transitivity difference. However, a follow-up analysis revealed that the experimental group was significantly more impaired than the control group for each type of movement, including the two types of buccofacial movements. Therefore, a lack of buccofacial impairment could not explain the nonsignificant buccofacial transitivity results. A second explanation for these results would suggest that buccofacial and limb apraxia are not manifestations of a unitary underlying mechanism. The transitivity factor is important for the limb movements but not for the buccofacial movements. In conclusion, these results would support a non-unitary construct and would suggest that the underlying mechanism (s) of these two disorders are, at least in part, functionally independent. Additionally, it is suggested that an analysis of the error types of both buccofacial and limb movements may give researchers insights into the similarity or dissimilarity of the underlying mechanism (s) The unitary motor disorder construct would predict a similar proportion

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68 of error types for both buccofacial and limb movements. In contrast, a non-unitary construct would predict a dissimilar proportion of error types for both disorders. The results of this study revealed that the proportion of error types was significantly dissimilar for buccofacial and limb movements. In addition, the follow-up analysis suggested that the proportion of temporal errors was similar for both buccofacial and limb movements. Therefore, temporal errors did not account for the differences found. However, the follow-up analysis also indicated that the proportions of content, spatial and other error types were significantly dissimilar for buccofacial and limb movements. Specifically, buccofacial movements exhibited a disproportionately large number of content and other errors, whereas limb movements exhibited a disproportionately large number of spatial errors. These results would support a non-unitary construct and would suggest that the underlying mechanism(s) of these two disorders are, at least in part, functionally independent. In addition, these results would suggest that the spatial and semantic aspects of movement production may account for the differences found. In summary, the results from these three questions supported a nonunitary construct for buccofacial and limb apraxia. Specifically, double dissociations between buccofacial and limb apraxia were noted, the transitivity factor was manifested in a dissimilar manner between the two disorders, and the proportion of error types was dissimilar between the two disorders. Additional analyses were completed in order to further elucidate the nature of the relationship between buccofacial and limb apraxia. As

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69 with the two types of ideomotor limb apraxia, it would logically follow that there may also be two types of buccofaciai apraxia. Specifically, one type would be characterized by impaired production and comprehension of buccofaciai movements, and a second type would be characterized by impaired production but preserved comprehension. The results of this study indicated that there was a nonsignificant association between the comprehension and production of buccofaciai movements. Specifically, buccofaciai comprehension and production may dissociate within an individual subject. Therefore, two different types of buccofaciai apraxia were exhibited: one type characterized by impaired production and comprehension, and the second type characterized by impaired production but preserved comprehension. This is similar to the pattern that has been previously reported for limb apraxia (Heilman, Rothi & Valenstein, 1982) The neuroanatomy of each disorder may also elucidate the nature of the relationship between buccofaciai and limb apraxia. The previous discussion of the neuroanatcmic distinctions for limb apraxia outlined the importance of the inferior parietal lobule (IPL) for the disorder. If a unitary mechanism for buccofaciai and limb praxis is accepted, it would logically follow that the IPL would also be a critical structure for buccofaciai praxis. Specifically, it was predicted that the IPL would be a critical neuroanatomic structure for both the comprehension and production of buccofaciai movements. The results of this study revealed a nonsignificant relationship between the comprehension of buccofaciai movements and the integrity of the IPL. Although the two factors were associated for six subjects,

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70 they were dissociated for nine subjects. Therefore, the integrity of tn* IPL does not appear to be a critical neuroanatomic structure for the comprehension of buccofacial movements. In contrast, previous research has suggested that the IPL is a critical neuroanatomic structure for the comprehension of limb movements (Heilman, Rothi & Valenstein, 1982) In addition, the results of this study revealed a nonsignificant relationship between the production of buccofacial movements and the integrity of the IPL. Although the two factors were associated for four subjects, they were dissociated for 11 subjects. Therefore, the integrity of the IPL does not appear to be a critical neuroanatomic structure for the production of buccofacial movements. In contrast, previous research has suggested that the IPL is a critical neuroanatomic structure for the production of limb movements. Because the results indicated that the IPL was not a critical neuroanatomic structure for either the comprehension or production of buccofacial movements, additional analyses were completed in order to determine what specific structures were associated with these impairments. Regarding the comprehension of buccofacial movements, anterior cortical areas, primarily frontal lobe structures, appeared to be critical. Specifically, the inferior frontal gyrus and the periSylvian central area were significantly related to the comprehension of buccofacial movements. The insula just approached reaching significance. Regarding the production of buccofacial movements, anterior cortical areas and several deeper structures appeared to be critical. Specifically, the inferior frontal gyrus, the peri-Sylvian central area, the insula and the striatum were significantly related to

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71 the production of buccofacial movements. A comparison between the two impairments revealed that ths anterior surface structures appeared critical for the comprehension of buccofacial movements, whereas the same anterior surface structures and several deeper anterior structures appeared critical for the production of buccofacial movements. In summary, buccofacial and limb apraxia are similar in the fact that both disorders are manifested as two types. Specifically, the comprehension and production of movements may be dissociated. However, buccofacial and limb apraxia are dissimilar in the fact that the IPL is a critical neuroanatamic structure for the comprehension and production of limb movements, but apparently is not a critical structure for the comprehension and production of buccofacial movements. In contrast, it appears that anterior structures are the crucial areas for buccofacial praxis performance. Are there alternative explanations of these results? In this study, the presence of impairments in the production of buccofacial or limb movements could not be explained by age or educational level, as there were no significant differences between the experimental and control groups for either of these factors. Although the experimental group performed significantly worse than the control group in the auditory comprehension subtest, the experimental group did demonstrate relatively preserved performance on this test. It is unlikely that the relatively mild deficits in auditory comprehension could account for the significant deficits exhibited during the movement production testing. As additional evidence of relatively spared auditory comprehension, the comprehension scores on the Western Aphasia Battery (Kertesz, 1982) were

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72 relatively preserved. Additionally, the presence of impairments in the comprehension of buccofacial movements could not be explained by poor visuoperceptual skills as there were no significant differences between the experimental and control groups for the visual subtests. The results of this study clearly support a non-unitary construct for the relationship between the production of buccofacial and limb movements. What could account for the non-unitary patterns observed? There was a disproportionately large number of spatial errors for the limb movements. Previous researchers have reported dissociations in behavior and dissociations in lesion localization in the representation of space surrounding the body. Rizzolatti and his colleagues (Rizzolatti, Matelli & Pavesi, 1983; Rizzolatti & Camarda, 1987) have defined the space surrounding the body in the following way. Peripersonal space is the space immediately around the body, including actual touching of the body, whereas distant peripersonal space is the space outside of the preceding area but within the reach of the arm. Rizzolatti and his colleagues made unilateral, left-hemisphere surgical ablations of specific frontal areas in macaque monkeys. The subsequent behavioral testing was accomplished by moving a piece of food held by a pair of forceps at different distances from the animal. After surgical ablation of the left-hemisphere postarcuate cortex, which is a premotor frontal area, the monkeys demonstrated a failure to grasp food with the mouth when presented contralaterally to the lesion and a severe hemiinattention of visual stimuli which was limited to peripersonal space. Specifically, when the food was presented in the contralateral peripersonal space, the monkey ignored the stimulus and did not produce

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73 the normal mouth-grasping response. Likewise, when a threatening stimulus was presented to the contralateral hemiface, the normal blink response was absent. In contrast, when a threatening stimulus was presented in distant contralateral peripersonal space, the monkey demonstrated facial movements and a rich emotional response. In contrast to these mouth deficits, the motor disturbances of the arm were markedly less severe and quite different in quality. The mild arm deficits consisted of a reluctance to use the contralateral arm and of mild clumsiness of finger movements. As part of the control experiment, Rizzolatti and his colleagues also made surgical ablations of a second area in the frontal cortex (the frontal eye fields) with a separate set of monkeys. These monkeys demonstrated a neglect of the contralateral hemispace which was more prominent for distant peripersonal space than peripersonal space. In summary, these results demonstrate that lesions of one area (postarcuate cortex) produce peripersonal neglect, whereas lesions of another area (frontal eye fields) produce distant peripersonal neglect. In addition, there is a close relationship between the spatial properties of the neglect and the type of motor disturbance. Specifically, peripersonal neglect is associated with a disturbance of mouth movements, whereas distant peripersonal neglect is associated with a disturbance of arm movements. These results would suggest that areas of the brain that organize complex motor acts also have attention functions that are specific for the space in which the movements occur. Employing Rizzolatti' s definitions of peripersonal and distant peripersonal space, an analysis of the specific stimulus items utilized

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74 in the present study was completed. All of the buccofacial movements would be classified as occurring in peripersonal space, whereas 70% of the limb movements would be classified as occurring in distant peripersonal space, with the remaining 30% classified as occurring in peripersonal space. The peripersonal— distant personal distinction could possibly explain the patterns of dissociations noted between buccofacial and limb movements. For example, there was a disproportionately large number of spatial errors for the limb movements. This might suggest that the distant peripersonal representation was severely affected, but the peripersonal representation was not. In addition, previous research has outlined the importance of the inferior parietal lobe (IPL) for both the comprehension and production of limb movements. In contrast, the results of the present study suggested that IPL is not a critical structure for either the comprehension or production of buccofacial movements. Instead, the present study suggests that structures anterior to the IPL are crucial areas for buccofacial performance. The localizations of the present study do not match the localizations that Rizzolatti proposed. However, localizations alternative to those proposed by Rizzolatti have been presented. Grusser (1983) suggested an anterior to posterior gradient for the localization of the representations of space. Specifically, he proposed the following neuronal networks for the perceptual and motor operations: oral grasping by the prefrontal neuronal networks, manual grasping by the "central" parietal mechanisms, the near distant action space by the posterior

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75 parietal regions, and the far-distant action space by occipital cortex. These data would approximate an anterior to posterior gradient. Implications for Future Research The results of this study clearly support a non-unitary construct for the relationship between buccofacial and limb apraxia. However, there are at least two alternative versions of the non-unitary construct. In the first alternative, there would be two totally separable praxis systems: one for planning and controlling buccofacial movements and another one for planning and controlling limb movements. This "totally separable" model would predict quantitative and qualitative differences to be noted in all factors between buccofacial and limb performance. In the second alternative model, the two praxis systems would be partially separable. This "partially separable" model would predict areas of concordance as well as areas of discordance between buccofacial and limb praxis. Given the results of this study, it is not possible to differentiate between these two alternatives of the non-unitary model. Although the results appeared to support the complete separation of buccofacial and limb praxis, which is consistent with the "totally separable" model, it is possible that additional factor (s) that were not tested would not support this model. Specifically, these additional factors may be associated for buccofacial and limb praxis and, therefore, would support the "partially separable" model. Additional research is needed to determine which non-unitary model best describes the relationship between buccofacial and limb apraxia. This additional research may take the form of recovery studies. In this

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76 type of study, the evolution of qualitative aspects of buccofacial and limb apraxia would be analyzed over a period of time post-onset. There are several possible patterns of results that might be observed. In the first alternative, all types of errors may evolve at dissimilar rates for buccofacial and limb apraxia. This pattern of results would suggest that buccofacial and limb praxis emanate from entirely separable mechanism (s) In the second alternative, some types of errors may evolve at similar rates for buccofacial and limb apraxia, whereas other types of errors may evolve at dissimilar rates. This pattern of results would suggest that, for the former type of errors, buccofacial and limb praxis share that mechanism, whereas for the latter type of errors, buccofacial and limb praxis emanate from different mechanism (s) In summary, detailed recovery studies may allow researchers to differentiate between the "totally separable" model and the "partially separable" model of buccofacial and limb praxis. Clinical Implications As discussed previously, buccofacial apraxia is frequently associated with left-hemisphere damage. And because this disorder is associated with left-hemisphere lesions, it frequently cxs-occurs with language and/or speech disorders. A speech-language pathologist may choose to use verbal prompting to facilitate the patient's compensation for articulatory deficits, such as, "close your lips," or "put your tongue up" (Square-Storer, 1989) The presence of a moderate or severe case of buccofacial apraxia would create a significant barrier to this type of treatment. Additionally, buccofacial apraxia may co-occur with a swallowing disorder. The assessment or treatment of a dysphagic

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77 patient may also involve verbal commands to, "cough now," or "move the bolus of food with your tongue." Again, the presence of a moderate or severe buccofacial apraxia would have a significant impact on the management of this type of patient. In order to treat a neuropsychological disorder, it is important to understand the neuropsychological mechanism (s) underlying the disorder. This study attempted to elucidate the underlying mechanism (s) of buccofacial and limb apraxia. The results suggested that buccofacial and limb apraxia are at least partially separable motor disorders. This would imply that a clinician should assess each disorder separately. Because a patient demonstrates a deficit in one disorder does not necessarily imply that the patient will demonstrate a deficit in the second disorder. In addition, the results of this study have implications for treatment decisions regarding buccofacial or limb apraxia. Because a non-unitary model was supported, treatment of one disorder may not generalize to the other disorder. Therefore, each disorder would need to be treated separately in order to assure improvement in each. In addition, because the underlying mechanisms are at least partially separable, a specific treatment task which is effective for one disorder may not be effective for the second disorder. Finally, the proportion of error types demonstrated may have clinical implications. Specifically, the proportion of spatial errors was significantly dissimilar between buccofacial and limb movements. The follow-up analysis revealed that the number of spatial errors for limb movements appeared disproportionately high. This would suggest

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78 that, if a clinician was choosing to treat limb praxis, the list of initial gestures targeted should be very distinct from each other spatially. Similarly, the proportion of content errors was significantly dissimilar between buccofacial and limb movements. The follow-up analysis revealed that the number of content errors for buccofacial movements appeared disproportionately high. This would suggest that, if a clinician was choosing to treat buccofacial praxis, the list of initial gestures targeted should be very distinct from each other semantically. In summary, the results of this study suggest that buccofacial and limb apraxia are at least partially separable, which would imply that a clinician should assess and treat each disorder separately.

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APPENDIX A ERROR TYPE CATEGORIES AND DEFINITIONS FOR LIMB MOVEMENTS CONTENT P Perseverat ive the subject produces a response that includes all or part of a previously produced pantomime. R Related = the pantomime is an accurately produced pantomime associated in content to the target. For example, the subject might pantomime playing a trombone for a target of a bugle. N Non-Related = the pantomime is an accurately produced pantomime not associated in content to the target. For example, the subject might pantomime playing a trombone for a target of shaving. TEMPORAL S Sequencing = some pantomimes require multiple positionings that are performed in a characteristic sequence. Sequencing errors involve any perturbation of this sequence including addition, deletion, or transposition of movement elements as long as the overall movement structure remains recognizable. T Timing = this error reflects any alterations from the typical timing or speed of a pantomime and may include abnormally increased, decreased, or irregular rate of production. Occurrence = pantomimes may involve either single (i.e. unlocking a door with a key) or repetitive (i.e. screwing in a screw with a screwdriver) movement cycles. This error type reflects any multiplication of single cycles or reduction of a repetitive cycle to a single event. D Delay = delay in the initiation of a movement. 79

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80 APPENDIX A (CONTINUED) SPATIAL A Amplitude = any amplification, reduction, or irregularity of the characteristic amplitude of a target pantomime. IC Internal Configuration = when pantomiming, the fingers and hand must be in a specific spatial relation to one another to reflect recognition and respect for the imagined tool. This error type reflects any abnormality of the required finger/hand posture and its relationship to the target tool. For example, when asked to pretend to brush teeth, the subject's hand may close tightly into a fist with no space allowed for the imagined toothbrush handle. BPO ECO OTHER Body-Part-as-Object = the subject uses his/her finger, hand, or arm as the imagined tool of the pantomime. For example, when asked to smoke a cigarette, the subject might puff on his index finger External Configuration Orientation = when pantomiming, the fingers/hand/arm and the imagined tool must be in a specific relationship to the "object" receiving the action. Errors of this type involve difficulties orienting to the "object" or in placing the "object" in space. For example, the subject might pantomime brushing teeth by holding his hand next to his mouth without reflecting the distance necessary to accommodate an imagined toothbrush. Another example would be when asked to hammer a nail, the subject might hammer in differing locations in space reflecting difficulty placing the imagined nail in a stable orientation. Movement = when acting on an object with a tool, a movement characteristic of the action and necessary to accomplishing the goal is required. Any disturbance of the characteristic movement reflects a movement error. For example, a subject, when asked to pantomime using a screwdriver, may orient the imagined screwdriver correctly to the imagined screw but instead of stabilizing the shoulder and wrist and twisting at the elbow, the subject stabilizes the elbow and twists at the wrist or shoulder. NR No Response. UR Unrecognizable Response = a response that is not recognizable and shares no temporal or spatial features of the target. Note. Adapted from Rothi, Mack, Verfaellie, Brown and Heilman (1988)

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APPENDIX B LIST OF BUCCOFACIAL AND LIMB STIMULUS ITEMS Buccofacial Intransitive 1. whistle 2 cough 3. puff out your cheeks 4. click your tongue 5. make a 'be quiet' sound 6. lick your lips 7. open your mouth 8. smack your lips 9. clear your throat 10. hold your breath Limb Intransitive 1.

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APPENDIX C ERROR TYPE CATEGORIES AND DEFINITIONS FOR BUCCOFACIAL AND LIMB MOVEMENTS CONTENT P Perseverative = the subject produces a response that includes all or part of a previously produced movement. R Related = the movement is an accurately produced movement associated in content to the target. N Non-Related the movement is an accurately produced movement which is not associated in content to the target. TEMPORAL S Sequencing = some movements require multiple positionings which are performed in a characteristic sequence. Sequencing errors involve any perturbation of this sequence including addition, deletion, or transposition of movement elements as long as the overall movement structure remains recognizable. T Timing = this error reflects any alterations from the typical timing or speed of a movement and may include abnormally increased, decreased, or irregular rate of production. Occurrence = movements may involve either single or repetitive movement cycles. This error type reflects any multiplication of single cycles or reduction of a repetitive cycle to a single event D Delay = delay in the initiation of a movement with no intervening facilitative movement. SPATIAL IC Internal Configuration (limb only) = when performing a movement, the fingers and hand must be in a specific spatial relation to one another to reflect recognition and respect for the imagined tool. This error type reflects any abnormality of the required finger/hand posture and its relationship to the target tool. 82

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83 APPENDIX C (CONTINUED) SPATIAL (continued) A Amplitude = any amplification, reduction, or irregularity of the characteristic amplitude of a target movement. ECO External Configuration/Orientation (limb only) = when performing a movement, the fingers/hand/arm and the imagined tool must be in a specific relationship to the "object" receiving the action. Errors of this type involve difficulties orienting to the "object" or in placing the "object" in space. BPO Body-Par t-as-Object (limb only) = the subject used the finger/hand/arm as the imagined tool of the movement. M Movement = when acting on an object with a tool, a movement characteristic of the action and necessary to accomplishing the goal is required. Any disturbance of the characteristic movement reflects a movement error. E Extraneous = recognizable production of a movement with additional or extra movement(s) involved of non-target articulators or body parts. P Place of Articulation (buccofacial only) = an inappropriate point or place of articulation was employed in production of the movement OTHER NR No Response = subject may conclude his response with a verbalization such as, "I can't" or "No." UR Unrecognizable Response = a response which is not recognizable and shares no temporal or spatial features of the target. V Verbalization = the subject produces a verbalization or written output instead of a movement. It should be recognizable and semantically related.

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APPENDIX D INTERRATER RELIABILITY MEASURES FOR THE ACCURACY JUDGEMENT FOR EACH BUCCOFACIAL AND LIMB MOVEMENT AS EXPRESSED BY A KAPPA STATISTIC Movement Kappa Movement Kappa Limb Intransitive 1. crossing fingers 2. victory sign 3. hitchhiking 4. waving good bye 5. signaling 'OK' 6. pinching nose 7. scratching head 8. saluting 9. snapping fingers 10. making a fist Buccofacial Intransitive 1

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APPENDIX E INTERRATER RELIABILITY MEASURES FOR THE MAIN TYPE OF ERROR JUDGEMENT FOR EACH MOVEMENT AS EXPRESSED BY PERCENTAGE AGREEMENT (P. A.) Movement P. A. Movement P. A. Limb Intransitive 1. crossing fingers 2. victory sign 3. hitchhiking 4. waving good bye 5. signaling 'OK' 6. pinching nose 7. scratching head 8. saluting 9. snapping fingers 10. making a fist Buccofacial Intransitive 100

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APPENDIX F BLANK CHECKLIST OF SPECIFIC NEUROANATOMIC STURCTURES Neuroanatomic Structures Subject Numbers 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Parietal 1. inferior parietal a) angular gyrus b) supramarginal gyrus 2. superior parietal Central (Sensorimotor Cortex) 1. Peri-Sylvian 2. Supra-Sylvian 3. Mesial 4. Insula Frontal 1. inferior gyrus (Broca s ) a) anterior b) posterior 2. middle 3. superior 4. mesial (SMA and Cingulate) Temporal 1. superior a) anterior b) posterior 2. middle a) anterior b) posterior 3. inferior a) anterior b) posterior 4. mesial a) anterior b) posterior 86

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APPENDIX F (CONTINUED) Neuroanatomic Structures Subject Numbers 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Occipital 1. inferior 2. superior 3. mesial Deep Gray Matter Structures 1. thalamus a) medial b) lateral 2. striatum Subcortical White Matter 1. internal capsule a) anterior b) posterior 2. corona radiata 3. arcuate fasiculus 4. temporal isthmus 5. anterior periventricular 6. posterior periventricular 7. corpus callosum a) genu b) body c) splenium Enlarged Ventricles Cortical Atrophy No Readable Lesion Note SMA = supplementary motor area.

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APPENDIX G COMPLETED CHECKLIST OF INVOLVEMENT OF SPECIFIC NEUROANATOMY STURCTURES FOR EACH EXPERIMENTAL SUBJECT Neuroanatomic Structures Subject Numbers 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Parietal 1. inferior parietal a) angular gyrus + + + b) supramarginal gyrus + + + 2. superior parietal + Central (Sensorimotor Cortex) 1. Peri-Sylvian + + + + + + + 2. Supra-Sylvian + + + 3. Mesial 4. Insula ++++ ++++ + Frontal 1. inferior gyrus(Broca' s) a) anterior + b) posterior + + + + + + + 2. middle + 3. superior 4. mesial (SMA and Cingulate) Temporal 1. superior a) anterior -+++++ + + b) posterior + + + 2. middle a) anterior b) posterior + 3. inferior a) anterior b) posterior 4. mesial a) anterior + b) posterior 88

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89 APPENDIX G (CONTINUED) Neuroanatomic Structures Subject Numbers 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Occipital 1. inferior 2. superior 3. mesial Deep Gray Matter Structures 1. thalamus a) medial b) lateral 2. striatum + + + + Subcortical White Matter 1. internal capsule a) anterior + + + + b) posterior + + 2. corona radiata + + + + + + 3. arcuate fasiculus + + + 4. temporal isthmus 5. anterior periventricular + + + + 6. posterior periventricular + + 7. corpus callosum a) genu b) body c) splenium Enlarged Ventricles Cortical Atrophy No Readable Lesion Note SMA = supplementary motor area. + = more than 50% involvement of the structure; = less than 50% involvement of the structure; + = periventricular lucency also noted in the right hemisphere.

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BIBLIOGRAPHY Basso, A., Capitani, E. Delia Sala, S., Laiacona, M. & Spinnler, H. (1987) Recovery from ideomotor apraxia: A study on acute stroke patients. Brain 110 747-760. Benson, F. Sheremata, W. Bouchard, R. Segarra, J., Price, D. & Geschwind, N. (1973) Conduction aphasia: A clinicopathological study. Archives of Neurology 28, 339-346. Borod, J.C., Iorch, M.P., Koff, E. & Nicholas, M. (1987). Effect of emotional context on buccofacial apraxia. Journal of Clinical and Experimental Neuropsychology 9, 155-161. Buschke, H. & Fuld, P. A. (1974) Evaluating storage, retention, and retrieval in disordered memory and learning. Neurology 24, 1019-1025. Critchley, M. (1953) The parietal lobes New York: Hafner Publishing Company. DeRenzi, E. Pieczuro, A. & Vignolo, L.A. (1966) Oral apraxia and aphasia. Cortex 2, 50-73. DeRenzi, E. Pieczuro, A. & Vignolo, L.A. (1968). Ideational apraxia: A Quantitative study. Neuropsychologia 6, 41-52. Duffy, R.J. & Liles, B.Z. (1979). A translation of Finkelnburg s (1870) lecture on aphasia as "asymbolia" with commentary. Journal of Speech and Hearing Disorders 44, 156-168. Geschwind, N. (1965) Disconexion syndromes in animals and man. Brain 88, 237-294, 585-644. Geschwind, N. (1975) The apraxias: Neural mechanisms of disorder of learned movement. American Scientist 63, 188-195. Goldstein, K. (1942) Aftereffects of brain injuries in war. New York: Grune and Stratton. Goodglass, H. & Kaplan, E. (1963) Disturbance of gesture and pantomime in aphasia. Brain 86, 703-720. 90

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91 Grusser, O.-J. (1983) Multimodal structure of the extrapersonal space. In A. Hein & M. Jeannerod (Eds.), Spatially oriented behavior (pp. 327-352) New York: Springer-Verlag. Haaland, K.Y. & Flaherty, D. (1984) The different types of limb apraxia errors made by patients with left vs. right hemisphere damage. Brain & Cognition 3, 370-384. Haaland, K.Y., Rubens, A. & Harrington, D.L. (1989). Anatomical correlates of limb and buccofacial apraxia. Journal of Clinical and Experimental Neuropsychology f 11, 42. Heilman, K.M. (1979). Apraxia. In K.M. Heilman & E. Valenstein (Eds.), Clinical neuropsychology (pp. 159-185) New York: Oxford University Press. Heilman, K.M. & Rothi, L.J.G. (1985). Apraxia. In K.M. Heilman & E. Valenstein (Eds.), Clinical neuropsychology (2nd ed. pp. 131-150) New York: Oxford University Press. Heilman, K.M. Rothi, L.J.G. & Kertesz, A. (1983). Localization of apraxia-producing lesions. In A. Kertesz (Ed.), Localization in neuropsychology (pp. 371-392) New York: Academic Press. Heilman, K.M. Rothi, L.J.G. & Valenstein, E. (1982). Two forms of ideomotor apraxia. Neurology (m) 32, 342-346. Hogg, S.C. Square-Storer, P. A. & Roy, E.A. (1988, December). Co-occurrence of limb, orofacial and verbal apraxia in left hemisphe re damaged subjects Paper presented at Neuropsychology Rounds, St. Joseph Health Centre, London, Ontario. Jackson, H. (1932) Remarks on non-protrusion of the tongue in some cases of aphasia. In J. Taylor (Ed.), Selected writings (Vol. II). London: Hodder & Stoughton. (Original work published 1878) Kertesz, A. (1979) Apraxia, aphasia and associated disorders New York: Grune & Stratton. Kertesz, A. (1982). The Western Aphasia Battery London, Ontario: University of Western Ontario. Kertesz, A. (1985) Apraxia and aphasia: Anatomical and clinical relationship. In E.A. Roy (Ed.), Neuropsychological studies of apraxia and related disorders (pp. 163-178) Amsterdam: Elsevier Science Publishers. Kertesz, A. & Ferro, J.M. (1984). Lesion size and location in ideomotor apraxia. Brain 107 921-933. Kimura, D. (1977) Acquisition of a motor skill after left-hemisphere damage. Brain 100 527-542.

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92 KLima, E. & Bellugi, U. (1979) The signs of language. Cambridge, MA: Harvard University Press. Kramer, J.H. Delis, D.C. & Nakada, T. (1985) Buccofacial apraxia without aphasia due to a right parietal lesion. Annals of Neurology 18, 512-514. Kramer, M.S. & Feintein, A.R. (1981). Clinical biostatistics: LIV. The biostatistics of concordance. Clinical Pharmacology and Therapeutics 29, 111-123. Landis, R.J. & Koch, G.G. (1977) The measurement of observer agreement for categorical data. Biometrics 33, 159-174. Lehmkuhl, G. Poeck, K. & WilLmes, K. (1983). Ideomotor apraxia and aphasia: An examination of types and manifestations of apraxic symptoms. Neuropsychologia 21, 199-212. Liepmann, H. (1980a) Small helpful hints in the examination of the brain damaged. In D. Kimura (Trans.) Translations from Liepmann 's essays o n apraxia (Research Bulletin #506, pp. 4-16) London, Ontario: The University of Western Ontario. (Original work published 1905) Liepmann, H. (1980b) The left hemisphere and action. In D. Kimura (Trans.) Translations from Liepmann 's essays on apraxia (Research Bulletin #506, pp. 17-50) London, Ontario: The University of Western Ontario. (Orignal work published 1905) Marquardt, T.P. & Sussman, H. (1984). The elusive lesion: Apraxia of speech link in Broca's aphasia. In J.C. Rosenbek, M.R. McNeil & A.E. Aronson (Eds.), Apraxia of speech: Physiology, acoustics, linguistics, management (pp. 91-112) San Diego: College Hill Press. Matsui, T. & Hirano, A. (1978) An atlas of the human brain for computerized tomography. New York: Igaku-Shoin. Mintz, T., Raade, A.S. & Kertesz, A. (1989, May). Lesion size and localization in buccofacial apraxia: A retrospective analysis Presentation at the annual convention of the Canadian Association of Speech-language Pathologists and Audiologists (CASLPA) Toronto, Ontario. Mohr, J. P., Pessin, M.S., Finkelstein, S. Funkenstein, H.H. Duncan, G.W. & Davis, K.R. (1978). Broca aphasia: Pathological and clinical. Neurology 28, 311-324. Ochipa, C. & Rothi, L.J.G. (1989) Buccofacial apraxia recovery in a patient with atypical cerebral dominance. ASHA 31, 73.

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93 Poeck, K. (1985) Clues to the nature of disruptions to limb praxis. In E.A. Roy (Ed.), Neuropsychological studies of apraxia an d related disorders (pp. 99-109) Amsterdam: Elsevier Science Publishers. Poeck, K. & Kerschensteiner, M. (1975) Analysis of the sequential motor events in oral apraxia. In K. Zulch, 0. Kreutzfeld & G. Galbraith (Eds.), Otfried Foerster Symposium (pp. 98-111). Berlin: Springer. Rapcsak, S.Z., Rothi, L.J.G. & Heilman, K.M. (1987). Apraxia in a patient with atypical cerebral dominance. Brain and Cognition 6 450-463. Rizzolatti, G. & Camarda, R. (1987). Neural circuits for spatial attention and unilateral neglect. In M. Jeannerod (Ed.), Neurophvsiol ogical and neuropsychological aspects of spatial neglect (pp. 289-313) North-Holland: Elsevier Science Publishers. Rizzolatti, G. Matelli, M. & Pavesi, G. (1983). Deficits in attention and movement following the removal of postarcuate (area 6) and prearcuate (area 8) cortex in macaque monkeys. Brain 106 655-673. Rothi, L.J.G. & Heilman, K.M. (1984) Acquisition and retention of gestures by apraxic patients. Brain & Cognition 3, 426-437. Rothi, L.J.G., Heilman K.M. & Watson, R.T. (1985). Pantomime comprehension and ideomotor apraxia. Journal of Neurology. Neurosurgery, & Psychiatry 48, 207-210. Rothi, L.J.G., Mack, L. Verfaellie, M. Brown, P. & Heilman, K.M. (1988) Ideomotor apraxia: Error pattern analysis. Aphasiology, 2 381-388. Roy, E.A. & Square, P. A. (1985). Common considerations in the study of limb, verbal and oral apraxia. In E.A. Roy (Ed.), Neuropsychological studies of apraxia and related disorders (pp. 111-162) Amsterdam: Elsevier Science Publishers. Schnitzlein, H.N. & Murtagh, F.R. (1985) Imaging anatomy of the head and spine Baltimore, MD: Urban and Scharzenberg. Shrout, P.E. & Fleiss, J.L. (1979). Intraclass correlations: Uses in assessing rater reliability. Psychological Bulletin 86, 420-428. Square-Storer, P. (1989). Traditional therapies for apraxia of speech reviewed and rationalized. In P. Square-Storer (Ed.) Acquired apraxia of speech in aphas ic adults (pp. 145-161) London: Taylor & Francis. Square-Storer, P. & Roy, E.A. (1989) The apraxias: Commonalities and distinctions. In P. Square-Storer (Ed.) Acquired apraxia of speech in aphasic adults (pp. 20-63) London: Taylor & Francis.

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94 Steinthal, P. (1871) Abriss der sprachwissenschaft Berlin. Stokoe, ™„C. (i960). Sign language structure: An outline of the visual ccsnraunication of the American deaf. Studies in linguistics Occasional Papers, No. 8. Tognola, G. & Vignolo, L.A. (1980). Brain lesions associated with oral apraxia in stroke patients: A clinico-neuroradiological investigation with the CT scan. Neuropsychologia 18, 257-272. Watson, R.T., Fleet, W.S., Rothi, L.J.G. & Heilman, K.M. (1986). Apraxia and the supplementary motor area. Archives of Neurology, 43, 787792.

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BIOGRAPHICAL SKETCH Adele S. Raade was born on May 14, 1956, in Calumet, Michigan. She attended Western Michigan University where, in 1978, she received a Bachelor of Science degree in speech pathology. She received the Master of Arts degree in speech-language pathology in 1982. In 1983, she received the Certificate in Clinical Competence in Speech-Language Pathology following her clinical fellowship year at Schwab Rehabilitation Center in Chicago, Illinois. During her doctoral program in speech-language pathology at the University of Florida, her major area of study was neurogenic communication disorders with a minor in neuropsychology. She has had a faculty position at the University of Western Ontario in London, Canada, for the past three years, where she has taught courses in aphasia, dysarthria, apraxia, and normal language development. 95

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I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. Leslie J. Gonzalei-Rotjii Chairman Associate Professor of Communication Processes and Disorders I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. /"*"} Thomas B. Abbott Professor of Communication Processes and Disorders I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. Michael A. Crary Associate Prof esso^'of Communication Processes and Disorders I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of 1 u_. X/ / Doctor of Philosophy. 7/ £> *y 'QjCcL &(&*-Kenneth "m. Heilman Professor of Neurology I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. [Russell M. Bauer/ Associate Professor of Clinical and Health Psychology

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This dissertation was submitted to the Graduate Faculty of the Department of Communication Processes and Disorders in the College of Liberal Arts and Sciences and to the Graduate School and was accepted as partial fulfillment of the requirements for the degree of Doctor of Philosophy. May 1990 Dean, Graduate School

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UNIVERSITY OF FLORIDA 3 1262 08285 225 1