Consistency of concussed athletes on a battery of motor performance and computerized neuropsychological tests

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Consistency of concussed athletes on a battery of motor performance and computerized neuropsychological tests
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Gearhart, Traci Napolitano
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Exercise and Sport Sciences thesis, Ph.D   ( lcsh )
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Thesis:
Thesis (Ph.D.)--University of Florida, 2002.
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Includes bibliographical references (leaves 72-78).
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by Traci Napolitano Gearhart.
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Printout.
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Vita.

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CONSISTENCY OF CONCUSSED ATHLETES ON A BATTERY
OF MOTOR PERFORMANCE AND
COMPUTERIZED NEUROPSYCHOLOGICAL TESTS
















By

TRACI NAPOLITANO GEARHART











A DISSERTATION 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

2002

























Copyright 2002

by

Traci Napolitano Gearhart















ACKNOWLEDGMENTS

I would like to take this opportunity to thank all those individuals who assisted me

in achieving my goal of obtaining a doctoral degree in athletic training/sports medicine.

First I would like to thank Dr. MaryBeth Horodyski for being a great leader,

advisor, mentor, and friend. She was instrumental in this process; not only has she spent

many hours reviewing this outrageous number of drafts and assisting with the many

dilemmas associated with this project, she has been a great friend. If it was not for her

accepting me into the graduate program many years ago I may not be at this point in my

life and career. Words cannot express how much her support and encouragement has

meant to me.

I would also like to that the members of my doctoral committee: Dr. Michael

Powers for all his help through the past three years, statistical knowledge, preparation and

review of this project, and Dr. Denis Brunt and Dr. Thomas Kaminski for their assistance

in the preparation and review of my dissertation.

I would like to thank all of the graduate students who assisted with subject

enrollment and data collection. Without their help, this project may not have been

completed.

I thank my parents and sister who are always there no matter where life takes me.

Without their love, guidance, trust, and support over the years, I would not have made it

this far. I thank them for all they have done and will continue to do in the future.









Last but by no means least, I thank my loving husband, Bob. He deserves this

degree as much as I do. I thank him for all of his love, support, help, and encouragement

through the stressed times when I was ready to give in. I thank him for helping me to

focus on the light at the end of the tunnel and not the stress that I would eventually

overcome. I don't know how I would have made it without him.















TABLE OF CONTENTS


ACKN OW LEDGM EN TS ....................................................... .................................... iii

LIST OF TABLES...................................................... ............................................... viii

LIST OF FIGURES ............................. ........................................................................ ix

ABSTRACT ................ ............................................. .............................. x

1 IN TRODUCTION ........................................................................................................ 1

State ent of the Problem .........................................................................................2......
Research Hypotheses ................................................................... ..............................4...
Definition of Terms ......................................................................................................4...
Assumptions ..................... ........................................................................6......
Lim itations....................................................................................................................... 6
Significance ..................................................................... .......................................6...

2 REVIEW OF LITERATURE ........................................................... ............................ 8

Introduction................................................................................................................... 8
Anatom y of the Head........................................................... 8
Scalp.................................. .................................................................................. 9
Skull .......................................................................................................................... 9
M eninges................................................................................................................ 9
Brain.................................................................................... .............................. 10
M echanism of Injury and Pathology............................................. ............................ 11
Definition of Concussion.................................................................. .......................... 13
Signs and Sym ptoms................................ ....................................... .......................15
Concussion Grading Scales .................... ............................................................... 16
Return to Play Guidelines............................................................ ............................. 20
Assessm ent Tools ........................... ......................................................................... 22
Neuropsychological Testing ....................................................................................... 25
Tests of Inform ation Processing ........................................... ............................. 28
Tests of V isual Scanning .................... ......................................................... 29
Tests of M otor Proficiency ..................................................... ........................... 30
Tests of Reaction Tim e.................................................................................... 31
Computerized Testing.................... ........................................................... 32
Postural Stability ...................................................... ................................................ 34
Conclusions............................. ................................................................................. 37

v









3 M ATERIALS AND M ETHODS ..................................................................................38

Introduction ...................................................................................................................38
Subjects.......................................................................................................................... 38
Instruments ....................................................................................................................39
Automated Neuropsychological Assessment M etrics ......................................... 39
M odified Rhomberg.............................................................. ............................. 40
Standardized Assessment of Concussion.............................................................. 41
Trail M making A and B..... ........................................... .. .............................. 42
Procedures................................ ................................................................................ 43
Design........................................................................................................................... 44
Analysis .........................................................................................................................44

4 RESULTS......................................................................................................................46

Subject Participation.................... ............................. ............................... 46
ANAM ................................................................................ ..................................... 48
Simple Reaction Time (SRT).................................................. ........................... 48
M watching to Sample (M SP) ............................................................................... 48
Running M emory (CPT) ........................................ ...... .............................. 49
Stanford Sleepiness Scale .................................................................................... 50
M odified Rhomberg........................................................ ......................................... 51
SAC...................................... .................................................................................... 51
Trail M making A ....................................................... ................................................. 52
Trail M making B ......................................................................... ................................ 52
Pearson Product M oment Correlation ................................ ..... ............................. 53

5 DISCUSSION, CONCLUSIONS, AND FUTURE IMPLICATIONS ......................54

Discussion.............................. .................................................................................. 54
ANAM ........................................................... ................................................... 56
Modified Rhomberg with BESS................................... 60
SAC............................... .................................................................................... 61
Trail M making A and B ..................... ........................................................... 62
Conclusions.................................. ......................................... 63
Future Implications................................. ................................................................. 64

APPENDICES

A American Academy of Neurology Concussion Grading Scale ..................... 65

B Balance Error Scoring System .................................................... ............................. 67

C Informed Consent Form ........... ...... .. .......................................................... 69

LIST OF REFERENCES.....................-................. ....... ............72



vi









BIOG RAPHICAL SKETCH .............................................................................................79















LIST OF TABLES

Table page
2-1 Concussion grading scales................... .................................................................17

2-2 Commonly used concussion grading scales .................................. ............................ 19

2-3 Return to play guidelines (RTP) after one concussion.................................................. 21

2-4 Internally and externally-paced neuropsychological tests ........................................... 28

2-5 Foot positioning........................................................ ................................................. 36

2-6 Balance Error Scoring System (BESS) ............................................ .......................... 36

4-1 Demographic information .................................................... ................................ 47

4-2 Year in school and educational history........................................... ............................ 47

4-3 Stance leg and hand dominance ................................................................................... 47

4-4 Race ............................... ............................................................ ......................47

4-5 Concussion demographics................. ............................................................ 48

4-6 CPT accuracy (%) means (SD).................................................................................... 49

4-7 CPT mean reaction time (msec) means (SD) ..................................... ........................ 50

4-8 CPT throughput means (SD)........................................................... .......................... 50

4-9 Stanford mean response time (msec) means (SD)........................................................... 51

4-10 Tandem eyes-closed means (SD) ..................................................... ........................ 51

4-11 Trail Making A time to completion means (SD)............................ ......................... 52

4-12 Trail Making B time to completion means (SD) ............................. ......................... 53

4-13 Trail Making B error means (SD) ................................................. .............................53





viii















LIST OF FIGURES

Figure Rae
2-1 Neuropsychological testing tree ..................................................... ........................... 28

5-1 CPT accuracy by days ................................................................................................... 58

5-2 CPT mean reaction time ................... ............................................................ 58

5-3 CPT throughput........................................................ .............................. ................... 59

5-4 Stanford Sleepiness Scale mean reaction time ................................ ........................... 60

5-5 Tandem-stance eyes closed ........................................................................................... 60














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

CONSISTENCY OF CONCUSSED ATHLETES ON A BATTERY OF MOTOR
PERFORMANCE AND COMPUTERIZED NEUROPSYCHOLOGICAL TESTS


By

Traci Napolitano Gearhart

May 2002


Chairman: MaryBeth Horodyski, EdD, ATC/L
Major Department: Exercise and Sport Sciences

Neuropsychological testing has been used to examine the effects of concussion on

collegiate and professional athletes; however, little research has been conducted

examining adolescent athletes. The purpose of this study was to assess performance of

concussed adolescent athletes over multiday time periods as compared with control

subjects. Twenty-four adolescent athletes participated in this study. Subjects performed

four randomized tests: Automated Neuropsychological Assessment Metrics [ANAM:

four subtests-Simple Reaction Time (SRT), Matching to Sample (MSP), Continuous

Performance (CPT), and Stanford Sleepiness Scale (SSS)], Standardized Assessment of

Concussion (SAC), Trail Making A and B, and modified Rhomberg on a foam surface

[four variations: tandem stance-eyes open (TO), tandem stance-eyes closed (TC),

single-leg stance--eyes open (SO), and single-leg stance-eyes closed (SC)]. Subjects

were tested within 24 hours of the injury and twice a day for four days. Data were








analyzed using one-way ANOVAs (day x first session), 2x4 (day x session) repeated

measures ANOVAs, and a Pearson Product Moment Correlation. No significant

differences were revealed between groups. No significant differences were revealed for

the SRT (accuracy, mean reaction time, and throughput), MSP response time and

throughput, and SAC. On the MSP, a session main effect for accuracy was revealed [F

(1,22)=5.947, p=.023]. On the CPT, significant day main effects were demonstrated for

accuracy [F (4,88) =7.89, p=.001], mean reaction time [F (4,88)=28.66, p=.000], and

throughput [F (4,88)=36.81, p=.000] while a significant session main effect was

demonstrated for accuracy [F (1,22) =11.98, p=.002]. A significant day main effect [F

(4,88)=5.93, p=.000] for TC was revealed. Significant day [F (4,88)=34.14, p=.000] and

session [F (1,22)=10.30, p=.004] main effects for Trail Making A time to completion

were revealed. Significant day [F (4,88)=27.20, p=.000] and session [F (1,22)=11.04,

p=.003] main effects for time to completion were demonstrated for the Trail Making B.

These findings suggest that the test measures were unable to detect differences between

groups; however the injured groups' scores were initially lower and remained lower over

the course of the study. Further research needs to be conducted using computerized test

batteries and examining the effects of concussion on adolescent athletes.














CHAPTER 1
INTRODUCTION

Approximately 300,000 sports-related traumatic brain injuries occur annually in

the United States.' Concussions occur in all collision and contact sports, with football

and soccer having the highest rates however, athletes often do not report their

concussions until after practice or game, making mild concussions difficult to monitor.2

Mild grade concussions represent 85% to 90% of reported concussions.3'4 In 2000,

Guskiewicz et al.5 reported that grade I concussions were the most common type

(88.9%), followed by grade 2 (10.6%), and grade 3 (0.4%). These data demonstrate that

grade 1 and 2 concussions are prevalent in athletics despite rule and equipment changes.

Not only are concussions common in athletics, but high school and collegiate football

players who sustain a concussion are nearly three times more likely to sustain a second

concussion in the same season than those players who have not sustained a previous

injury.5

In the past decade, research focusing on the effects of a concussion on the

cognitive and motor performance of athletes has increased.'13 Most of the research has

been completed using collegiate athletes and traditional neuropsychological tests.

However, with the advances in technology, the desire to use computerized

neuropsychological testing to test these athletes has increased.

Some of the benefits of computerized testing are ease and standardization of

administration, availability of multiple forms, brief administration time, and measurement






2


accuracy. With computerized testing many athletes can be tested in a shorter period of

time without compromising the accuracy of testing. Koffler14 stated that for response

variables such as speed, consistency, and efficiency, computerized testing offers accuracy

of measurement greater than that of an examiner. Daniel et al.1 also suggested that

sensitivity to long-term effects of concussion greatly increases when using computerized

neuropsychologic tests.

Since most of the research conducted has examined the effects of concussion on

the neuropsychological function and postural stability of collegiate athletes with the use

of traditional neuropsychological testing, research needs to be completed on high school

athletes and with computerized neuropsychological testing.

Statement of the Problem

Currently, all return to play guidelines call for at least 15 to 20 minute monitoring

periods on the sideline, followed by a week of rest and monitoring of symptoms for those

athletes who fail to clear quickly. These guidelines are based on reviews of literature and

deliberations of panels of experts, rather than empirical data. Until guidelines are

proposed based on empirical data, clinicians are likely not to adhere to any one

protocol.6 Guskiewicz et al.5 reported that clinicians do not follow the recommended

guidelines for return to play with players averaging only 4.2 days of rest before returning

to participation. Similarly, Powell and Barber-Foss17 reported that the median time loss

from participation is three days. These data support the idea that clinical practice

contradicts the recommendation of a one-week period of rest after a grade 1 or 2

concussion. If injured athletes are allowed to return to activity prior to full recovery, the

sports medicine professional could be placing these athletes in a position for further

injury. Gagnon et al.'8 stated that children return to sports and play requiring fast actions









and rapid adaptations despite the presence of speed performance deficits. Allowing

adolescent athletes to return to activities with these deficits could be harmful to their

health. As children and adolescents return to their regular activities, sports medicine

professionals must ensure no deficits exist that will affect their return to activity and risk

re-injury.8

Past studies have examined the effects of concussions on neuropsychological

function in collegiate athletes.7'"13"9 These studies have examined the effects at 24, 48,

72 hours, five days, and seven days post injury with each testing session taking

approximately an hour to complete. Few studies have examined the effects of concussion

in high school athletes at these time frames.15 Even fewer studies have examined the

cognitive effects of a concussion on repeated testing within a day and across days. Sports

medicine professionals in the high school setting do not have an hour to test each athlete

and do not have the equipment used at the collegiate setting for this testing. The problem

is to find an accurate and reliable test protocol that is conducive to the high school

setting. Follow-up evaluations, both immediately after the injury and throughout the

post-concussive period, yield important clues as to the stability and severity of the

insult.20

The purposes of this study are to determine if concussed adolescent athletes have

initial levels of performance comparable with those of control adolescent subjects on a

battery of motor performance and computerized neuropsychological tests and to

determine if the concussed adolescent athletes demonstrate inconsistent performance over

multiday time periods as compared with control subjects on the same tests.








Research Hypotheses

Based on the review of literature the following research hypotheses were

developed.

1. High school athletes with a sports-related concussion will take
significantly longer to complete the Trail Making A and B tests as
compared to uninjured athletes.

2. High school athletes with a sports-related concussion will have
significantly higher error scores on all versions of the modified
Rhomberg test using the Balance Error Scoring System (BESS).

3. Injured high school athletes will have significantly lower initial scores
on the subtests of the Automated Neuropsychological Assessment
Metrics (ANAM) test battery than their matched counterparts.

4. High school athletes who sustain a sports-related concussion and
exhibit significantly poorer test results will take longer to return to
play.

Definition of Terms

The following are definitions of terms used throughout this study.

Cerebral concussion was defined as a clinical syndrome characterized by

immediate and transient posttraumatic impairment of neural functions, such as alteration

of consciousness, disturbance of vision, equilibrium, etc., due to brain stem

involvement.21

Cognitive function was defined as the ability of the brain to successfully process

and integrate various information presented.12

Internally paced (self-paced) was defined as subjects are allowed to determine the

speed of responding.22

Externally paced was defined as subjects are required to sustain their attention and

level of performance in response to a continuous rate of stimulus presented.22








Mild Traumatic Brain Injury (MTBI) was defined by the following criteria: 1)

head trauma due to contact forces or acceleration/deceleration, 2) a brief duration of

unconsciousness, usually seconds to minutes, and in some cases no loss of consciousness

(LOC) occurs but simply a brief period of dazed consciousness, and 3) the Glasgow

Coma Scale (GCS) must be 13 to 15 at the scene or during the emergency room

evaluation.23.24

Postural stability was defined as the maintenance of the body over the center of

gravity; requires the integration of information from the somatosensory, visual, and

vestibular sensory systems.2

Skill leg was defined as the preferred leg used to kick a ball.

Stance leg was defined as the preferred leg used to bear weight.

Standardized Assessment of Concussion (SAC) is a test designed for use by a

non-neuropsychologist with no previous expertise in psychometric testing and to assist

athletic trainers and other medical professionals with the assessment of concussion

immediately on the sideline.26

Trail Making Test is a neuropsychological test with two sections (A and B),

which provides information regarding attention, visual scanning, speed of eye-hand

coordination, and information processing.27

Trail Making Test A is the first version of the Trail Making Test which

consists of 25 numbered circles, where the subject is required to connect each

circle in order from one to twenty-five as quickly as possibly.27

Trail Making Test B is the second version of the Trail Making Test and

consists of the numbers one through thirteen and letters A through L within








circles. The subject is required to connect each circle in sequence, alternating

between numbers and letters as quickly as possible.27

Assumptions

The following list of assumptions were made for this study:

1. All athletes and parents completed the medical questionnaire honestly
and completely.

2. All subjects completed the neuropsychological and postural stability test
battery to the best of his/her ability.

3. All subjects reported all concussions and symptoms to the certified
athletic trainer.

4. All certified athletic trainers assessed the concussions using the
American Academy of Neurology grading scale.

5. All certified athletic trainers used form A of the Standardized
Assessment of Concussion for the initial testing period.

Limitations

Due to the nature of the study the following limitations were identified.

1. Baseline neuropsychological and postural stability data were not
collected on all possible subjects.

2. The same two pieces of foam were used for all subjects. Varying
weights of the subjects may have had an effect on the ability of the
subjects to balance. The foam was rotated 90 to prevent wearing
unevenly over many trials.9'25

3. Environmental conditions could not always be controlled for,
depending on testing situation.

Significance

Research is lacking in the area of how a concussion affects the cognitive functions

of adolescent athletes. Many studies have examined these effects on the collegiate

athlete.7'8'13'19 With the use of the ANAM, this study will provide information on how an

adolescent athlete is cognitively affected by a concussion. The ANAM will allow the








principal investigator to obtain neuropsychological test results in approximately 20-30

minutes of testing. The length of the testing is significant because the athlete will be able

to complete the necessary testing in a shorter period of time and not become as mentally

fatigued as with longer testing sessions. This will assist in obtaining an accurate testing

result. This study will also provide data on how an adolescent athlete is affected by a

concussion during repeated testing sessions within the same day.

Currently, testing is completed over multiple days but only once a day. Bleiberg

et al.28 suggested that single point assessments, standardized neuropsychological tests or

ANAM, may not reveal potential dynamic abnormalities in the pattern of acquisition and

maintenance of performance across days. Therefore, repeated sessions within a day

should be conducted. Bleiberg et al.28 also reported that individuals with traumatic brain

injury exhibited a decrease in cognitive function on the sixth day of testing. If this result

is similar in the adolescent sports-related concussion group, then returning these athletes

to play 4-7 days after an injury could be detrimental. This study will help provide data

that in the future may be able to adjust some of the current return to play guidelines.
















CHAPTER 2
REVIEW OF LITERATURE

Introduction

Approximately 300,000 sports-related traumatic brain injuries occur annually in

the United States' despite the advances in protective equipment available to athletes

today. Concussions occur in all sports with collision and contact sports, such as football

and soccer, having the highest rates. Athletes often do not report their concussion until

after practice or a game, thus making mild concussions difficult to monitor.2 Because of

the occurrence of concussions and the need to better understand the effects a concussion

has on the cognitive function of an individual an increased research interest has occurred.

The assessment and treatment of a concussion can be difficult due to the wide variety of

concussion grading scales and return to play criteria.

In the past most head injury research has been conducted on individuals whose

injury was caused by other mediums than athletics. Researchers were examining the

cognitive effects of the brain injury using traditional neuropsychological tests. This

review of literature will cover the areas such as the definition of a concussion, concussion

grading scales, return to play criteria, neuropsychological testing, and postural stability.

Anatomy of the Head

In order to understand the occurrence and effects of head injuries, individuals

should have a basic understanding of the anatomy of the brain. Therefore, a brief









description of the head anatomy will be reviewed. The areas that will be discussed

include the scalp, skull, meninges, and the brain.

Scalp

The term scalp is an acronym for the names of the five layers covering the skull;

skin, connective tissue, aponeurosis, loose connective tissue, and pericranium.29 The first

three layers are connected and move as a unit. The skin is a thin layer, except in the

occipital region, and contains sweat glands, sebaceous glands, and hair follicles. It has an

abundant arterial supply and good venous and lymphatic drainage.29 The connective

tissue forms a thick, dense, richly vascularized subcutaneous layer and is well supplied

with cutaneous nerves.29 The aponeurosis, a strong tendinous sheet, covers the calavaria

between the occipitalis, superior auricular, and frontalis muscles.29 The loose connective

tissue is like a sponge and allows free movement of the first three layers.29 The last layer

is the pericranium, a dense layer of connective tissue forming the external periosteum of

the calavaria.29

Skull

The skull is the skeleton of the head and is composed of a series of bones forming

two parts, the neurocranium and facial skeleton.29 The neurocranium in adults consists of

a series of bones: 1) frontal bone, 2) paired parietal bones, 3) paired temporal bones, 4)

occipital bone, 5) sphenoid bone, and 6) ethmoid bone.29 The neurocranium or brainbox

provides a case for the brain and cranial meninges, proximal parts of the cranial nerves,

and blood vessels.29

Meninges

The meninges consist of three layers: the dura mater, arachnoid mater, and pia

mater. The cranial meninges are internal to the skull and serve to 1) protect the brain, 2)








form the supporting framework for arteries, veins, and venous sinuses, and 3) enclose a

fluid-filled cavity, the subarachnoid space, which is vital to the normal function of the

brain.29 The dura mater is an external thick, dense fibrous membrane adherent to the

internal surface of the skull and described as a two-layered membrane.29 The arachnoid,

the middle layer, contains fibroblasts, collagen fibers, and some elastic fibers.29

Cerebrospinal fluid is contained between the arachnoid and pia mater membrane and

completely surrounds and suspends the brain. Its main function is to act as a cushion,

helping to diminish the transmission of shocking forces.3" The pressure of the

cerebrospinal fluid (CSF) holds the arachnoid against the inner surface of the dura.29 The

pia mater, an even thinner membrane, is a highly vascularized network of fine blood

vessels and adheres to the surface of the brain following all its contours.29

Associated with the three cranial meninges are three meningeal spaces. These

spaces include the dura-skull interface (epidural space), the dura-arachnoid

junction/interface (subdural space) and the subarachnoid space. The dura-skull interface

exists between the cranial bones and external periosteal layer of the dura since the dura is

attached to the bones.29 This is only a potential space and becomes real when an injury

occurs to the area. The dura-arachnoid interface is also only a potential space that

develops in the dural border of the dura mater after an injury to the head.29 The

subarachnoid space exists between the arachnoid and pia mater. This space actually

contains the CSF, trabelcular cells, arteries, and veins.29

Brain

The brain is composed of three parts, the cerebrum, cerebellum, and brain stem,

and is contained within the cranial cavity.29 The cerebrum, the principal part of the brain,

includes the cerebral hemispheres and diencephalon but not the brainstem (medulla, pons,








and midbrain).29 The cerebrum controls motor functions, sensory information, and

cognition.31 The cerebrum has two hemispheres, with each hemisphere divided into four

lobes: frontal, parietal, temporal, and occipital. At the base of each hemisphere is a

number of nuclear masses known as the basal ganglia with the largest of these being the

corpus striatum. Movement disorders are common with obvious symptoms of basal

ganglia damage but various neuropsychological dysfunctions occur as well.32 The effects

of injury to the basal ganglia depend upon the site of injury. Memory and learning

disorders are prominent among basal ganglia diseases.32 Damage to the corpus striatum

can cause problems with cognitive flexibility.

The pons and cerebellum are structures of the hindbrain where together they

correlate postural and kinesthetic information, refining, and regulating motor impulses

relayed from the cerebrum at the top of the brain stem.32 The cerebellum provides the

functions necessary to maintain balance and coordination.3" Cerebellar damage is

commonly reflected in problems of fine motor control, coordination, and postural

regulation.32 Dizziness and jerky eye movements may also be associated with cerebellar

damage.

Mechanism of Injury and Pathology

The brain is still susceptible to injury even though the skull, meninges, and CSF

protect it. A concussion can be caused by any direct or indirect trauma to the head,

specifically, an accelerative or decelerative force. Compressive and rotational forces can

also cause head injuries. The site of the maximal brain injury is usually beneath the point

of cranial impact (coup injury).33 Decelerative forces are generated when an athlete's

head strikes the ground or some stationary object producing maximal brain injury

opposite the site of impact (contrecoup injury).33 Direct compressive forces, such as a









forceful blow to a resting head, are generally well tolerated unless they cause focal

pathology (fractures, hematomas).20 Rotational acceleration and/or deceleration create

tensile and shearing forces between the brain and its surrounding attachments, resulting

in more serious injury which often occurs in an area other than the site of impact.34

Cantu35 describes three distinct types of stress that can be generated by an

acceleration force to the head: 1) compressive, 2) tensile, and 3) shearing. A tensile force

sometimes refers to a negative pressure while a shearing force refers to a force applied

parallel to the surface. Compressive and tensile forces are generally well tolerated by the

brain whereas shearing forces are poorly tolerated. During a compressive force the CSF

surrounding the brain acts as a protective shock absorber and converts focally applied

external stress to compressive stress. This occurs because the fluid is able to follow the

contours of the sulci and gyri of the brain, therefore distributing the force in a uniform

fashion.35"36 The CSF does not totally prevent shearing forces from being transmitted to

the brain, especially in the instance of rotational forces.3'-6 The shearing forces are

maximal at sites where rotational gliding is hindered within the brain. Characteristically,

there are three such sites: 1) the dura mater-brain attachments, impeding brain motion, 2)

the rough irregular surface contact between the brain and skull that hinder smooth

movement, and 3) dissipation of CSF between the brain and skull.36 When the head is

accelerated before impact, the brain lags toward the trailing surface, thus squeezing away

the protective CSF and allowing excess CSF to accumulate in the opposite surface. This

allows the shearing forces to be maximal at the site where CSF is thinnest and thus has

the least cushioning effect, which is opposite the site of impact.1 When the head is

stationary before impact, neither brain lag nor disproportionate distribution of CSF








occurs. In this situation the shearing stresses are greatest at the site of cranial impact and

help to explain the mechanism of the coup injury.36

The primary neuropathology of a mild traumatic brain injury (MTBI) is diffuse

axonal injury (DAI).37 Shearing forces generated in the brain by sudden deceleration

usually cause DAI.23 Vascular injury can disrupt small veins, producing petechial

hemorrhages and local or focal edema.38 The magnitude of DAI changes is proportional

to the deceleration force.39 The inertial force transmitted by sudden deceleration causes

DAI; more force means more injury.23

At present no biologically objective measure quantifies the severity of the

neuropathology more accurately than the clinical measures of the Glasgow Coma Scale

(GCS), loss of consciousness (LOC), and posttraumatic amnesia (PTA).23 The type of

neurons injured by acceleration/deceleration forces largely depends on the amount of

force and the direction of movement of the head.40

Definition of Concussion

In the sports medicine setting, a number of concussion definitions and

management protocols exist, thus making comparisons between presented research

difficult. A generally accepted definition of concussion would have major implications

with respect to the treatment of injured athletes. A common definition would be

beneficial because definitions often determine management protocols.41 The medical

profession should strive to minimize the confusion by using terms that mean the same to

everyone.42 Because of the subjective nature of the signs and symptoms of a concussion,

the sports medicine professional relies on feedback from the athlete, making the

assessment of the injury an issue of trying to determine if the athlete is experiencing

specific signs and symptoms.








The term concussion describes a physical injury to the head which results in a

short-lived impairment of neurological function,43 and has been used interchangeably

with mild traumatic brain injury (MTBI)." The definition of MTBI in the medical

literature has been confusing and varies depending on the type of research completed.

MTBI patients are ill served if they are not diagnosed on the basis of clearly delineated

definitions."4 The term "mild head injury" should mean minor injury with no significant

consequences or long-term sequelae,24 but this is not always the case. The hallmark

features for diagnosing a MTBI are LOC and PTA.44

Even though researchers cannot decide on a common definition of concussion,

one of the most commonly used definitions is a clinical syndrome characterized by

immediate and transient posttraumatic impairment of neural function, such as an

alteration of consciousness and disturbance of vision or equilibrium due to brain-stem

involvement.21 Guskiewicz et al.5 used the following definition, an acceleration or

deceleration injury of the head characterized by immediate and transient posttraumatic

impairment of neural functions, such as alteration of consciousness, blurred vision,

dizziness, amnesia, or memory. The American Academy of Neurology (AAN)45 defined

concussion as a trauma-induced alteration in mental status that may or may not involve a

loss of consciousness. This definition recognizes the poorly appreciated fact that cerebral

concussions do, indeed, occur without the loss of consciousness, and establishes that

confusion and amnesia are major factors in decisions regarding whether to permit athletes

to return to contact sport participation.41

The following criteria often define MTBI: 1) head trauma due to contact forces or

acceleration/deceleration, 2) a brief duration of unconsciousness, usually seconds to








minutes, and in some cases no LOC occurs but simply a brief period of dazed

consciousness, and 3) the GCS must be 13 to 15 at the scene or during the emergency

room evaluation.2324 The typical patient with MTBI (brief LOC, GCS 15 in the

emergency room, and PTA of <1 hour) recovers in 6 to 12 weeks if no complicating

factors arise,4647 while the well-motivated, young patient with the mildest concussion -

so-called ding without loss of consciousness recover within 10 days of the injury.10

All of these definitions deal with impairment to the brain caused by some force or

trauma. The problem lies in the area of comparing research among studies when a

common definition is not used.

Signs and Symptoms

A closed head injury has the potential to cause brain injury but also the potential

to cause injury to the head (scalp, face, etc.), neck (whiplash soft tissue damage),

vestibular system, and psychological functions.23 A problem many clinicians face when

assessing a concussion is that the common signs of inflammation (redness, swelling,

warmth, pain, and loss of function) cannot be seen. Two of the most common, but not

always present, signs of a concussion include loss of consciousness and amnesia but a

number of other physical and cognitive symptoms have been attributed to neural injury.

Studies of outcome following MTBI in adults suggested that cognitive and

behavioral symptoms are common in the early days or weeks after injury." Many

patients who sustain MTBI complain of numerous physical symptoms including

headache, dizziness, fatigue, irritability, insomnia, nausea, neurasthenia, hyperesthesia,

and emotional labiality.220,2343'49'50 The jarring of the brain within the skull during the

acceleration, deceleration, or impact of the head causes a headache in nearly all








concussions;2 therefore, the clinician should never underestimate the presence of a

headache.

Other documented cognitive symptoms include impaired information-processing

speed, difficulty concentrating and performing mental tasks, impairment of memory, and

impaired attention.23'149"'1 Due to he neural injury, initial complaints of poor

concentration, forgetfulness, and sleep-wake disturbances may be present while dizziness

can be contributed to a peripheral vestibular injury.23 Anxiety, mood disorder,

depression, and irritability may be due to neural injury, pain, or psychological factors.23'43

Early deficits in arousal, excluding disrupted sleep-wake cycles, quickly clear, but

impairments in attention may last longer.23

Once the clinician has identified the signs and symptoms, the problem of which

grading scale and return to play guidelines to use arises. The definition of concussion

does not have as much gray area as the grading scales of concussion used by sports

medicine professionals.

Concussion Grading Scales

The disparity among concussion grading scales creates a major stumbling block

that athletic trainers and health care professionals must overcome.52 Discrepancies and

controversies in the literature exist because of the inconsistencies of reporting procedures

and grading scales used by the medical profession.

Concussion grading scales serve three purposes: 1) to provide a tool for triaging

the injury and eventually placing it into a management algorithm based on injury

severity, 2) to assist in predicting outcome, and 3) to prevent catastrophic outcomes of

acute structural brain injury, second impact syndrome, or cumulative brain injury caused

by repetitive trauma.2 The sports medicine professional has approximately 12 grading









scales to choose from. Table 2-1 represents the grading scales in the literature while

Table 2-2 represents four of the most commonly used grading scales.

Table 2-1. Concussion grading scales
Reference Grade of Signs and Symptoms
Concussion
AAN45 1 Transient confusion, no LOC, symptoms
resolve in < 15 minutes
2 Transient confusion, no LOC, symptoms last
> 15 minutes
3 Any LOC, either brief (seconds) or prolonged
(minutes)

Cantu" 1 No LOC, PTA lasts < 30 min

2 LOC < 1 min or PTA or symptoms last >30
min

3 LOC > 1 min or PTA > 24 hr and/or
symptoms > 7 days

Colorado Medical 1 Confusion, no LOC, no amnesia
Society'4
2 Confusion, no LOC, amnesia

3 LOC

Fick"3 1 Confusion without amnesia, no LOC,
symptoms resolve in < 20 minutes
2 Confusion with amnesia, no LOC
_3 LOC

Hugenholtz & Mild Transient or no LOC, PTA <1 hour
Richard55
Moderate Unconsciousness < 5 minutes, PTA 1-24
hours
Severe Unconsciousness > 5 minutes, PTA > 24
hours

Kelly56 1 Confusion, no LOC
2 No LOC, amnesia present
3 Any LOC









Table 2-1. Concussion grading scales
Reference Grade of Signs and Symptoms
Concussion
Jordan"7 1 Confusion, no LOC, no amnesia

2 Confusion, no LOC, amnesia lasts < 24 hours
3 LOC with an altered level lasting < 2-3 min,
PTA lasts > 24 hr
4 LOC with an altered level lasting > 2-3 min

Maroon'5 1 No LOC
2 LOC < 5 minutes
3 LOC > 5 minutes

Nelson"9 Ding Delayed symptoms, headache, concentration
problems
1 No LOC or PTA, "bell-ring" clears < 1
minute
2 Symptoms < 1 minute, no LOC, tinnitus,
PTA, other adverse effects
3 LOC < 1 minute, grade 2 symptoms later
4 LOC > 1 minute, not comatose, grade 2
symptoms later

Ommaya & 1 Confusion, no LOC, no amnesia
Gennarelli"
2 Confusion, no LOC, PTA
3 Confusion, no LOC, PTA and retrograde
amnesia
4 Confusion, coma (paralytic), amnesia
5 Coma, persistent vegetative state
6 Death

Roberts" Bell ringer No LOC or PTA, symptoms < 10 minutes
1 No LOC, PTA, symptoms > 10 minutes but <
30 minutes
2 LOC < 5 minutes or PTA > 30 minutes
3 LOC > 5 minutes or PTA > 24 hours

Wilberger & I Minimal or no LOC, PTA 15-20 minutes
Maroon62
2 LOC < 5 minutes, PTA > 20 minutes
3 LOC > 5 minutes, PTA > 12 hours








Table 2-2. Commonly used concussion grading scales
Grade American Cantu" Colorado Jordan"
Level Academy of Medical
Neurology45 Society54
1 *Transient *No LOC *No LOC *No LOC
confusion *PTA lasts < 30 *Confusion *Confusion
*No LOC min *No amnesia *No amnesia
*Symptoms &
mental status
abnormalities
resolve < 15 min
2 *Transient *LOC < 1 min *No LOC *No LOC
confusion *PTA lasts > 30 *Confusion *Confusion
*No LOC min *Amnesia *Amnesia lasts
*Symptoms & *Symptoms last < 24 hr
mental-status > 30 min
abnormalities last
> 15 min
3 *Any LOC, Brief *LOC>l min or *LOC *LOC with an
(seconds) or *PTA> 24 hr altered level
prolonged *Symptoms last lasting < 2-3
(minutes) > 7 days min
*PTA lasts >
24 hr
4 N/A N/A N/A *LOC with an
altered level
lasting > 2-3
min


Researchers find it difficult to compare studies because of the confusion that

exists with the grading scales and definitions present in the research. For these purposes,

research completed on concussions should always identify the criteria the research team

used to define and grade a concussion.

The defined length of LOC and PTA are two main signs and symptoms causing

confusion among the grading scales. In the AAN grading scale, confusion and amnesia

are emphasized. The four scales represented in Table 2-2 have similar definitions for a

grade I concussion except that the Cantu53 defines a grade I concussion as having less









than 30 minutes of PTA while the AAN45 scale defines a grade I concussion as no LOC

and only momentary confusion. The definition of a grade 2 concussion is one of the

major differences among the four scales described in Table 2-2. Cantu53 defines a grade

2 concussion as having LOC less than one minute while the other three define it as

having no LOC. The AAN45 grading scale differs in that the athlete has no LOC but

experiences symptoms and mental status abnormalities for more than 15 minutes. Based

on the time frames for LOC and PTA in all three grades of concussion, Cantu's grading

scale can be considered a bit more conservative. The athletic trainer and team physician

should be in agreement as to which grading scale to use and should always keep the

athlete's well being in mind regardless of the grading scale used. If the athletic trainer

uses the AAN scale while the physician uses the Cantu scale a problem with return to

play criteria and compliance can occur.

Return to Play Guidelines

Deciding when an athlete returns to activity can be a difficult decision for many

sports medicine professionals. The numerous grading scales and corresponding return to

play guidelines add to the confusion. The decision regarding when an injured player

should return to play must ultimately be based on clinical judgment.49 The problem lies

in the fact that return to play guidelines are not based on empirical data. The AAN

guidelines and practice options were based on a review of the literature and deliberations

of a panel of experts, rather than on empirical data that validated the importance of

specific markers of concussion severity.41 Until guidelines are proposed based on

empirical data, clinicians are likely to not adhere to any one protocol.2 Table 2-3 depicts

the return to play guidelines based on the concussion grading scales in Table 2-2.









Table 2-3. Return to play guide ines (RTP) after one concussion
Grade American Academy Cantu" Colorado Jordan57
Level of Neurology45 Medical
Society54
1 Permitted if Permitted if no Permitted if Permitted if
abnormalities or post symptoms are asymptomatic at asymptomatic at
concussive present at rest or rest and rest and exertion
symptoms at rest and after exertion; exertion after at after at least 20
after exertion resolve otherwise, least 20 minutes minutes of
within 15 minutes asymptomatic for of observation observation
1 week at rest and
during exertion
before RTP
2 Permitted after 1 full Permitted if Permitted if Permitted if
asymptomatic week asymptomatic for asymptomatic asymptomatic for
at rest and with I week at rest and for I week 1 week
exertion during exertion
3 Brief: Permitted after Not permitted for Not permitted Not permitted for
asymptomatic for 1 at least I month. for at least I at least I month.
week at rest and with May RTP if month. May May RTP if
exertion asymptomatic for RTP if asymptomatic for
Prolonged: Permitted I week at rest and asymptomatic 1 week
after asymptomatic during exertion for at least 2
for 2 weeks at rest weeks
and with exertion
4 N/A N/A N/A Not permitted for
at least I month.
May RTP if
asymptomatic for
at least 2 weeks


None of the guidelines for return to play were developed on the basis of specific

scientific knowledge regarding the process of recovery from concussion.4' Collins et al.6

stated that concussion management guidelines have not evolved to the extent that they

can be used to make reliable return-to-play decisions. The lack of evolution can be

attributed to the subjectivity of the evaluation tools. Guidelines are based on the concept

that injuries resulting in a traumatic loss of consciousness require a greater degree of

mechanical force than do blows to the head that do not result in a loss of consciousness.41








Despite the lack of scientific validation, all the proposed grading scales and return

to play guidelines are considered safe and injured athletes are placed at little risk when

the guidelines are adhered to closely.2 No matter which set of return to play guidelines

the sports medicine professional chooses it can be agreed that 1) any concussed athlete

should be removed from competition, examined, and observed, 2) serial assessment is

important, 3) if the athlete exhibits signs of deterioration, no matter how 'mild' the injury

seemed initially, he/she should be referred to a physician for further evaluation (imaging

and neurosurgical consultation), 4) an athlete with loss of consciousness (even transient)

or amnesia should not return to play, and 5) no athlete should be returned to play until

completely asymptomatic, both at rest and with exertion.2 The overwhelming majority

of players seem able to return to play by five days after injury, but players with extended

periods of posttraumatic disorientation, cognitive impairment, and most importantly,

prolonged symptoms may require longer periods of recovery after injury.49 Despite the

presence of these symptoms, athletes return to participation in three to four days.s17

Sports medicine professionals must remember to use the proposed guidelines as just that,

guidelines to assist in the decision making process. Each sports-related concussion is

different and should be treated as such.

Assessment Tools

The complexity of the brain and the lack of objective signs and symptoms after

injury make the assessment of concussion challenging.5 The sports medicine professional

has a number of MTBI assessment tools at his/her disposal. These tools consist of the

Glasgow Coma Scale (GCS), Galveston Orientation Amnesia Test (GOAT), Children's

Orientation Amnesia Test (COAT), and Standardized Assessment of Concussion (SAC).

Teasdale and Jennette5 developed the practical GCS, which has international application.








The GCS was developed to help standardize clinical observations in head-injured patients

with impaired consciousness.'5 The GCS assists the neurosurgeon or trauma physician in

the early triaging of a MTBI.4 The GCS can be used to monitor changes in the

neurological status of an impaired patient. The key limitation of the GCS is that it is a

time-dependent assessment tool and cannot be administered to evaluate a symptom

complex retrospectively.44 The three behaviors rated by the GCS consist of eye opening,

motor response, and verbal response. The GCS allows for a classification between

severe, moderate, and mild brain injuries along a scale of 3-15. Scores of 13-15 usually

classify patients with MTBI. Reliability of the GCS has been shown with experienced

practitioners"'6 and with use by non-speaking individuals.'9 Menegazzi et al.70 also

established reliability of the GCS when used by emergency physicians and paramedics.

Levin and colleagues71 developed the GOAT which evaluates early recovery of

memory and orientation serially. The GOAT was designed to be a practical, reliable

scale that can be used at the bedside or in the emergency room by health care

professionals.71 The GOAT measures orientation to person, place, and time; provides an

estimate of the duration of anterograde and retrograde amnesia; and can be predictive of

long-term outcome.71 Levin et al.71 established a reliability coefficient for individual

items consistently approximating 0.99. Similarly the COAT was developed to evaluate

orientation and memory objectively in children and adolescents with head injuries.72 The

COAT consists of 16 items assessing three areas: 1) general orientation, 2) temporal

orientation, and 3) memory. General orientation consists of orientation to person, place,

and recall of biographical information. Temporal orientation items include recall of the

month, date, year, and hour. Memory items include recall of digits in the same order as









they were orally presented, recall of a major television character, and recall of the

examiner's name.72 Ewing-Cobbs et aLn demonstrated adequate inter-observer

reliability of the COAT (a=0.98).

Another tool developed to assist the sports medicine professional on the field is

the SAC. The SAC was developed based on the AAN Practice Parameter45 and Colorado

Medical Society Guidelines.54 The SAC was designed for use by a non-

neuropsychologist with no previous expertise in psychometric testing and to assist

athletic trainers and other medical professionals with the assessment of concussion

immediately on the sideline.26 The SAC has three alternate forms (A, B, and C) and

takes approximately five minutes to administer. The SAC contains four sections:

1) Orientation The sports medicine professional asks the athlete to provide the
day of the week, month, date, year, and time of day within one hour.

2) Immediate Memory The sports medicine professional reads the athlete a list
of five words and then asks the athlete to repeat the list and the process is
repeated two more times.

3) Concentration The athlete is asked to repeat a series of digits, in reverse
order, that increase in length from three to six numbers. The athlete is also
asked to recite the months of the years in reverse order.

4) Delayed Memory The athlete repeats the list of words from the immediate
recall section.

The maximum score an athlete can receive is 30 points. The total score computed

derives a composite index of the athlete's overall level of impairment following the

concussion.26'73 McCrea et al.73 reported that the three forms were equivalent with no

significant difference in total scores. This equivalency allows for reassessment of the

individual and reduces the risk of practice effects. McCrea et al.26 suggested that sports

medicine professionals obtain preseason baseline data on individual athletes. The









preseason data can be used as a valid and reliable standard to assist in detecting mental

status changes due to concussions.

Athletic trainers using the SAC and other tools mentioned must remember that

these assessment tools are mental status exams and not neuropsychological exams.

Based on the lack of objective signs and symptoms present with a concussion and

assessment tools, researchers and clinicians have been examining the role of

neuropsychological testing in assessing the severity and recovery of a concussion.

Neuropsychological Testing

Neuropsychological and postural stability testing have become important areas of

research associated with sports-related concussions. Problems lie in the feasibility to pre-

test multiple athletes in a timely fashion and the ability to convert research to clinical

application. In an athletic setting, most neuropsychological testing is performed at the

beginning of the season and after the occurrence of a concussion. Neuropsychological

testing provides a sensitive guide to ongoing and possibly cumulative problems after an

athletic MTBI.41 Such testing has been advocated as a means of monitoring concussed

athletes during recovery and cognitive deficits measured by neuropsychological tests are

highly prevalent immediately after concussion.15 For a neuropsychological test to be

useful in monitoring recovery from concussion, it should have test-retest reliability and

this reliability should be known by the examiners.15'74 Before choosing a specific

neuropsychological test the sports medicine professional should know if multiple forms

exist, the variability and reliability of the chosen instrument, and the sensitivity of the

test. Tests with multiple versions should be selected whenever possible to minimize

practice effects.41









A neuropsychological assessment evaluates neurological improvement or

deterioration over time.74 Important tools in the evaluation of recovery after a mild

concussion include neuropsychological tests of attention and central processing. These

types of tests become especially important for subjects whose recovery seems to be

prolonged for no obvious reason and for those who need to resume activities that involve

risk of further injury.75 Usually return to activity occurs once the subject has returned to

baseline test scores but Daniel et al.15 suggested that return to baseline cognitive function,

as criteria for evidence of recovery from concussion, may not be sufficient in adolescent

athletes. According to Fischer and Rose,76 a period of rapid cognitive change occurs at

approximately 14-16 years of age. This rapid change corresponds with the fourth of

life's five-brain growth "spurts" occurring after infancy.

The literature presents discrepancies as to how long neuropsychological deficits

last related to MTBI occurrence. Maddocks and Saling77 stated that neuropsychological

changes are evident five days after concussion while Leininger et al.7' stated that

neuropsychological deficits could be seen in patients three months to three years post

injury. Head-injured players had impaired neuropsychological test performance

immediately after injury (relative to controls) but were essentially equivalent to controls

by the fifth day after injury.49 In contrast, Leininger et al.7' reported that symptomatic

minor head injury patients displayed significantly poorer performance than uninjured

controls on several neuropsychological tests.78 It was previously believed the length of

time for the deficits was dependent on the severity of the injury. Maddocks and Saling"

reported that neuropsychological deficits were detectable after resolution of neurological

symptoms in the early stages following mild head injuries. Leininger et al.7' reported that








patients with minor head injuries scored significantly poorer than controls on five of eight

neuropsychological tests. Deficits were evident on tests of reasoning, information

processing, and verbal learning.

Researchers have examined the effects of head injuries on cognitive function,

typically using tests of visual scanning, reasoning, information processing, verbal

learning, memory and reaction time. Tests of divided attention and working memory

may be quite abnormal for weeks, even in patients who are not overtly symptomatic. '75

Common tests used to assess deficits in cognitive and motor performance after a MTBI

are the Paced Auditory Serial Addition Test (PASAT), Continuous Performance Test of

Attention (CPTA), Stroop Color-Word Interference Test, Hopkins Verbal Learning,

Weschler Digit Span Forward and Backward, Digit Symbol Substitution Test (DSST),

Trail Making A and B, Bruininks-Oseretsky Test of Motor Proficiency (BOTMP), Four

Choice Reaction Time, and Stop-Signal Reaction Time (SSRT). Each neuropsychological

test and the cognitive function it evaluates are reported in Figure 2-1. Table 2-4 lists

whether a test is internally paced or externally paced. The PASAT, CPTA, Digit Span

Forward and Backward, Trail Making A and B, BOTMP, Four Choice Reaction Time,

and Stop-Signal Reaction Time (SSRT) will be reviewed.








Cognitive Function




Visual Attention Information Veral Auditory Concent- Cognitive
Scanning/ Processing Memory Attention ration Flexibility
Tracng I I I I

Trail Trail Trail Making Hopkins Wechsler Wechsler Stroop
Making Making A & B Verbal Digit Span Digit Color-Word
A&B A&B Learning Span Interference
I I I
Symbol Stroop Paced
Digit Color- Auditory
Modali- Word Serial
ties Interfer- Addition
ence I
Continuous
Performance
Test of
Attention

Figure 2-1. Neuropsychological testing tree


Table 2-4. Internally and externally-paced neuropsychological tests
Internally-Paced (self-paced) Externally-Paced
Trail Making A & B Paced Auditory Serial Addition
Hopkins Verbal Learning Continuous Performance Test of Attention
Wechsler Digit Span Stroop Color-Word Interference
Symbol Digit Modalities
Controlled Oral Word-Association Test

Tests of Information Processing

The Paced Auditory Serial Addition Test (PASAT) has two components, which

account for its sensitivity to processing deficits after MTBI. The first component

demands speed of information processing, because reducing the rate of stimulus

presented dramatically reduces the sensitivity of this procedure. The second component

relates to the demands on processing capacity required to perform the task.2 The









Continuous Performance Test of Attention (CPTA) was developed to be a sensitive

measure of speed of processing deficits while allowing for the assessment of several

levels of processing complexity, which may influence patients' performance.22 The

PASAT and CPTA are externally paced because subjects must sustain their attention and

level of performance in response to a continuous rate of stimulus presentation.22

Cicerone22 believes that the PASAT and CPTA are sensitive measures of impairment

after MTBI because these two tests incorporate multiple sources of information. The

interaction of the processing speeds and capacity demands contribute to the sensitivity of

these measures. Macciocchi et al.49 stated that impairment in sustained auditory attention

(PASAT) was apparent, but the deficits were primarily evident in the failure of players to

show improved performance over time.

Tests of Visual Scanning

Two tests of visual scanning, attention, and executive function include the Trail

Making A and B, which are included in the Halstead-Reitan Battery. The Trail Making

test (parts A and B) provides information regarding attention, visual scanning, speed of

eye-hand coordination, and information processing.27 Trail Making A measures attention

and concentration abilities involving visual motor, conceptual tracking, and sequencing

skills. Trail Making A consists of the numbers 1 through 25 within circles randomly

scattered over a sheet of paper. The patient connects the series of numbers in order.

Trail Making B measures attention and concentration processes involving more complex

sequencing tasks requiring cognitive flexibility. Trail Making B also assesses the ability

to alternate between sets of stimuli and executive function.27 These abilities are known to

be highly vulnerable to deterioration resulting from brain pathology of different

etiologies.27 Trail Making B includes numbers 1 through 13 and letters A through L









within circles. The patient connects the circles by alternating between numbers and

letters in serial order (1-A-2-B, etc). In parts A and B the time to completion and the

numbers of errors are recorded. Test administration takes less than five minutes. The

Trail Making test, parts A and B, are internally-paced because the subjects determine the

speed of responding.

Tests of Motor Proficiency

The Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) has been used to

assess motor performance in children after a head injury. The BOTMP examines motor

proficiency in eight domains: 1) running speed and agility, 2) balance, 3) bilateral

coordination, 4) strength, 5) upper limb coordination, 6) response speed, 7) visual-motor

control, and 8) upper limb speed and dexterity. The eight domains are categorized into a

Gross Motor Composite and a Fine Motor Composite. The Gross Motor Composite

consists of the following domains: running speed and agility, balance, bilateral

coordination, and strength while the Fine Motor Composite consists of response speed,

visual-motor control, and upper limb speed and dexterity. Gagnon et al.'8 reported that

deficits in motor performance appear to be present in children during the weeks following

a MTBI and provide further basis for investigating real life consequences. More than

40% of the children demonstrated a below average standard score performance on three

of the eight motor performance domains assessed, namely running speed and agility,

balance, and response speed.18 Children with MTBI did not perform as well on the Gross

Motor Composite as they did on the Fine Motor Composite, whereas the performance of

the normal children was similar on both composites.79 Therefore, following MTBI

children are more likely to demonstrate deficits in gross motor than fine motor skill areas.

Based on the results of their study, Chaplin et al.79 suggested that specific deficits are









most likely to be found on short, timed tests that require fast motor responses and that

speed of eye-hand coordination is particularly sensitive to the effects of brain injury.

Therefore, tasks requiring speed and precision of movement appear to be most sensitive

to the effects of brain injury.

Tests of Reaction Time

Changes in reaction time after a concussion have been identified as highly

sensitive indicators of brain dysfunction.s Depending upon the instrument used to test

reaction time an average normal time can range from 186 milliseconds to 245

milliseconds.51'82 Patients with mild to moderate traumatic brain injury show abnormality

in the consistency and stability of their performance over time.80 Using traditional

neuropsychological testing methods, recovery is generally noted within one to three

months, though reaction time impairments may take six months to resolve.8s Reaction

time impairments of 20 to 110 milliseconds have been observed in concussed subjects.5

This amount of time may not appear to be excessive but can lead to further injury if the

athlete is unable to respond appropriately. Results from Gagnon et al.' confirmed that

speeded performance deficits exist and demonstrated that children with MTBI had

deficits in reaction times. Sports medicine professionals should take the presence of

these deficits into consideration when making return to play decisions because if reaction

time deficits are present following mild head injury then returning an athlete to play

could be detrimental.

Complex inhibitory control is defined as the ability to inhibit a planned ongoing

action.3 When a stop-signal paradigm was used to assess inhibitory control, individuals

who experienced a MTBI had more difficulty inhibiting an ongoing action than matched

control subjects.83 The MTBI individuals had a slower stop-signal reaction time (SSRT)








but interestingly, the MTBI group did not differ from the control group on reaction time

to the "go" signal, thus suggesting they were not slow in responding to all signals.83

These results are supported by Maddocks and Saling" who reported that the MTBI group

were significantly slower to initiate a response.

Computerized Testing

Neuropsychological testing of mild traumatic brain injured individuals has been

used for a number of years. The length of a general neuropsychological assessment

ranges from three to eight hours. While this level of testing is quite comprehensive, in

the athletic setting three to eight hours cannot be spent with every athlete who suffers a

concussion and decisions on playing status must be made immediately or within 20

minutes after the injury. The need to pre-test a large number of athletes in a short period

of time requires the test battery to be brief and accurate. Because computer-based testing

can be administered in large group settings, individuals have been researching the use of

computerized testing for concussion assessment in athletic populations. Daniel et al.15

suggested that sensitivity to long-term effects of concussion greatly increases when using

computerized neuropsychologic tests.

Some advantages of computerized neuropsychological testing include availability

of multiple forms, brief administration time, standardization of administration, and

measurement accuracy. When an athlete suffers a concussion, numerous testing sessions

occur over a short time span. The availability of alternate test forms is a highly desirable

feature because of the multiple examinations associated with sports injuries.14 Because

of testing frequency, the availability of the multiple forms helps to minimize practice

effects and the establishment of reliable baseline prior to injury.4 Another advantage of

computerized testing is the standardization of test administration. This standardization








assists in avoiding problems related to variables introduced by the examiner and reduces

the number of differences between examiners.14 For response variables such as speed,

consistency, and efficiency, computerized testing offers accuracy of measurement greater

than that of an examiner.14

The need for procedures assessing mental processing efficiency over repeated

trials prompted the development of the Automated Neuropsychological Assessment

Metrics (ANAM).14 The ANAM computer program has been used to assess

neuropsychological deficits in mild head injured individuals and shown to be reliable in

prior studies using U.S. Marines and college graduates. The adaptability of the ANAM

battery allows it to be very attractive when considering testing numerous athletes.

Daniel et al."5 used the ANAM to examine whether adolescent athletes, in the

absence of concussion, would be expected to show an improvement in cognitive function

during the course of a football season. Improvements in processing efficiency were noted

on tests of visual scanning, sustained attention, immediate recall, and short-term memory.

These findings suggest that the ANAM is sensitive to differences and improvements in

cognitive function of uninjured adolescents. The improvements noted may reflect

cognitive brain maturation during the adolescent period and further research needs to be

completed.

In order for computerized testing to be valid and reliable it must be compared to a

standard norm. Bleiberg et al." examined the relationship between the ANAM and a set

of traditional neuropsychological tests. The results of the study demonstrated that the

ANAM and traditional neuropsychological tests assess similar underlying constructs in

the areas of cognitive efficiency, working memory, and resistance to interference." This









finding is reassuring due to the increased research in concussion neuropsychological

testing. A positive result of the Bleiberg et al.4 study is that the ANAM test battery can

be administered in less than 20 minutes while traditional testing can take more than three

hours. The short testing time and use of multiple computers allow for numerous athletes

to be tested in short periods of time.

Postural Stability

The postural control system operates as a feedback control circuit between the

brain and the musculoskeletal system.s5 If an injury occurs to the brain or part of the

musculoskeletal system, the circuit can be disrupted. Mild head injuries appear to cause a

communication or interaction problem preventing the vestibular and/or visual systems

from compensating for altered somatosensory feedback during foam and moving

platform conditions.6 Guskiewicz et al.6 stated that balance deficits may be present in the

absence of amnesia and/or other post concussive syndromes and may be evident for one

to three days following an injury.

Initially many athletic trainers used the Rhomberg test to assess the balance of an

athlete suffering from a MTBI. The Rhomberg test requires subjects to stand erect with

their heels and toes together, and hands at their sides for 30 seconds with eyes open, and

30 seconds with eyes closed. This test was easy to administer and does not require any

extra material on the sideline but because of the subjective nature of the Rhomberg test

researchers have been examining other methods to assess the effects of MTBI on postural

stability.

Postural stability testing can be completed using the Rhomberg test, a force plate,

the Chattecx Balance System, Biodex Stability System, or the NeuroCom Smart Balance

Master. Force platforms ideally evaluate four aspects of postural control: steadiness,









symmetry, dynamic stability, and dynamic balance." Athletes with MTBI demonstrated

increases in postural sway when tested using the Clinical Test of Sensory Interaction and

Balance protocol.6 These postural stability decreases were present for up to three days

after an injury when compared to control subjects. These deficits were evident when the

subjects were standing on a foam or moving surface. Decreases in postural stability were

also reported for up to three days post injury when MTBI subjects were tested using the

Sensory Organization Test (SOT) on the NeuroCom Smart Balance Master.'9 The

NeuroCom Smart Balance Master and Clinical Test of Sensory Interaction and Balance

require force plate systems to test the effects of MTBI on postural stability. Even though

these testing procedures and materials have demonstrated the effects of MTBI on postural

stability, not all athletic trainers and sports medicine professionals have access to such

instruments; therefore the Balance Error Scoring System (BESS) was developed.

The BESS is a method of evaluating postural stability without the use of complex

or expensive equipment The BESS is a system of scoring the errors committed by an

individual when performing three stance variations (double-leg, single-leg, and tandem)

of the Rhomberg test. Foot position for each stance is described in Table 2-5. Each

stance is performed on a firm and foam surface and the individual has their eyes open or

closed based on the testing situation. Each error committed during the individual's

performance causes one error point to be added to the performance score (Table 2-6).








Table 2-5. Foot positioning25
Stance-surface Foot position
Double-firm Narrow bilateral stance with medial aspects of feet on midline of
platform
Single-firmn Standing on nondominant leg in middle of the platform
Tandem-firm Standing diagonally across the platform, feet in line with the heel of
dominant foot touching toes of nondominant foot
Double-foam Narrow bilateral stance with medial aspects of feet on midline of the
foam
Single-foam Standing on nondominant leg in middle of the foam
Tandem-foam Standing diagonally across the middle of the foam, feet in line with
the heel of dominant foot touching toes of nondominant foot

Table 2-6. Balance Error Scoring System (BESS)25
Errors
Lifting hands off the iliac crests
Opening the eyes
Stepping, stumbling, or falling
Moving the hip into more than 300 of flexion or abduction
Lifting the forefoot or heel
Remaining out of the testing position for more than 5 seconds


Significant correlations between the BESS and force-platform sway measures

using normal subjects have been established for five static balance tests (single-leg stance

on a firm surface, tandem stance on a firm surface, double-leg stance on a foam surface,

single-leg stance on a foam surface, and tandem stance on a foam surface) with intertester

reliability coefficients ranging from 0.78 to 0.96.25 The use of this test battery in normal

subjects failed to reveal performance improvements over repeated testing;25 therefore,

sports medicine professionals using the test battery can be confident that improvements

across days one, three, and five post injury represent resolution of the postural instability

after MTBI.9

Riemann and Guskiewicz9 examined the effects of MTBI on postural stability

using the BESS system. Results from the studied failed to reveal significant differences

between MTBI and control subjects using the double-leg, single-leg, and tandem stances








on a firm surface. One possible reason given for the failure to find significant differences

was that balance tests on a firm surface fail to challenge the postural control system of

conditioned athletes.9 Therefore, sports medicine professionals may need to reconsider

the use of the standard Rhomberg test when assessing a concussion. In contrast, all three

stances on the foam surface elicited significantly higher postural instability in the MTBI

subjects. Based on these results, it is recommended that balance performance be assessed

using a battery of tests, rather than one specific test, and specifically using the three

stances on a foam surface.9'25

Conclusions

Research indicates that approximately 300,000 sports-related head injuries occur a

year in athletics. The treatment of these injuries varies depending upon the concussion

grading scale and return to play criteria used. Much research has been performed on

collegiate athletes to determine the effect a concussion can have on the cognitive and

postural stability of the athlete. This increase in research has attempted to determine

more objective measures to help the clinician in return to play decisions. The problem

lies in the fact that most of the testing previously performed has examined collegiate

athletes, used expensive equipment, or used traditional neuropsychological tests. A

whole group of athletes has been left out in the area of neuropsychological testing, youth

and adolescent athletes. With the advances in technology the use of computerized

neuropsychological testing has been warranted.















CHAPTER 3
MATERIALS AND METHODS

Introduction

The American Academy of Neurology (AAN) guidelines and practice options

were based on a review of the literature and deliberations of a panel of experts, rather

than on empirical data that validated the importance of specific markers of concussion

severity.4' Until guidelines are proposed based on empirical data, clinicians are likely not

to adhere to any one protocol.2 The present study was designed to attempt to obtain

empirical data to support the guidelines or possibly redesign current guidelines.

Subiects

Subjects for this study were male and female members of freshman, junior varsity

and varsity football, volleyball, soccer, and basketball teams from Alachua, Bradford and

Gilchrist counties in Florida. Age of the subjects ranged from 13-19 years. A total of 11

high schools were selected to participate in this study because of their participation in the

University of Florida's Athletic Training Outreach Program. All of the selected high

schools had a certified athletic trainer (ATC) who had daily contact with the principal

investigator. Subjects who suffered a grade I or 2 concussion based on the AAN grading

scale45 (Appendix A) and a control subject matched by sport, age, gender, race, education

level, learning disability, and dominant hand were asked to participate in this study.

Subjects who had suffered a head injury, lower extremity injury, or upper extremity

injury within the last three months prior to the initiation of the study were excluded from








the study. Subjects who sustained a second concussion during the study period were

tested again but only the initial concussion data was used in the analysis.

Instruments

Data were collected using the Automated Neuropsychological Assessment

Metrics (ANAM), modified Rhomberg test using the Balance Error Scoring System

(BESS) (Appendix B), Standardized Assessment of Concussion (SAC), and Trail Making

A and B.

Automated Neuropsvchological Assessment Metrics

The Automated Neuropsychological Assessment Metrics (ANAM) is a

computerized neuropsychological test battery that consists of four components: 1) Simple

Reaction Time (visual motor response), 2) Matching to Sample (spatial processing and

working memory), 3) Running Memory (sustained attention and concentration), and 4)

Stanford Sleepiness Scale. The tests are described below.

1) Simple Reaction Time (SRT) A large asterisk (snowflake) appears on
the screen at various time intervals. The subject was instructed to press
the left mouse button as quickly as possible after the asterisk appears.

2) Matching to Sample (MSP) A large box with light and dark squares,
called the sample box, was displayed on the screen. After a period of
time (determined by the program) the sample box disappears and two
comparison boxes appear side by side. The subject was instructed to
decide which comparison box matches the sample (only one matches)
and press the left mouse button if the left box matched and the right
mouse button if the right box matched.

3) Running Memory (CPT) Single letters appear on the screen one at a
time, one right after the other. As each letter appears the subject must
decide if it is the same as the previous letter. If the letter is the same as
the previous letter the subject must press the left mouse button and if it
is different the subject must press the right mouse button.

4) Stanford Sleepiness Scale" The scale consists of statements that
describe how the subject is feeling at the time of the test. The
following are the statements the subject has to choose from.









1. Feeling alert, wide-awake, and energetic.
2. Able to concentrate, but not quite at peak.
3. Relaxed and awake, but not fully alert.
4. A little tired and having difficulty concentrating.
5. Feeling tired and struggling to concentrate.
6. Sleepy and want to lie down.
7. Very sleepy and cannot stay awake much longer.

The SRT, MSP, and CPT all had brief practice sessions that are a function of the

software program before the actual test session and these practice sessions were

completed during each test session. The results recorded for each test (SRT, MSP, and

CPT) include the accuracy of response, a mean reaction time (msec), standard deviation,

throughput, lapses, median reaction time (msec), and number of errors. Throughput is a

measure of performance efficiency that combines accuracy and speed (number of correct

responses per minute).4 The results reported for the Stanford Sleepiness Scale are the

score the subject rated and the time to response (reaction time in msec).

Modified Rhomberg

The modified Rhomberg Test of postural stability with the BESS was used for

data collection. Medium density foam (Airex, 50.8cm x 41.66cm x 6.35cm) was used for

the unstable surface variations and rotated 900 after each subject to prevent uneven

wearing over the course of the trials. The BESS was used to measure postural sway

(Appendix B). Significant correlations between the BESS and force-platform sway

measures using normal subjects have been established for five static balance tests (single-

leg stance on a firm surface, tandem stance on a firm surface, double-leg stance on a

foam surface, single-leg stance on a foam surface, and tandem stance on a foam surface)

with intertester reliability coefficients ranging from 0.78 to 0.96.25 For the current study

intratester reliability coefficients for the principal investigator ranged from 0.95 to 0.99.









Each subject performed two stance variations (single leg stance and tandem

stance) on a foam surface. Skill leg was defined as the preferred leg used to kick a ball.

During the single leg stance, the subject was instructed to stand erect on their stance leg,

skill leg flexed to 70 degrees, and with their hands on their iliac crests. The subject was

told to hold this position as accurately as possible. During the tandem stance, the subject

was instructed to stand diagonally across the foam surface, feet in line, with the heel of

skill foot touching toes of stance foot, and hands on the iliac crest. The subject was

instructed to return to the correct stance as quickly as possible if they were to lose their

balance during any stance situation. Each subject performed four variations: 1) tandem

stance, eyes open, 2) tandem stance, eyes closed, 3) single-leg stance, eyes open, and 4)

single-leg stance, eyes closed. Before performing the test, each subject was given a

randomly selected practice trial completed for 20 seconds. The order of tests was

randomized between each subject, with each test lasting 20 seconds.

Standardized Assessment of Concussion

The Standardized Assessment of Concussion (SAC), a mental status exam, was

developed based on the AAN Practice Parameter45 and Colorado Medical Society

Guidelines.54 The SAC was designed to be used by individuals with no previous

expertise in neuropsychological testing and to assist athletic trainers and other medical

professionals with the assessment of concussion immediately on the sideline.26 The SAC

has three equivalent alternate forms (A, B, and C) and takes approximately five minutes

to administer. The SAC contains four sections:

1. Orientation The sports medicine professional asks the athlete to provide the
day of the week, month, date, year, and time of day within one hour.









2. Immediate Memory The sports medicine professional reads the athlete a list
of five words and then asks the athlete to repeat the list and the process is
repeated two more times.

3. Concentration The athlete is asked to repeat a series of digits, in reverse
order, that increase in length from three to six numbers. The athlete is also
asked to recite the months of the years in reverse order.

4. Delayed Memory The athlete repeats the list of words from the immediate
recall section.

The total score gives a composite index of the athlete's overall level of

impairment following the concussion. The maximum score an athlete can receive is 30

points.

The first SAC testing session was performed by the ATC at the high school site

using form A to ensure standardization of testing between the ATC and principal

investigator. If the ATC at the site used a different SAC version, they were to inform the

principal investigator prior to the initiation of data collection. For all remaining testing

sessions the principal investigator randomized the forms.

Trail Making A and B

Trail Making A measures attention and concentration abilities involving visual

motor, conceptual tracking and sequencing skills.27'32 Trail Making A consists of

numbers I through 25 within circles randomly scattered over a sheet of paper. The

subject was instructed to connect in order, the series of numbers as quickly as possible.

Trail Making B is a test of visual scanning, attention, and executive function. The

test measures attention and concentration processes involving complex sequencing tasks

requiring cognitive flexibility.27,32 Trail Making B includes numbers I through 13 and

letters A through L within circles. The subject was asked to connect the circles by

alternating between numbers and letters in serial order (I -A-2-B, etc). For the Trail








Making A and Trail Making B time to completion and the number of errors were

recorded with the total test administration time taking less than 5 minutes.

Procedures

The principal investigator met with the coaches of 11 high school football,

volleyball, basketball, and soccer teams. The coaches were given information regarding

the purposes of the study and assistance in disseminating information about injury risk to

the athletes' parents. Subjects, at the selected high schools, who suffered a grade 1 or 2

concussion based on the AAN grading scale and a control subject matched by sport, age,

gender, race, education level, and dominant hand were asked to participate in this study.

Subjects and their parents were instructed on the methods, risks, and benefits of the

study. After being informed about the study, the appropriate informed consent form

(Appendix C) was signed and each subject was asked to complete a medical history

questionnaire containing questions about current medications, previous head injuries,

injuries to dominant arm/hand or lower extremity, learning disabilities, and neurological

illnesses. After completing the informed consent and medical history questionnaire, each

subject was given an alphanumeric identification code to protect confidentiality. Any

subject with an upper extremity, lower extremity, or head injury within the last three

months was excluded from the study. Any subject with an equilibrium disorder or

diagnosed learning disability was also excluded from the study.

Subjects were then asked to complete the series of neuropsychological and motor

performance tests. Testing consisted of the ANAM, modified Rhomberg test using

BESS, SAC, and Trail Making A and B. At the conclusion of the ANAM test battery,

subjects were asked to rate their frustration on a likert scale. The scale ranged from 1 to

10 with 1 being very little frustration and 10 being the most frustrated they have ever









been. The order of testing was randomized using a 4x4 Latin square. Subjects were

instructed on the procedures for each test at the start of each testing session. The initial

testing session was completed within the first 24 hours after the concussion. Each subject

was then tested twice a day for the next four days within a 7-day period. A total of nine

testing sessions were completed with each individual session lasting 20 minutes. Testing

was completed at the same time each day and all testing sessions were followed by a 15-

minute rest period where the subjects were allowed to walk around, use the restroom, or

drink water as necessary. During the first session of testing subjects were given a

randomized practice trial of the modified Rhomberg. The modified Rhomberg was

videotaped in all cases the principal investigator was unable to attend to assist in the

scoring of the test.

Any subject that received a second sports-related concussion during the same

season was subsequently re-tested following the same procedures but only the first set of

data points were used for data analysis.

Design

The design of the study was a matched control prospective study for the first

testing session across the days and a 2x4 matched control prospective study for the two

sessions on the final four days. The independent variables in the study were group

(injured and control) and time (session and day). The dependent variables in the study

were the scores of the ANAM tests, SAC, BESS error scores, and Trail Making A and B

scores.

Analysis

Descriptive statistics were completed on each group to obtain demographic

information. Separate mixed model, repeated measures analyses of variance (ANOVA)









were used to detect differences between groups (injured and control) on each of the

ANAM subtests for the measures of accuracy, mean reaction time, and throughput

performance across the first session of each day and across the two sessions on days two

through five. A mixed model, repeated measures ANOVA was used to detect differences

between groups (injured and control) on the SAC across the first session of each day and

across the two sessions on days two through five. Four repeated measures ANOVAs for

the Modified Rhomberg (two stances and two eye conditions) and two each for the Trail

Making A and Trail Making B (time to completion and errors) were used to detect

differences between groups across the first session of each day and across the two

sessions on days two through five. A significance level ofp < .05 was set a priori.

Tukey's post hoc was used to examine significant differences of interest.

A Pearson Product Moment Correlation was conducted on the injured group to

investigate if any relationships existed between the Stanford Sleepiness Scale score and

all other test variables. A significance level ofp < .05 was set a priori.














CHAPTER 4
RESULTS

The current concussion guidelines are based on subjective information and not

empirical data; therefore this study was designed to obtain empirical data to support or

possibly assist in redesigning these guidelines. The purposes of this study were to

determine if concussed adolescent athletes have levels of performance comparable with

those of adolescent control subjects on a battery of motor performance and computerized

neuropsychological tests and to determine if concussed adolescent athletes show

inconsistent performance over multiday time periods as compared with control subjects

on the same tests.

Subject Participation

A total of 24 adolescent athletes (12 injured and 12 healthy) participated in this

study. Demographic information is located in Tables 4-1 through 4-5. No significant

differences existed between the groups for age, height, weight, education level, or race.

Only one subject in the injured group had previously sustained a concussion while two

control subjects had suffered from a concussion more than six months ago. Of the

subjects in the injured group, three had grade one concussions and nine had grade two

concussions. Six of the concussions occurred in practice, five in games, and one outside

of a scheduled activity. The mean time loss for the injured group was 9.8 + 9.7 days with

arangeof to31 days.








Table 4-1. Demographic information
Group Age (yrs) Height (cm)

Injured 15.4+ 1.5 178.0+7.8
Control 15.7+ 1.9 175.9+ 8.1
Total 15.5+1.7 176.9+8.1


Weight (kg) Years of playing
experience
77.8 + 15.5 3.3 + 1.6
77.3+ 13.9 4.2 +2.4
S77.6+14.4 3.8 +2.0


Table 4-2. Year in school and educational history
Eighth Freshman Sophomore Junior Senior Learning
Disability
Injured 2 4 2 1 3 2
Control 1 5 1 1 4 2
Total 3 9 3 2 7 4


Table 4-3. Stance leg and hand dominance
Right stance Left stance leg
leg
Injured 2 10
Control 0 12


Total


Right handed

11
12
23


Left handed

1
0
1


Table 4-4. Race
Caucasian African Hispanic
American
Injured 7 4 1
Control 7 5 0
Total 14 9 1








Table 4-5. Concussion demog aphics
Subject Sport Mechanism of injury Signs/Symptoms
1 Football Repetitive blocking Headache and dizziness
against dummies
2 Football Contact with another Headache, dizziness, blurred
Player vision, and fatigue
3 Football Contact with opponent Headache, nausea, dizziness
4 Football Contact with another Headache
player
5 Football Did not remember Headache, fatigue, and
decreased attention
6 Football Contact with another Headache, nausea, and
__ player dizziness
7 Football Contact with playing Headache, nausea, dizziness,
S_ surface and fatigue

surface
9 Football Contact with another Headache and dizziness
player
10 Football Contact with another Headache, dizziness, and
individual decreased attention
11 Basketball Contact with playing Headache and dizziness
surface
12 Basketball Contact with another Headache, nausea, dizziness,
player and difficulty concentrating

ANAM

Simple Reaction Time (SRT)

No significant differences were revealed between groups, days, or sessions for the

SRT subtest in the areas of accuracy, mean reaction time, and throughput.

Matching to Sample (MSP)

No significant differences between groups or days were revealed for accuracy on

the MSP. A session main effect was revealed for accuracy [F (1,22)=5.947, p=.023].

Subjects were significantly more accurate during session one (87.71 + 3.29) as compared

to session two (84.75 + 4.17). No significant group differences, day main effects, or

session main effects were revealed for mean reaction time or throughput.








Running Memory (CPT)

No significant differences were demonstrated between groups on the measures of

accuracy, mean reaction time, or throughput for the CPT. Significant day [F (4,88)

=7.89, p=.001] and session [F (1,22) =11.98, p=.002] main effects were demonstrated for

accuracy. Tukey's post hoc revealed that subjects exhibited a significantly lower

accuracy on day one as compared to any other day (Table 4-6). Subjects were

significantly more accurate during session one (89.43 + 3.04) as compared to session two

(87.46 + 3.21). No significant interactions were revealed for the measure of accuracy. A

significant day [F (4,88)=28.66, p=.000] main effect was demonstrated for mean reaction

time. Tukey's post hoc revealed that subjects took significantly longer to respond on day

one as compared to any other day and a significant difference existed between day two

and day four (Table 4-7). No significant session main effects or interactions were

demonstrated for mean reaction time. A significant day [F (4,88)=36.81, p=.000] main

effect was demonstrated on throughput. Tukey's post hoc indicated that subjects were

significantly less efficient on day one as compared to any other day and a significant

difference existed between days two, four and five (Table 4-8). Subjects were

significantly less efficient on day two as compared to day four and day five. No

significant session main effects or interactions were demonstrated for throughput.

Table 4-6. Day CPT accuracy (%) means (SD)
Group Day I Day 2 Day 3 Day 4 Day 5
Injured 82.11 (11.02) 86.39(11.14) 87.89(10.85) 87.49(7.36) 88.04(7.95)
Control 86.16 (9.42) 92.04 (4.47) 90.36 (6.18) 91.04 (7.84) 92.22 (5.84)
Total 84.14 (10.24) 89.21 (8.79) 89.12 (8.72) 89.26 (7.65) 90.13 (7.15)
p<.05








Table 4-7. Day CPT mean reaction time (msec) means (SD)
Group Day 1 Day 2 Day 3 Day 4 Day 5
Injured 529.03 461.14 453.20 434.87 452.23
(62.03) (69.05) (58.94) (52.19) (72.62)
Control 522.56 468.20 441.35 428.23 426.82
l (81.02) (91.18) (75.63) (76.99) (114.58)
Total 525.79 464.68 447.28 431.55 439.52
(70.64)A (79.18)B (66.59) (64.41)B (94.71)
p<.05 significantly different from all means
B p<.05 significant difference between day 2 and 4

Table 4-8. Day CPT throughput means (SD)_
Group Day 1 Day 2 Day 3 Day 4 Day 5
Injured 94.87 114.71 119.24 123.01 120.48
___ (15.92) (18.14) (24.57) (21.62) (27.78)
Control 101.87 121.89 125.73 131.91 135.17
___ (18.24) (23.74) (19.97) (25.94) (26.03)
Total 98.37 118.30 122.48 127.46 127.83
1 (17.12)A (20.98)" (22.15) (23.80)8 (27.37)B
p<.05 significantly different from all means
Bp<.05 significant difference between day 2 and days 4 and 5

Stanford Sleepiness Scale

No significant group differences or day main effects were demonstrated for the

Stanford Sleepiness scale. A significant session main effect [F (1,22)-15.06, p=.001)]

was revealed. Subjects reported being significantly sleepier during session two (3.56

0.65) as compared to session one (2.82 + 0.42). Significant day [F (4,88)=18.85, p=.000]

and session [F (1,22)=12.50, p=.002] main effects were revealed for mean response time.

Tukey's post hoc demonstrated that subjects took significantly longer to respond during

day one as to all other days and a significant difference between days two and four (Table

4-9). Subjects also took significantly longer to respond during session one (10156.83 +

2559.17 msec) as compared to session two (6355.27 + 921.76 msec). No significant

interactions were revealed for mean response time.








Table 4-9. Day Stanford mean response time (msec) means (SD)
Group Day 1 Day 2 Day 3 Day 4 Day 5
Injured 21704.17 14747.08 12507.42 10399.50 6922.33
C (8323.15) (9356.20) (7545.57) (7494.53) (6717.18)
Control 20995.08 13988.75 9554.25 6701.08 6434.25
T (10303.18) (11026.78) (7015.26) (4396.74) (3675.79)
Total 21349.63 14367.92 11030.83 8550.29 6678.29
A I (9166.93)A (10008.39)" (7283.01) (6298.94)B (5301.28)
A p<.05 significantly different from all means
B p<.05 significant difference between day 2 and day 4

Modified Rhomberg

No significant differences between groups were revealed for the tandem eyes-

open (TO), tandem eyes-closed (TC), single-leg eyes-open (SO), or single-leg eyes-

closed (SC) modified Rhomberg stance variations. No significant day or session main

effects or interactions were revealed for TO. A significant day main effect [F

(4,88)=5.93, p=.000] for TC was revealed. Tukey's post hoc indicated that subjects

committed significantly more errors during day one as compared to all other days (Table

4-10). Tukey's post hoc also revealed a significant difference between days two and four

(Table 4-10). No significant session main effect or interactions were reported for TC.

For variations SO and SC, no significant day or session main effects or interactions were

demonstrated.

Table 4-10. Tandem eyes-closed means (SD)
Group Day 1 Day 2 Day 3 Day 4 Day 5
Injured 7.67(3.23) 7.17 (2.72) 5.58 (3.18) 6.08(2.71) 5.58 (2.12)
Control 7.42 (2.87) 6.50 (2.43) 4.92 (2.68) 3.75 (2.22) 5.58 (2.87)
Total 7.54 (2.99)- 6.83 (2.55) 5.25 (2.89) 4.92 (2.70) 5.58 (2.47)
p<.05 significantly different from all means
p<.05 significant difference between day 2 and 4

SAC
No significant group differences were revealed for the SAC. No significant day

or session main effects or interactions were demonstrated.








Trail Making A

No significant differences between groups were demonstrated for the Trail

Making A time to completion or number of errors committed. Significant day [F

(4,88)=34.14, p=.000] and session [F (1,22)=10.30, p=.0041 main effects for time to

completion were revealed on the Trail Making A. Tukey's post hoc revealed that

subjects took significantly longer to complete the test on days one and two as compared

to the other days (Table 4-11). A significant difference was also revealed between day

three and day five (Table 4-11). Subjects also took significantly longer to complete the

test during session one (20.20 + 2.05 sec) as compared to session two (18.29 + 2.02 sec)

across all days. No significant interactions for the time to completion were observed.

For the number of errors, a significant session main effect was revealed [F(1,22)=4.91,

p=.037]. Subjects committed significantly more errors during session two (0.20 + 0.12)

as compared to session one (0.12 + 0.08). No significant interactions were demonstrated

for number of errors committed on the Trail Making A.

Table 4-11. Day Trail Making A time to completion means (SD)
Group Day 1 Day 2 Day 3 Day4 Day 5
Injured 30.78(9.04) 28.11 (6.60) 22.06(6.78) 18.07(4.02) 18.58(7.54)
Control 27.84 (8.77) 25.00 (7.19) 18.79 (5.11) 16.88 (4.77) 14.07 (2.83)
Total 29.31 (8.84)A 26.55 (6.94)^ 20.43 (6.10)" 17.47 (4.35) 16.32 (6.03)
p<.05 significantly different from all means
p<.05 significant difference between day 3 and 5

Trail Making B
No significant group differences were noted for time to completion or number of

errors committed for Trail Making B. Significant day [F (4,88)=27.20, p=.000] and

session [F (1,22)=11.04, p=.003] main effects for time to completion were demonstrated

for the Trail Making B. Tukey's post hoc revealed that subjects took significantly longer

to complete the test on day one as compared to all other days (Table 4-12). A significant








difference was also revealed for the following comparisons day two and day four, day

two and day five, day three and day five (Table 4-12). Subjects also took significantly

longer to respond during session one (43.74 + 5.77 sec) as compared to session two

(38.58 + 6.25 sec) regardless of day or group. No significant interactions were reported

for time to completion. For the number of errors, a significant day main effect [F

(4,88)=4.17, p=.004] was revealed while there was not a significant session main effect.

Subjects committed significantly more errors on day one, as compared to all other days

(Table 4-13). No significant interactions were revealed for number of errors committed.

Table 4-12. Day Trail Making B time to completion means (SD)
Group Day 1 Day 2 Day 3 Day 4 Day 5
Injured 70.62 (22.24) 58.19 (20.45) 50.53 (23.05) 46.02 (17.95) 37.30 (18.38)
Control 61.23 (18.34) 51.83 (14.90) 42.27 (15.72) 31.65 (8.10) 32.13 (11.50)
Total 65.93 55.01 46.40 38.83 34.71
(20.51)A (17.80)a (19.75) (15.47)B (15.23)8,c
p<.05 significantly different from all means
B p<.05 significant difference between day 2 and days 4 and 5
cp<.05 significant difference between day 3 and 5

Table 4-13. Day Trail Making B error means (SD)
Group Day 1 Day2 Day 3 Day 4 Day 5
Injured 600 (7.56) 2.83 (6.13) 0.42 (1.00) 0.67 (1.44) 0.58 (2.02)
Control 1.75 (3.14) 1.33 (2.02) 0.50 (1.00) 0.83 (2.59) 0.33 (0.65)
Total 3.88 (6.06)* 2.08 (4.53) 0.46 (0.98) 0.75 (2.05) 0.46 (1.47)
*p<.05

Pearson Product Moment Correlation
A Pearson Product Moment Correlation was conducted on the injured group to

investigate if any relationships existed between the Stanford Sleepiness Scale score and

all other test variables. No significant correlations were revealed for the Stanford

Sleepiness Scale score and the SRT, MSP, CPT, Modified Rhomberg with BESS, or Trail

Making A and B.















CHAPTER 5
DISCUSSION, CONCLUSIONS, AND FUTURE IMPLICATIONS

Discussion

Research examining the effects of mild head injury on neuropsychological

functionl'%12,13'22,49,82 and postural stability9 has been available for a number of years.

Few studies have combined these elements19 and fewer have conducted testing at

multiple points within a day or used computerized testing. A problem lies in the fact that

most of this research has been conducted on collegiate or professional athletes neglecting

adolescent athletes. Because of the lack of research conducted examining adolescent

athletes and computerized neuropsychological testing, this study was conducted.

Computerized neuropsychological testing has recently been introduced into the

athletic setting.15'41 Some of the benefits of computerized testing are baseline testing for

multiple athletes can take place simultaneously, multiple forms are available,

improvement of measurement accuracy, and a standardization of administration.14 The

purposes of this study were to determine if concussed adolescent athletes have initial

levels of performance comparable with healthy subjects on a battery of motor

performance and computerized neuropsychological tests and to determine if concussed

athletes show inconsistent performance over multiple testing sessions.

The test instruments used were the Automated Neuropsychological Assessment

Metrics (ANAM), Modified Rhomberg with the Balance Error Scoring System (BESS),

Standardized Assessment of Concussion (SAC), and the Trail Making A and B. On all of









the tests no significant differences were noted between the injured group and the control

group. These results contradict previously published studies reporting

neuropsychological deficits between concussed individuals and controls.10,47'49'77',7'87

Macciocchi et al.49 reported that injured athletes displayed impaired performance

compared to controls when tested within 24 hours of sustaining a concussion. Maddocks

and Saling77 also stated that concussed individuals demonstrated neuropsychological

deficits after sustaining a concussion. This contradiction in results can be due to several

factors; the definition of concussion used, age of participants, and the test measures used.

Only three of the studies previously mentioned examined an athletic population (Barth et

al,'0 Macciocchi et al.49 and Maddocks and Saling77). Macciocchi et al.49 and Maddocks

and Saling77 also used a matched control design based on age, gender, and education

level. Similar to the results of the current study, other researchers have failed to find

significant differences between groups or group by day interactions on

neuropsychological tests.19 The authors reported that a significant day main effect

occurred revealing that all subjects improved progressively and possibly at the same rate

and revealing practice effects."9 Possible reasons suggested for the nonsignificant results

included an accelerated learning curve in an athletic collegiate population and a test

sensitivity insufficient for discriminating between injured and healthy subjects. This

could also be true with an adolescent population. As stated by Fischer and Rose,76 the

adolescent brain is continuously growing and thus can cause an improvement in scores

for both groups or negate the difference that may have been detected. The ANAM has

been demonstrated to assess the same cognitive abilities as traditional neuropsychological

tests" but this test battery is unique to the current study and therefore could be a factor.








ANAM

To the author's knowledge, this is one of the first studies to examine the effects of

a sports-related concussion in adolescent athletes using the ANAM. Previous research

has been conducted using the ANAM in the military sector and examining the effects of

traumatic brain injury (TBI) in adults.28'82 When TBI individuals were tested over

multiple days and sessions a significant difference between injured and uninjured groups

was reported.2 It was also reported that TBI individuals demonstrated erratic and

inconsistent performance over a four-day period while uninjured subjects demonstrated a

consistent performance on the ANAM test battery. These results are contradictory to the

present study and can be attributed to subject age and severity of injury. In the Bleiberg

et al.28 study the mean age of subjects was 31.8 years and the injury was sustained in an

automobile accident while the mean age of the subjects in the current study was 15.5

years with the injury caused by sport activity. The severity of the injury in the Bleiberg

et al.28 was more severe than that of the current study thus creating the discrepancy in the

findings.

The ANAM consisted of 4 subtests: Simple Reaction Time (SRT), Matching to

Sample (MSP), Running Memory (CPT), and the Stanford Sleepiness Scale. Daniel et

al.5 used the ANAM to examine cognitive differences in adolescent athletes over the

course of a football season. The authors reported healthy adolescent athletes improved

between pre- and post-season tests. Based on this result Daniel et al.15 concluded that

baseline testing may not be necessary for adolescent athletes because they may

experience cognitive growth during the course of a season and thus it was not conducted

in the current study.








Subjects did not demonstrate any significant differences on the SRT subtest but

demonstrated a significant difference between session one and session two for the

measure of accuracy on the MSP. Subjects were more accurate during session one

regardless of group or day. This could be attributed to subjects being more attentive and

concentrating more during session one and also it was a new day of testing and therefore

they felt challenged. Similarly, subjects demonstrated higher accuracy on the CPT during

session one but also lower accuracy on day one. The lower accuracy on day one would

be expected and can be credited to the test being a new experience and subjects were not

familiar with the procedure (Figure 5-1). This can also be associated to the increased

response time on day one as compared to all other days. Again, all subjects were

unfamiliar with the test and therefore took longer to respond. A significant difference

was also noted between days two and four for the total group. This difference may be

because subjects became familiar with the test on day two and then performance plateau

for day three but improved on day four (Figure 5-2). Regardless of group, subjects were

less efficient on day one but a significant difference was again demonstrated between

days two and four and also five (Figure 5-3). Subjects became increasingly more

efficient on their performance of the test after day one. Many of these improvements can

be attributed to learning effects. Daniel et al.15 did not report such findings because

subjects only completed the test twice, whereas subjects in the present study completed

the tests a total of nine times. Even though multiple variations of the test are computer

generated, a learning effect or familiarization occurs. Subjects obtain a better

understanding of the test procedures and instructions. In a study by Bleiberg et al,2'

control subjects demonstrated consistent improvement in performance over a four day










testing period with multiple tests sessions in a day but the TBI patients demonstrated

erratic performance. As stated this discrepancy in results between the studies could be

due to the nature and extent of the injury. Other comparisons to published research are

difficult since the ANAM has not been widely used.


94-
92-







1" 2 3 4 5









84-
1" 2^ 3 4^ 5
Day

*p<.05-significanly different from all means

Figure 5-1. CPT accuracy by days







C M- -4 total
480- Injured
40 control
440 -
420
1. 2A 3 4A 5
Day

*p<05-significantly different from all means
^p<.05-significant between days 2 & 4
Figure 5-2. CPT mean reaction time










140-
130 -
S120 "*-total
-*-Injured
110- L c o
100 -
90
1* 2A 3 4^ 5^
Day

*p<.05-significantly different from all means
^p<.05-significant between day 2 & days 4 & 5
Figure 5-3. CPT throughput



One interesting result was that a significant differences existed between days two

and four on the measures of CPT mean reaction time and throughput (Figures 5-2 and 5-

3), Stanford Sleepiness scale mean response time (Figure 5-4), tandem eyes-closed (TC)

of the modified Rhomberg (Figure 5-5), Trail Making A time to completion and Trail

Making B time to completion. This significant difference was regardless of group.

Bleiberg et al.28 also noted a difference between day one and day three of testing. The

difference exhibited in the current study could be due to a familiarization of the testing

procedures since most subjects appeared to score significantly better on day four as

compared to day two. One important point to remember is that according to Powell and

Barber-Foss17 a concussed individual has a median time loss of three days and

Guskiewicz et al.5 reported a mean time loss of 4.2 days. If the results of the current

study are an indication, most concussed athletes have not improved significantly between

days one and two or days two and three on the battery of tests. Therefore careful

consideration should be taken before returning these individuals to play.










22400
20400
18400
16400 --total
I 14400 ---injured
12400 control
10400
8400
6400
1* 2^ 3 4A 5
Day

*p<05-significantly different from all means
ps<.05-sigificant between days 2 & 4
Figure 5-4. Stanford Sleepiness Scale mean reaction time








-6
4--total
-- injured
control


1" 2^ 3 4A^
Day

*p<.05-significantly different from all means
^p<.05-significant between days 2 & 4
Figure 5-5. Tandem-stance eyes closed



Modified Rhomberg with BESS

Discrepancies with published research also exist concerning the modified

Rhomberg with the BESS. Postural stability deficits have been observed for three days

following a mild head injury.19 These deficits were detected using the Sensory

Organization test on the NeuroCom Smart Balance Master. Because not all athletic

facilities have this expensive equipment at their disposal, Riemann et al.25 developed the








BESS. Reimann et al.9 reported significant postural instability in MHI subjects using the

BESS. Theses instabilities were demonstrated through day three of testing. In the

present study no significant differences were noted between groups, day or session,

except for TC. Although it should be noted that injured subjects exhibited higher error

scores on the four variations. A significant day main effect was demonstrated with

subjects committing more errors during day one compared to all other days and a

significant difference was noted between days two and four (Figure 5-5). Again this can

be due to a familiarization with the test and a resulting plateau. Riemann et al.9 stated

that the single-leg and tandem stance on a foam surface should diminish the

somatosensory information delivered to the postural control system. These factors

combined with the removal of vision should present enough of a challenge to the central

sensory integration and processing mechanisms to elicit deficits resulting from a mild

head injury. This conclusion was made after assessing collegiate athletes.9 However,

adolescent athletes respond differently as indicated in the current study or the degree of

injury was not comparable.

SAC

The SAC, a mental status exam, was designed to assist sports medicine

professionals in the initial field assessment of a concussion. To eliminate the learning

effect three equivalent forms were designed.2673 This equivalency was demonstrated in

the present study as no significant differences were indicated between groups, days or

sessions. Because the SAC was developed to be used as a mental status exam after the

occurrence of a concussion, it is expected that a difference would have occurred.

Furthermore, the age and education level of the groups were equal thus, deficits due to








the concussion should have been present. It is possible that the SAC was not sensitive

enough to detect a difference in the mental status of injured adolescent athletes.

Trail Making A and B

The Trail Making A and B tests have been widely used to detect cognitive deficits

after mild head injury.7,10,13,'1949 Improvement over the test period on both the Trail

Making A and B have been demonstrated, thus demonstrating a practice effect.7 ',19 Even

though practice effects have been demonstrated the tests were included in the present

study to serve as a common measure. One obvious reason for the practice effect is the

use of only one form for each test. In order to reduce the risk of a practice effect multiple

forms of a test should exist.41

Contrary to previous research, the concussed athletes in this study did not display

significantly poorer performance than healthy controls on any of the motor performance

or computerized neuropsychological tests. These findings suggest that the ANAM, SAC,

Trail Making A and B may not be sensitive enough to reveal cognitive deficits in

adolescent athletes sustaining a concussion or that practice effects occurred in both

groups. It should be remembered that any neuropsychological measure administered

numerous times over a brief period are likely to be affected by practice.49 These

differences in results of the current study compared to the results of previous studies

could be attributed to the combination of the ANAM and adolescent athletes since neither

of these has been used in previous research. Adolescent athletes perform cognitive

functions differently than collegiate or professional athletes and therefore the results of

the current study should differ from those of past studies. The injured adolescent athletic

population has been neglected in this area of research and the ANAM has only been used








to examine healthy adolescent athletes, adults with TBI, or in the military setting.

Research needs to continue using the ANAM with injured adolescent athletes.

Conclusions

Regarding research hypothesis one: High school athletes with a sports-related

concussion will take significantly longer to complete the Trail Making A and B tests as

compared to uninjured athletes, the following conclusion was made:

High school athletes with a sports-related concussion did not take significantly

longer to respond on the Trail Making A and B tests. Concussed subjects did take longer

to respond but this was not statistically significant.

Regarding hypothesis number two: High school athletes with a sports-related

concussion will have significantly higher error scores on all versions of the modified

Rhomberg test using the BESS, the following conclusion was made:

High school athletes with a sports-related concussion did not have significantly

higher error scores on all versions of the modified Rhomberg test using the BESS. On

average across the days concussed athletes exhibited higher error scores on the four

variations of the modified Rhomberg but these differences were not statistically

significant.

Regarding hypothesis number three: Injured high school athletes will have

significantly lower initial scores on the subtests of the Automated Neuropsychological

Assessment Metrics (ANAM) test battery than their matched counterparts, the following

conclusion was made:

Concussed athletes did not demonstrated statistically significant lower initial

scores on the subtests of the Automated Neuropsychological Assessment Metrics








(ANAM) test battery than their matched counterparts. The initial test scores of the

concussed group were lowered but this was not reported as statistically significant.

Regarding hypothesis number four: High school athletes who sustain a sports-

related concussion and exhibit significantly poorer test results will take longer to return to

play, the following conclusion was made:

Injured athletes did not exhibit significantly poorer test results and therefore the

correlation to time loss was not demonstrated.

Future Implications

Research in the area of sports-related concussion and adolescent athletes is

needed to assist in improving the healthcare provided to this population. Some

recommended future research ideas based on the results of this study are:

1. Collect data at time intervals further apart than 15 minutes.

2. Collect baseline data on a group of adolescent athletes for the ANAM,
modified Rhomberg with the BESS, SAC, Trail Making A, and Trail
Making B.

3. Collect baseline data on adolescent athletes at the beginning of each
season (yearly and/or multiple times a year) to determine if cognitive
growth occurs over the length of a season and therefore changes from
once season to the next.

4. Perform a study obtaining baseline data on adolescent athletes, test at
daily intervals for 5 to 7 days all those athletes who sustain a
concussion and determine if a rehabilitative factor occurs.

5. Monitor adolescent athletes over the course of their high school athletic
career and examine the cognitive changes in athletes sustaining one or
multiple concussions.

6. Examine the cognitive and postural stability of athletes as they perform
multiple tasks at one time.













APPENDIX A
AMERICAN ACADEMY OF NEUROLOGY CONCUSSION GRADING SCALE









American Academy of Neurology Concussion Grading Scale45


Grade 1 Transient confusion, no loss of consciousness, symptoms resolve in< 15
minutes

Grade 2 Transient confusion, no loss of consciousness, symptoms last > 15 minutes

Grade 3 Any loss of consciousness, either brief (seconds) or prolonged (minutes)














APPENDIX B
BALANCE ERROR SCORING SYSTEM









Subject #:


Day #: __ Session #:


Balance Error Scoring System25

Athlete is given one error point for each of the following errors:
* Lifting hands off iliac crests
* Opening eyes
* Stepping, stumbling, or falling
* Remaining out of the test position for more than five seconds
* Moving hip into more than 30 degrees of flexion or abduction
* Lifting forefoot or heel


STANCE ERROR POINTS

2
3
4


TOTAL ERROR POINTS:













APPENDIX C
INFORMED CONSENT FORM











Informed Consent
Protocol Title: Consistency of concussed athletes on a battery of cognitive and motor
performance tests.

Please read this document carefully before you decide to participate in this study.

Purpose of the research study:
To determine if athletes suffering from a sports-related mild head injury
(concussion/bell-rung) have initial levels of performance comparable with those
of uninjured athletes on thinking and coordination tests. Also to determine if
athletes with mild head injuries show inconsistencies and unstable performance
over five days of testing as compared with uninjured athletes.

What will you be asked to do in this study:
Your son/daughter will be asked to complete a medical history questionnaire at
the beginning of the study. This questionnaire contains questions regarding your
son/daughter's age, gender, race, height, weight, sports participating in, number of
years of participation, current medications, presence of a learning disability,
previous head injury (cause, how many, when, how long did it last, medical
treatment), and other orthopedic injuries (sprains, strains, and fracture). Your
son/daughter will also be asked to complete a test of concentration, memory,
reaction time, and balance/coordination 3 times each day for 5 days. Some of the
testing will be completed using a computer. These tests will be given to your
son/daughter by the principal investigator and are similar to those tests given to an
athlete when he/she has a suffered from a mild head injury (concussion).

Time required:
There will be 3 sessions per day for 5 days with each session of testing taking
approximately 20 minutes.

Risks and Benefits:
Information collected in this study will help determine if the score of an
individual differs on each individual day and between injured and non-injured
subjects. Medical professionals will find the results of this study useful because
this study will supply information on the thinking and coordination effects of a
concussion and how these effects differ between days. This information will
assist medical professionals in making decisions regarding when it is appropriate
to return an athlete to activity.
There will be no risk to your son/daughter as a result of participating in this study.

Compensations:
Your son/daughter will receive $25.00 for completing the first 3 days of testing
and another $25.00 for completing the last 2 days of testing.









Confidentiality:
Your son/daughter's identity will be kept confidential to the extent provided by
law. Your son/daughter's information will be assigned a code number. The list
connecting your son/daughter's name to this number will be kept in a locked file
at the University of Florida. When the study is completed and the data have been
analyzed the list will be destroyed. Your son/daughter's name will not be used in
any report.

Voluntary participation:
Your son/daughter's participation in this study is completely voluntary. There is
no penalty for not participating.

Right to withdraw from the study:
You and your son/daughter have the right to withdraw from the study at anytime
without consequence. If your son/daughter withdraws from the study before
completing the first 3 days of testing he/she will receive no compensation.

Whom to contact if you have questions about the study:
Traci N. Gearhart MS, ATC/L, Doctoral Student, Exercise and Sport Sciences,
PO Box 118205, ph 392-0584 ext.1402, tracinap@aol.com, fax 392-5262
or
MaryBeth Horodyski, EdD, ATC/L, Associate Professor, Exercise and Sport
Sciences, FLG 149, PO Box 118205, ph 392-0584 ext.1261,
marybeth@hhp.ufl.edu, fax 392-5262

Whom to contact about your rights as a research participant in the study:
UFIRB office, Box 112250, University of Florida, Gainesville, FL 32611-2250;
ph 392-0433

Agreement:
I have read the procedure described above. I voluntarily agree to allow my
son/daughter to participate and I have received a copy of this description.


Participant: Date:

Parent/Guardian: Date:


Principal Investigator:


Date:














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BIOGRAPHICAL SKETCH

Traci Napolitano Gearhart was born in Newport, Rhode Island and attended

Middletown High School graduating in 1990. She continued her education at Slippery

Rock University in Slippery Rock, Pennsylvania majoring in Athletic Training. At

Slippery Rock University she obtained valuable clinical experience with the various

athletic teams she worked with. In April of 1994 she passed the National Athletic

Trainers' Association Board of Certification Examination and then became a certified

athletic trainer upon graduation from Slippery Rock University.

Traci then began her graduate work in a NATA-accredited graduate Athletic

Training Program at the University of Florida. While at the University of Florida she

worked as a graduate assistant and head athletic trainer at Bradford County High School.

At Bradford County High School she was responsible for beginning the athletic training

program. This is also where she met her husband Robert Gearhart and they married in

1998. Traci graduated from the University of Florida in 1996 and was employed by

Orlando Regional Healthcare Systems as an athletic trainer at South Lake High School.

Prior to her employment with Orlando Regional Healthcare Systems, she volunteered at

the 1996 Summer Olympics in Atlanta, Georgia. Traci worked at South Lake High

School for two years before leaving to teach at Bradford County High School for a year.

After gaining additional professional experience she enrolled in the doctoral Athletic

Training Program at the University of Florida.






80

Upon receiving her doctorate she hopes to obtain a position at the

university/collegiate level as an assistant professor. Obtaining such a position would

allow her to instruct and guide future athletic trainers.








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.


M r orodyski, Chair
As ociate Professor of Exercise and
Sport Sciences

I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully uate, in scope and quality,
as a dissertation for the degree of Doctor of Philosophy.


Michael Powers
Assistant Professor of Exercise and Sport
Sciences

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.


Denis Brunt
Associate Professor of Physical Therapy

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 Kaminski
Assistant Professor of Exercise and Sport
Sciences

This dissertation was submitted to the Graduate Faculty of the Collegf Health
and Human Performance and to the Graduate School and ed as p
fulfillment of the requirements for the degree of Doctor / y

May, 2002
Dean, ollge of Health and Human
Perform ace


Dean, Graduate School















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1780
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3 1262 08556 6445




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