Concussion Positioning Statement
Journal of Athletic Training
2004;39(3):280–297
by the National Athletic Trainers’ Association, Inc
www.journalofathletictraining.org
National Athletic Trainers’ Association
Position Statement: Management of Sport-
Related Concussion
Kevin M. Guskiewicz*; Scott L. Bruce†; Robert C. Cantu‡; Michael S.
Ferrara§; James P. Kelly ; Michael McCrea¶; Margot Putukian#;
Tamara C. Valovich McLeod**
*University of North Carolina at Chapel Hill, Chapel Hill, NC; †California University of Pennsylvania, California, PA;
‡Emerson Hospital, Concord, MA; §University of Georgia, Athens, GA; University of Colorado, Denver, CO;
¶Waukesha Memorial Hospital, Waukesha, WI; #Princeton University, Princeton, NJ; **Arizona School of Health
Sciences, Mesa, AZ
Kevin M. Guskiewicz, PhD, ATC, FACSM; Scott L. Bruce, MS, ATC; Robert C. Cantu, MD, FACSM; Michael S. Ferrara, PhD,
ATC; James P. Kelly, MD; Michael McCrea, PhD; Margot Putukian, MD, FACSM; and Tamara C. Valovich McLeod, PhD, ATC,
CSCS, contributed to conception and design, acquisition and analysis and interpretation of the data; and drafting, critical
revision, and final approval of the article.
Address correspondence to National Athletic Trainers’ Association, Communications Department, 2952 Stemmons Freeway,
Dallas, TX 75247.
Sport in today’s society is more popular than probably is the key to reducing the incidence and severity of sport-
ever imagined. Large numbers of athletes participate in
related concussion and improving return-to-play decisions.
a variety of youth, high school, collegiate, professional,
This position statement should provide valuable information
and recreational sports. As sport becomes more of a fixture in
and recommendations for certified athletic trainers (ATCs),
the lives of Americans, a burden of responsibility falls on the
physicians, and other medical professionals caring for athletes
shoulders of the various organizations, coaches, parents, cli-
at the youth, high school, collegiate, and elite levels. The fol-
nicians, officials, and researchers to provide an environment
lowing recommendations are derived from the most recent sci-
that minimizes the risk of injury in all sports. For example,
entific and clinic-based literature on sport-related concussion.
the research-based recommendations made for football be-
The justification for these recommendations is presented in the
tween 1976 and 1980 resulted in a significant reduction in the
summary statement following the recommendations. The sum-
incidence of fatalities and nonfatal catastrophic injuries. In
mary statement is organized into the following sections: ‘‘De-
1968, 36 brain and cervical spine fatalities occurred in high
fining and Recognizing Concussion,’’ ‘‘Evaluating and Mak-
school and collegiate football. The number had dropped to
ing the Return-to-Play Decision,’’ ‘‘Concussion Assessment
zero in 1990 and has averaged about 5 per year since then.1
Tools,’’ ‘‘When to Refer an Athlete to a Physician After Con-
This decrease was attributed to a variety of factors, including
cussion,’’ ‘‘When to Disqualify an Athlete,’’ ‘‘Special Consid-
(1) rule changes, which have outlawed spearing and butt
erations for the Young Athlete,’’ ‘‘Home Care,’’ and ‘‘Equip-
blocking, (2) player education about the rule changes and the
ment Issues.’’
consequences of not following the rules, (3) implementation
of equipment standards, (4) availability of alternative assess-
RECOMMENDATIONS
ment techniques, (5) a marked reduction in physical contact
time during practice sessions, (6) a heightened awareness
among clinicians of the dangers involved in returning an ath-
Defining and Recognizing Concussion
lete to competition too early, and (7) the athlete’s awareness
of the risks associated with concussion.
1. The ATC should develop a high sensitivity for the various
Research in the area of sport-related concussion has provid-
mechanisms and presentations of traumatic brain injury
ed the athletic training and medical professions with valuable
(TBI), including mild, moderate, and severe cerebral con-
new knowledge in recent years. Certified athletic trainers, who
cussion, as well as the more severe, but less common,
on average care for 7 concussive injuries per year,2 have been
head injuries that can cause damage to the brain stem and
forced to rethink how they manage sport-related concussion.
other vital centers of the brain.
Recurrent concussions to several high-profile athletes, some of
2. The colloquial term ‘‘ding’’ should not be used to describe
whom were forced into retirement as a result, have increased
a sport-related concussion. This stunned confusional state
awareness among sports medicine personnel and the general
is a concussion most often reflected by the athlete’s initial
public. Bridging the gap between research and clinical practice
confusion, which may disappear within minutes, leaving
280
Volume 39 • Number 3 • September 2004
no outwardly observable signs and symptoms. Use of the
vision, and so on. It is recommended that ATCs and phy-
term ‘‘ding’’ generally carries a connotation that dimin-
sicians consistently use a symptom checklist similar to the
ishes the seriousness of the injury. If an athlete shows
one provided in Appendix A.
concussion-like signs and reports symptoms after a con-
10. In addition to a thorough clinical evaluation, formal cog-
tact to the head, the athlete has, at the very least, sustained
nitive and postural-stability testing is recommended to as-
a mild concussion and should be treated for a concussion.
sist in objectively determining injury severity and readi-
3. To detect deteriorating signs and symptoms that may in-
ness to return to play (RTP). No one test should be used
dicate a more serious head injury, the ATC should be able
solely to determine recovery or RTP, as concussion pre-
to recognize both the obvious signs (eg, fluctuating levels
sents in many different ways.
of consciousness, balance problems, and memory and
11. Once symptom free, the athlete should be reassessed to
concentration difficulties) and the more common, self-
establish that cognition and postural stability have re-
reported symptoms (eg, headache, ringing in the ears, and
turned to normal for that player, preferably by comparison
nausea).
with preinjury baseline test results. The RTP decision
4. The ATC should play an active role in educating athletes,
should be made after an incremental increase in activity
coaches, and parents about the signs and symptoms as-
with an initial cardiovascular challenge, followed by
sociated with concussion, as well as the potential risks of
sport-specific activities that do not place the athlete at risk
playing while still symptomatic.
for concussion. The athlete can be released to full partic-
5. The ATC should document all pertinent information sur-
ipation as long as no recurrent signs or symptoms are
rounding the concussive injury, including but not limited
present.
to (1) mechanism of injury; (2) initial signs and symp-
toms; (3) state of consciousness; (4) findings on serial test-
ing of symptoms and neuropsychological function and
Concussion Assessment Tools
postural-stability tests (noting any deficits compared with
baseline); (5) instructions given to the athlete and/or par-
ent; (6) recommendations provided by the physician; (7)
12. Baseline testing on concussion assessment measures is
date and time of the athlete’s return to participation; and
recommended to establish the individual athlete’s ‘‘nor-
(8) relevant information on the player’s history of prior
mal’’ preinjury performance and to provide the most re-
concussion and associated recovery pattern(s).3
liable benchmark against which to measure postinjury re-
covery. Baseline testing also controls for extraneous
variables (eg, attention deficit disorder, learning disabili-
Evaluating and Making the Return-to-Play Decision
ties, age, and education) and for the effects of earlier con-
cussion while also evaluating the possible cumulative ef-
6. Working together, ATCs and team physicians should agree
fects of recurrent concussions.
on a philosophy for managing sport-related concussion be-
13. The use of objective concussion assessment tools will help
fore the start of the athletic season. Currently 3 approaches
ATCs more accurately identify deficits caused by injury
are commonly used: (1) grading the concussion at the time
and postinjury recovery and protect players from the po-
of the injury, (2) deferring final grading until all symp-
tential risks associated with prematurely returning to com-
toms have resolved, or (3) not using a grading scale but
petition and sustaining a repeat concussion. The concus-
rather focusing attention on the athlete’s recovery via
sion assessment battery should include a combination of
symptoms, neurocognitive testing, and postural-stability
tests for cognition, postural stability, and self-reported
testing. After deciding on an approach, the ATC-physician
symptoms known to be affected by concussion.
team should be consistent in its use regardless of the ath-
14. A combination of brief screening tools appropriate for use
lete, sport, or circumstances surrounding the injury.
on the sideline (eg, Standardized Assessment of Concus-
7. For athletes playing sports with a high risk of concussion,
sion [SAC], Balance Error Scoring System [BESS], symp-
baseline cognitive and postural-stability testing should be
tom checklist) and more extensive measures (eg, neuro-
considered. In addition to the concussion injury assess-
psychological testing, computerized balance testing) to
ment, the evaluation should also include an assessment of
more precisely evaluate recovery later after injury is rec-
the cervical spine and cranial nerves to identify any cer-
ommended.
vical spine or vascular intracerebral injuries.
15. Before instituting a concussion neuropsychological testing
8. The ATC should record the time of the initial injury and
battery, the ATC should understand the test’s user require-
document serial assessments of the injured athlete, noting
ments, copyright restrictions, and standardized instruc-
the presence or absence of signs and symptoms of injury.
tions for administration and scoring. All evaluators should
The ATC should monitor vital signs and level of con-
be appropriately trained in the standardized instructions
sciousness every 5 minutes after a concussion until the
for test administration and scoring before embarking on
athlete’s condition improves. The athlete should also be
testing or adopting an instrument for clinical use. Ideally,
monitored over the next few days after the injury for the
the sports medicine team should include a neuropsychol-
presence of delayed signs and symptoms and to assess
ogist, but in reality, many ATCs may not have access to
recovery.
a neuropsychologist for interpretation and consultation,
9. Concussion severity should be determined by paying close
nor the financial resources to support a neuropsychologi-
attention to the severity and persistence of all signs and
cal testing program. In this case, it is recommended that
symptoms, including the presence of amnesia (retrograde
the ATC use screening instruments (eg, SAC, BESS,
and anterograde) and loss of consciousness (LOC), as well
symptom checklist) that have been developed specifically
as headache, concentration problems, dizziness, blurred
for use by sports medicine clinicians without extensive
Journal of Athletic Training
281
training in psychometric or standardized testing and that
exercises should include sideline jogging followed by
do not require a special license to administer or interpret.
sprinting, sit-ups, push-ups, and any sport-specific, non-
16. Athletic trainers should adopt for clinical use only those
contact activities (or positions or stances) the athlete might
neuropsychological and postural stability measures with
need to perform on returning to participation. Athletes
population-specific normative data, test-retest reliability,
who return on the same day because symptoms resolved
clinical validity, and sufficient sensitivity and specificity
quickly ( 20 minutes) should be monitored closely after
established in the peer-reviewed literature. These stan-
they return to play. They should be repeatedly reevaluated
dards provide the basis for how well the test can distin-
on the sideline after the practice or game and again at 24
guish between those with and without cerebral dysfunc-
and 48 hours postinjury to identify any delayed onset of
tion in order to reduce the possibility of false-positive and
symptoms.
false-negative errors, which could lead to clinical deci-
23. Athletes who experience LOC or amnesia should be dis-
sion-making errors.
qualified from participating on the day of the injury.
17. As is the case with all clinical instruments, results from
24. The decision to disqualify from further participation on
assessment measures to evaluate concussion should be in-
the day of a concussion should be based on a comprehen-
tegrated with all aspects of the injury evaluation (eg, phys-
sive physical examination; assessment of self-reported
ical examination, neurologic evaluation, neuroimaging,
postconcussion signs and symptoms; functional impair-
and player’s history) for the most effective approach to
ments, and the athlete’s past history of concussions. If
injury management and RTP decision making. Decisions
assessment tools such as the SAC, BESS, neuropsycho-
about an athlete’s RTP should never be based solely on
logical test battery, and symptom checklist are not used,
the use of any one test.
a 7-day symptom-free waiting period before returning to
participation is recommended. Some circumstances, how-
ever, will warrant even more conservative treatment (see
When to Refer an Athlete to a Physician After
recommendation 25).
Concussion
25. Athletic trainers should be more conservative with athletes
who have a history of concussion. Athletes with a history
18. The ATC or team physician should monitor an athlete
of concussion are at increased risk for sustaining subse-
with a concussion at 5-minute intervals from the time of
quent injuries as well as for slowed recovery of self-re-
the injury until the athlete’s condition completely clears
ported postconcussion signs and symptoms, cognitive dys-
or the athlete is referred for further care. Coaches should
function, and postural instability after subsequent injuries.
be informed that in situations when a concussion is sus-
In athletes with a history of 3 or more concussions and
pected but an ATC or physician is not available, their
experiencing slowed recovery, temporary or permanent
primary role is to ensure that the athlete is immediately
disqualification from contact sports may be indicated.
seen by an ATC or physician.
19. An athlete with a concussion should be referred to a phy-
sician on the day of injury if he or she lost consciousness,
Special Considerations for the Young Athlete
experienced amnesia lasting longer than 15 minutes, or
meets any of the criteria outlined in Appendix B.
26. Athletic trainers working with younger (pediatric) athletes
20. A team approach to the assessment of concussion should
should be aware that recovery may take longer than in
be taken and include a variety of medical specialists. In
older athletes. Additionally, these younger athletes are ma-
addition to family practice or general medicine physician
turing at a relatively fast rate and will likely require more
referrals, the ATC should secure other specialist referral
frequent updates of baseline measures compared with old-
sources within the community. For example, neurologists
er athletes.
are trained to assist in the management of patients expe-
27. Many young athletes experience sport-related concussion.
riencing persistent signs and symptoms, including sleep
Athletic trainers should play an active role in helping to
disturbances. Similarly, a neuropsychologist should be
educate young athletes, their parents, and coaches about
identified as part of the sports medicine team for assisting
the dangers of repeated concussions. Continued research
athletes who require more extensive neuropsychological
into the epidemiology of sport-related concussion in
testing and for interpreting the results of neuropsycholog-
young athletes and prospective investigations to determine
ical tests.
the acute and long-term effects of recurrent concussions
21. A team approach should be used in making RTP decisions
in younger athletes are warranted.
after concussion. This approach should involve input from
28. Because damage to the maturing brain of a young athlete
the ATC, physician, athlete, and any referral sources. The
can be catastrophic (ie, almost all reported cases of sec-
assessment of all information, including the physical ex-
ond-impact syndrome are in young athletes), athletes un-
amination, imaging studies, objective tests, and exertional
der age 18 years should be managed more conservatively,
tests, should be considered prior to making an RTP de-
using stricter RTP guidelines than those used to manage
cision.
concussion in the more mature athlete.
When to Disqualify an Athlete
Home Care
22. Athletes who are symptomatic at rest and after exertion
29. An athlete with a concussion should be instructed to avoid
for at least 20 minutes should be disqualified from return-
taking medications except acetaminophen after the injury.
ing to participation on the day of the injury. Exertional
Acetaminophen and other medications should be given
282
Volume 39 • Number 3 • September 2004
only at the recommendation of a physician. Additionally,
depends on the nature and severity of the injury. Several terms
the athlete should be instructed to avoid ingesting alcohol,
are used to describe this injury, the most global being TBI,
illicit drugs, or other substances that might interfere with
which can be classified into 2 types: focal and diffuse. Focal
cognitive function and neurologic recovery.
or posttraumatic intracranial mass lesions include subdural he-
30. Any athlete with a concussion should be instructed to rest,
matomas, epidural hematomas, cerebral contusions, and intra-
but complete bed rest is not recommended. The athlete
cerebral hemorrhages and hematomas. These are considered
should resume normal activities of daily living as tolerated
uncommon in sport but are serious injuries; the ATC must be
while avoiding activities that potentially increase symp-
able to detect signs of clinical deterioration or worsening
toms. Once he or she is symptom free, the athlete may
symptoms during serial assessments. Signs and symptoms of
resume a graded program of physical and mental exertion,
these focal vascular emergencies can include LOC, cranial
without contact or risk of concussion, up to the point at
nerve deficits, mental status deterioration, and worsening
which postconcussion signs and symptoms recur. If symp-
symptoms. Concern for a significant focal injury should also
toms appear, the exertion level should be scaled back to
be raised if these signs or symptoms occur after an initial lucid
allow maximal activity without triggering symptoms.
period in which the athlete seemed normal.
31. An athlete with a concussion should be instructed to eat
Diffuse brain injuries can result in widespread or global
a well-balanced diet that is nutritious in both quality and
disruption of neurologic function and are not usually associ-
quantity.
ated with macroscopically visible brain lesions except in the
32. An athlete should be awakened during the night to check
most severe cases. Most diffuse injuries involve an accelera-
on deteriorating signs and symptoms only if he or she
tion-deceleration motion, either within a linear plane or in a
experienced LOC, had prolonged periods of amnesia, or
rotational direction or both. In these cases, lesions are caused
was still experiencing significant symptoms at bedtime.
by the brain being shaken within the skull.4,5 The brain is
The purpose of the wake-ups is to check for deteriorating
suspended within the skull in cerebrospinal fluid (CSF) and
signs and symptoms, such as decreased levels of con-
has several dural attachments to bony ridges that make up the
sciousness or increasing headache, which could indicate a
inner contours of the skull. With a linear acceleration-decel-
more serious head injury or a late-onset complication,
eration mechanism (side to side or front to back), the brain
such as an intracranial bleed.
experiences a sudden momentum change that can result in tis-
33. Oral and written instructions for home care should be giv-
sue damage. The key elements of injury mechanism are the
en to the athlete and to a responsible adult (eg, parent or
velocity of the head before impact, the time over which the
roommate) who will observe and supervise the athlete
force is applied, and the magnitude of the force.4,5 Rotational
during the acute phase of the concussion while at home
acceleration-deceleration injuries are believed to be the pri-
or in the dormitory. The ATC and physician should agree
mary injury mechanism for the most severe diffuse brain in-
on a standard concussion home-instruction form similar to
juries. Structural diffuse brain injury (diffuse axonal injury
the one presented in Appendix C, and it should be used
[DAI]) is the most severe type of diffuse injury because axonal
consistently for all concussions.
disruption occurs, typically resulting in disturbance of cogni-
tive functions, such as concentration and memory. In its most
severe form, DAI can disrupt the brain-stem centers respon-
Equipment Issues
sible for breathing, heart rate, and wakefulness.4,5
Cerebral concussion, which is the focus of this position
34. The ATC should enforce the standard use of helmets for
statement, can best be classified as a mild diffuse injury and
protecting against catastrophic head injuries and reducing
is often referred to as mild TBI (MTBI). The injury involves
the severity of cerebral concussions. In sports that require
an acceleration-deceleration mechanism in which a blow to the
helmet protection (football, lacrosse, ice hockey, baseball/
head or the head striking an object results in 1 or more of the
softball, etc), the ATC should ensure that all equipment
following conditions: headache, nausea, vomiting, dizziness,
meets either the National Operating Committee on Stan-
dards for Athletic Equipment (NOCSAE) or American So-
balance problems, feeling ‘‘slowed down,’’ fatigue, trouble
ciety for Testing and Materials (ASTM) standards.
sleeping, drowsiness, sensitivity to light or noise, LOC,
35. The ATC should enforce the standard use of mouth guards
blurred vision, difficulty remembering, or difficulty concen-
for protection against dental injuries; however, there is no
trating.6 In 1966, the Congress of Neurological Surgeons pro-
scientific evidence supporting their use for reducing con-
posed the following consensus definition of concussion, sub-
cussive injury.
sequently endorsed by a variety of medical associations:
36. At this time, the ATC should neither endorse nor dis-
‘‘Concussion is a clinical syndrome characterized by imme-
courage the use of soccer headgear for protecting against
diate and transient impairment of neural functions, such as
concussion or the consequences of cumulative, subcon-
alteration of consciousness, disturbance of vision, equilibrium,
cussive impacts to the head. Currently no scientific evi-
etc, due to mechanical forces.’’7 Although the definition re-
dence supports the use of headgear in soccer for reducing
ceived widespread consensus in 1966, more contemporary
concussive injury to the head.
opinion (as concluded at the First International Conference on
Concussion in Sport, Vienna, 20018) was that this definition
fails to include many of the predominant clinical features of
DEFINING AND RECOGNIZING CONCUSSION
concussion, such as headache and nausea. It is often reported
Perhaps the most challenging aspect of managing sport-re-
that there is no universal agreement on the standard definition
lated concussion is recognizing the injury, especially in ath-
or nature of concussion; however, agreement does exist on
letes with no obvious signs that a concussion has actually oc-
several features that incorporate clinical, pathologic, and bio-
curred. The immediate management of the head-injured athlete
mechanical injury constructs associated with head injury:
Journal of Athletic Training
283
1. Concussion may be caused by a direct blow to the head or
or stretching of tissue, whereas shearing involves a force that
elsewhere on the body from an ‘‘impulsive’’ force trans-
moves across the parallel organization of the tissue. Brief, uni-
mitted to the head.
form compressive stresses are fairly well tolerated by neural
2. Concussion may cause an immediate and short-lived im-
tissue, but tension and shearing stresses are very poorly tol-
pairment of neurologic function.
erated.4,9
3. Concussion may cause neuropathologic changes; however,
the acute clinical symptoms largely reflect a functional dis-
Neuroimaging of Cerebral Concussion
turbance rather than a structural injury.
4. Concussion may cause a gradient of clinical syndromes that
Traditionally, computed tomography (CT) and magnetic res-
may or may not involve LOC. Resolution of the clinical
onance imaging (MRI) have been considered useful in iden-
and cognitive symptoms typically follows a sequential
tifying certain types of brain lesions; however, they have been
course.
of little value in assessing less severe head injuries, such as
5. Concussion is most often associated with normal results on
cerebral concussion, and contributing to the RTP decision. A
conventional neuroimaging studies.8
CT scan is often indicated emergently if a focal injury such
as an acute subdural or epidural bleed is suspected; this study
Occasionally, players sustain a blow to the head resulting
easily demonstrates acute blood collection and skull fracture,
in a stunned confusional state that resolves within minutes.
but an MRI is superior at demonstrating an isodense subacute
The colloquial term ‘‘ding’’ is often used to describe this initial
or chronic subdural hematoma that may be weeks old.10,11
state. However, the use of this term is not recommended be-
Newer structural MRI modalities, including gradient echo, per-
cause this stunned confusional state is still considered a con-
fusion, and diffusion-weighted imaging, are more sensitive for
cussion resulting in symptoms, although only very short in
structural abnormalities (eg, vascular shearing) compared with
duration, that should not be dismissed in a cavalier fashion. It
other diagnostic imaging techniques.10 Functional imaging
is essential that this injury be reevaluated frequently to deter-
technologies (eg, positron emission tomography [PET], single-
mine if a more serious injury has occurred, because often the
photon emission computerized tomography [SPECT], and
evolving signs and symptoms of a concussion are not evident
functional MRI [fMRI]) are also yielding promising early re-
until several minutes to hours later.
sults and may help define concussion recovery.12 Presently, no
Although it is important for the ATC to recognize and even-
neuroanatomic or physiologic measurements can be used to
tually classify the concussive injury, it is equally important for
determine the severity of a concussion or when complete re-
the athlete to understand the signs and symptoms of a con-
covery has occurred in an individual athlete after a concussion.
cussion as well as the potential negative consequences (eg,
second-impact syndrome and predisposition to future concus-
sions) of not reporting a concussive injury. Once the athlete
EVALUATING AND MAKING THE RETURN-TO-PLAY
has a better understanding of the injury, he or she can provide
DECISION
a more accurate report of the concussion history.
Clinical Evaluation
Mechanisms of Injury
Results from a thorough clinical examination conducted by
A forceful blow to the resting, movable head usually pro-
both the ATC and the physician cannot be overlooked and
duces maximum brain injury beneath the point of cranial im-
should be considered very important pieces of the concussion
pact (coup injury). A moving head hitting an unyielding object
puzzle. These evaluations should include a thorough history
usually produces maximum brain injury opposite the site of
(including number and severity of previous head injuries), ob-
cranial impact (contrecoup injury) as the brain shifts within
servation (including pupil responses), palpation, and special
the cranium. When the head is accelerated before impact, the
tests (including simple tests of memory, concentration, and
brain lags toward the trailing surface, thus squeezing away the
coordination and a cranial nerve assessment). In many situa-
CSF and creating maximal shearing forces at this site. This
tions, a physician will not be present at the time of the con-
brain lag actually thickens the layer of CSF under the point
cussion, and the ATC will be forced to act on behalf of the
of impact, which explains the lack of coup injury in the mov-
sports medicine team. More formal neuropsychological testing
ing head. Alternatively, when the head is stationary before
and postural-stability testing should be viewed as adjuncts to
impact, neither brain lag nor disproportionate distribution of
the initial clinical and repeat evaluations (see ‘‘Concussion As-
CSF occurs, accounting for the absence of contrecoup injury
sessment Tools’’). The ATC-physician team must also consider
and the presence of coup injury.4,5
referral options to specialists such as neurologists, neurosur-
No scientific evidence suggests that one type of injury (coup
geons, neuropsychologists, and neuro-otologists, depending on
or contrecoup) is more serious than the other or that symptoms
the injury severity and situation. Referrals for imaging tests
present any differently. Many sport-related concussions are the
such as CT, MRI, or electronystagmography are also options
result of a combined coup-contrecoup mechanism, involving
that sometimes can aid in the diagnosis and/or management of
damage to the brain on both the side of initial impact and the
sport-related concussion but are typically used only in cases
opposite side of the brain due to brain lag. Regardless of
involving LOC, severe amnesia, abnormal physical or neuro-
whether the athlete has sustained a coup, contrecoup, or com-
logic findings, or increasing or intensified symptoms.
bined coup-contrecoup injury, the ATC should manage the in-
jury the same.
Determining Injury Severity
Three types of stresses can be generated by an applied force
to injure the brain: compressive, tensile, and shearing. Com-
The definition of concussion is often expanded to include
pression involves a crushing force in which the tissue cannot
mild, moderate, and severe injuries. Several early grading
absorb any additional force or load. Tension involves pulling
scales and RTP guidelines early were proposed for classifying
284
Volume 39 • Number 3 • September 2004
and managing cerebral concussions.6,13–20 None of the scales
Table 1. American Academy of Neurology Concussion Grading
Scale6
have been universally accepted or followed with much con-
sistency by the sports medicine community. In addition, most
Grade 1 (mild)
Transient confusion; no LOC*; symptoms
of these classification systems denote the most severe injuries
and mental status abnormalities resolve
as associated with LOC, which we now know is not always
15 min
predictive of recovery after a brain injury.21,22 It is important
Grade 2 (moderate)
Transient confusion; no LOC; symptoms and
mental status abnormalities last
15 min
for the ATC and other health care providers to recognize the
Grade 3 (severe)
Any LOC
importance of identifying retrograde amnesia and anterograde
amnesia, LOC, and other signs and symptoms present and to
*LOC indicates loss of consciousness.
manage each episode independently.
The ATC must recognize that no 2 concussions are identical
and that the resulting symptoms can be very different, de-
sured until asymptomatic). Although these findings suggest
pending on the force of the blow to the head, the degree of
that initial symptom severity is probably a better indicator than
metabolic dysfunction, the tissue damage and duration of time
either LOC or amnesia in predicting length of recovery, am-
needed to recover, the number of previous concussions, and
nesia was recently found to predict symptom and neurocog-
the time between injuries. All these factors must be considered
nitive deficits at 2 days postinjury.42 More research is needed
when managing an athlete suffering from cerebral concussion.3
in this area to help improve clinical decision making.
The 2 most recognizable signs of a concussion are LOC and
It has been suggested that LOC and amnesia, especially
amnesia; yet, as previously mentioned, neither is required for
when prolonged, should not be ignored,43,44 but evidence for
an injury to be classified as a concussion. A 2000 study of
their usefulness in establishing RTP guidelines is scarce. Loss
1003 concussions sustained by high school and collegiate foot-
of consciousness, whether it occurs immediately or after an
ball players revealed that LOC and amnesia presented infre-
initially lucid interval, is important in that it may signify a
quently, 9% and 27% of all cases, respectively, whereas other
more serious vascular brain injury. Other postconcussion signs
signs and symptoms, such as headache, dizziness, confusion,
and symptoms should be specifically addressed for presence
disorientation, and blurred vision, were much more common.23
and duration when the ATC is evaluating the athlete. Deter-
After the initial concussion evaluation, the ATC should deter-
mining whether a cervical spine injury has occurred is also of
mine whether the athlete requires more advanced medical in-
major importance because it is often associated with head in-
tervention on an emergent basis or whether the team physician
jury and should not be missed. If the athlete complains of neck
should be contacted for an RTP decision (Appendix B). It may
pain or has cervical spine tenderness, cervical spine immobi-
be helpful if the injury is graded throughout the process, but
lization should be considered. If a cervical spine injury is ruled
this grading is likely to be more important for treating sub-
out and the athlete is taken to the sideline, a thorough clinical
sequent injuries than the current injury.
examination should follow, including a complete neurologic
Most grading systems rely heavily on LOC and amnesia as
examination and cognitive evaluation. The ATC must note the
indicators of injury severity. Recent research, however, sug-
time of the injury and then maintain a timed assessment form
gests that these 2 factors, either alone or in combination, are
to follow the athlete’s symptoms and examinations serially. It
not good predictors of injury severity. A number of authors
is often difficult to pay attention to the time that has passed
have documented no association between brief ( 1 minute)
after an injury. Therefore, it is important for one member of
LOC and abnormalities on neuropsychological testing at 48
the medical team to track time during the evaluation process
hours, raising concern for brief LOC as a predictor of recovery
and record all pertinent information. After an initial evalua-
after concussion.8,22,24–27 Studies involving high school and
tion, the clinician must determine whether the injured athlete
collegiate athletes with concussion revealed no association be-
requires more advanced medical intervention and eventually
tween (1) LOC and duration of symptoms or (2) LOC and
grade the injury and make an RTP decision that can occur
neuropsychological and balance tests at 3, 24, 48, 72, and 96
within minutes, hours, days, or weeks of the injury.
hours postinjury.21,28,29 In other words, athletes experiencing
There are currently 3 approaches to grading sport-related
LOC were similar to athletes without LOC on these same in-
concussion. One approach is to grade the concussion at the
jury-severity markers.
time of the injury on the basis of the signs and symptoms
With respect to amnesia, the issue is more clouded because
present at the time of the concussion and within the first 15
findings have been inconsistent. Several studies of nonath-
minutes after injury. The American Academy of Neurology
letes30–37 suggest that the duration of posttraumatic amnesia
Concussion Grading Scale (Table 1)6 has been widely used
correlates with the severity and outcome of severe TBI but not
with this approach. It permits the ATC to grade the injury
with mild TBI or concussion.38–40 More contemporary studies
primarily on the basis of LOC and to provide the athlete,
of athletes with concussion are also clouded. Two unrelated,
coach, and parent with an estimation of injury severity. A dis-
prospective studies of concussion suggest that the presence of
advantage to this approach is that many injuries behave dif-
amnesia best correlates with abnormal neuropsychological
ferently than expected on initial evaluation, potentially creat-
testing at 48 hours and with the duration and number of other
ing more difficulties with the athlete, coach, or parent and
postconcussion signs and symptoms.24,41 However, more re-
making the RTP decision more challenging. Another approach
cently, investigations of high school and collegiate athletes
is to grade the concussion on the basis of the presence and
with concussion revealed no association between (1) amnesia
overall duration of symptoms. This approach is best addressed
and duration of symptoms or (2) amnesia and neuropsycho-
using the Cantu Evidence-Based Grading Scale (Table 2),43
logical and balance tests at 3, 24, 48, 72, and 96 hours post-
which guides the ATC to grade the injury only after all con-
injury.21,28,29 Of importance in these studies is the significant
cussion signs and symptoms have resolved. This scale places
association between symptom-severity score (within the initial
less emphasis on LOC as a potential predictor of subsequent
3 hours postinjury) and the total duration of symptoms (mea-
impairment and additional weight on overall symptom dura-
Journal of Athletic Training
285
Table 2. Cantu Evidence-Based Grading System for
include shooting baskets or participating in walk-throughs, and
Concussion43
for the soccer player, this may include dribbling or shooting
Grade 1 (mild)
No LOC*, PTA†
30 min, PCSS‡
24 h
drills or other sport-specific activities. These restricted and
Grade 2 (moderate)
LOC
1 min or PTA
30 min
24 h or
monitored activities should be continued for the first few days
PCSS
24 h
7 d
after becoming symptom free. The athlete should be monitored
Grade 3 (severe)
LOC
1 min or PTA
24 h or PCSS
7 d
periodically throughout and after these sessions to determine
*LOC indicates loss of consciousness.
if any symptoms develop or increase in intensity. Before re-
†PTA indicates posttraumatic amnesia (anterograde/retrograde).
turning to full contact participation, the athlete should be re-
‡PCSS indicates postconcussion signs and symptoms other than am-
assessed using neuropsychological and postural-stability tests
nesia.
if available. If all scores have returned to baseline or better,
return to full participation can be considered after further clin-
tion.3,43 Finally, a third approach to the grading-scale dilemma
ical evaluation. It is strongly recommended that after recurrent
is to not use a grading scale but rather focus attention on the
injury, especially within-season repeat injuries, the athlete be
athlete’s recovery via symptoms, neuropsychological tests, and
withheld for an extended period of time (approximately 7
postural-stability tests. This line of thinking is that the ATC
days) after symptoms have resolved.
should not place too much emphasis on the grading system or
grade but should instead focus on whether the athlete is symp-
CONCUSSION ASSESSMENT TOOLS
tomatic or symptom free. Once the athlete is asymptomatic, a
stepwise progression should be implemented that increases de-
Sports medicine clinicians are increasingly using standard-
mands over several days. This progression will be different for
ized methods to obtain a more objective measurement of post-
athletes who are withheld for several weeks compared with
concussion signs and symptoms, cognitive dysfunction, and
those athletes withheld for just a few days. This multitiered
postural instability. These methods allow the clinician to quan-
approach was summarized and supported by consensus at the
tify the severity of injury and measure the player’s progress
2001 Vienna Conference on Concussion in Sport.8
over the course of postinjury recovery. An emerging model of
sport concussion assessment involves the use of brief screen-
ing tools to evaluate postconcussion signs and symptoms, cog-
Making the Return-to-Play Decision
nitive functioning, and postural stability on the sideline im-
The question raised most often regarding the concussion
mediately after a concussion and neuropsychological testing to
grading and RTP systems is one of practicality in the sport
track recovery further out from the time of injury. Ultimately,
setting. Many clinicians believe that the RTP guidelines are
these tests, when interpreted with the physical examination and
too conservative and, therefore, choose to base decisions on
other aspects of the injury evaluation, assist the ATC and other
clinical judgment of individual cases rather than on a general
sports medicine professionals in the RTP decision-making pro-
recommendation. It has been reported that 30% of all high
cess.
school and collegiate football players sustaining concussions
Data from objective measures of cognitive functioning, pos-
return to competition on the same day of injury; the remaining
tural stability, and postconcussion signs and symptoms are
70% average 4 days of rest before returning to participation.23
most helpful in making a determination about severity of in-
Many RTP guidelines call for the athlete to be symptom free
jury and postinjury recovery when preinjury baseline data for
for at least 7 days before returning to participation after a
an individual athlete are available.3,8,24,29,41 Baseline testing
grade 1 or 2 concussion.6,13,15,17,43,44 Although many clini-
provides an indicator of what is ‘‘normal’’ for that particular
cians deviate from these recommendations and are more liberal
athlete while also establishing the most accurate and reliable
in making RTP decisions, recent studies by Guskiewicz and
benchmark against which postinjury results can be compared.
McCrea et al21,29 suggest that perhaps the 7-day waiting period
It is important to obtain a baseline symptom assessment in
can minimize the risk of recurrent injury. On average, athletes
addition to baseline cognitive and other ability testing. Without
required 7 days to fully recover after concussion. Same-season
baseline measures, the athlete’s postinjury performance on
repeat injuries typically take place within a short window of
neuropsychological testing and other concussion assessment
time, 7 to 10 days after the first concussion,21 supporting the
measures must be interpreted by comparison with available
concept that there may be increased neuronal vulnerability or
population normative values, which ideally are based on a
blood-flow changes during that time, similar to those reported
large sample of the representative population. Normative data
by Giza, Hovda, et al45–47 in animal models.
for competitive athletes on conventional (ie, paper-and-pencil)
Returning an athlete to participation should follow a pro-
and computerized neuropsychological tests and other concus-
gression that begins once the athlete is completely symptom
sion assessment measures are now more readily available from
free. All signs and symptoms should be evaluated using a
large-scale research studies, but baseline data on an individual
graded symptom scale or checklist (described in ‘‘Concussion
athlete still provide the greatest clinical accuracy in interpret-
Assessment Tools’’) when performing follow-up assessments
ing postinjury test results. When performing baseline testing,
and should be evaluated both at rest and after exertional ma-
a suitable testing environment eliminates all distractions that
neuvers such as biking, jogging, sit-ups, and push-ups. Base-
could alter the baseline performance and enhances the likeli-
line measurements of neuropsychological and postural stability
hood that all athletes are providing maximal effort. Most im-
are strongly recommended for comparing with postinjury mea-
portant, all evaluators should be aware of a test’s user require-
surements. If these exertional tests do not produce symptoms,
ments and be appropriately trained in the standardized
either acutely or in delayed fashion, the athlete can then par-
instructions for test administration and scoring before embark-
ticipate in sport-specific skills that allow return to practice but
ing on baseline testing or adopting a concussion testing par-
should remain out of any activities that put him or her at risk
adigm for clinical use.
for recurrent head injury. For the basketball player, this may
Several models exist for implementing baseline testing. Ide-
286
Volume 39 • Number 3 • September 2004
ally, preseason baseline testing is conducted before athletes are
A number of concussion symptom checklists43,50–52 and
exposed to the risk of concussion during sport participation
scales26,41,48,53 have been used in both research and clinical
(eg, before contact drills during football). Some programs
settings. A symptom checklist that provides a list of concus-
choose to conduct baseline testing as part of the prepartici-
sion-related symptoms allows the athlete to report whether the
pation physical examination process. In this model, stations
symptom is present by responding either ‘‘yes’’ (experiencing
are established for various testing methods (eg, history collec-
the symptom) or ‘‘no’’ (not experiencing the symptom). A
tion, symptom assessment, neuropsychological testing, and
symptom scale is a summative measure that allows the athlete
balance testing), and athletes complete the evaluation sequence
to describe the extent to which he or she is experiencing the
after being seen by the attending physician or ATC. This ap-
symptom. These instruments commonly incorporate a Likert-
proach has the advantage of testing large groups of athletes in
type scale that allows the player to rate the severity or fre-
1 session, while they are already in the mindset of undergoing
quency of postconcussion symptoms. These scores are then
a preseason physical examination. When preseason examina-
summed to form a composite score that yields a quantitative
tions are not conducted in a systematic group arrangement,
measure of overall injury severity and a benchmark against
alternative approaches can be considered. In any case, it is
which to track postinjury symptom recovery. Initial evidence
helpful to conduct all modules of baseline testing on players
has been provided for the structural validity of a self-report
in 1 session to limit the complications of scheduling multiple
concussion symptom scale.48 Obtaining a baseline symptom
testing times and to keep testing conditions constant for the
score is helpful to establish any preexisting symptoms attrib-
athletes. One should allow adequate planning time (eg, 3
utable to factors other than the head injury (eg, illness, fatigue,
months) to implement a baseline testing module. Often this
or somatization). Serial administration of the symptom check-
equates to conducting baseline testing for fall sports during the
list is the recommended method of tracking symptom resolu-
spring semester, before school is recessed for the summer. The
tion over time (see Appendix A).
benefits of interpreting postinjury data for an athlete after a
concussion far outweigh the considerable time and human re-
sources dedicated to baseline testing.
Mental Status Screening
Collecting histories on individual athletes is also a vital part
of baseline testing, especially in establishing whether the ath-
Cognitive screening instruments similar to the physician’s
lete has any history of concussion, neurologic disorder, or oth-
mini mental status examination objectify what is often a sub-
er remarkable medical conditions. Specifically with respect to
jective impression of cognitive abnormalities. Various methods
concussion, it is important to establish (1) whether the player
have been suggested for a systematic survey of mental status
has any history of concussions and, if so, how many and (2)
and cognitive function in the athlete with a concussion. The
injury characteristics of previous concussions (eg, LOC, am-
SAC was developed to provide sports medicine clinicians with
nesia, symptoms, recovery time, time lost from participation,
a brief, objective tool for assessing the injured athlete’s mental
and medical treatment). For athletes with a history of multiple
status during the acute period after concussion (eg, sport side-
concussions, it is also important to clarify any apparent pattern
line, locker room, and clinic).54 The SAC includes measures
of (1) concussions occurring as a result of lighter impacts, (2)
of orientation, immediate memory, concentration, and delayed
concussions occurring closer together in time, (3) a lengthier
recall that sum to 30 points.55 Lower scores on the SAC in-
recovery time with successive concussions, and (4) a less com-
dicate more severe cognitive impairment. The SAC also in-
plete recovery with each injury. Documenting a history of at-
cludes assessments of strength, sensation, and coordination
tentional disorders, learning disability, or other cognitive de-
and a standard neurologic examination but should not replace
velopment disorders is also critical, especially in interpreting
the clinician’s thorough physical examination or referral for
an individual player’s baseline and postinjury performance on
more extensive neuropsychological evaluation when indicated.
neuropsychological testing. If resources do not allow for pre-
Information about the occurrence and duration of LOC and
season examinations in all athletes, at least a concerted effort
amnesia is also recorded on the SAC. Alternate forms of the
to evaluate those athletes with a previous history of concussion
SAC are available to minimize the practice effects during re-
should be made because of the awareness of increased risk for
testing. The SAC takes about 5 minutes to administer and
subsequent concussions in this group.
should be used only after the clinician’s thorough review of
the training manual and instructional video on the administra-
tion, scoring, and interpretation of the instrument.
Postconcussion Symptom Assessment
The SAC has demonstrated reliability29,55,56 and validi-
Self-reported symptoms are among the more obvious and
ty29,56,57 in detecting mental status changes after a concussion.
recognizable ways to assess the effects of concussion. Typical
Recent evidence suggests that a decline of 1 point or more
self-reported symptoms after a concussion include but are not
from baseline classified injured and uninjured players with a
limited to headache; dizziness; nausea; vomiting; feeling ‘‘in
level of 94% sensitivity and 76% specificity.56 The SAC is
a fog’’; feeling ‘‘slowed down’’; trouble falling asleep; sleep-
also sensitive to detecting more severe neurocognitive changes
ing more than usual; fatigue; drowsiness; sensitivity to light
in injured athletes with LOC or amnesia associated with their
or noise; unsteadiness or loss of balance; feeling ‘‘dinged,’’
concussions.57 The SAC is most useful in the assessment of
dazed, or stunned; seeing stars or flashing lights; ringing in
acute cognitive dysfunction resulting from concussion, with
the ears; and double vision.8,26,48 Self-reported symptoms are
sensitivity and specificity comparable with extensive neuro-
referenced by many of the concussion grading scales.10,43,44,49
psychological testing batteries during the initial 2 to 3 days
The presence of self-reported symptoms serves as a major con-
after concussion.29,58,59 As with neuropsychological testing,
traindication for RTP, and, based on current recommendations,
sensitivity and specificity of the SAC in concussion assess-
the athlete should be fully symptom free for at least 7 days at
ment are maximized when individual baseline test data are
rest and during exertion before returning to play.43,44
available.29,55,56,60
Journal of Athletic Training
287
Postural-Stability Assessment
Before implementing a neuropsychological testing program,
the ATC must consider several issues, including test-specific
A number of postural-stability tests have been used to assess
training requirements and methodologic issues, the practicality
the effects of concussion in the clinical and laboratory settings.
of baseline testing, the reliability and validity of individual
The Romberg and stork stand were basic tests used to assess
tests comprising the test battery, and the protocol for interpre-
balance and coordination. Riemann et al61–62 developed the
tation of the postinjury test results. Barr76 provided an excel-
Balance Error Scoring System (BESS) based on existing the-
lent review on the methodologic and professional issues as-
ories of posturography. The BESS uses 3 stance positions and
sociated with neuropsychological testing in sport concussion
tests on both a firm and a foam surface with the eyes closed
assessment. Most states require advanced training and licen-
(for a total of 6 trials). The administration and scoring pro-
sure to purchase and use neuropsychological tests for clinical
cedures are found in several publications.61–63 The BESS has
purposes. Neuropsychological tests are also copyright protect-
established good test-retest reliability and good concurrent va-
ed to prevent inappropriate distribution or use by unqualified
lidity when compared with laboratory forceplate measures52,62
professionals. At present, these requirements necessitate that a
and significant group differences, with an increased number of
licensed psychologist, preferably one Board certified in clinical
errors for days 1, 3, and 5 postinjury when compared with
neuropsychology or with clinical experience in the evaluation
controls.52 Thus, the BESS can be used as a clinical measure
of sport-related concussion, oversee and supervise the clinical
in identifying balance impairment that could indicate a neu-
application of neuropsychological testing for sport concussion
rologic deficit.
assessment. These factors likely restrict how widely neuropsy-
The NeuroCom Smart Balance Master System (NeuroCom
chological testing can be used to assess sport-related concus-
International, Clackamas, OR) is a forceplate system that mea-
sion, especially at the high school level and in rural areas
sures vertical ground reaction forces produced by the body’s
where neuropsychologists are not readily available for con-
center of gravity moving around a fixed base of support. The
sultation.
Sensory Organization Test (SOT, NeuroCom International) is
Neuropsychologists, ATCs, and sports medicine clinicians
designed to disrupt various sensory systems, including the vi-
are faced with the challenge of designing a model that jointly
sual, somatosensory, and vestibular systems. The SOT consists
upholds the testing standards of neuropsychology and meets
of 6 conditions with 3 trials per condition, for a total of 18
the clinical needs of the sports medicine community without
trials, with each trial lasting 20 seconds. The complete admin-
undue burden. The cost of neuropsychological testing, either
istration has been described previously.52,64 The SOT has pro-
conventional or computerized, is also a factor in how widely
duced significant findings related to the assessment of concus-
this method can be implemented, especially at the high school
sion recovery. In a sample of 36 athletes with concussion, the
level. Consultation fees for the neuropsychologist can be con-
mean stability (composite score) and vestibular and visual ra-
siderable if work is not done on a pro bono basis, and some
tios demonstrated deficits for up to 5 days postinjury.52 The
computerized testing companies charge a consulting fee for
greatest deficits were seen 24 hours postinjury, and the athletes
interpreting postinjury test results by telephone.
with concussion demonstrated a gradual recovery during the
Although no clear indications exist as to which are the best
5-day period to within 6% of baseline scores. These results
individual neuropsychological tests to evaluate sport concus-
were confirmed by Peterson et al,65 who found that these def-
icits continued for up to 10 days after concussion. These find-
sion, the use of multiple instruments as a ‘‘test battery’’ offers
ings reveal a sensory interaction problem from the effects of
clinicians greater potential for recognizing any cognitive def-
concussion with measurable changes in overall postural sta-
icits incurred from the injury. A number of neuropsychological
bility.
tests and test batteries have been used to assess sport-related
concussion. Table 3 provides a brief description of the paper-
and-pencil neuropsychological tests commonly used by neu-
Neuropsychological Testing
ropsychologists in the assessment of sport concussion. Sport
Neuropsychological testing has historically been used to
concussion batteries should include measures of cognitive abil-
evaluate various cognitive domains known to be preferentially
ities most susceptible to change after concussion, including
susceptible to the effects of concussion and TBI. In recent
attention and concentration, cognitive processing (speed and
years, neuropsychological testing to evaluate the effects of
efficiency), learning and memory, working memory, executive
sport-related concussion has gained much attention in the sport
functioning, and verbal fluency. Tests of attention and concen-
concussion literature.20,21,26,29,48,52,58,59,65–69 The work of
tration50,52,74,77 and memory functioning41 have been reported
Barth et al,70 who studied more than 2000 collegiate football
as the most sensitive to the acute effects of concussion. The
players from 10 universities, was the first project to institute
athlete’s age, sex, primary language, and level of education
baseline neuropsychological testing. Similar programs are now
should be considered when selecting a test battery.68
commonplace among many collegiate and professional teams,
Computerized Neuropsychological Tests. Recently, a
and interest is growing at the high school level. Several recent
number of computerized neuropsychological testing programs
studies have supported the use of neuropsychological testing
have been designed for the assessment of athletes after con-
as a valuable tool to evaluate the cognitive effects and recov-
cussion. The Automated Neuropsychological Assessment Met-
ery after sport-related concussion,24,28,29,41,42,50–52,57,65,66,71–75
rics (ANAM), CogSport, Concussion Resolution Index, and
but its feasibility for sideline use is not likely realistic. As is
Immediate Postconcussion Assessment and Cognitive Testing
the case with other concussion assessment tools, baseline neu-
(ImPACT) are all currently available and have shown promise
ropsychological testing is recommended, when possible, to es-
for reliable and valid concussion assessment (Table
tablish a normative level of neurocognitive functioning for in-
4).24,41,51,53,66,71,72,75,78–84 The primary advantages to comput-
dividual athletes.24,28,29,41,50–52,57–59,66,69,73–75 Baseline
erized testing are the ease of administration, ability to baseline
neuropsychological testing typically takes 20 to 30 minutes per
test a large number of athletes in a short period of time, and
athlete.
multiple forms used within the testing paradigm to reduce the
288
Volume 39 • Number 3 • September 2004
Table 3. Common Neuropsychological Tests Used in Sport
to provide clinicians with the most effective neuropsycholog-
Concussion Assessment
ical assessment tools and maintain the testing standards of neu-
Neuropsychological Test
Cognitive Domain
ropsychology.
Neuropsychological Testing Methods. Neuropsychologi-
Controlled Oral Word Association
Verbal fluency
cal testing is not a tool that should be used to diagnose the
Test
injury (ie, concussion); however, it can be very useful in mea-
Hopkins Verbal Learning Test
Verbal learning, immediate and
suring recovery once it has been determined that a concussion
delayed memory
Trail Making: Parts A and B
Visual scanning, attention, infor-
has occurred. The point(s) at which postinjury neuropsycho-
mation processing speed, psy-
logical testing should occur has been a topic of debate. A
chomotor speed
variety of testing formats has been used to evaluate short-term
Wechsler Letter Number Se-
Verbal working memory
recovery from concussion.24,41,50,73,75,82 Two approaches are
quencing Test
most common. The first incorporates neuropsychological test-
Wechsler Digit Span: Digits For-
Attention, concentration
ing only after the injured player reports that his or her symp-
ward and Digits Backward
toms are completely gone. This approach is based on the con-
Wechsler Digit Symbol Test
Psychomotor speed, attention,
ceptual foundation that an athlete should not participate while
concentration
symptomatic, regardless of neuropsychological test perfor-
Symbol Digit Modalities Test
Psychomotor speed, attention,
mance. Unnecessary serial neuropsychological testing, in ad-
concentration
Paced Auditory Serial Addition
Attention, concentration
dition to being burdensome and costly to the athlete and med-
Test
ical staff, also introduces practice effects that may confound
Stroop Color Word Test
Attention, information processing
the interpretation of performance in subsequent postinjury test-
speed
ing sessions.85 The second approach incorporates neuropsy-
chological testing at fixed time points (eg, postinjury day 1,
day 7, and so on) to track postinjury recovery. This approach
practice effects. Collie et al71 summarized the advantage and
is often appropriate for prospective research protocols but is
disadvantages of computerized versus traditional paper-and-
unnecessary in a clinical setting when the player is still symp-
pencil testing.
tomatic and will be withheld from competition regardless of
As outlined, in the case of conventional neuropsychological
the neuropsychological test results. In this model, serial testing
testing, several of the same challenges must be addressed be-
can be used until neuropsychological testing returns to normal,
fore computerized testing becomes a widely used method of
preinjury levels and the player is completely symptom free.
sport concussion assessment. Issues requiring further consid-
Measuring ‘‘recovery’’ on neuropsychological tests and oth-
eration include demonstrated test reliability; validity, sensitiv-
er clinical instruments is often a complex statistical matter,
ity, and specificity in the peer-reviewed literature; required
further complicated by practice effects and other psychometric
user training and qualifications; the necessary role of the li-
dynamics affected by serial testing, even when preinjury base-
censed psychologist for clinical interpretation of postinjury
line data are available for individual athletes. The use of sta-
test results; hardware and software issues inherent to comput-
tistical models that empirically identify meaningful change
erized testing; and user costs.71 Progress is being made on
while controlling for practice effects on serial testing may pro-
many of these issues, but further clinical research is required
vide the clinician with the most precise benchmark in deter-
Table 4. Computerized Neuropsychological Tests
Neuropsychological Test
Developer (Contact Information)
Cognitive Domains
Automated Neuropsychological
National Rehabilitation Hospital
Simple Reaction Metrics
Assessment Metrics (ANAM)
Assistive Technology and
Sternberg Memory
Neuroscience Center, Washington, DC84
Math Processing
(jsb2@mhg.edu)
Continuous Performance
Matching to Sample
Spatial Processing
Code Substitution
CogSport
CogState Ltd, Victoria, Australia
Simple Reaction Time
(www.cogsport.com)
Complex Reaction Time
One-Back
Continuous Learning
Concussion Resolution
HeadMinder Inc, New York, NY
Reaction Time
Index
(www.headminder.com)
Cued Reaction Time
Visual Recognition 1
Visual Recognition 2
Animal Decoding
Symbol Scanning
Immediate Postconcussion Assessment
University of Pittsburgh
Verbal Memory
and Cognitive Testing (ImPACT)
Medical Center, Pittsburgh, PA
Visual Memory
(www.impacttest.com)
Information Processing Speed
Reaction Time
Impulse Control
Journal of Athletic Training
289
Table 5. Factors Influencing Neuropsychological Test
minutes after a concussion until the athlete’s condition stabi-
Performance68*
lizes and improves. The athlete should also be monitored over
Previous concussions
the next few hours and days after the injury for delayed signs
Educational background
and symptoms and to assess recovery. Appendix B outlines
Preinjury level of cognitive functioning
scenarios that warrant physician referral or, in many cases,
Cultural background
transport to the nearest hospital emergency department.
Age
Test anxiety
Distractions
WHEN TO DISQUALIFY AN ATHLETE
Sleep deprivation
Medications, alcohol, or drugs
Return to participation after severe or repetitive concussive
Psychiatric disorders
Learning disability
injury should be considered only if the athlete is completely
Attention deficit/hyperactivity
symptom free and has a normal neurologic examination, nor-
Certain medical conditions
mal neuropsychological and postural-stability examinations,
Primary language other than English
and, if obtained, normal neuroimaging studies (ie, MRI with
Previous neuropsychological testing
gradient echo). It may not be practical or even possible to use
*Reprinted with permission of Grindel SH, Lovell MR, Collins MW. The
all these assessments in all athletes or young children, but a
assessment of sport-related concussion: the evidence behind neuro-
cautious clinical judgment should take into account all eval-
psychological testing and management. Clin J Sport Med. 2001; 11:
uation options. Each injured athlete should be considered in-
134–143.
dividually, with consideration for factors including age, level
of participation, nature of the sport (high risk versus low risk),
mining postinjury recovery, above and beyond the simple con-
and concussion history.
clusion that the player is ‘‘back to baseline.’’ The complexity
Standardized neuropsychological testing, which typically
of this analysis is the basis for the neuropsychologist oversee-
assesses orientation, immediate and delayed memory recall,
ing the clinical interpretation of test data to determine injury
and concentration may assist the ATC and physician in deter-
severity and recovery. Further research is required to clarify
mining when to disqualify an athlete from further participa-
the guidelines for determining and tracking recovery on spe-
tion.60 Balance testing may provide additional information to
cific measures after concussion. The clinician should also be
assist the clinician in the decision-making process of whether
aware that any concussion assessment tool, either brief screen-
to disqualify an individual after a concussion.52 When to dis-
ing instruments or more extensive neuropsychological testing,
qualify the athlete is one of the most important decisions fac-
comes with some degree of risk for false negatives (eg, a play-
ing the ATC and team physician when dealing with an athlete
er performs within what would be considered the normal range
suffering from a concussion. This includes not only when to
on the measure before actually reaching a complete clinical
disqualify for a single practice or event but also when to dis-
recovery after concussion). Therefore, test results should al-
qualify for the season or for a career.
ways be interpreted in the context of all clinical information,
including the player’s medical history. Also, caution should be
exercised in neuropsychological test interpretation when pre-
Disqualifying for the Game or Practice
injury baseline data do not exist. Numerous factors apart from
the direct effects of concussion can influence test performance
The decision to disqualify an individual from further partic-
(Table 5).
ipation on the day of the concussive episode is based on the
sideline evaluation, the symptoms the athlete is experiencing,
WHEN TO REFER AN ATHLETE TO A PHYSICIAN
the severity of the apparent symptoms, and the patient’s past
AFTER CONCUSSION
history.86 The literature is clear: any episode involving LOC
or persistent symptoms related to concussion (headache, diz-
Although most sport-related concussions are considered
ziness, amnesia, and so on), regardless of how mild and tran-
mild head injuries, the potential exists for complications and
sient, warrants disqualification for the remainder of that day’s
life-threatening injuries. Each ATC should be concerned about
activities.8,9,13,19,43,60,87 More recent studies of high school and
the potential for the condition of an athlete with a concussion
collegiate athletes underscore the importance of ensuring that
to deteriorate. This downward trend can occur immediately
the athlete is symptom free before returning to participation
(minutes to hours) or over several days after the injury. As
discussed earlier, the spectrum of sport-related head injuries
on the same day; even when the player is symptom free within
includes more threatening injuries, such as epidural and sub-
15 to 20 minutes after the concussive episode, he or she may
dural hematomas and second-impact syndrome. Postconcus-
still demonstrate delayed symptoms or depressed neurocog-
sion syndrome, however, is a more likely consequence of a
nitive levels. Lovell et al88 found significant memory deficits
sport-related concussion. Not every sport-related concussion
36 hours postinjury in athletes who were symptom free within
warrants immediate physician referral, but ATCs must be able
15 minutes of a mild concussion. Guskiewicz et al21 found
to recognize those injuries that require further attention and
that 33% (10/30) of the players with concussion who returned
provide an appropriate referral for advanced care, which may
on the same day of injury experienced delayed onset of symp-
include neuroimaging. Serial assessments and physician fol-
toms at 3 hours postinjury, as compared with only 12.6% (20/
low-up are important parts of the evaluation of the athlete with
158) of those who did not return to play on the same day of
a concussion. Referrals should be made to medical personnel
injury. Although more prospective work is needed in this area,
with experience managing sport-related concussion. The ATC
these studies raise questions as to whether the RTP criteria for
should monitor vital signs and level of consciousness every 5
grade 1 (mild) concussions are conservative enough.
290
Volume 39 • Number 3 • September 2004
Disqualifying for the Season
tle damage may lead to deficits in learning that adversely in-
fluence development. Therefore, it has been suggested that pe-
Guidelines from Cantu43 and the American Academy of
diatric athletes suffering a concussion should be restricted
Neurology6 both recommend termination of the season after
from further participation for the day and that additional con-
the third concussion within the same season. The decision is
sideration should be given as to when to return these individ-
more difficult if one of the injuries was more severe or was a
uals to activity.46
severe injury resulting from a minimal blow, suggesting that
Recent epidemiologic investigations of head-injury rates in
the athlete’s brain may be at particular risk for recurrent injury.
high school athletes have shown that 13.3% of all reported
In addition, because many athletes participate in year-round
injuries in high school football affect the head and neck,
activities, once they are disqualified for the ‘‘season,’’ it may
whereas the numbers in other sports range from 1.9% to 9.5%
be difficult to determine at what point they can resume contact
in baseball and wrestling, respectively.89 Guskiewicz et al23
play. Other issues without clear-cut answers in the literature
prospectively examined concussion incidence in high school
are when to disqualify an athlete who has not been rendered
and collegiate football players and found that the greatest in-
unconscious and whose symptoms cleared rapidly or one who
cidence was at the high school level (5.6%), compared with
suffered multiple mild to moderate concussions throughout the
the National Collegiate Athletic Association Division I (4.4%),
career and whether youth athletes should be treated differently
Division II (4.5%), and Division III (5.5%).
for initial and recurrent concussive injuries.
Authors who have tracked symptoms and neuropsycholog-
ical function after concussion suggest that age-related differ-
Disqualifying for the Career
ences exist between high school and collegiate athletes with
When to disqualify an athlete for a career is a more difficult
regard to recovery. Lovell et al41 reported that the duration of
question to answer. The duration of symptoms may be a better
on-field mental status changes in high school athletes, such as
criterion as to when to disqualify an athlete for the season or
retrograde amnesia and posttraumatic confusion, was related
longer. Merril Hoge, Eric Lindros, Chris Miller, Al Toon, and
to the presence of memory impairment at 36 hours, 4 days,
Steve Young provide highly publicized cases of athletes sus-
and 7 days postinjury as well as slower resolution of self-
taining multiple concussions with recurrent or postconcussion
reported symptoms. These findings further emphasize the need
signs and symptoms that lasted for lengthy periods of time.43
to collect these on-field measures after concussion and to use
Once an athlete has suffered a concussion, he or she is at
the information wisely in making RTP decisions, especially
increased risk for subsequent head injuries.21,43,86 Guskiewicz
when dealing with younger athletes. Field et al90 found that
et al21,23 found that collegiate athletes had a 3-fold greater risk
high school athletes who sustained a concussion demonstrated
of suffering a concussion if they had sustained 3 or more pre-
prolonged memory dysfunction compared with collegiate ath-
vious concussions in a 7-year period and that players with 2
letes who sustained a concussion. The high school athletes
or more previous concussions required a longer time for total
performed significantly worse on select tests of memory than
symptom resolution after subsequent injuries.21 Players also
age-matched control subjects at 7 days postinjury when com-
had a 3-fold greater risk for subsequent concussions in the
pared with collegiate athletes and their age-matched control
same season,23 whereas recurrent, in-season injuries occurred
subjects. We hope these important studies and others will
within 10 days of the initial injury 92% of the time.21 In a
eventually lead to more specific guidelines for managing con-
similar study of high school athletes, Collins et al82 found that
cussions in high school athletes.
athletes with 3 or more prior concussions were at an increased
Very few investigators have studied sport-related injuries in
risk of experiencing LOC (8-fold greater risk), anterograde
the youth population, and even fewer focused specifically on
amnesia (5.5-fold greater risk), and confusion (5.1-fold greater
sport-related concussion. One group91 reported that 15% of the
risk) after subsequent concussion. Despite the increasing body
children (mean
8.34
5.31 years) who were admitted to
of literature on this topic, debate still surrounds the question
hospitals after MTBI suffered from a sport-related mechanism
of how many concussions are enough to recommend ending
of injury. Another group92 found that sport-related head injury
the player’s career. Some research suggests that the magic
accounted for 3% of all sport-related injuries and 24% of all
number may be 3 concussions in a career.21,23,82 Although
serious head injuries treated in an emergency department. Ad-
these findings are important, they should be carefully inter-
ditionally, sport-related concussion represented a substantial
preted because concussions present in varying degrees of se-
percentage of all head injuries in children under the age of 10
verity, and all athletes do not respond in the same way to
years (18.2%) and 10- to 14-year-old (53.4%) and 15- to 19-
concussive insults. Most important is that these data provide
year-old (42.9%) populations.92 Thus, sport-related head in-
evidence for exercising caution when managing younger ath-
jury has a relatively high incidence rate and is a significant
letes with concussion and athletes with a history of previous
public health concern in youth athletes, not just participants at
concussions.
higher competitive levels.
Although no prospective investigations in younger athletes
(younger than 15 years old) have been undertaken regarding
SPECIAL CONSIDERATIONS FOR THE YOUNG
symptom resolution and cognitive or postural-stability recov-
ATHLETE
ery, Valovich McLeod et al93 recently determined the reli-
Many epidemiologic studies on concussion have focused on
ability and validity of brief concussion assessment tools in a
professional or collegiate athletes. However, this focus seems
group of healthy young athletes (9–14 years old). The SAC is
to now be shifting to the high school level and even to youth
valid within 48 hours of injury and reliable for testing of
sports. Special consideration must be given to the young ath-
youths above age 5 years, but younger athletes score slightly
lete. The fact that the brain of the young athlete is still de-
below high school and collegiate athletes.55 This issue is rem-
veloping cannot be ignored, and the effect of concussion on
edied, however, if preseason baseline testing is conducted for
the developing brain is still not entirely understood. Even sub-
all players and a preinjury baseline score established for each
Journal of Athletic Training
291
athlete against which changes resulting from concussion can
symptoms and rule out the possibility of an intracranial bleed,
be detected and other factors that affect test performance can
such as a subdural hematoma. This recommendation has raised
be controlled. Users of standardized clinical tools should be
some debate about unnecessary wake-ups that disrupt the ath-
aware of the effects of age and education on cognitive test
lete’s sleep pattern and may increase symptoms the next day
performance and make certain to select the appropriate nor-
because of the combined effects of the injury and sleep dep-
mative group for comparison when testing an injured athlete
rivation. It is further suggested that the concussed athlete have
at a specific competitive level. Uncertainties about the effects
a teammate or friend stay during the night and that the athlete
of concussion on young children warrant further study.
not be left alone. No documented evidence suggests what se-
verity of injury requires this treatment. However, a good rule
to use is if the athlete experienced LOC, had prolonged periods
HOME CARE
of amnesia, or is still experiencing significant symptoms, he
Once the athlete has been thoroughly evaluated and deter-
or she should be awakened during the night. Both oral and
mined to have sustained a concussion, a comprehensive med-
written instructions should be given to both the athlete and the
ical management plan should be implemented. This plan
caregiver regarding waking.96 The use of written and oral in-
should include frequent medical evaluations and observations,
structions increases the compliance to 55% for purposeful
continued monitoring of postconcussion signs and symptoms,
waking in the middle of the night. In the treatment of con-
and postinjury cognitive and balance testing. If symptoms per-
cussion, complete bed rest was ineffective in decreasing post-
sist or worsen or the level of consciousness deteriorates at all
concussion signs and symptoms.97 The athlete should avoid
after a concussion, neuroimaging should be performed. Al-
activities that may increase symptoms (eg, staying up late
though scientific evidence for the evaluation and resolution of
studying and physical education class) and should resume nor-
the concussion is ample, specific management advice to be
mal activities of daily living, such as attending class and driv-
given to the athlete on leaving the athletic training room is
ing, once symptoms begin to resolve or decrease in severity.
lacking.94 Athletic trainers and hospital emergency rooms have
As previously discussed, a graded test of exertion should be
created various home instruction forms, but minimal scientific
used to determine the athlete’s ability to safely return to full
evidence supports these instructions. However, despite these
activity.
limitations, a concussion instruction form (Appendix C)
should be given to the athlete and a responsible adult who will
Diet
have direct contact with the athlete for the initial 24 hours
after the injury. This form helps the companion to know what
Evidence is limited to support the best type of diet for aiding
signs and symptoms to watch for and provides useful recom-
in the recovery process after a concussion. A cascade of neu-
mendations on follow-up care.
rochemical, ionic, and metabolic changes occur after brain in-
jury.47 Furthermore, some areas of the brain demonstrate gly-
colytic increases and go into a state of metabolic depression
Medications
as a result of decreases in both glucose and oxidative metab-
At this time, the clinician has no evidence-based pharma-
olism with a reduction in cerebral blood flow. Severely brain-
cologic treatment options for an athlete with a concussion.95
injured subjects ate larger meals and increased their daily ca-
Most pharmacologic studies have been performed in severely
loric intake when compared with controls.98 Although limited
head-injured patients. It has been suggested that athletes with
information is available regarding the recommended diet for
concussion avoid medications containing aspirin or nonsteroi-
the management of concussion, it is well accepted that athletes
dal anti-inflammatories, which decrease platelet function and
should be instructed to avoid alcohol, illicit drugs, and central
potentially increase intracranial bleeding, mask the severity
nervous system medications that may interfere with cognitive
and duration of symptoms, and possibly lead to a more severe
function. A normal, well-balanced diet should be maintained
injury. It is also recommended that acetaminophen (Tylenol,
to provide the needed nutrients to aid in the recovery process
McNeil Consumer & Specialty Pharmaceuticals, Fort Wash-
from the injury.
ington, PA) be used sparingly in the treatment of headache-
like symptoms in the athlete with a concussion. Other sub-
EQUIPMENT ISSUES
stances to avoid during the acute postconcussion period
include those that adversely affect central nervous function, in
particular alcohol and narcotics.
Helmets and Headgear
Although wearing a helmet will not prevent all head inju-
ries, a properly fitted helmet for certain sports reduces the risk
Wake-Ups and Rest
of such injuries. A poorly fitted helmet is limited in the amount
Once it has been determined that a concussion has been
of protection it can provide, and the ATC must play a role in
sustained, a decision must be made as to whether the athlete
enforcing the proper fitting and use of the helmet. Protective
can return home or should be considered for overnight obser-
sport helmets are designed primarily to prevent catastrophic
vation or admission to the hospital. For more severe injuries,
injuries (ie, skull fractures and intracranial hematomas) and
the athlete should be evaluated by the team physician or emer-
are not designed to prevent concussions. A helmet that protects
gency room physician if the team physician is not available.
the head from a skull fracture does not adequately prevent the
If the athlete is allowed to return home or to the dormitory
rotational and shearing forces that lead to many concussions.99
room, the ATC should counsel a friend, teammate, or parent
The National Collegiate Athletic Association requires hel-
to closely monitor the athlete. Traditionally, part of these in-
mets be worn for the following sports: baseball, field hockey
structions included a recommendation to wake up the athlete
(goalkeepers only), football, ice hockey, women’s lacrosse
every 3 to 4 hours during the night to evaluate changes in
(goalkeepers only), men’s lacrosse, and skiing. Helmets are
292
Volume 39 • Number 3 • September 2004
also recommended for recreational sports such as bicycling,
protecting the teeth and preventing fractures and avulsions that
skiing, mountain biking, roller and inline skating, and speed
could require many years of expensive dental care.
skating. Headgear standards are established and tested by the
National Operating Committee on Standards for Athletic
ACKNOWLEDGMENTS
Equipment and the American Society for Testing and Mate-
rials.99
We gratefully acknowledge the efforts of Kent Scriber, PhD, ATC;
Efforts to establish and verify standards continue to be test-
Scott Anderson, MS, ATC; Michael Collins, PhD; Vito A. Perriello,
ed and refined, but rarely are the forces and conditions expe-
Jr, MD, PhD; Karen Johnston, MD, PhD; and the Pronouncements
Committee in the preparation of this document.
rienced on the field by the athletes duplicated. In addition to
direction, speed, and amount of the forces delivered and re-
ceived by the athlete, conditions not controlled in the testing
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Journal of Athletic Training
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Appendix A. Graded Symptom Checklist
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Appendix B. Physician Referral Checklist
Day-of-injury referral
14. Motor deficits subsequent to initial on-field assessment
1. Loss of consciousness on the field
15. Sensory deficits subsequent to initial on-field assessment
2. Amnesia lasting longer than 15 min
16. Balance deficits subsequent to initial on-field assessment
3. Deterioration of neurologic function*
17. Cranial nerve deficits subsequent to initial on-field assessment
4. Decreasing level of consciousness*
18. Postconcussion symptoms that worsen
5. Decrease or irregularity in respirations*
19. Additional postconcussion symptoms as compared with those on
6. Decrease or irregularity in pulse*
the field
7. Increase in blood pressure
20. Athlete is still symptomatic at the end of the game (especially at
8. Unequal, dilated, or unreactive pupils*
high school level)
9. Cranial nerve deficits
10. Any signs or symptoms of associated injuries, spine or skull
Delayed referral (after the day of injury)
fracture, or bleeding*
1. Any of the findings in the day-of-injury referral category
11. Mental status changes: lethargy, difficulty maintaining arousal,
2. Postconcussion symptoms worsen or do not improve over time
confusion, or agitation*
3. Increase in the number of postconcussion symptoms reported
12. Seizure activity*
4. Postconcussion symptoms begin to interfere with the athlete’s
13. Vomiting
daily activities (ie, sleep disturbances or cognitive difficulties)
*Requires that the athlete be transported immediately to the nearest emergency department.
Appendix C. Concussion Home Instructions
I believe that
sustained a concussion on
. To make sure
he/she recovers, please follow the following important recommendations:
1. Please remind
to report to the athletic training room tomorrow at
for a follow-
up evaluation.
2. Please review the items outlined on the enclosed Physician Referral Checklist. If any of these problems develop prior to his/her visit, please
call
at
or contact the local emergency medical system or your family
physician. Otherwise, you can follow the instructions outlined below.
It is OK to:
There is NO need to:
Do NOT:
● Use acetaminophen (Tylenol)
● Check eyes with flashlight
● Drink alcohol
for headaches
● Wake up every hour
● Eat spicy foods
● Use ice pack on head and
● Test reflexes
neck as needed for comfort
● Stay in bed
● Eat a light diet
● Return to school
● Go to sleep
● Rest (no strenuous
activity or sports)
Specific recommendations:
Recommendations provided to:
Recommendations provided by:
Date:
Time:
Please feel free to contact me if you have any questions. I can be reached at:
Signature:
Date:
Journal of Athletic Training
297
