Evaluation of Neuropsychological Domain Scores and Postural Stability Following Cerebral Concussion in Sports Subject-Specific Increases in Serum S-100B Distinguish Sports-Related Concussion from Sports-Related Exertion Immediate Neurocognitive Effects of Concussion Acute Effects and Recovery After Sport‐Related Concussion: A Neurocognitive and Quantitative Brain Electrical Activity Study MEASUREMENT OF HEAD IMPACTS IN COLLEGIATE FOOTBALL PLAYERS: RELATIONSHIP BETWEEN HEAD IMPACT BIOMECHANICS AND ACUTE CLINICAL OUTCOME AFTER CONCUSSION Predicting and preventing postconcussive problems in paediatrics (5P) study: protocol for a prospective multicentre clinical prediction rule derivation study in children with concussion Effect of concussion on clinically measured reaction time in 9 NCAA division I collegiate athletes: a preliminary study. Depression and neurocognitive performance after concussion among male and female high school and collegiate athletes. Is neuropsychological testing useful in the management of sport-related concussion? Persistent motor system abnormalities in formerly concussed athletes. Tracking Neurocognitive Performance following Concussion in High School Athletes The “Value Added” of Neurocognitive Testing after Sports-Related Concussion Time course and dimensions of postural control changes following neuromuscular training in youth field hockey athletes SEX DIFFERENCES IN NEUROPSYCHOLOGICAL FUNCTION AND POST‐CONCUSSION SYMPTOMS OF CONCUSSED COLLEGIATE ATHLETES Exploring differences in computerized neurocognitive concussion testing between African American and White athletes. Adding Vision to Concussion Testing: A Prospective Study of Sideline Testing in Youth and Collegiate Athletes FUNCTIONAL BRAIN ABNORMALITIES ARE RELATED TO CLINICAL RECOVERY AND TIME TO RETURN‐TO‐PLAY IN ATHLETES
Context With increasing knowledge and research about concussion , there have been few objective studies that have used neuropsychological domain scores and postural stability to assess concussion . Objective To evaluate the recovery curve of athletes who incur sport-related concussion from repeated serial testing of neuropsychological and posturography testing . Design A prospect i ve epidemiological model was used for the course of the study . Setting Division I intercollegiate athletics . Participants Athletes participating in football , soccer , basketball , softball , and cheerleading . Main Outcome Measures  Neuropsychological scores and posturography measures  were obtained preseason and serially at day 1 , day 2 , day 3 , and day 10 postconcussion .  Control participants  were tested at the same intervals .  Neuropsychological scores were converted to st and ards score and then into domains of attention , learning , speed of information processing , concentration , memory , and verbal fluency . Analysis of covariance with the baseline test as the covariate was used to analyze the data with univariate post hoc tests performed . Results Significant group differences were found for self reported symptoms ( P = 0.001 ) , speed of information processing ( P = 0.005 ) , mean stability ( P = 0.002 ) , and vestibular function ( P = 0.003 ) between injured and control participants . A group , by day , planned comparison found that speed of information processing and composite balance measures demonstrated significant differences through day 10 postinjury , while symptoms and the vestibular ratio remained significant only through day 3 . Conclusions The concussion recovery curve demonstrated short-term neuropsychological and posturography deficits following injury . A comprehensive approach to concussion management should be used to assess the injury and make return-to-play decisions Background The on-field diagnosis of sports-related concussion ( SRC ) is complicated by the lack of an accurate and objective marker of brain injury . Purpose To compare subject-specific changes in the astroglial protein , S100B , before and after SRC among collegiate and semi-professional contact sport athletes , and compare these changes to differences in S100B before and after non-contact exertion . Study Design Longitudinal cohort study . Methods From 2009–2011 , we performed a prospect i ve study of athletes from Munich , Germany , and Rochester , New York , USA .  Serum S100B was measured in all SRC athletes at pre-season baseline , within 3 hours of injury , and at days 2 , 3 and 7 post-SRC . Among a subset of athletes , S100B was measured after non-contact exertion but before injury . All sample s were collected identically and analyzed using an automated electrochemiluminescent assay to quantify serum S100B levels . Results Forty-six athletes ( 30 Munich , 16 Rochester ) underwent baseline testing . Thirty underwent additional post-exertion S100B testing . Twenty-two athletes ( 16 Rochester , 6 Munich ) sustained a SRC , and 17 had S100B testing within 3 hours post-injury . The mean 3-hour post-SRC S100B was significantly higher than pre-season baseline ( 0.099±0.008 µg/L vs. 0.058±0.006 µg/L , p = 0.0002 ) . Mean post-exertion S100B was not significantly different than the preseason baseline . S100B levels at post-injury days 2 , 3 and 7 were significantly lower than the 3-hour level , and not different than baseline . Both the absolute change and proportional increase in S100B 3-hour post-injury were accurate discriminators of SRC from non-contact exertion without SRC ( AUC 0.772 and 0.904 , respectively ) . A 3-hour post-concussion S100B > 0.122 µg/L and a proportional S100B increase of > 45.9 % over baseline were both 96.7 % specific for SRC . Conclusions Relative and absolute increases in serum S100B can accurately distinguish SRC from sports-related exertion , and may be a useful adjunct to the diagnosis of SRC OBJECTIVE To prospect ively measure the immediate neurocognitive effects and early course of recovery from concussion and to examine the effects of loss of consciousness ( LOC ) and posttraumatic amnesia ( PTA ) on the severity of neurocognitive impairment immediately after concussion . METHODS A sports-related concussion research model was used to allow prospect i ve immediate evaluation of concussion . A total of 2385 high school and college football players were studied . Ninety-one players ( 3.8 % ) sustained concussions during the study . A brief neurocognitive and neurological screening measure , the St and ardized Assessment of Concussion  , was used to assess cognitive functioning before the football season , immediately after injury , and 15 minutes , 48 hours , and 90 days after injury . RESULTS St and ardized Assessment of Concussion scores immediately after concussion were significantly lower than the preseason baseline score and the noninjured population baseline mean , even for injured subjects without LOC or PTA . Subjects with LOC were most severely impaired immediately after injury , whereas those without LOC or PTA were least impaired . Significant impairment was also detected 15 minutes after injury , but all three groups returned to baseline levels of cognitive functioning within 48 hours . CONCLUSION These findings are the first to demonstrate not only that a gradient of increasing concussion severity is represented by PTA and LOC but also that measurable neurocognitive abnormalities are evident immediately after injury without PTA or LOC Objective To investigate the clinical utility and sensitivity of a portable , automatic , frontal quantitative electroencephalographic ( QEEG ) acquisition device currently in development in detecting abnormal brain electrical activity after sport-related concussion . Design This was a prospect i ve , non-r and omized study of 396 high school and college football players , including cohorts of 28 athletes with concussion and 28 matched controls . All subjects underwent preseason baseline testing on measures of postconcussive symptoms , postural stability , and cognitive functioning , as well as QEEG . Clinical testing and QEEG were repeated on day of injury and days 8 and 45 postinjury for the concussion and control groups . Main Outcomes and Results The injured group reported more significant postconcussive symptoms during the first 3 days postinjury , which resolved by days 5 and 8 . Injured subjects also performed poorer than controls on neurocognitive testing on the day of injury , but no differences were evident on day 8 or day 45 . QEEG studies revealed significant abnormalities in electrical brain activity in the injured group on day of injury and day 8 postinjury , but not on day 45 . Conclusions Results from the current study on clinical recovery after sport-related concussion are consistent with early reports indicating a typical course of full recovery in symptoms and cognitive dysfunction within the first week of injury . QEEG results , however , suggest that the duration of physiological recovery after concussion may extend longer than observed clinical recovery . Further study is required to replicate and extend these findings in a larger clinical sample , and further demonstrate the utility of QEEG as a marker of recovery after sport-related concussion OBJECTIVE To determine the relationship between recorded head accelerations and impact locations and acute clinical outcome of symptomatology , neuropsychological , and postural stability tests after cerebral concussion in Division I collegiate football players . METHODS A prospect i ve field study was used in which accelerometers were embedded in the football helmets of 88 collegiate football players .  Linear and rotational accelerations of all head impacts sustained over the course of 2004 to 2006 National Collegiate Athletic Association football seasons were collected in real-time . Change scores were calculated on clinical measures from the players ' preseason baseline to postinjury ( within 48 h ) and regressed against the recorded linear and rotational accelerations of the head at the time of the concussion . RESULTS Thirteen concussions were recorded ranging in impact magnitudes of 60.51 to 168.71 g. Linear regression showed no significant relationships between impact magnitude ( linear or rotational acceleration ) or impact location and change scores for symptom severity , postural stability , or neurocognitive function ( P > 0.05 ) . CONCLUSION Our findings suggest that football players are concussed by impacts to the head that occur at a wide range of magnitudes and that clinical measures of acute symptom severity , postural stability , and neuropsychological function all appear to be largely independent of impact magnitude and location . Because of the varying magnitudes and locations of impacts result ing in concussion as well as other factors such as the frequency of subconcussive impacts and number of previous concussions , it may be difficult to establish a threshold for concussive injury that can be applied to all football players Introduction Persistent postconcussive symptoms ( PCSs ) is the persistence of somatic , cognitive , physical , psychological and /or behavioural changes lasting more than 1 month following concussion . Persistent concussion impacts the quality of life through impaired cognition , memory and attention affecting school performance , mood and social engagement . No large epidemiological studies have determined the true prevalence of persistent concussion symptoms . Vali date d , easy-to-use prognosticators do not exist for clinicians to identify children at highest risk . The goal of Predicting and Preventing Postconcussive Problems in Pediatrics study is to derive a clinical prediction rule for the development of persistent postconcussion symptoms in children and adolescents presenting to emergency department following acute head injury . Methods and analysis This study is a prospect i ve , multicentre cohort study across nine academic Canadian paediatric emergency departments . We will recruit the largest prospect i ve epidemiological cohort of children with concussion . Eligible children will be followed using  Post-Concussion Symptom Inventory , a vali date d tool in children as young as 5 years . Patients will follow-up at 1 , 2 , 4 , 8 and 12 weeks postinjury . The main outcome will be the presence/absence of PCSs defined as three or more persistent concussion symptoms 1 month following the injury .  1792 patients provide adequate power to derive a clinical decision rule using multivariate analyses to find predictor variables sensitive for detecting cases of persistent postconcussion symptoms . Ethics and dissemination Results of this large prospect i ve study will enable clinicians to identify children at highest risk , optimise treatment and provide families with realistic and appropriate anticipatory guidance . Ethics has been obtained through the Children 's Hospital of Eastern Ontario Research Ethics Board . Results will be disseminated at international conferences and in four manuscripts to peer- review ed journals . Trial registration This study is registered at Clinical trials.gov through the US National Institute of Health/National Library of Medicine ( NCT01873287 ; http:// clinical trials.gov/ct2/show/NCT01873287 ) OBJECTIVES To evaluate the effect of concussion on clinical ly measured reaction time ( RT(clin ) ) and in comparison to a computerized reaction time measure ( RT(comp ) ) . DESIGN Prospect i ve , repeated measures observational study . SETTING Athletic training clinic at a National Collegiate Athletic Association ( NCAA ) Division I university . PARTICIPANTS Data are reported for 9 collegiate athletes with acute concussion who were part of a larger cohort of 209 athletes recruited from the university 's football , women 's soccer , and wrestling teams before the start of their respective athletic seasons . METHODS  Baseline RT(clin ) and RT(comp )  were measured during preparticipation physical examinations . RT(clin ) measured the time required to catch a suspended vertical shaft by h and closure after its release by the examiner . RT(comp ) was derived from the simple RT component of the CogState-Sport computerized neurocognitive test battery . Athletes who subsequently sustained a physician-diagnosed concussion underwent repeated RT(clin ) and RT(comp ) testing within 72 hours of injury . A Wilcoxon signed rank test was used to compare baseline and after-injury RTs . MAIN OUTCOME MEASUREMENTS After-injury changes in RT(clin ) and RT(comp ) were calculated with respect to each athlete 's own preseason baseline value . RESULTS After-injury RT(clin ) was prolonged in 8 of the 9 athletes with concussions , whereas RT(comp ) was prolonged in 5 of the 9 athletes with concussions . The mean ( st and ard deviation ) RT(clin ) increased from 193 ± 21 ms to 219 ± 31 ms ( P = .050 ) , and mean RT(comp ) increased from 247 ± 75 to 462 ± 120 ms ( P = .214 ) . CONCLUSIONS We concluded that RT(clin ) appears to be sensitive to the known prolongation of RT after concussion and compares favorably with an accepted computerized RT measure . This study supports the potential utility of RT(clin ) as part of a multifaceted concussion assessment battery OBJECTIVES To prospect ively examine the relationship of sport-related concussion with depression and neurocognitive performance and symptoms among male and female high school and college athletes . A secondary objective was to explore age and sex differences . DESIGN Pretest , multiple posttest , repeated- measures design . SETTING Laboratory . PARTICIPANTS High school and collegiate athletes ( N=75 ) with a diagnosed concussion . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES  Beck Depression Inventory-II and computerized neurocognitive test battery ( Immediate Post-concussion Assessment and Cognitive Test )  , which includes concussion symptoms ( Post-concussion Symptom Scale ) at baseline and at 2 , 7 , and 14 days postinjury . RESULTS Concussed athletes exhibited significantly higher levels of depression from baseline at 2 days ( P≤.001 ) , 7 days ( P=.006 ) , and 14 days postconcussion ( P=.04 ) . Collegiate athletes demonstrated a significant increase in depression at 14 days postconcussion than did high school athletes ( P=.03 ) . There were no sex differences in depression levels . Neurocognitive decrements at 14 days were supported for reaction time ( P=.001 ) and visual memory ( P=.001 ) . Somatic depression at 7 days postconcussion was related to slower reaction time at 7 days postconcussion . Somatic depression at 14 days postinjury was related to lower visual memory scores at 14 days postinjury . CONCLUSIONS Although not clinical ly significant , athletes experienced increased depression scores up to 14 days after concussion that coincided with neurocognitive decrements in reaction time and visual memory . Somatic depression appears to be most salient with regard to lower neurocognitive performance . Mood assessment s after concussion are warranted to help monitor and enhance recovery OBJECTIVE Neuropsychological ( NP ) testing has been used for several years as a way of detecting the effects of sport-related concussion in order to aid in return-to-play determinations . In addition to st and ard pencil- and -paper tests , computerized NP tests are being commercially marketed for this purpose to professional , collegiate , high school , and elementary school programs . However , a number of important questions regarding the clinical validity and utility of these tests remain unanswered , and these questions present serious challenges to the applicability of NP testing for the management of sport-related concussion . Our purpose is to outline the criteria that should be met in order to establish the utility of NP instruments as a tool in the management of sport-related concussion and to review the degree to which existing tests have met these criteria . DATA SOURCES A comprehensive literature review of MEDLINE and PsychLit from 1990 to 2004 , including all prospect i ve , controlled studies of NP testing in sport-related concussion . DATA SYNTHESIS The effects of concussion on NP test performance are so subtle even during the acute phase of injury ( 1 - 3 days postinjury ) that they often fail to reach statistical significance in group studies . Thus , this method may lack utility in individual decision making because of a lack of sensitivity . In addition , most of these tests fail to meet other psychometric criteria ( eg , adequate reliability ) necessary for this purpose . Finally , it is unclear that NP testing can detect impairment in players once concussion-related symptoms ( eg , headache ) have resolved . Because no current guideline for the management of sport-related concussion allows a symptomatic player to return to sport , the incremental utility of NP testing remains question able . CONCLUSIONS / RECOMMENDATIONS Despite the theoretic rationale for the use of NP testing in the management of sport-related concussion , no NP tests have met the necessary criteria to support a clinical application at this time . Additional research is necessary to establish the utility of these tests before they can be considered part of a routine st and ard of care , and concussion recovery should be monitored via the st and ard clinical examination and subjective symptom checklists until NP testing or other methods are proven effective for this purpose CONTEXT The known detrimental effects of sport concussions on motor system function include balance problems , slowed motor execution , and abnormal motor cortex excitability . OBJECTIVE To assess whether these concussion-related alterations of motor system function are still evident in collegiate football players who sustained concussions but returned to competition more than 9 months before testing . DESIGN Case-control study . SETTING University laboratory . PATIENTS OR OTHER PARTICIPANTS A group of 21 active , university-level football players who had experienced concussions was compared with 15 university football players who had not sustained concussions . INTERVENTION(S ) A force platform was used to assess center-of-pressure ( COP ) displacement and COP oscillation regularity ( approximate entropy ) as measures of postural stability in the upright position . A rapid alternating-movement task was also used to assess motor execution speed . Transcranial magnetic stimulation over the motor cortex was used to measure long-interval intracortical inhibition and the cortical silent period , presumably reflecting y-aminobutyric acid subtype B receptor-mediated intracortical inhibition . MAIN OUTCOME MEASURE(S ) COP displacement and oscillation regularity , motor execution speed , long-interval intracortical inhibition , cortical silent period . RESULTS Relative to controls , previously concussed athletes showed persistently lower COP oscillation r and omness , normal performance on a rapid alternating-movement task , and more M1 intracortical inhibition that was related to the number of previous concussions . CONCLUSIONS Sport concussions were associated with pervasive changes in postural control and more M1 intracortical inhibition , providing neurophysiologic and behavioral evidence of lasting , sub clinical changes in motor system integrity in concussed athletes Abstract Objective : To extend previous research design s and examine cognitive performance up to 30 days postconcussion . Method : A prospect i ve cohort design was used to examine 2000 athletes from 8 mid-Michigan area high schools to compare baseline neurocognitive performance with postconcussion neurocognitive performance . All concussed athletes were readministered the Immediate Post Assessment and Cognitive Test ( ImPACT ) at 2 , 7 , 14 , 21 , and 30 days postconcussion . Results : A total of 72 high school athletes ( aged 15.8 ± 1.34 years ) sustained a concussion . A significant with in-subjects effect for reaction time ( F = 10.01 ; P = 0.000 ) , verbal memory ( F = 3.05 ; P = 0.012 ) , motor processing speed ( F = 18.51 ; P = 0.000 ) , and total symptoms following an injury ( F = 16.45 ; P = 0.000 ) was found . Concussed athletes demonstrated a significant decrease in reaction time up to 14 days postconcussion ( P = 0.001 ) compared with baseline reaction time . Reaction time returned to baseline levels at 21 days postinjury ( P = 0.25 ) . At 7 days postinjury , impairments in verbal memory ( P = 0.003 ) and motor processing speed ( P = 0.000 ) were documented and returned to baseline levels by 14 days postinjury . Concussed athletes self-reported significantly more symptoms at 2 days postconcussion ( P = 0.000 ) and exhibited a resolution of symptoms by 7 days postinjury ( P = 0.06 ) . Conclusion : High school athletes could take up to 21 days to return to baseline levels for reaction time . These data support current recommendations for the conservative management of concussion in the high school athlete Background Neurocognitive testing has been endorsed as a “ cornerstone ’ of concussion management by recent Vienna and Prague meetings of the Concussion in Sport Group . Neurocognitive testing is important given the potential unreliability of athlete self-report after injury . Relying only on athletes'ormalities after injury . Study Design Case control study ; Level of evidence , 3 . Methods High school and college athletes with a diagnosed concussion were tested 2 days after injury . Postinjury neurocognitive performance ( Immediate Postconcussion Assessment and Cognitive Testing ) and symptom ( postconcussion symptom ) scores were compared with preinjury ( baseline ) scores and with those of an agex and education-matched noninjured athlete control group . “ Abnormal ” test performance was determined statistically with Reliable Change Index scores . Results Sixty-four percent of concussed athletes reported a significant increase in symptoms , as judged by postconcussion symptom scores , compared with preinjury baseline at 2 days after injury . Eighty-three percent of the concussed sample demonstrated significantly poorer neurocognitive test results relative to their own baseline performance . The addition of neurocognitive testing result ed in a net increase in sensitivity of 19 % . Ninety-three percent of the sample had either abnormal neurocognitive test results or a significant increase in symptoms , relative to their own baseline ; 30 % of a control group demonstrated either abnormalities in neurocognitive testing or elevated symptoms , as judged by postconcussion symptom scores . For the concussed group , use of symptom and neurocognitive test results result ed in an increased yield of 29 % overreliance on symptoms alone . In contrast , 0 % of the control group had both symptoms and abnormal neurocognitive testing . Conclusion Reliance on patients ’ self-reported symptoms after concussion is likely to result in underdiagnosis of concussion and may result in premature return to play . Neurocognitive testing increases diagnostic accuracy when used in conjunction with self-reported symptoms Purpose Injury prevention effects of neuromuscular training have been partly attributed to postural control adaptations . Uncertainty exists regarding the magnitude of these adaptations and on how they can be adequately monitored . The objective was to determine the time course of neuromuscular training effects on functional , dynamic and static balance measures . Methods Thirty youth ( 14.9 ± 3 years ) field hockey athletes were r and omised to an intervention or control group . The intervention included a 20-min neuromuscular warm-up program performed twice weekly for 10 weeks . Balance assessment s were performed at baseline , week three , week six and post-intervention . They included the star excursion balance test ( SEBT ) , balance error scoring system ( BESS ) , jump-l and ing time to stabilization ( TTS ) and center of pressure ( COP ) sway velocity during single-leg st and ing . Results No baseline differences were found between groups in demographic data and balance measures . Adherence was at 86 % . All balance measures except the medial – lateral TTS improved significantly over time ( p < 0.05 ) in both groups . Significant group by time interactions were found for the BESS score ( p < 0.001 ) . The intervention group showed greater improvements ( 69.3 ± 10.3 % ) after 10 weeks in comparison to controls ( 31.8 ± 22.1 % ) . There were no significant group by time interactions in the SEBT , TTS and COP sway velocity . Conclusions Neuromuscular training was effective in improving postural control in youth team athletes . However , this effect was not reflected in all balance measures suggesting that the neuromuscular training did not influence all dimensions of postural control . Further studies are needed to confirm the potential of specific warm-up programs to improve postural control OBJECTIVE Our purpose was to determine whether sex differences exist with respect to post-concussion symptoms and neurocognitive function in concussed collegiate athletes . METHODS A prospect i ve dependent- sample cohort design was used to compare baseline and post-concussion neuropsychological test scores and endorsed symptoms as functions of serial post-concussion assessment with respect to time and sex . The Immediate Post-concussion Assessment and Cognitive Testing ( ImPACT ) battery was administered to a multicenter analysis group of 79 concussed athletes . This computerized neuropsychological test was given to the athletes during the preseason and , on average , 2 and 8 days postinjury . RESULTS Multivariate analyses revealed no significant between-group differences on baseline test performance with respect to sex on any of the ImPACT composite scores or on the total symptom score . Multivariate analyses of post-concussion data revealed a significant main effect of time on ImPACT scores , but no main effect of sex was identified , and no time-by-sex interaction existed . Post hoc analysis revealed that concussed female athletes performed significantly worse than concussed male athletes on visual memory tasks ( P = 0.001 ) , and analysis of endorsed post-concussion symptoms revealed that concussed men were significantly more likely than concussed women to report post-concussion symptoms of vomiting ( P = 0.001 ) and sadness ( P = 0.017 ) . Athletes ' scores were examined individually using the reliable-change methodology . At 2 days post-injury , 58 % of concussed athletes had one or more reliable incidents of performance decline or increases in symptom reporting . At 8 days post-concussion , 30 % of concussed athletes were still showing one or more reliable change from preseason values . CONCLUSIONS College athletes exhibit differences on visual memory composite scores and symptoms post-concussion as a function of sex . These data support the importance of evaluating neuropsychological status and post-concussion symptoms in concussed athletes . In addition , these data illustrate the importance of analyzing an individual athlete 's recovery pattern , because individual differences in recovery trajectories may be overshadowed by global norm-group comparisons The purpose of the current study was to explore potential differences in pre- and post-concussion performance on a computerized neurocognitive concussion test between African American and White high-school and collegiate student-athletes . A prospect i ve case-control design was used to compare baseline and 2- and 7-day post-concussion computerized neurocognitive performance and symptoms between 48 White and 48 African American athletes matched for age , gender , and concussion history . The Immediate Post-Concussion Assessment Cognitive Test ( ImPACT ) version 2.0 ( NeuroHealth System , LLC , Pittsburgh , PA , USA ) computer software program was used to assess neurocognitive function ( i.e. , verbal and visual memory , motor processing speed , and reaction time ) and concussion symptoms . Regardless of race/ethnicity , there were significant decrements in computerized neurocognitive performance and increased symptoms following a concussion for the entire sample . African Americans and Whites did not differ significantly on baseline or post-concussion verbal memory , visual memory , reaction time , and total reported symptoms . However , African American participants were 2.4 × more likely to have at least one clinical ly significant cognitive decline on ImPACT at 7 days post-concussion and scored lower at 7 days post-concussion compared with baseline on processing speed than White participants . The authors concluded that the baseline ImPACT test was culturally equivalent and construct valid for use with these two racial/ethnic groups . However , in contrast , the findings support deleterious performance for the African American athletes compared with the White athletes on the ImPACT post-concussion evaluation that is of critical clinical relevance and warrants further research Background : Sports-related concussion commonly affects the visual pathways . Current sideline protocol s test cognition and balance but do not include assessment s of visual performance . We investigated how adding a vision-based test of rapid number naming could increase our ability to identify concussed athletes on the sideline at youth and collegiate levels . Methods : Participants in this prospect i ve study included members of a youth ice hockey and lacrosse league and collegiate athletes from New York University and Long Isl and University . Athletes underwent preseason baseline assessment s using : 1 ) the King – Devick ( K-D ) test , a < 2-minute visual performance measure of rapid number naming , 2 ) the St and ardized Assessment of Concussion ( SAC ) , a test of cognition , and 3 ) a timed t and em gait test of balance .  The SAC and timed t and em gait are components of the currently used Sport Concussion Assessment Tool , 3rd Edition ( SCAT3 and Child-SCAT3 ) . In the event of a concussion during the athletic season , injured athletes were retested on the sideline/rink-side . Nonconcussed athletes were also assessed as control participants under the same testing conditions . Results : Among 243 youth ( mean age 11 ± 3 years , range 5–17 ) and 89 collegiate athletes ( age 20 ± 1 years , range 18–23 )  , baseline time scores for the K-D test were lower ( better ) with increasing participant age ( P < 0.001 , linear regression models ) . Among 12 athletes who sustained concussions during their athletic season , K-D scores worsened from baseline by an average of 5.2 seconds ; improvement by 6.4 seconds was noted for the nonconcussed controls ( n = 14 ) . The  vision-based K-D test  showed the greatest capacity to distinguish concussed vs control athletes based on changes from preseason baseline to postinjury ( receiver operating characteristic [ ROC ] curve areas from logistic regression models , accounting for age = 0.92 for K-D , 0.87 for timed t and em gait , and 0.68 for SAC ; P = 0.0004 for comparison of ROC curve areas ) . Conclusions : Adding a vision-based performance measure to cognitive and balance testing enhances the detection capabilities of current sideline concussion assessment . This observation in patients with mild traumatic brain injury reflects the common involvement and widespread distribution of brain pathways dedicated to vision OBJECTIVE The relationship between athlete reports of symptoms , neurophysiological activation , and neuropsychological functioning is investigated in a sample of high school athletes . METHODS All athletes were evaluated using functional magnetic resonance imaging ( fMRI ) , a computer-based battery of neurocognitive tests , and a subjective symptom scale . Athletes were evaluated within approximately 1 week of injury and again after clinical recovery using all assessment modalities . RESULTS This study found that abnormal fMRI results during the first week of recovery predicted clinical recovery . As a group , athletes who demonstrated hyperactivation on fMRI scans at the time of their first fMRI scan demonstrated a more prolonged clinical recovery than athletes who did not demonstrate hyperactivation at the time of their first fMRI scan . CONCLUSION These results demonstrate the relationship between neurophysiological , neuropsychological , and subjective symptom data in a relatively large sample composed primarily of concussed high school athletes .  fMRI represents an important evolving technology for the underst and ing of brain recovery after concussion and may help shape return-to-play guidelines in the future
Due to differences in modalities , time course , study design and outcomes , it is not possible to define a single ‘ physiological time window ’ for SRC recovery .
Multiple studies suggest physiological dysfunction may outlast current clinical measures of recovery , supporting a buffer zone of gradually increasing activity before full contact risk .
Aim or objective The aim of this study is to consoli date studies of physiological measures following sport-related concussion ( SRC ) to determine if a time course of postinjury altered neurobiology can be outlined .
This biological time course was considered with respect to clinical ly relevant outcomes such as vulnerability to repeat injury and safe timing of return to physical contact risk .