title: The “Value Added” of Neurocognitive Testing after Sports-Related Concussion Prediction of intracranial computed tomography findings in patients with minor head injury by using logistic regression. Examining Concussion Rates and Return to Play in High School Football Players Wearing Newer Helmet Technology: A Three-Year Prospective Cohort Study 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. FUNCTIONAL BRAIN ABNORMALITIES ARE RELATED TO CLINICAL RECOVERY AND TIME TO RETURN‐TO‐PLAY IN ATHLETES Serum levels of ubiquitin C-terminal hydrolase distinguish mild traumatic brain injury from trauma controls and are elevated in mild and moderate traumatic brain injury patients with intracranial lesions and neurosurgical intervention Clinical decision instruments for CT scan in minor head trauma. Predicting Intracranial Traumatic Findings on Computed Tomography in Patients with Minor Head Injury: The CHIP Prediction Rule Elevated levels of serum glial fibrillary acidic protein breakdown products in mild and moderate traumatic brain injury are associated with intracranial lesions and neurosurgical intervention. Immediate Neurocognitive Effects of Concussion Acute effects and recovery time following concussion in collegiate football players: the NCAA Concussion Study. Diagnostic value of S100B and neuron-specific enolase in mild pediatric traumatic brain injury. The assessment of orientation following concussion in athletes.
abstract: 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 OBJECT The aim of this study was to develop a decision rule for physicians in developing countries to identify patients with minor head injury who will benefit from emergency brain CT scanning .  METHODS Three hundred eighteen patients with a history of blunt head trauma and a Glasgow Coma Scale ( GCS ) score > or= 13 who had presented within 12 hours of trauma underwent nonenhanced brain CT and were included in this prospect i ve study . Computed tomography findings that necessitated neurosurgical care ( either observation or intervention ) were considered as positive findings . Logistic regression was used to develop the decision rule . RESULTS Computed tomography scans  were always normal in patients < 65 years old who did not have an obvious head wound , a raccoon sign , vomiting , memory deficit , or a decrease in their GCS score .  Patients with 1 major criterion ( GCS score < 14 , raccoon sign , failure to remember the impact , age > 65 years , or vomiting ) or 2 minor criteria ( wound at the scalp or GCS score < 15 ) had an abnormal CT scan in 13 % of the cases . CONCLUSIONS The decision rule developed by the authors appears to be 100 % sensitive and 46 % specific for positive findings on brain CT and will , in developing countries , help clarify the decision to obtain scans OBJECTIVE : The purpose of this study was to compare concussion rates and recovery times for athletes wearing newer helmet technology compared to traditional helmet design . METHODS : This was a three-year , prospect i ve , naturalistic , cohort study . Participants were 2,141 high school athletes from Western Pennsylvania . Approximately half of the sample wore the Revolution helmet manufactured by Riddell , Inc.  ( n = 1,173 ) and the remainder of the sample used  st and ard helmets ( n = 968 ) . Athletes underwent computerized neurocognitive testing through the use of ImPACT at the beginning of the study . Following a concussion , players were reevaluated at various time intervals until recovery was complete . RESULTS : In the total sample , the concussion rate in athletes wearing the Revolution was 5.3 % and in athletes wearing st and ard helmets was 7.6 % [ & khgr;2 ( 1 , 2 , 141 ) = 4.96 , P < 0.027 ] . The relative risk estimate was 0.69 ( 95 % confidence interval = 0.499– 0.958 ) . Wearing the Revolution helmet was associated with approximately a 31 % decreased relative risk and 2.3 % decreased absolute risk for sustaining a concussion in this cohort study . The athletes wearing the Revolution did not differ from athletes wearing st and ard helmets on the mechanism of injury ( e.g. , head-to-head strike ) , on-field concussion markers ( e.g. , amnesia or loss of consciousness ) , or on-field presentation of symptoms ( e.g. , headaches , dizziness , or balance problems ) . CONCLUSION : Recent sophisticated laboratory research has better eluci date d injury biomechanics associated with concussion in professional football players . This data has led to changes in helmet design and new helmet technology , which appears to have beneficial effects in reducing the incidence of cerebral concussion in high school football players 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 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 BACKGROUND : This study compared early serum levels of ubiquitin C-terminal hydrolase ( UCH-L1 ) from patients with mild and moderate traumatic brain injury ( TBI ) with uninjured and injured controls and examined their association with traumatic intracranial lesions on computed tomography ( CT ) scan ( CT positive ) and the need for neurosurgical intervention ( NSI ) . METHODS : This prospect i ve cohort study enrolled adult patients presenting to three tertiary care Level I trauma centers after blunt head trauma with loss of consciousness , amnesia , or disorientation and a Glasgow Coma Scale ( GCS ) score 9 to 15 . Control groups included normal uninjured controls and nonhead injured trauma controls presenting to the emergency department with orthopedic injuries or motor vehicle crash without TBI . Blood sample s were obtained in all trauma patients within 4 hours of injury and measured by enzyme-linked immunosorbent assay for UCH-L1 ( ng/mL ± st and ard error of the mean ) . RESULTS : There were 295 patients enrolled , 96 TBI patients ( 86 with GCS score 13–15 and 10 with GCS score 9–12 ) , and 199 controls ( 176 uninjured , 16 motor vehicle crash controls , and 7 orthopedic controls ) . The AUC for distinguishing TBI from uninjured controls was 0.87 ( 95 % confidence interval [ CI ] , 0.82–0.92 ) and for distinguishing those TBIs with GCS score 15 from controls was AUC 0.87 ( 95 % CI , 0.81–0.93 ) . Mean UCH-L1 levels in patients with CT negative versus CT positive were 0.620 ( ±0.254 ) and 1.618 ( ±0.474 ) , respectively ( p < 0.001 ) , and the AUC was 0.73 ( 95 % CI , 0.62–0.84 ) . For patients without and with NSI , levels were 0.627 ( 0.218 ) versus 2.568 ( 0.854 ; p < 0.001 ) , and the AUC was 0.85 ( 95 % CI , 0.76–0.94 ) . CONCLUSION : UCH-L1 is detectable in serum within an hour of injury and is associated with measures of injury severity including the GCS score , CT lesions , and NSI . Further study is required to vali date these findings before clinical application . LEVEL OF EVIDENCE : II , prognostic study Previous studies have presented conflicting results regarding the predictive value of various clinical symptoms and signs for performing computed tomography ( CT ) scan in minor head injury . Moreover , despite the presence in the literature of several similar publications regarding whether or not CT should be employed at the time of presentation of minor head injured patients , data regarding delayed CT are limited . The objective of this study was to determine whether high-risk criteria represent a significant indication for initial CT scan in patients with minor head trauma , and whether or not analysis using delayed CT scan is necessary in patients with high-risk criteria before being discharged . Patients presenting to the Emergency Department with minor head trauma between September 1 , 2003 and September 1 , 2004 were evaluated prospect ively . After being divided into two main groups , low- and high-risk , four separate sub-groups based on age were established . Initial spiral CT examination was done within 3 h of trauma on all patients in addition to a delayed control CT scan in those with high-risk criteria between 16 and 24 h after trauma . The difference between the high- and low-risk groups in terms of abnormal CT findings was statistically significant ( p < 0.0005 ) . Among high-risk patients there was a significant difference between patients with a Glasgow Coma Scale ( GCS ) score of 13 or 14 and those with a GCS score of 15 ( p < 0.0005 ) . The relationship between vomiting and abnormal CT scan was significant ( odds ratio 4.61 , 95 % confidence interval 2.20 - 9.64 , p = 0.0001 ) , and the relationship between abnormal CT scan and suspected skull fracture was also significant ( odds ratio 3.46 , 95 % confidence interval 1.52 - 7.91 , p = 0.0032 ) . No significant correlations between other high-risk criteria and abnormal CT scan were determined . The difference between initial and delayed CT scans  in patients with high-risk criteria was not significant ( p = 0.161 ) . Low-risk patients with a  GCS score of 15 may be discharged without initial CT scan being performed . Initial CT scan absolutely must be performed , however , on patients with GCS < or = 15 in the event of vomiting or suspected skull fracture , even if isolated . Even though the difference between initial and delayed CT scans in patients with high-risk criteria is not significant , it is our opinion that it is still prudent for delayed CT scan to be performed , particularly on patients whose GCS score does not rise to 15 , or decreases Context Available prediction rules to guide selective use of computed tomography in patients with minor head injuries were developed for use in patients with a history of loss of consciousness . Contribution This prospect i ve study included 3181 adults with minor head injury with or without loss of consciousness . A prediction rule based on risk factors ( such as age ; Glasgow Coma Scale score ; skull fracture ; and posttraumatic vomiting , amnesia , or seizure ) successfully identified patients who had intracranial computed tomography findings ( sensitivity , approximately 95 % ) or neurosurgical intervention ( sensitivity , 100 % ) . Caution External validation in different population s is needed before widespread application of the rule . The Editors Minor head injury is one of the most common injuries seen in western emergency departments , with an estimated incidence of 100 to 300 per 100000 people ( 1 ) . Patients with minor head injury include those with blunt injury to the head who have a normal or minimally altered level of consciousness on presentation in the emergency department , that is , a Glasgow Coma Scale ( GCS ) score of 13 to 15 , and a maximum loss of consciousness of 15 minutes , posttraumatic amnesia for 60 minutes , or both ( 2 ) . Intracranial complications after minor head injury are infrequent but commonly require in-hospital observation and occasionally require neurosurgical intervention ( 3 , 4 ) . The imaging procedure of choice for reliable , rapid diagnosis of intracranial complications is computed tomography ( CT ) ( 5 , 6 ) . Because most patients with minor head injury do not show traumatic abnormalities on CT , it seems inefficient to scan all patients with minor head injury to exclude intracranial complications . Of the published prediction rules for the selective use of CT in patients with minor head injury , the New Orleans Criteria ( NOC ) and the Canadian CT Head Rule ( CCHR ) have been externally vali date d ( 79 ) . Research ers in internal and external validation studies have shown that both rules identify 100 % of patients requiring neurosurgical intervention and most patients with traumatic intracranial findings on CT ( 3 , 1012 ) . The external validation studies , however , yielded lower specificities than the development studies ( 10 , 12 ) . The originally reported specificities were probably too optimistic because of their partial derivation from data sets that were also used for the model development ( 13 ) . Also , in both studies research ers included only a subset of patients with minor head injury . Most notably , research ers developed the NOC and the CCHR for patients with minor head injury who have a history of loss of consciousness or amnesia , which many of these patients presenting to emergency departments do not have . Generalizability of the NOC and the CCHR is therefore limited . We aim ed to develop a widely applicable and easy-to-implement prediction rule for the selective use of CT in all patients with minor head injury with or without a history of loss of consciousness . To avoid optimism for the model 's performance , we used penalty factors and internal validation by using bootstrapping procedures to attain more realistic predictions of the model 's performance in an external patient population ( 13 ) . Methods Patients We prospect ively collected data on consecutive patients in 4 university hospitals in the Netherl and s that were participating in the CT in Head Injury Patients ( CHIP ) study ( Figure 1 ) ( 14 ) . Inclusion criteria included initial presentation within 24 hours of blunt injury to the head , a minimum age of 16 years , and a Glasgow Coma Scale ( GCS ) score of 13 to 14 or a GCS score of 15 , with at least 1 of the following risk factors : history of loss of consciousness , short-term memory deficit , amnesia for the traumatic event , posttraumatic seizure , vomiting , severe headache , clinical evidence of intoxication with alcohol or drugs , use of anticoagulants or history of coagulopathy , external evidence of injury above the clavicles , and neurologic deficit . Exclusion criteria were transfer from another hospital , contraindications for CT , or concurrent injuries precluding a head CT at presentation . Figure 1 . Study flow diagram . The number of patients presenting with head injury is an estimate based on the proportion of patients included out of the total number of trauma patients seen by a neurologist or neurologist-in-training in the emergency department of the participating center that included most patients . CT = computed tomography . A neurologist or a neurologist-in-training under telephone supervision of a neurologist examined patients , after which a head CT was performed as soon as possible , in accordance with the current Dutch guidelines ( 15 ) . We performed head CT according to a routine trauma protocol , with a maximum slice thickness of 5 mm infratentorially and 8 mm supratentorially , without intravenous contrast administration . A neuroradiologist or a trauma radiologist ( 9 in total , not blinded to the patients ' history and clinical findings ) interpreted scans in brain and bone window setting s. The institutional review board waived patient informed consent after review of our study protocol because current Dutch guidelines and European Federation of Neurological Societies ' guidelines recommend routine head CT for patients meeting our inclusion criteria ( 15 , 16 ) . Definitions We considered a patient to have a history of loss of consciousness when a witness or the patient reported it . We defined short-term memory deficit as persistent antero grade amnesia . We deemed amnesia present for the traumatic event if the patient could not recall the entire traumatic event . We defined posttraumatic seizure as a seizure witnessed or suspected after the injury and vomiting as an episode of emesis after the traumatic event . We classified headache as being either diffuse or localized . We evaluated the presence and severity of intoxication clinical ly by evidence of slurred speech , alcoholic fetor , or nystagmus ; we did not perform routine blood toxicology tests . Anticoagulant treatment included only coumarin derivatives . We scored the use of platelet aggregation inhibitors ( for example , aspirin and clopidrogel ) , but we did not consider it to be a risk factor . We assessed noniatrogenic coagulopathy , which we considered a risk factor , by patient history , but we did not perform routine blood coagulation tests . We defined external evidence of injury as clinical ly significant discontinuity of the skin or extensive bruising . We classified injury suspect of a fracture as clinical signs of fracture , whereas we classified other injuries , such as contusions , lacerations , or abrasions , as contusion . We defined focal neurologic deficit as any abnormality on routine clinical neurologic examination that indicated a focal cerebral lesion . Data Collection We collected data on patient and trauma characteristics , symptoms , and risk factors ; physical and neurologic examination ; CT findings ; and neurosurgical intervention . Examining physicians entered data on patient history and examination into a data base ( OpenSDE , Erasmus MCUniversity Medical Center Rotterdam , Rotterdam , the Netherl and s ) before the patient underwent CT . If this interfered with their clinical workflow , they entered the data after the CT ( 17 ) . The reading radiologist added the CT findings . We collected data on neurosurgical intervention , additional CT scans performed , and the clinical outcomes of patients by search ing the hospital 's patient information system . Outcome Measures Our primary outcome measure for this analysis was any intracranial traumatic finding on CT , which included all neurocranial traumatic findings except for isolated linear skull fractures . A secondary outcome measure was neurosurgical intervention contingent to initial CT . We defined neurosurgical intervention as any neurosurgical procedure ( craniotomy , intracranial pressure monitoring , elevation of skull fracture , or ventricular drainage ) within 30 days of the traumatic event . Risk Factors We selected all of the risk factors from the NOC and the CCHR ( 7 , 9 ) : age , headache , vomiting , intoxication , persistent antero grade amnesia , retro grade amnesia more than 30 minutes , injury above the clavicles ( including clinical signs of skull or basal skull fracture ) , GCS score less than 15 at 2 hours postinjury , and dangerous trauma mechanism ( pedestrian vs. vehicle , fall from height , and ejected from motor vehicle ) . We tested other risk factors from clinical guidelines for the use of CT in minor head injury ( 15 , 16 , 1821 ) for additional effects . We combined the variables cyclist versus vehicle and pedestrian versus vehicle into 1 variable ( pedestrian or cyclist vs. vehicle ) for statistical analysis because they are similar trauma mechanisms . Statistical Analysis We based sample size on an estimated 25 variables for multivariable logistic regression analysis . For reliable analysis , we required at least 10 events of the primary outcome measure per variable , that is , 250 events for 25 variables ( 22 ) . Given an incidence of traumatic findings on CT of 8 % to 10 % , we needed to include 3125 patients . We assumed that missing data were missing at r and om , and we imputed them on the basis of the available data means to avoid bias ( 2327 ) . The proportion of imputed data was 3.8 % , which included items documented as unknown and items that were not documented . Of all cases , 1956 ( 62 % ) were complete .  Loss of consciousness and posttraumatic amnesia had the highest proportion of missing or unknown data ( 18 % and 10 % , respectively ) . We imputed both as present on the basis of the available variable means and as consistent with clinical practice . We used the entire data set , after missing value imputation , for all analyses . We evaluated the study sample for demographic characteristics , mechanism of injury , traumatic findings , neurosurgical intervention , GCS scores , and the presence of risk factors . We tested associations of each risk factor with the primary STUDY OBJECTIVE This study examines whether serum levels of glial fibrillary acidic protein breakdown products ( GFAP-BDP ) are elevated in patients with mild and moderate traumatic brain injury compared with controls and whether they are associated with traumatic intracranial lesions on computed tomography ( CT ) scan ( positive CT result ) and with having a neurosurgical intervention . METHODS This prospect i ve cohort study enrolled adult patients presenting to 3 Level I trauma centers after blunt head trauma with loss of consciousness , amnesia , or disorientation and a Glasgow Coma Scale ( GCS ) score of 9 to 15 . Control groups included normal uninjured controls and trauma controls presenting to the emergency department with orthopedic injuries or a motor vehicle crash without traumatic brain injury .  Blood sample s were obtained in all patients within 4 hours of injury and measured by enzyme-linked immunosorbent assay for GFAP-BDP ( nanograms/milliliter ) . RESULTS Of the 307 patients enrolled , 108 were patients with traumatic brain injury ( 97 with GCS score 13 to 15 and 11 with GCS score 9 to 12 ) and 199 were controls ( 176 normal controls and 16 motor vehicle crash controls and 7 orthopedic controls ) . Receiver operating characteristic curves demonstrated that early GFAP-BDP levels were able to distinguish patients with traumatic brain injury from uninjured controls with an area under the curve of 0.90 ( 95 % confidence interval [ CI ] 0.86 to 0.94 ) and differentiated traumatic brain injury with a GCS score of 15 with an area under the curve of 0.88 ( 95 % CI 0.82 to 0.93 ) . Thirty-two patients with traumatic brain injury ( 30 % ) had lesions on CT . The area under these curves for discriminating patients with CT lesions versus those without CT lesions was 0.79 ( 95 % CI 0.69 to 0.89 ) . Moreover , the receiver operating characteristic curve for distinguishing neurosurgical intervention from no neurosurgical intervention yielded an area under the curve of 0.87 ( 95 % CI 0.77 to 0.96 ) . CONCLUSION GFAP-BDP is detectable in serum within an hour of injury and is associated with measures of injury severity , including the GCS score , CT lesions , and neurosurgical intervention . Further study is required to vali date these findings before clinical application 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 CONTEXT Lack of empirical data on recovery time following sport-related concussion hampers clinical decision making about return to play after injury . OBJECTIVE To prospect ively measure immediate effects and natural recovery course relating to symptoms , cognitive functioning , and postural stability following sport-related concussion . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve cohort study of 1631 football players from 15 US colleges . All players underwent preseason baseline testing on concussion assessment measures in 1999 , 2000 , and 2001 . Ninety-four players with concussion ( based on American Academy of Neurology criteria ) and 56 noninjured controls underwent assessment of symptoms  , cognitive functioning  , and postural stability immediately , 3 hours , and 1 , 2 , 3 , 5 , 7 , and 90 days after injury . MAIN OUTCOME MEASURES Scores on the Grade d Symptom Checklist ( GSC ) , St and ardized Assessment of Concussion ( SAC ) , Balance Error Scoring System ( BESS ) , and a neuropsychological test battery . RESULTS No player with concussion was excluded from participation ; 79 players with concussion ( 84 % ) completed the protocol through day 90 . Players with concussion exhibited more severe symptoms ( mean GSC score 20.93 [ 95 % confidence interval [ CI ] , 15.65 - 26.21 ] points higher than that of controls ) , cognitive impairment ( mean SAC score 2.94 [ 95 % CI , 1.50 - 4.38 ] points lower than that of controls ) , and balance problems ( mean BESS score 5.81 [ 95 % CI , -0.67 to 12.30 ] points higher than that of controls ) immediately after concussion . On average , symptoms gradually resolved by day 7 ( GSC mean difference , 0.33 ; 95 % CI , -1.41 to 2.06 ) , cognitive functioning improved to baseline levels within 5 to 7 days ( day 7 SAC mean difference , -0.03 ; 95 % CI , -1.33 to 1.26 ) , and balance deficits dissipated within 3 to 5 days after injury ( day 5 BESS mean difference , -0.31 ; 95 % CI , -3.02 to 2.40 ) . Mild impairments in cognitive processing and verbal memory evident on neuropsychological testing 2 days after concussion resolved by day 7 . There were no significant differences in symptoms or functional impairments in the concussion and control groups 90 days after concussion . CONCLUSIONS Collegiate football players may require several days for recovery of symptoms , cognitive dysfunction , and postural instability after concussion . Further research is required to determine factors that predict variability in recovery time after concussion . St and ardized measurement of postconcussive symptoms , cognitive functioning , and postural stability may enhance clinical management of athletes recovering from concussion OBJECT During recent years , several biomarkers have been introduced for use in the diagnosis of traumatic brain injury ( TBI ) . The primary objective of this investigation was to determine if S100B ( or S100 calcium-binding protein B ) and neuron-specific enolase ( NSE ) serum concentrations can effectively be used to discriminate between symptomatic and asymptomatic children with minor head trauma . METHODS The authors conducted a prospect i ve clinical study that involved patients age 6 months to 15 years who had sustained minor head trauma . Children with concomitant extracranial injuries were excluded .  Blood sample s were obtained within 6 hours of injury to measure  S100B and NSE levels in serum . The authors defined 2 diagnostic groups : a  mild TBI group ( patients with Glasgow Coma Scale [ GCS ] scores of 13 - 15 ) in whom there were clinical signs of concussion ( short loss of consciousness , amnesia , nausea , vomiting , somnolence , headache , dizziness , or impaired vision ) and a head contusion group ( patients with a GCS score of 15 ) in whom symptoms were absent . Both S100B and NSE concentrations were compared between the 2 groups . Secondary end points were defined as follows : correlation of S100B/NSE and a ) the presence of scalp lacerations , b ) GCS score , c ) age , and d ) correlation between S100B and NSE . RESULTS One hundred forty-eight patients were enrolled ( 53 in the contusion group , 95 in the mild TBI group ) . After adjusting for differences in age and time of injury to blood sample withdrawal , there was no significant difference in S100B or NSE between patients in the 2 groups . Scalp lacerations and GCS score had no affect on posttraumatic S100B or NSE concentrations . The correlation between S100B and NSE was significant . Both markers showed a significant negative correlation with age . CONCLUSIONS The authors demonstrated that S100B and NSE do not discriminate between symptomatic and asymptomatic children with minor head injury . There seem to be limitations in marker sensitivity when investigating pediatric patients with mild TBI The purpose of this study was to investigate the sensitivity of  orientation and recent memory questions  in the diagnosis of concussion . In a prospect i ve study over 7 consecutive years ( 1985 - 1991 ) , all players at a professional Australian Rules Football club who sustained a concussive injury ( n = 28 ) were administered a set of questions evaluating orientation and recent memory .  Concussion was diagnosed independently on the basis of loss or disturbance of consciousness and clinical symptoms . A control group of age-matched nonconcussed players was administered the same set of questions . The results showed that items evaluating recently acquired information were more sensitive in the assessment of concussion than st and ard orientation items . The relative sensitivity of orientation questions must be considered when they are used in the clinical diagnosis of concussion in sport
target: : The results of this systematic review identify the consistent and prevalent indicators of concussion and their associations , derived from the strongest evidence in the published literature .
background: BACKGROUND : Currently , there is no evidence -based definition for concussion that is being uniformly applied in clinical and research setting s. OBJECTIVE : To conduct a systematic review of the highest- quality literature about concussion and to assemble evidence about the prevalence and associations of key indicators of concussion .
  The goal was to establish an evidence -based foundation from which to derive , in future work , a definition , diagnostic criteria , and prognostic indicators for concussion .