Is neuropsychological testing useful in the management of sport-related concussion? Predicting and preventing postconcussive problems in paediatrics (5P) study: protocol for a prospective multicentre clinical prediction rule derivation study in children with concussion Recovery of cerebral blood flow following sports-related concussion. Prevalence of neurocognitive and balance deficits in collegiate aged football players without clinically diagnosed concussion. The reliability and validity of video analysis for the assessment of the clinical signs of concussion in Australian football. Acute effects and recovery time following concussion in collegiate football players: the NCAA Concussion Study. Predicting Slow Recovery From Sport-Related Concussion: The New Simple-Complex Distinction Effectiveness of education in evidence-based healthcare: the current state of outcome assessments and a framework for future evaluations. Predictors of delayed recovery following pediatric sports-related concussion: a case-control study. Epidemiology of sports-related concussion in seven US high school and collegiate sports Persistent motor system abnormalities in formerly concussed athletes. Identification of risk factors by systematic review and development of risk-adjusted models for surgical site infection. HISTORY OF MULTIPLE SELF‐REPORTED CONCUSSIONS IS NOT ASSOCIATED WITH REDUCED COGNITIVE ABILITIES Athletic Trainers' Concussion-Assessment and -Management Practices: An Update. A prospective study of physician-observed concussions during junior ice hockey: implications for incidence rates. Immediate Neurocognitive Effects of Concussion Cumulative effects associated with recurrent concussion in collegiate football players: the NCAA Concussion Study. Concussions in amateur rugby union identified with the use of a rapid visual screening tool Associations among self-reported balance problems, post-concussion symptoms and performance-based tests: a longitudinal follow-up study Acute Effects and Recovery After Sport‐Related Concussion: A Neurocognitive and Quantitative Brain Electrical Activity Study The “Value Added” of Neurocognitive Testing after Sports-Related Concussion Cognition in the days following concussion: comparison of symptomatic versus asymptomatic athletes. Ten years of evidence to guide physiotherapy interventions: Physiotherapy Evidence Database (PEDro) MEASUREMENT OF HEAD IMPACTS IN COLLEGIATE FOOTBALL PLAYERS: RELATIONSHIP BETWEEN HEAD IMPACT BIOMECHANICS AND ACUTE CLINICAL OUTCOME AFTER CONCUSSION Return to play after an initial or recurrent concussion in a prospective study of physician-observed junior ice hockey concussions: implications for return to play after a concussion. Sensitivity and specificity of the ImPACT Test Battery for concussion in athletes. Risk of injury associated with body checking among youth ice hockey players. Grade 1 or “Ding” Concussions in High School Athletes Recovery From Mild Head Injury in Sports: Evidence From Serial Functional Magnetic Resonance Imaging Studies in Male Athletes Exploring differences in computerized neurocognitive concussion testing between African American and White athletes.
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 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 ) IMPORTANCE Animal models suggest that reduced cerebral blood flow ( CBF ) is one of the most enduring physiological deficits following concussion . Despite this , longitudinal studies documenting serial changes in regional CBF following human concussion have yet to be performed . OBJECTIVE To longitudinally assess the recovery of CBF in a carefully selected sample of collegiate athletes and compare time course of CBF recovery with that of cognitive and behavioral symptoms . DESIGN , SETTING , AND PARTICIPANTS A cohort of collegiate football athletes ( N = 44 ) participated in this mixed longitudinal and cross-sectional study at a private research institute specializing in neuroimaging between March 2012 and December 2013 .  Serial imaging occurred approximately 1 day , 1 week , and 1 month postconcussion for a subset of participants ( n = 17 ) . All athletes reported no premorbid mood disorders , anxiety disorders , substance abuse , or alcohol abuse . MAIN OUTCOMES AND MEASURES  Arterial spin labeling magnetic resonance imaging  was used to collect voxelwise relative CBF at each visit . Neuropsychiatric evaluations and a brief cognitive screen  were also performed at all 3 points . Clinicians trained in sports medicine provided an independent measure of real-world concussion outcome ( ie , number of days withheld from competition ) . RESULTS The results indicated both cognitive ( simple reaction time ) and neuropsychiatric symptoms at 1 day postinjury that resolved at either 1 week ( cognitive ; P < .005 ) or 1 month ( neuropsychiatric ; P < .005 ) postinjury . Imaging data suggested both cross-sectional ( ie , healthy vs concussed athletes ; P < .05 ) and longitudinal ( 1 day and 1 week vs 1 month postinjury ; P < .001 ) evidence of CBF recovery in the right insular and superior temporal cortex . Importantly , CBF in the dorsal midinsular cortex was both decreased at 1 month postconcussion in slower-to-recover athletes ( t11 = 3.45 ; P = .005 ) and was inversely related to the magnitude of initial psychiatric symptoms ( Hamilton Depression Scale : r = -0.64 , P = .02 ; Hamilton Anxiety Scale : r = -0.56 , P = .046 ) , suggesting a potential prognostic indication for CBF as a biomarker . CONCLUSIONS AND RELEVANCE To our knowledge , these results provide the first prospect i ve evidence of reduced CBF in human concussion and subsequent recovery . The resolution of CBF abnormalities closely mirrors previous reports from the animal literature and show real-world validity for predicting outcome following concussion STUDY DESIGN Prospect i ve cohort . OBJECTIVES To identify the prevalence of neurocognitive and balance deficits in collegiate football players 48 hours following competition . BACKGROUND Neurocognitive testing , balance assessment s , and subjective report of symptoms are a commonly used test battery in examining athletes when concussion is suspected . Previous literature suggests many concussions go unreported . Little research exists examining the prevalence of neurocognitive or balance deficits in athletes who do not report concussion-like symptoms to a health care provider . METHODS Forty-five Division IA collegiate football players participated in this study . Preseason baseline scores using the  Balance Error Scoring System , the Immediate Post-Concussion Assessment and Cognitive Testing , and the Postconcussion Symptom Scale  were compared to posttest results obtained 48 hours following a game . Prevalence of symptoms was analyzed and reported . RESULTS Thirty-two ( 71 % ) of the 45 athletes tested demonstrated at least 1 deficit in either the Postconcussion Symptom Scale , Balance Error Scoring System , or at least 1 composite score of the Immediate Post-Concussion Assessment and Cognitive Testing . Nineteen of the 32 subjects demonstrated a change in 2 or more categories of neurocognitive and balance function . CONCLUSION In a cohort of football players tested 48 hours following their last game of the season , who did not seek medical attention related to a concussion , a significant number demonstrated limitations in neurocognitive and balance performance , suggesting that further research may need to be performed to improve recognition of an athlete 's deficits and to improve the ability to assess concussion . LEVEL OF EVIDENCE Differential diagnosis/symptom prevalence , level 3b OBJECTIVES The objective of this study was to determine the reliability and validity of identifying clinical signs of concussion using  video analysis in Australian football . DESIGN Prospect i ve cohort study . METHODS All impacts and collisions potentially result ing in a concussion were identified during 2012 and 2013 Australian Football League seasons . Consensus definitions were developed for clinical signs associated with concussion . For intra- and inter-rater reliability analysis , two experienced clinicians independently assessed 102 r and omly selected videos  on two occasions . Sensitivity , specificity , positive and negative predictive values were calculated based on the diagnosis provided by team medical staff . RESULTS 212 incidents result ing in possible concussion were identified in 414 Australian Football League games . The intra-rater reliability of the  video-based identification of signs associated with concussion was good to excellent . Inter-rater reliability was good to excellent for impact seizure , slow to get up , motor incoordination , ragdoll appearance ( 2 of 4 analyses ) , clutching at head and facial injury . Inter-rater reliability for loss of responsiveness and blank and vacant look was only fair and did not reach statistical significance . The feature with the highest sensitivity was slow to get up ( 87 % ) , but this sign had a low specificity ( 19 % ) . Other video signs had a high specificity but low sensitivity . Blank and vacant look ( 100 % ) and motor incoordination ( 81 % ) had the highest positive predictive value . CONCLUSIONS Video analysis may be a useful adjunct to the side-line assessment of a possible concussion . Video analysis however should not replace the need for a thorough multimodal clinical assessment 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 Objective : Following the Second International Conference on Concussion in Sport in 2005 , a summary agreement statement was published that introduced new terminology for sport-related concussions . This new classification system is binary ( ie , “ simple ” versus “ complex ” concussions ) . Athletes who are slow to recover ( ie , > 10 days ) are classified as having complex concussions . The purpose of this study was to determine if high school football players , retrospectively classified as having a simple or a complex concussion , could be differentiated in the first 48 after injury on the basis of symptom reporting or neuropsychological testing . Design : Case-control study . Setting : Pennsylvania high school football programs . Participants : The total sample consisted of 114 concussed high school football players who were identified through a 3 year prospect i ve cohort study . Interventions : All completed a computerized neuropsychological screening evaluation within 72 hours of injury . They were followed clinical ly until they recovered and were cleared to return to play . They were classified retrospectively as having a simple ( n = 55 ) or complex ( n = 59 ) concussion based on their recovery times . Main Outcome Measurements : Neurocognitive test performance and symptom ratings . Results : Within 72 hours after injury , athletes with complex concussions performed more poorly on neuropsychological testing and reported more symptoms than those with simple concussions . Athletes with complex concussions who were slow to recover were 18 times more likely to have 3 unusually low neuropsychological test scores than those with simple concussions ( 95 % CI = 2.3 - 144.9 ) . Athletes with previous concussions did not recover more slowly . Conclusions : This study provides evidence that supports and refutes the clinical usefulness of the new simple-complex concussion classification system Background A discipline which critically looks at the evidence for practice should itself be critically examined . Credible evidence for the effectiveness of training in evidence -based healthcare ( EBHC ) is essential . We attempted to summarise the current knowledge on evaluating the effectiveness of training in EBHC while identifying the gaps . Methods A working group of EBHC teachers developed a conceptual framework of key areas of EBHC teaching and practice in need of evidence mapped to appropriate methods and outcomes . A literature search was conducted to review the current state of research in these key areas . Studies of training interventions that evaluated effectiveness by considering learner , patient or health system outcomes in terms of knowledge , skills , attitude , judgement , competence , decision-making , patient satisfaction , quality of life , clinical indicators or cost were included . There was no language restriction . Results Of 55 articles review ed , 15 met the inclusion criteria : six systematic review s , three r and omised controlled trials and six before-after studies . We found weak indications that undergraduate training in EBHC improves knowledge but not skills , and that clinical ly integrated postgraduate teaching improves both knowledge and skills . Two r and omised controlled trials reported no impact on attitudes or behaviour . One before-after study found a positive impact on decision-making , while another suggested change in learners ' behaviour and improved patient outcome . We found no studies assessing the impact of EBHC training on patient satisfaction , health-related quality of life , cost or population -level indicators of health . Conclusions Literature evaluating the effectiveness of training in EBHC has focused on short-term acquisition of knowledge and skills . Evaluation design s were method ologically weak , controlled trials appeared inadequately powered and systematic review s could not provide conclusive evidence owing to weakness of study design OBJECT Pediatric sports-related concussions are a growing public health concern . The factors that determine injury severity and time to recovery following these concussions are poorly understood . Previous studies suggest that initial symptom severity and diagnosis of attention deficit hyperactivity disorder ( ADHD ) are predictors of prolonged recovery ( > 28 days ) after pediatric sports-related concussions . Further analysis of baseline patient characteristics may allow for a more accurate prediction of which patients are at risk for delayed recovery after a sports-related concussion . METHODS The authors performed a single-center retrospective case-control study involving patients cared for at the multidisciplinary Concussion Clinic at Children 's of Alabama between August 2011 and January 2013 . Patient demographic data , medical history , sport concussion assessment tool 2 ( SCAT2 ) and symptom severity scores , injury characteristics , and patient balance assessment s were analyzed for each outcome group . The control group consisted of patients whose symptoms resolved within 28 days . The case group included patients whose symptoms persisted for more than 28 days . The presence or absence of the SCAT2 assessment had a modifying effect on the risk for delayed recovery ; therefore , stratum-specific analyses were conducted for patients with recorded SCAT2 scores and for patients without SCAT2 scores . Unadjusted ORs and adjusted ORs ( aORs ) for an association of delayed recovery outcome with specific risk factors were calculated with logistic regression analysis . RESULTS A total of 294 patients met the inclusion criteria of the study . The case and control groups did not statistically significantly differ in age ( p = 0.7 ) . For the patients who had received SCAT2 assessment s , a previous history of concussion ( aOR 3.67 , 95 % CI 1.51 - 8.95 ) , presenting SCAT2 score < 80 ( aOR 5.58 , 95 % CI 2.61 - 11.93 ) , and female sex ( aOR 3.48 , 95 % CI 1.43 - 8.49 ) were all associated with a higher risk for postconcussive symptoms lasting more than 28 days . For patients without SCAT2 scores , female sex and reporting a history of ADHD significantly increased the odds of prolonged recovery ( aOR 4.41 , 95 % CI 1.93 - 10.07 and aOR 3.87 , 95 % CI 1.13 - 13.24 , respectively ) . Concussions result ing from playing a nonhelmet sport were also associated with a higher risk for prolonged symptoms in patients with and without SCAT2 scores ( OR 2.59 , 95 % CI 1.28 - 5.26 and OR 2.17 , 95 % CI 0.99 - 7.73 , respectively ) . Amnesia , balance abnormalities , and a history of migraines were not associated with symptoms lasting longer than 28 days . CONCLUSIONS This case-control study suggests c and i date risk factors for predicting prolonged recovery following sports-related concussion . Large prospect i ve cohort studies of youth athletes examined and treated with st and ardized protocol s will be needed to definitively establish these associations and confirm which children are at highest risk for delayed recovery Background The epidemiology of sports-related concussion is not well-described in the literature . This paper presents a descriptive epidemiology of concussion in seven high school and collegiate sports . Methods We used the data from Concussion Prevention Initiative ( CPI ) , which enrolled 8905 athletes at 210 high schools and 26 colleges in a prospect i ve cohort study of 7 sports ( football , men ’s and women ’s soccer , men ’s and women ’s lacrosse , and men ’s and women ’s ice hockey ) between 1999 and 2001 . Injury risks and injury rates were used to characterize the incidence of concussion , and changes in symptoms over time were described . Results A total of 375 concussions were observed . The incidence of concussion was highest in football , followed by women ’s lacrosse , men ’s lacrosse , men ’s soccer , and women ’s soccer ( only 10 ice hockey teams were included , too few to quantify incidence ) . The rate of incident concussion was strongly associated with history of concussion in the previous 24 months ( rate ratio = 5.5 ; 95 % CI : 3.9 , 7.8 , for 2 or more concussions relative to no previous concussion ) . The most common symptoms at time of injury were headache ( 87 % ) , balance problems/dizziness ( 77 % ) , and feeling “ in a fog ” ( 62 % ) . Loss of consciousness and amnesia were present in relatively few cases ( 9 and 30 % ) . The most common mechanism of injury was collision with another player . Conclusions Sports-related concussions present with a diverse range of symptoms and are associated with previous concussion history 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 BACKGROUND  Surgical site infections ( SSIs ) are complications of surgery that cause significant postoperative morbidity . SSI has been proposed as a potential indicator of the quality of care in the context of clinical governance and monitoring of the performance of NHS organisations against targets . OBJECTIVES We aim ed to address a number of objectives . Firstly , identify risk factors for SSI , criteria for stratifying surgical procedures and evidence about the importance of postdischarge surveillance ( PDS ) . Secondly , test the importance of risk factors for SSI in surveillance data bases and investigate interactions between risk factors . Thirdly , investigate and vali date different definitions of SSI . Lastly , develop models for making risk-adjusted comparisons between hospitals . DATA SOURCES A single hospital surveillance data base was used to address objectives 2 and 3 and the UK Surgical Site Infection Surveillance Service data base to address objective 4 . STUDY DESIGN There were four elements to the research : ( 1 ) systematic review s of risk factors for SSI ( two review ers assessed titles and abstract s of studies identified by the search strategy and the quality of studies was assessed using the Newcastle Ottawa Scale ) ; ( 2 ) assessment of agreement between four SSI definitions ; ( 3 ) validation of definitions of SSI , quantifying their ability to predict clinical outcomes ; and ( 4 ) development of operation-specific risk models for SSI , with hospitals fitted as r and om effects . RESULTS Review s of SSI risk factors other than established SSI risk indices identified other risk ; some were operation specific , but others applied to multiple operations . The factor most commonly identified was duration of preoperative hospital stay . The review of PDS for SSI confirmed the need for PDS if SSIs are to be compared meaningfully over time within an institution . There was wide variation in SSI rate ( SSI% ) using different definitions . Over twice as many wounds were classified as infected by one definition only as were classified as infected by both . Different SSI definitions also classified different wounds as being infected . The two most established SSI definitions had broadly similar ability to predict the chosen clinical outcomes . This finding is paradoxical given the poor agreement between definitions . Elements of each definition not common to both may be important in predicting clinical outcomes or outcomes may depend on only a subset of elements which are common to both . Risk factors fitted in multivariable models and their effects , including age and gender , varied by surgical procedure . Operative duration was an important risk factor for all operations , except for hip replacement . Wound class was included least often because some wound classes were not applicable to all operations or were combined because of small numbers . The American Association of Anesthesiologists class was a consistent risk factor for most operations . CONCLUSIONS The research literature does not allow surgery-specific or generic risk factors to be defined . SSI definitions varied between surveillance programmes and potentially between hospitals . Different definitions do not have good agreement , but the definitions have similar ability to predict outcomes influenced by SSI . Associations between components of the National Nosocomial Infections Surveillance risk index and odds of SSI varied for different surgical procedures . There was no evidence for effect modification by hospital . Estimates of SSI% should be disseminated within institutions to inform infection control . Estimates of SSI% across institutions or countries should be interpreted cautiously and should not be assumed to reflect quality of medical care . Future research should focus on developing an SSI definition that has satisfactory psychometric properties , that can be applied in everyday clinical setting s , includes PDS and is formulated to detect SSIs that are important to patients or health services . FUNDING The National Institute for Health Research Technology Assessment programme OBJECTIVE The long-term impact of sports-related concussion is uncertain . Several studies using traditional neuropsychological measures have found a relationship between a previous history of concussion and reduced cognitive abilities . In contrast , studies using computerized neuropsychological measures have typically found no relationship between concussion history and cognition . In the present study , we examined the association between a self-reported concussion history and cognition using traditional and computer-based neuropsychological tests . METHODS A computerized neuropsychological battery was administered to a sample of 858 collegiate male athletes . Of this sample , 298 athletes reported a history of concussion . A traditional neuropsychological battery was administered to a separate sample of 479 male collegiate athletes , 187 of whom reported a history of concussion . Finally , both a computerized and a traditional neuropsychological battery were administered to a third distinct sample of 175 male collegiate athletes , 57 of whom reported a history of concussion . Concussion history was assessed via self-report . None of the athletes had been concussed in the 6 months before testing . RESULTS No significant association was found between self-reported concussion history and performance on either  computerized or traditional neuropsychological tests .  CONCLUSION Findings suggest that athletes who report a distant history of concussion have minimal enduring neurocognitive deficits . Given conflicting findings in the literature , prospect i ve studies that attempt to identify moderating factors are necessary to help determine who is at risk for long-term cognitive difficulties after concussion CONTEXT Athletic trainers ( ATs ) are often the first health care providers to conduct concussion assessment s and carry out postinjury management . Best practice s for concussion evaluation and management have changed rapidly in recent years , outdating previous reports of ATs ' concussion practice s. OBJECTIVE To examine ATs ' current concussion- assessment and -management techniques . DESIGN Cross-sectional study . SETTING Web-based survey . PATIENTS OR OTHER PARTICIPANTS A r and om convenience sample of 8777 ATs ( response rate = 15.0 % [ n = 1307 ] ; years certified = 15.0 ± 10.6 ) from the National Athletic Trainers ' Association membership . MAIN OUTCOME MEASURE(S ) Survey Web links were e-mailed to prospect i ve participants , with 2 follow-up e-mails sent by the National Athletic Trainers ' Association . The survey collected demographic information , the number of concussions assessed , the concussion-recovery patterns , and the assessment and return-to-participation ( RTP ) decision-making methods used . RESULTS The ATs reported assessing a median of 12.0 ( range = 0 - 218 ) concussions per year . A total of 95.3 % ( 953/1000 ) ATs cited clinical examination as the most frequently used concussion- assessment tool , followed by symptom assessment ( 86.7 % ; 867/1000 ) . A total of 52.7 % ( 527/1000 ) ATs described a 3-domain minimum multidimensional concussion- assessment battery . Published RTP guidelines were the most common RTP decision-making tool ( 91.0 % ; 864/949 ) , followed by clinical examination ( 88.2 % ; 837/949 ) . The ATs with master 's degrees were 1.36 times ( 95 % confidence interval [ CI ] = 1.02 , 1.81 ) more likely to use a 3-domain concussion- assessment battery than ATs with only bachelor 's degrees ( χ2 = 4.44 , P = .05 ) . Collegiate ATs were 2.12 ( 95 % CI = 1.59 , 2.84 ) and 1.63 ( 95 % CI = 1.03 , 2.59 ) times more likely to use a 3-domain concussion- assessment battery than high school and clinic-based ATs , respectively ( χ2 = 26.29 , P < .001 ) . CONCLUSIONS Athletic trainers were using the clinical examination , st and ardized assessment tools , and a 3-domain concussion- assessment -battery approach more frequently in clinical practice than previously reported . However , despite practice improvements , nearly half of ATs were not using a 3-domain minimum concussion- assessment battery . Clinicians should strive to implement multidimensional concussion assessment s in their practice s to ensure optimal diagnosis and management OBJECT The objective of this study was to measure the incidence of concussion ( scaled relative to number of athlete exposures ) and recurrent concussion within 2 teams of fourth-tier junior ice hockey players ( 16 - 21 years old ) during 1 regular season . METHODS A prospect i ve cohort study called the Hockey Concussion Education Project was conducted during 1 junior ice hockey regular season ( 2009 - 2010 ) involving 67 male fourth-tier ice hockey players ( mean age 18.2 ± 1.2 years , range 16 - 21 years ) from 2 teams . Prior to the start of the season , every player underwent baseline assessment s using the Sideline Concussion Assessment Tool 2 ( SCAT2 ) and the Immediate Post-Concussion Assessment and Cognitive Test ( ImPACT ) . The study protocol also required players who entered the study during the season to complete baseline SCAT2 and ImPACT testing . If the protocol was not followed , the postinjury test results of a player without true baseline test results would be compared against previously established age and gender group normative levels . Each regular season game was observed by a qualified physician and at least 1 other neutral nonphysician observer . Players who suffered a suspected concussion were evaluated at the game . If a concussion diagnosis was made , the player was subsequently examined in the physician 's office for a full clinical evaluation and the SCAT2 and ImPACT were repeated . Based on these evaluations , players were counseled on the decision of when to return to play . Athlete exposure was defined as 1 game played by 1 athlete . RESULTS Twenty-one concussions occurred during the 52 physician-observed games ( incidence 21.5 concussions per 1000 athlete exposures ) . Five players experienced repeat concussions . No concussions were reported during practice sessions . A concussion was diagnosed by the physician in 19 ( 36.5 % ) of the 52 observed games . One of the 5 individuals who suffered a repeat concussion sustained his initial concussion in a regular season game that was not observed by a physician , and as a result this single case was not included in the total of 21 total concussions . This initial concussion of the player was identified during baseline testing 2 days after the injury and was subsequently medically diagnosed and treated . CONCLUSIONS The incidence of game-related concussions ( per 100 [ corrected ] athlete exposures ) in these fourth-tier junior [ corrected ] ice hockey players was 7 [ corrected ] times higher than [ corrected ] previously reported in the literature . This difference may be the result of the use of st and ardized direct physician observation , diagnosis , and subsequent treatment . The results of this study demonstrate the need for follow-up studies involving larger and more diverse sample groups to reflect generalizability of the findings . These follow-up studies should involve other contact sports ( for example football and rugby ) and also include the full spectrum of gender , age , and skill levels 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 Approximately 300 000 sport-related concussions occur annually in the United States , and the likelihood of serious sequelae may increase with repeated head injury . OBJECTIVE To estimate the incidence of concussion and time to recovery after concussion in collegiate football players . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve cohort study of 2905 football players from 25 US colleges were tested at preseason baseline in 1999 , 2000 , and 2001 on a variety of measures and followed up prospect ively to ascertain concussion occurrence . Players injured with a concussion were monitored until their concussion symptoms resolved and were followed up for repeat concussions until completion of their collegiate football career or until the end of the 2001 football season . MAIN OUTCOME MEASURES Incidence of concussion and repeat concussion ; type and duration of symptoms and course of recovery among players who were injured with a concussion during the seasons . RESULTS During follow-up of 4251 player-seasons , 184 players ( 6.3 % ) had a concussion , and 12 ( 6.5 % ) of these players had a repeat concussion within the same season . There was an association between reported number of previous concussions and likelihood of incident concussion .  Players reporting a history of 3 or more previous concussions were 3.0 ( 95 % confidence interval , 1.6 - 5.6 ) times more likely to have an incident concussion than players with no concussion history . Headache was the most commonly reported symptom at the time of injury ( 85.2 % ) , and mean overall symptom duration was 82 hours . Slowed recovery was associated with a history of multiple previous concussions ( 30.0 % of those with > or =3 previous concussions had symptoms lasting > 1 week compared with 14.6 % of those with 1 previous concussion ) . Of the 12 incident within-season repeat concussions , 11 ( 91.7 % ) occurred within 10 days of the first injury , and 9 ( 75.0 % ) occurred within 7 days of the first injury . CONCLUSIONS Our study suggests that players with a history of previous concussions are more likely to have future concussive injuries than those with no history ; 1 in 15 players with a concussion may have additional concussions in the same playing season ; and previous concussions may be associated with slower recovery of neurological function AIM To use the King-Devick ( KD ) test and Sports Concussion Assessment Tool 2 ( SCAT2 ) in amateur rugby union players to identify witnessed and unrecognised episodes of concussion that occurred from match participation . METHODS A prospect i ve observational cohort study was conducted on a premier club level amateur rugby union team during the 2012 competition in New Zeal and . Every player completed a pre-competition question naire on concussion history , a baseline PCSS and two trials of the KD before they participated in any match activities . RESULTS For players reporting a concussion in the previous three years there was an average of 4.0±2.8 concussions per player . There were 22 concussive incidents recorded over the duration of the competition ( 46 per 1000 match hours ) . Five concussive incidents were witnessed ( 11 per 1000 match hours ) and 17 unrecognised concussive incidents were identified with the KD ( 37 per 1000 match hours ) . Witnessed concussions recorded , on average , a longer KD on the day of injury ( 5.5±2.4s ) than unrecognised concussions ( 4.4±0.9s ) when compared with their baseline KD . DISCUSSION The KD was able to identify players that had not shown , or reported , any signs or symptoms of a concussion but who had meaningful head injury . The current rate of concussion reported was a ten-fold increase in previously reported concussion injury rates . This makes the KD suitable for rapid assessment in a limited time frame on the sideline such as a five-minute window to assess and review suspected concussed players in rugby union Purpose : The main objectives of this study were to describe long-term self-reported balance problems  and to explore their associations with post-concussion symptoms and performance-based tests . Method : Prospect i ve study of patients with mild traumatic brain injury ( MTBI ) .  Self-reported balance problems and post-concussion symptoms were measured with the Rivermead Post-concussion Symptoms Question naire at 1 and 4 years after injury . Performance-based tests were performed 4 years after injury and included  posturography , the Dynamic Gait Index ( DGI ) , walking speed tests , and the six-minute walk test . Results : Self-reported balance problems were reported in 31 % of patients 4 years after injury and correlated significantly with post-concussion symptoms . The correlations with performance-based tests varied from ρ = 0.18 to ρ = 0.70 and were strongest for the maximum walking speed test ( ρ = 0.70 ) and a dual-task test ( ρ = 0.43 ) . The DGI had a considerable ceiling effect . Conclusions : Balance problems were long-term consequences of MTBI in one third of this study sample . Self-reported balance problems correlated with post-concussion symptoms and some of the performance-based tests . Future research needs to develop and evaluate appropriate rehabilitation strategies that also address the balance problems . Implication s for Rehabilitation Balance problems may persist several years after a mild traumatic brain injury . We need to develop and evaluate appropriate rehabilitation strategies that also address the balance problems 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 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 BACKGROUND Concussion is a common neurological injury occurring during contact sport . Current guidelines recommend that no athlete should return to play while symptomatic or displaying cognitive dysfunction . This study compared post-concussion cognitive function in recently concussed athletes who were symptomatic/asymptomatic at the time of assessment with that of non-injured ( control ) athletes . METHODS Prospect i ve study of 615 male Australian Rules footballers . Before the season , all participants ( while healthy ) completed a battery of baseline computerised ( CogSport ) and paper and pencil cognitive tasks .  Sixty one injured athletes ( symptomatic = 25 and asymptomatic = 36 ) were reassessed within 11 days of being concussed ; 84 controls were also reassessed . The serial cognitive function of the three groups was compared using analysis of variance . RESULTS The performance of the symptomatic group declined at the post-concussion assessment on computerised tests of simple , choice , and complex reaction times compared with the asymptomatic and control groups . The magnitude of changes was large according to conventional statistical criteria . On paper and pencil tests , the symptomatic group displayed no change at re assessment , whereas large improvements were seen in the other two groups . CONCLUSION Injured athletes experiencing symptoms of concussion displayed impaired motor function and attention , although their learning and memory were preserved . These athletes displayed no change in performance on paper and pencil tests in contrast with the improvement observed in asymptomatic and non-injured athletes . Athletes experiencing symptoms of concussion should be withheld from training and competition until both symptoms and cognitive dysfunction have resolved Clinicians are increasingly using evidence from high- quality clinical research to guide clinical decision making . Recent articles in this journal have examined research evidence to assist in clinical decisions as diverse as the prescription of running shoes,1 exercise therapy in the treatment of chronic disease2 and the use of protective equipment to prevent concussion.3 The most valid information about the effectiveness of healthcare interventions is provided by r and omised controlled trials and systematic review s of r and omised controlled trials.4 The Physiotherapy Evidence Data base ( PEDro ; http://www.pedro.org.au ) provides easy access to r and omised controlled trials and systematic review s of physiotherapy interventions . PEDro also includes links to evidence -based clinical practice guidelines . October 2009 marked the 10th anniversary of the launch of PEDro . PEDro is freely available on the internet . The data base indexes citation details , author abstract s and , where available , links to full text for r and omised controlled trials , systematic review s and practice guidelines in physiotherapy . Although the PEDro data base is design ed primarily for health professionals , a subsite , called Physiotherapy Choices ( http://www.physiotherapychoices.org.au ) , provides information in lay terms directly to consumers of physiotherapy services . As of August 2009 , more than 15 000 records ( 12 408 trials , 2060 review s and 603 guidelines ) have been indexed on PEDro . Each record is coded according to the subdiscipline(s ) of physiotherapy it addresses . PEDro now includes 615 r and omised controlled trials and 102 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 OBJECT The authors investigated return-to-play duration for initial and recurrent concussion in the same season in 2 teams of junior ( 16 - 21-year-old ) ice hockey players during a regular season . METHODS The authors conducted a prospect i ve cohort study during 1 junior regular season ( 2009 - 2010 ) of 67 male fourth-tier ice hockey players ( mean age 18.2 ± 1.2 years [ SD ] , range 16 - 21 years ) from 2 teams . Prior to the start of the season , every player underwent baseline assessment s that were determined using the  Sideline Concussion Assessment Tool 2 ( SCAT2 ) and the Immediate Post-Concussion Assessment and Cognitive Test ( ImPACT ) . The study protocol also required players who entered the study during the season to complete a baseline SCAT2 and ImPACT . If the protocol was not followed , the postinjury test results of a player without true baseline test results were compared with previously established age- and sex-matched group normative levels . Each game was directly observed by a physician and at least 1 neutral nonphysician observer . Players suspected of suffering a concussion were evaluated by the physician during the game . If a concussion was diagnosed , the player underwent clinical evaluation at the physician 's office within 24 hours . The return-to-play decision was based on clinical evaluation guided by the Zurich return-to-play protocol ( contained in the consensus statement of international expert opinion at the 3rd International Conference on Concussion in Sport held in Zurich , November 2008 ) . This clinical evaluation and return-to-play protocol was augmented by the 2 tests ( SCAT2 and ImPACT ) also recommended by the Zurich consensus statement , for which baseline values had been obtained . RESULTS Seventeen players sustained a physician-observed or self-reported , physician-diagnosed concussion during a physician-observed ice hockey game . The mean clinical return-to-play duration ( in 15 cases ) was 12.8 ± 7.02 days ( median 10 days , range 7 - 29 days ) ; the mean number of physician office visits by players who suffered a concussion ( 15 cases ) was 2.1 ± 1.29 ( median 1.5 visits ) . Five of the 17 players who sustained a concussion also suffered a recurrent or second concussion . One of the 5 individuals who suffered a repeat concussion sustained his initial concussion in a regular season game that was not observed by a physician , and as a result this single case was not included in the total of 21 concussions . This initial concussion of the player was identified during baseline testing 2 days after the injury and was subsequently medically diagnosed and treated . The mean interval between the first and second concussions in these 5 players was 78.6 ± 39.8 days ( median 82 days ) , and the mean time between the return-to-play date of the first and second concussions was 61.8 ± 39.7 days ( median 60 days ) . CONCLUSIONS The mean rates of return to play for single and recurrent concussions were higher than rates cited in recent studies involving sport concussions . The time interval between the first and second concussions was also greater than previously cited . This difference may be the result of the methodology of direct independent physician observation , diagnosis , and adherence to the Zurich return-to-play protocol This study explored the diagnostic utility of the composite scores of Immediate Post-Concussion Assessment and Cognitive Testing ( ImPACT ) and Post Concussion Symptom Scale scores ( PCSS ) . Recently concussed high school athletes ( N=72 ) were tested within 72 h of sustaining a concussion , and data were compared to non-concussed high school athletes with no history of concussion ( N=66 ) . Between-groups MANOVA revealed a significant multivariate effect of concussion on test performance ( p<.001 ) ; univariate ANOVAS revealed all six measures contributed to the between-groups differences . A discriminant function analyses was conducted to measure the ability of the five ImPACT composite scores , as well as the PCSS to classify concussion status . One discriminant function was identified that consisted of the Visual Memory , Processing Speed , and Impulse Control composite scores PCSS , which correctly classified 85.5 % of the cases . Approximately 82 % of participants in the concussion group and 89 % of participants in the control group were correctly classified . Using these data , the sensitivity of ImPACT was 81.9 % , and the specificity was 89.4 % . As part of a formal concussion management program , ImPACT is a useful tool for the assessment of the neurocognitive and neurobehavioral sequelae of concussion , and can also provide post-injury cognitive and symptom data that can assist a practitioner in making safer return to play decisions CONTEXT Ice hockey has one of the highest sport participation and injury rates in youth in Canada .  Body checking is the predominant mechanism of injury in leagues in which it is permitted . OBJECTIVE To determine if risk of injury and concussion differ for Pee Wee ( ages 11 - 12 years ) ice hockey players in a league in which body checking is permitted ( Alberta , Canada ) vs a league in which body checking is not permitted ( Quebec , Canada ) . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve cohort study conducted in Alberta and Quebec during the 2007 - 2008 Pee Wee ice hockey season . Participants ( N = 2154 ) were players from teams in the top 60 % of divisions of play . MAIN OUTCOME MEASURES Incidence rate ratios adjusted for cluster based on Poisson regression for game- and practice -related injury and concussion . RESULTS Seventy-four Pee Wee teams from Alberta ( n = 1108 players ) and 76 Pee Wee teams from Quebec ( n = 1046 players ) completed the study . In total , there were 241 injuries ( 78 concussions ) reported in Alberta ( 85 077 exposure-hours ) and 91 injuries ( 23 concussions ) reported in Quebec ( 82 099 exposure-hours ) . For game-related injuries , the Alberta vs Quebec incidence rate ratio was 3.26 ( 95 % confidence interval [ CI ] , 2.31 - 4.60 [ n = 209 and n = 70 for Alberta and Quebec , respectively ] ) for all injuries , 3.88 ( 95 % CI , 1.91 - 7.89 [ n = 73 and n = 20 ] ) for concussion , 3.30 ( 95 % CI , 1.77 - 6.17 [ n = 51 and n = 16 ] ) for severe injury ( time loss , > 7 days ) , and 3.61 ( 95 % CI , 1.16 - 11.23 [ n=14 and n=4 ] ) for severe concussion ( time loss , > 10 days ) . The estimated absolute risk reduction ( injuries per 1000 player-hours ) that would be achieved if body checking were not permitted in Alberta was 2.84 ( 95 % CI , 2.18 - 3.49 ) for all game-related injuries , 0.72 ( 95 % CI , 0.40 - 1.04 ) for severe injuries , 1.08 ( 95 % CI , 0.70 - 1.46 ) for concussion , and 0.20 ( 95 % CI , 0.04 - 0.37 ) for severe concussion . There was no difference between provinces for practice -related injuries . CONCLUSION Among 11- to 12-year-old ice hockey players , playing in a league in which body checking is permitted compared with playing in a league in which body checking is not permitted was associated with a 3-fold increased risk of all game-related injuries and the categories of concussion , severe injury , and severe concussion Background Recent concussion management guidelines have suggested that athletes with mild ( grade 1 ) concussions may be returned to play if asymptomatic for 15 minutes . The purpose of this study was to assess the utility of a current concussion management guideline in classifying and managing mild concussion . Hypothesis High school athletes diagnosed with a grade 1 concussion will demonstrate measurable decline in neuropsychological functioning that persists during the 1st week of recovery . Study Design Prospect i ve study design ed to evaluate neuropsychological functioning both prior to and following concussion . Methods Forty-three high school athletes completed  neuropsychological test performance  and  symptom ratings  prior to the season and at two times during the 1st week following  mild concussion . Results Thirty-six hours after injury , mildly concussed high school athletes demonstrated a decline in memory ( P < 0.003 ) and a dramatic increase in self-reported symptoms ( P < 0.00001 ) compared to baseline performance . Conclusions Athletes with grade 1 concussion demonstrated memory deficits and symptoms that persisted beyond the context in which they were injured . These data suggest that current grade 1 return-to-play recommendations that allow for immediate return to play may be too liberal . Clinical Relevance A reconsideration of current concussion grading systems appears to be warranted Objective : To examine functional brain activation patterns before and after postconcussive symptoms ( PCS ) resolution . Design : Prospect i ve serial study with male athletes using functional magnetic resonance imaging ( fMRI ) . Setting : Hospital laboratory and imaging facility . Participants : 9 symptomatic concussed athletes who experienced persisting PCS at least 1 month postinjury and 6 healthy athletes . Interventions : All athletes filled out a PCS checklist and underwent an fMRI session during which they performed a working-memory task . Main outcome measurements : Behavioral outcomes were response speed and accuracy on the working memory tasks performed during the fMRI session . Functional imaging outcomes were blood oxygen level-dependent fMRI activation patterns associated with a working memory task . Results : There was no difference in behavioral performance between the groups . Despite normal structural MRI findings , all symptomatic concussed athletes initially showed atypical brain activation patterns in the dorsolateral prefrontal cortex ( DLPC ) . Compared to the initial postinjury evaluation , those athletes at follow-up with PCS resolved showed significant increases in activation in the left DLPC . Concussed athletes whose PCS status remained unchanged at follow-up continued to show atypical activation in DLPC . Healthy athletes showed remarkably clear and consistent brain activations in DLPC initially as well as in follow-up , highlighting the test-retest reliability of fMRI . Conclusions : The results demonstrate the feasibility of using fMRI to detect an underlying pathology in symptomatic concussed athletes with normal structural imaging results and its potential to document recovery . Such information may be of considerable value for clinical judgment and patient management 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
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 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 .