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Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to repetitive head impacts. CTE has been linked to disruptions in cognition, mood, and behavior. Unfortunately, the diagnosis of CTE can only be made post-mortem. Neuropathological evidence suggests limbic structures may provide an opportunity to characterize CTE in the living. Using 3 T magnetic resonance imaging, we compared select limbic brain regional volumes - the amygdala, hippocampus, and cingulate gyrus - between symptomatic former National Football League (NFL) players (n = 86) and controls (n = 22). Moreover, within the group of former NFL players, we examined the relationship between those limbic structures and neurobehavioral functioning (n = 75). The former NFL group comprised eighty-six men (mean age = 55.2 ± 8.0 years) with at least 12 years of organized football experience, at least 2 years of active participation in the NFL, and self-reported declines in cognition, mood, and behavior within the last 6 months. The control group consisted of men (mean age = 57.0 ± 6.6 years) with no history of contact-sport involvement or traumatic brain injury. All control participants provided neurobehavioral data. Compared to controls, former NFL players exhibited reduced volumes of the amygdala, hippocampus, and cingulate gyrus. Within the NFL group, reduced bilateral cingulate gyrus volume was associated with worse attention and psychomotor speed (r = 0.4 (right), r = 0.42 (left); both p < 0.001), while decreased right hippocampal volume was associated with worse visual memory (r = 0.25, p = 0.027). Reduced volumes of limbic system structures in former NFL players are associated with neurocognitive features of CTE. Volume reductions in the amygdala, hippocampus, and cingulate gyrus may be potential biomarkers of neurodegeneration in those at risk for CTE.

Background: There is increasing focus on the number of concussions after which an athlete should discontinue participating in contact or collision sports. This is a clinically subjective and, in some cases, a preference-sensitive decision., Purpose: Our goal was to assess whether there is personal subjectivity in when athletic trainers (ATs) discuss the possibility of sport retirement post-concussion with athletes., Methods: A national sample of ATs who provide clinical care to college athletes completed a questionnaire (n = 677, 34% response rate). Structural equation modeling was used to assess the association between risk perceptions, risk tolerance, social influences (beliefs about athlete, coach and parent preferences), expectancies about athlete success (on and off field), and the number of concussions after which retirement would be discussed., Results: There was a significant direct effect of AT risk tolerance on the number of concussions after which sport retirement would be discussed, among both male and female ATs (male B = 0.54, p < 0.001; female B = 0.31, p < 0.001). ATs who more strongly prioritized athletes' on-field achievements indicated that they would discuss sport retirement after a larger number of concussions compared to their peers who less strongly valued athletic achievement., Conclusions: The results suggest the potential utility of standardized approaches to communicating concussion risk consistently to athletes. This can help ensure that all athletes are uniformly able to make informed decisions about continued exposure to concussion risk that are based on their values and preferences., (Copyright © 2018. Published by Elsevier Ltd.)

Introduction: Cerebrospinal fluid (CSF) protein analysis may facilitate detection and elucidate mechanisms of neurological consequences from repetitive head impacts (RHI), such as chronic traumatic encephalopathy. We examined CSF concentrations of total tau (t-tau), phosphorylated tau, and amyloid β 1-42 and their association with RHI in former National Football League (NFL) players. The role of microglial activation (using sTREM2) was examined as a pathogenic mechanism of chronic traumatic encephalopathy., Methods: Sixty-eight former NFL players and 21 controls underwent lumbar puncture to quantify t-tau, p-tau 181 , amyloid β 1-42 , and sTREM2 in the CSF using immunoassays. The cumulative head impact index estimated RHI., Results: No between-group differences for CSF analytes emerged. In the former NFL players, the cumulative head impact index predicted higher t-tau concentrations (P = .041), and higher sTREM2 levels were associated with higher t-tau concentrations (P = .009)., Discussion: In this sample of former NFL players, greater RHI and increased microglial activation were associated with higher CSF t-tau concentrations., (Copyright © 2018 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)

Thalamic atrophy has been associated with exposure to repetitive head impacts (RHI) in professional fighters. The aim of this study is to investigate whether or not age at first exposure (AFE) to RHI is associated with thalamic volume in symptomatic former National Football League (NFL) players at risk for chronic traumatic encephalopathy (CTE). Eighty-six symptomatic former NFL players (mean age = 54.9 ± 7.9 years) were included. T1-weighted data were acquired on a 3T magnetic resonance imager, and thalamic volumes were derived using FreeSurfer. Mood and behavior, psychomotor speed, and visual and verbal memory were assessed. The association between thalamic volume and AFE to playing football and to number of years playing was calculated. Decreased thalamic volume was associated with more years of play (left: p = 0.03; right: p = 0.03). Younger AFE was associated with decreased right thalamic volume (p = 0.014). This association remained significant after adjusting for total years of play. Decreased left thalamic volume was associated with worse visual memory (p = 0.014), whereas increased right thalamic volume was associated with fewer mood and behavior symptoms (p = 0.003). In our sample of symptomatic former NFL players at risk for CTE, total years of play and AFE were associated with decreased thalamic volume. The effect of AFE on right thalamic volume was almost twice as strong as the effect of total years of play. Our findings confirm previous reports of an association between thalamic volume and exposure to RHI. They suggest further that younger AFE may result in smaller thalamic volume later in life.

Background: There were 18,844 volleyball players in the National Collegiate Athletic Association (NCAA) in the 2014-2015 academic year. Little research has examined sex-based differences among these athletes., Purpose: To examine injury epidemiology in NCAA men's and women's volleyball athletes., Study Design: Descriptive epidemiology study., Level of Evidence: Level 3., Methods: Injury surveillance data from the 2013-2014 through 2014-2015 academic years were obtained from the NCAA Injury Surveillance Program for 6 men's and 33 women's collegiate volleyball teams. Injury rates per 1000 athlete-exposures (AEs) and injury rate ratios (IRRs) with 95% CIs were calculated. Time-loss (TL) injuries resulted in participation restriction for at least 24 hours, and non-time-loss (NTL) injuries resulted in participation restriction of less than 24 hours., Results: Overall, 83 and 510 injuries were reported in men and women, respectively, leading to injury rates of 4.69 and 7.07 per 1000 AEs. The injury rate was greater in women than men (IRR, 1.51; 95% CI, 1.19-1.90). TL injury rates were 1.75 and 2.62 per 1000 AEs for men and women, respectively. The ankle was the most commonly injured body part among TL injuries (men, 25.8%; women, 24.3%); the knee was the most commonly injured body part among NTL injuries (men, 25.5%; women, 16.3%). Among TL injuries, common diagnoses included sprains (men, 25.8%; women, 31.2%) and concussions (men, 19.4%; women, 14.8%). Most TL concussions were due to ball contact (men, 83.3%; women, 53.6%). Compared with men, women had a greater NTL overuse injury rate (IRR, 3.47; 95% CI, 1.61-7.46). Compared with women, men had a greater TL injury rate associated with ball contact (IRR, 2.24; 95% CI, 1.07-4.68)., Conclusion: There are differences in injury patterns and rates between male and female intercollegiate volleyball players. Although a limited-contact sport, a notable number of concussions were sustained, mostly from ball contact., Clinical Relevance: Understanding injury patterns may aid clinicians in injury diagnosis, management, and prevention.

Previous research suggests that age of first exposure (AFE) to football before age 12 may have long-term clinical implications; however, this relationship has only been examined in small samples of former professional football players. We examined the association between AFE to football and behavior, mood and cognition in a large cohort of former amateur and professional football players. The sample included 214 former football players without other contact sport history. Participants completed the Brief Test of Adult Cognition by Telephone (BTACT), and self-reported measures of executive function and behavioral regulation (Behavior Rating Inventory of Executive Function-Adult Version Metacognition Index (MI), Behavioral Regulation Index (BRI)), depression (Center for Epidemiologic Studies Depression Scale (CES-D)) and apathy (Apathy Evaluation Scale (AES)). Outcomes were continuous and dichotomized as clinically impaired. AFE was dichotomized into <12 and ⩾12, and examined continuously. Multivariate mixed-effect regressions controlling for age, education and duration of play showed AFE to football before age 12 corresponded with >2 × increased odds for clinically impaired scores on all measures but BTACT: (odds ratio (OR), 95% confidence interval (CI): BRI, 2.16,1.19-3.91; MI, 2.10,1.17-3.76; CES-D, 3.08,1.65-5.76; AES, 2.39,1.32-4.32). Younger AFE predicted increased odds for clinical impairment on the AES (OR, 95% CI: 0.86, 0.76-0.97) and CES-D (OR, 95% CI: 0.85, 0.74-0.97). There was no interaction between AFE and highest level of play. Younger AFE to football, before age 12 in particular, was associated with increased odds for impairment in self-reported neuropsychiatric and executive function in 214 former American football players. Longitudinal studies will inform youth football policy and safety decisions.

Importance: Players of American football may be at increased risk of long-term neurological conditions, particularly chronic traumatic encephalopathy (CTE)., Objective: To determine the neuropathological and clinical features of deceased football players with CTE., Design, Setting, and Participants: Case series of 202 football players whose brains were donated for research. Neuropathological evaluations and retrospective telephone clinical assessments (including head trauma history) with informants were performed blinded. Online questionnaires ascertained athletic and military history., Exposures: Participation in American football at any level of play., Main Outcomes and Measures: Neuropathological diagnoses of neurodegenerative diseases, including CTE, based on defined diagnostic criteria; CTE neuropathological severity (stages I to IV or dichotomized into mild [stages I and II] and severe [stages III and IV]); informant-reported athletic history and, for players who died in 2014 or later, clinical presentation, including behavior, mood, and cognitive symptoms and dementia., Results: Among 202 deceased former football players (median age at death, 66 years [interquartile range, 47-76 years]), CTE was neuropathologically diagnosed in 177 players (87%; median age at death, 67 years [interquartile range, 52-77 years]; mean years of football participation, 15.1 [SD, 5.2]), including 0 of 2 pre-high school, 3 of 14 high school (21%), 48 of 53 college (91%), 9 of 14 semiprofessional (64%), 7 of 8 Canadian Football League (88%), and 110 of 111 National Football League (99%) players. Neuropathological severity of CTE was distributed across the highest level of play, with all 3 former high school players having mild pathology and the majority of former college (27 [56%]), semiprofessional (5 [56%]), and professional (101 [86%]) players having severe pathology. Among 27 participants with mild CTE pathology, 26 (96%) had behavioral or mood symptoms or both, 23 (85%) had cognitive symptoms, and 9 (33%) had signs of dementia. Among 84 participants with severe CTE pathology, 75 (89%) had behavioral or mood symptoms or both, 80 (95%) had cognitive symptoms, and 71 (85%) had signs of dementia., Conclusions and Relevance: In a convenience sample of deceased football players who donated their brains for research, a high proportion had neuropathological evidence of CTE, suggesting that CTE may be related to prior participation in football.

Background: Regulators must act to protect the public when evidence indicates safety problems with medical devices. This requires complex tradeoffs among risks and benefits, which conventional safety surveillance methods do not incorporate., Objective: To combine explicit regulator loss functions with statistical evidence on medical device safety signals to improve decision making., Methods: In the Hospital Cost and Utilization Project National Inpatient Sample, we select pediatric inpatient admissions and identify adverse medical device events (AMDEs). We fit hierarchical Bayesian models to the annual hospital-level AMDE rates, accounting for patient and hospital characteristics. These models produce expected AMDE rates (a safety target), against which we compare the observed rates in a test year to compute a safety signal. We specify a set of loss functions that quantify the costs and benefits of each action as a function of the safety signal. We integrate the loss functions over the posterior distribution of the safety signal to obtain the posterior (Bayes) risk; the preferred action has the smallest Bayes risk. Using simulation and an analysis of AMDE data, we compare our minimum-risk decisions to a conventional Z score approach for classifying safety signals., Results: The 2 rules produced different actions for nearly half of hospitals (45%). In the simulation, decisions that minimize Bayes risk outperform Z score-based decisions, even when the loss functions or hierarchical models are misspecified., Limitations: Our method is sensitive to the choice of loss functions; eliciting quantitative inputs to the loss functions from regulators is challenging., Conclusions: A decision-theoretic approach to acting on safety signals is potentially promising but requires careful specification of loss functions in consultation with subject matter experts.

This study examined the extent to which concussion management plans at National Collegiate Athletic Association (NCAA) member schools were in line with NCAA Concussion Policy and best practice recommendations in absence of any process to ensure compliance. Most schools' concussion management plans were in compliance with 3 (60%) or 4 (25.6%) of the NCAA's 4 required components. Annual athlete education and acknowledgement was the requirement least often included, representing an area for improvement. Further, schools tended to more often include best practices that were more medically-oriented (e.g., including baseline examination), compared to best practices that were less medical in nature (e.g., avoiding flagrant head hits).

Background: In response to concerns over concussions and repeated head impacts that occur during sports, the National Collegiate Athletic Association (NCAA) mandated that all member institutions enact a concussion management plan (CMP). Although institutional and health care provider self-reports have been investigated, compliance with NCAA protocol recommendations has not been examined., Purpose: To examine the CMPs from the 65 institutions within the NCAA Power 5 conferences for compliance with the NCAA 2015 concussion guidelines., Study Design: Descriptive epidemiology study., Methods: Each institution's publicly available CMP was obtained in 2015, reviewed, and coded for compliance with each of the required 47 components. Overall compliance rate, item-level, category-level, and institution-level compliance was assessed. Independent predictors of compliance, including each institution's athletic training staff size, academic performance, and athletic performance, were examined with quasi-binomial regression., Results: CMPs varied substantially in length and level of detail. The overall compliance rate for all components across all institutions was 94.3% (2880/3055). Twelve components achieved 100% (65/65) compliance, and the lowest levels of compliance were clustered in "return to learn." There were 22 institutions that achieved a 100% compliance rate; the lowest institutional compliance was 59.6%. There were no significant associations between the independent predictors and institutional compliance., Conclusion: Overall compliance with NCAA concussion management requirements was high, but there remains room for improvement. The lowest level of compliance was clustered in the return-to-learn section. There were limited details provided in the reducing head trauma component. Items with lower compliance (reducing head trauma, return to learn) tended to be outside the core competencies of the medical staff, indicating an area for improvement. Encouragingly, many institutions and specific components demonstrated full compliance., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: T.A.B. has received research-related funding from the NCAA as part of the NCAA/DoD CARE consortium (award number W81XWH-14-2-0151). W.P.M. receives royalties from ABC-Clio Publishing, Springer, and Wolters Kluwer, and his research is funded in part by a grant from the Football Players’ Health Study, funded by the NFL Players’ Association, and philanthropic support from the National Hockey League Alumni Association through the Corey C. Griffin Pro-Am Tournament. C.M.B. receives research support from the Football Players’ Health Study, funded by the NFL Players’ Association; has received funding from the NCAA; and is supported by the National Institute of Mental Health (award number T32MH019733).

Evidence-based clinical practice guidelines can facilitate proper evaluation and management of concussions in the emergency department (ED), often the initial and primary point of contact for concussion care. There is no universally adopted set of guidelines for concussion management, and extant evidence suggests that there may be variability in concussion care practices and limited application of clinical practice guidelines in the ED. This study surveyed EDs throughout New England to examine current practices of concussion care and utilization of evidence-based clinical practice guidelines in the evaluation and management of concussions. In 2013, a 32-item online survey was e-mailed to 149/168 EDs throughout New England (Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire, Maine). Respondents included senior administrators asked to report on their EDs use of clinical practice guidelines, neuroimaging decision-making, and discharge instructions for concussion management. Of the 72/78 respondents included, 35% reported absence of clinical practice guidelines, and 57% reported inconsistency in the type of guidelines used. Practitioner preference guided neuroimaging decision-making for 57%. Although 94% provided written discharge instructions, there was inconsistency in the recommended time frame for follow-up care (13% provided no specific time frame), the referral specialist to be seen (25% did not recommend any specialist), and return to activity instructions were inconsistent. There is much variability in concussion care practices and application of evidence-based clinical practice guidelines in the evaluation and management of concussions in New England EDs. Knowledge translational efforts will be critical to improve concussion management in the ED setting.

Concussion is increasingly recognized as a risk of participation in contact and collision sports. There have been few examinations of athletes' perceptions of their susceptibility to concussion or concussion-related health consequences. We examine college football players' perceptions of their risk of sustaining a concussion and concussion-related health consequences in their future, whether these perceptions change over time, and how concussion history is related to perceived future risk of concussion and concussion-related health consequences. A survey was administered to National Collegiate Athletic Association Division I Football Championship Series athletes on 10 teams in 2013 and to nine of those teams in 2014. Athletes answered questions assessing their perceptions of concussion and potential concussion-related health consequences. Approximately 40% of athletes believed there was a strong possibility that they would sustain a concussion in the future, while approximately one-in-four thought a concussion would make them miss a few games. About one-in-10 athletes predicted dementia, Alzheimer's disease, or chronic traumatic encephalopathy would develop from concussions. These beliefs were stronger among athletes who had sustained previous concussions. Across the two years studied, athletes' perceptions of the risk of concussion and missing a few games because of concussion decreased significantly. Overall, a substantial proportion of college football players believe they will have long-term health consequences as a result of sustaining sport-related concussions. The true incidence and prevalence of many of these outcomes are unknown. Further research is needed to determine whether athletes have an accurate perception of the risks of these outcomes developing.

Professional American football players incur thousands of repetitive head impacts (RHIs) throughout their lifetime. The long-term consequences of RHI are not well characterized, but may include olfactory dysfunction. RHI has been associated with changes to brain regions involved in olfaction, and olfactory impairment is common after traumatic brain injury. Olfactory dysfunction is a frequent early sequelae of neurodegenerative diseases (e.g., Alzheimer's disease), and RHI is associated with the neurodegenerative disease, chronic traumatic encephalopathy (CTE). We examined olfaction, and its association with clinical measures, in former National Football League (NFL) players. Ninety-five former NFL players (ages 40-69) and 28 same-age controls completed a neuropsychological and neuropsychiatric evaluation as part of a National Institutes of Health-funded study. The Brief Smell Identification Test (B-SIT) assessed olfaction. Principal component analysis generated a four-factor structure of the clinical measures: behavioral/mood, psychomotor speed/executive function, and verbal and visual memory. Former NFL players had worse B-SIT scores relative to controls (p = 0.0096). A B-SIT cutoff of 11 had the greatest accuracy (c-statistic = 0.61) and specificity (79%) for discriminating former NFL players from controls. In the former NFL players, lower B-SIT scores correlated with greater behavioral/mood impairment (p = 0.0254) and worse psychomotor speed/executive functioning (p = 0.0464) after controlling for age and education. Former NFL players exhibited lower olfactory test scores relative to controls, and poorer olfactory test performance was associated with worse neuropsychological and neuropsychiatric functioning. Future work that uses more-comprehensive tests of olfaction and structural and functioning neuroimaging may improve understanding on the association between RHI and olfaction.

This study assessed whether between-sex differences in concussion reporting intention and behavior among young adults are explained by the extent to which the individual conforms to traditional masculine norms that often characterize contemporary sport culture. A survey of college athletes in the United States (n = 328) found greater symptom reporting intention among females as compared to males, but no difference in their likelihood continued play while experiencing symptoms of a possible concussion. Greater conformity to the norms of risk-taking was associated with greater likelihood of continued play while symptomatic among female athletes but not among male athletes. These findings suggest that gendered behavior, rather than biologically determined sex, is an important consideration for concussion safety in this age group. Addressing elements of the contemporary sport ethos that reinforce risk taking in service of athletic achievement may be a relevant direction for interventions aimed at improving injury reporting among all athletes., (Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.)

Objective: Former National Football League (NFL) players' working knowledge of concussion has not yet been evaluated, despite this population being a major clinical research target due to the association between repetitive head impacts (RHI) and long-term clinical impairments. This study examined former NFL players' understanding of the current concussion definition, and the association between number of concussions with clinical function., Methods: 95 former NFL players (mean age = 55.29; mean NFL year = 8.10) self-reported number of concussions before being provided with a concussion definition and after being read a modern definition of concussion. Subjects reported number of concussions with loss of consciousness (LOC). Principal Component Analysis of a battery of tests generated behaviour/mood, psychomotor speed/executive function, and verbal and visual memory factor scores., Results: Post-definition number of concussions (median = 50) was five times the pre-definition (median = 10; p < 0.001). Greater pre- (p = 0.019) and post-definition concussions (p = 0.036) correlated with worse behaviour/mood scores, after controlling for years of football played, with specific effects for depressive symptoms and impulsivity. LOC did not account for variance beyond number of concussions., Conclusions: Practitioners and clinical researchers should provide a definition of concussion in the assessment of concussion history in former football players to facilitate accuracy and standardization.

Introduction: Blood protein analysis of total tau (t-tau) may be a practical screening biomarker for chronic traumatic encephalopathy (CTE), a neurodegenerative tauopathy associated with repetitive head impact (RHI) exposure. We examined plasma t-tau in symptomatic former National Football League (NFL) players compared with controls and the relationship between RHI exposure and later-life plasma t-tau., Methods: Ninety-six former NFL players (age 40-69) and 25 same-age controls underwent blood draw to determine plasma t-tau levels. The cumulative head impact index (CHII) quantified RHI exposure. Subjects completed measures of clinical function., Results: A higher CHII predicted greater plasma t-tau in the former NFL players ( P  = .0137). No group differences in plasma t-tau emerged, but a concentration ≥3.56 pg/mL was 100% specific to former NFL players. Plasma t-tau did not predict clinical function., Discussion: Greater RHI exposure predicted higher later-life plasma t-tau concentrations, and further study on plasma t-tau as a candidate screening biomarker for CTE is warranted.

Using the liminality N-body simulations of Shi et al., we present the first predictions for galaxy clustering in f(R) gravity using subhalo abundance matching. We find that, for a given galaxy density, even for an f(R) model with f&#95;{R0}=-10^{-6}, for which the cold dark matter clustering is very similar to the cold dark matter model with a cosmological constant (ΛCDM), the predicted clustering of galaxies in the f(R) model is very different from ΛCDM. The deviation can be as large as 40% for samples with mean densities close to that of L&#95;{*} galaxies. This large deviation is testable given the accuracy that future large-scale galaxy surveys aim to achieve. Our result demonstrates that galaxy surveys can provide a stringent test of general relativity on cosmological scales, which is comparable to the tests from local astrophysical observations.

Objective: The primary objective of this study was to examine the proportion of US college coaches who receive annual concussion education from their institution and to describe the content and delivery modalities of this education. This study also tested the hypothesis that coaches receiving concussion education from their institution will have greater knowledge about concussions independent of other individual and institutional characteristics., Design: Cross-sectional online survey., Setting: US college sport., Participants: College coaches in National Collegiate Athletic Association Division I, II, and III (n = 1818)., Independent Variables: Self-reported receipt of education from institution, sex, sport coached, division of competition., Main Outcome Measures: Concussion identification and management knowledge., Results: Two-thirds of coaches reported receiving informational materials about concussion from their institution. The content of the education most frequently referred to symptoms of a concussion and information about proper management of a concussion. Coaches who received educational materials from their institution were better able to identify symptoms and had more conservative responses to concussion management scenarios. Male coaches of male contact or collision teams less frequently endorsed safe or correct response as compared with female coaches of noncontact or collision teams., Conclusions: Not all US college coaches receive concussion education from their institution. Male Division I coaches of male contact/collision sport are a population for whom targeted educational outreach may be particularly valuable., Clinical Relevance: Education for coaches, delivered by clinicians at many institutions, is an important component of ensuring that coaches are prepared to be informed partners in supporting concussion safety.

Concussion underreporting contributes to the substantial public health burden of concussions from sport. Teammates may be able to play an important role in encouraging injury identification and help seeking. This study assessed whether there was an association between beliefs about the consequences of continued play with a concussion and intentions to engage as a proactive bystander in facilitating or encouraging teammate help seeking for a possible concussion. Participants were 328 (male and female) members of 19 U.S. collegiate contact or collision sports teams. Athletes who believed that there were negative health or performance consequences of continued play with a concussion were significantly more likely than their peers to intend to encourage teammate help seeking, but not more likely to alert a coach or medical personnel. Additionally, athletes who believed that their teammates were more supportive of concussion safety were more likely to intend to engage as proactive bystanders in encouraging teammate help seeking. Exploring how to encourage bystander promotion of concussion safety is an important direction for future programming and evaluation research and may provide an opportunity to improve the effectiveness of concussion education., (© 2015 Society for Public Health Education.)

Background: In recent years, sports leagues and sports medicine experts have developed guidelines for concussion management. The extent to which current clinical practice is consistent with guideline recommendations is unclear. At the collegiate level, there have been few examinations of concussion management practices and the extent to which meaningful differences across divisions of competition exist., Purpose: The purposes of this study were to (1) examine current practices in concussion diagnosis and management at National Collegiate Athletic Association (NCAA) member colleges, (2) explore the extent to which current practices reflect current recommendations for concussion diagnosis and management, and (3) determine whether there are differences in management patterns across divisions of competition., Design: Descriptive epidemiology study., Methods: An electronic questionnaire was sent to sports medicine clinicians at all NCAA member colleges during September and October 2013. Clinicians were asked about baseline assessments, diagnosis and management practices, return-to-play protocols, the perceived prevalence of underdiagnosis, and basic demographic information., Results: Approximately 30% (n = 866) of contacted clinicians, representing nearly 50% (n = 527) of NCAA member colleges, responded to the questionnaire. Preparticipation baseline examinations were administered at the majority of schools (95%), but most (87.5%) administered baseline assessments only to selected high-risk athletes. Computerized neurocognitive testing and balance assessments were most commonly used as preseason baseline and postinjury assessments. Multimodal examination in line with NCAA and other guidance was used only at a minority of institutions. Athletic trainers most commonly administered and interpreted the preseason baseline examination. Most clinicians reported that their institutions' practices were in line with NCAA guidelines during the first 24 hours of an athlete's concussion diagnosis, with exact percentages varying across measures. Differences across divisions of competition included shorter return-to-play time at Division I schools than Division III schools (9.13 vs 10.31 days, respectively) and more frequently referring concussed athletes to a physician within 24 hours of diagnosis at Division I schools., Conclusion: Concussion management at many colleges in the United States incorporates elements recommended by current guidelines; however, there is room to improve. Increasing the use of a multimodal baseline and postinjury examination will elevate the concussion care provided to college athletes and better align with best practice guidance., (© 2016 The Author(s).)

Concussion education for athletes has the potential to play a role in reducing the health burden of concussions from sport by modifying individual risk-related behaviors. In U.S. collegiate sport, decisions about content and delivery of concussion education are left up to the individual institution. This may result in a high degree of variability in what educational materials athletes receive and is particularly problematic as few concussion education programs have demonstrated efficacy. Health educators can play an important role in working collaboratively with sports medicine clinicians to design and evaluate evidence-based concussion education materials for athletes that meet their learning needs. As a first step in this process, the present study characterizes the content, source, and delivery modalities of concussion currently being provided to U.S. collegiate athletes. It also describes the reported concussion education preferences of a sample of U.S. collegiate athletes. Participants were 789 athletic trainers from 276 schools and 325 athletes from four schools. Results indicated that education is most frequently provided by athletic trainers but that many athletes would also like coaches and physicians to be involved in this process. Athletes also indicated a preference for content provision across a range of topics, including athletic and academic consequences of continued play with a concussion. Implications for the design and delivery of concussion education for athletes are discussed., (© 2015 Society for Public Health Education.)

Context: Data on high school (HS) rowing injuries are lacking., Objective: To describe the epidemiology of HS boys' and girls' rowing injuries during the 2011-2012 through 2013-2014 academic years., Design: Descriptive epidemiology study., Setting: Injury and exposure data from 8 and 11 boys' and girls' rowing programs providing 13 and 17 team-seasons of data, respectively., Patients or Other Participants: High school boys' and girls' varsity rowing student-athletes., Intervention(s): High school rowing data from the National Athletic Treatment, Injury and Outcomes Network., Main Outcome Measure(s): Injury rates and rate ratios were reported with 95% confidence intervals (CIs)., Results: In HS boys' and girls' rowing, 59 and 190 injuries were reported, respectively, for rates of 2.39/1000 athlete-exposures (95% CI = 1.78, 3.00) and 8.60/1000 athlete-exposures (95% CI = 7.38, 9.82). The girls' rowing injury rate was 3.60 times that of boys' (95% CI = 2.69, 4.82)., Conclusions: These findings suggest a higher injury rate among HS female rowers than HS male rowers. Additional research exploring reasons for the sex difference is warranted.

Reducing the frequency and severity of concussions from sport is an important issue in public health currently addressed by a multifaceted approach. Given the large number of participants and the comparatively high risk of injury, American football is an important sport to consider when examining concussion management practices. Focusing on American football at the collegiate level, this manuscript describes current research regarding concussion epidemiology, policy, implementation of clinical diagnosis, management and return-to-play standards and athlete concussion education. Although American collegiate sports leagues have put forth concussion-related policies in recent years, the implementation of these policies and related effects on athlete concussion education, clinical management of concussion and ultimately athlete health outcomes are not well understood. Additional research is needed.

Post-mortem studies reveal a high rate of cavum septi pellucidi (CSP) in chronic traumatic encephalopathy (CTE). It remains, however, to be determined whether or not the presence of CSP may be a potential in vivo imaging marker in populations at high risk to develop CTE. The aim of this study was to evaluate CSP in former professional American football players presenting with cognitive and behavioral symptoms compared with noncontact sports athletes. Seventy-two symptomatic former professional football players (mean age 54.53 years, standard deviation [SD] 7.97) as well as 14 former professional noncontact sports athletes (mean age 57.14 years, SD 7.35) underwent high-resolution structural 3T magnetic resonance imaging. Two raters independently evaluated the CSP, and interrater reliability was calculated. Within National Football League players, an association of CSP measures with cognitive and behavioral functioning was evaluated using a multivariate mixed effects model. The measurements of the two raters were highly correlated (CSP length: rho = 0.98; Intraclass Correlation Coefficient [ICC] 0.99; p < 0.0001; septum length: rho = 0.93; ICC 0.96; p < 0.0001). For presence versus absence of CSP, there was high agreement (Cohen kappa = 0.83, p < 0.0001). A higher rate of CSP, a greater length of CSP, as well as a greater ratio of CSP length to septum length was found in symptomatic former professional football players compared with athlete controls. In addition, a greater length of CSP was associated with decreased performance on a list learning task (Neuropsychological Assessment Battery List A Immediate Recall, p = 0.04) and decreased test scores on a measure of estimate verbal intelligence (Wide Range Achievement Test Fourth Edition Reading Test, p = 0.02). Given the high prevalence of CSP in neuropathologically confirmed CTE in addition to the results of this study, CSP may serve as a potential early in vivo imaging marker to identify those at high risk for CTE. Future research is needed to investigate the pathomechanism underlying the development of CSP after repetitive head impacts, and its potential association with neuropathologically confirmed CTE.

Background: Chronic traumatic encephalopathy (CTE) is a tauopathy associated with prior exposure to repetitive head impacts, such as those incurred through American football and other collision sports. Diagnosis is made through neuropathological examination. Many of the clinical features of CTE are common in the general population, with and without a history of head impact exposure, making clinical diagnosis difficult. As is now common in the diagnosis of other neurodegenerative disorders, such as Alzheimer's disease, there is a need for methods to diagnose CTE during life through objective biomarkers., Objective: The aim of this study was to examine tau-positive exosomes in plasma as a potential CTE biomarker., Methods: Subjects were 78 former National Football League (NFL) players and 16 controls. Extracellular vesicles were isolated from plasma. Fluorescent nanoparticle tracking analysis was used to determine the number of vesicles staining positive for tau., Results: The NFL group had higher exosomal tau than the control group (p <  0.0001). Exosomal tau discriminated between the groups, with 82% sensitivity, 100% specificity, 100% positive predictive value, and 53% negative predictive value. Within the NFL group, higher exosomal tau was associated with worse performance on tests of memory (p = 0.0126) and psychomotor speed (p = 0.0093)., Conclusion: These preliminary findings suggest that exosomal tau in plasma may be an accurate, noninvasive CTE biomarker.

Background: Previous studies examining nondisclosure among athletes in various settings have found substantial proportions of athletes with undisclosed concussions. Substantial gaps exist in our understanding of the factors influencing athletes' disclosure of sports-related concussions., Purpose: To examine the prevalence of, and factors associated with, nondisclosure of recalled concussions in former collegiate athletes., Study Design: Cross-sectional study; Level of evidence, 3., Methods: Former collegiate athletes (N = 797) completed an online questionnaire. Respondents recalled self-identified sports-related concussions (SISRCs) that they sustained while playing sports in high school, college, or professionally, and whether they disclosed these SISRCs to others. Respondents also recalled motivations for nondisclosure. The prevalence of nondisclosure was calculated among those who recalled SISRCs. Multivariate binomial regression estimated adjusted prevalence ratios (PRs) with 95% CIs, controlling for sex, level of contact in sports, and year the athletes began playing collegiate sports., Results: A total of 214 respondents (26.9%) reported sustaining at least 1 SISRC. Of these, 71 (33.2%) reported not disclosing at least 1 SISRC. Former football athletes were most likely to report nondisclosure (68.3% of those recalling SISRCs); female athletes who participated in low/noncontact sports were the least likely to report nondisclosure (11.1% of those recalling SISRC). The prevalence of nondisclosure was higher among men than women in the univariate analysis (PR, 2.88; 95% CI, 1.62-5.14), multivariate analysis (PR, 2.11; 95% CI, 1.13-3.96), and multivariate analysis excluding former football athletes (PR, 2.11; 95% CI, 1.12-3.94). The most commonly reported motivations were as follows: did not want to leave the game/practice (78.9%), did not want to let the team down (71.8%), did not know it was a concussion (70.4%), and did not think it was serious enough (70.4%)., Conclusion: Consistent with previous studies, a substantial proportion of former athletes recalled SISRCs that were not disclosed. Male athletes were less likely to disclose all of their SISRCs than female athletes., (© 2015 The Author(s).)

Secondary prevention of harm from sport-related concussion is contingent on immediate removal from play post-injury. To-date, educational efforts to reduce the prevalent risk behavior of continued play while symptomatic have been largely ineffective. Social norms theory may hold promise as a foundation for more effective concussion education aimed at increasing concussion reporting. The primary objective of this study was to assess whether perceived team concussion reporting norms would be less supportive of an individual's safe concussion symptom reporting behavior than objective team norms. Participants were 328 male and female US collegiate athletes. Written surveys were completed in person during the spring of 2014. Among both male and female athletes, team concussion reporting norms were significantly misperceived, with athletes tending to think that they themselves have safer attitudes about concussion reporting than their teammates. Perceived norms were associated with symptom reporting intention, independent of the team's objective reporting norm. A social norms approach to concussion education, in which misperceived group norms are corrected and shifted in the direction of safety, is an important avenue for program development and evaluation research aimed at the secondary prevention of harm from concussion. Implications for the design of this type of educational programming are discussed., (© The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Youth football players may incur hundreds of repetitive head impacts (RHI) in one season. Our recent research suggests that exposure to RHI during a critical neurodevelopmental period prior to age 12 may lead to greater later-life mood, behavioral, and cognitive impairments. Here, we examine the relationship between age of first exposure (AFE) to RHI through tackle football and later-life corpus callosum (CC) microstructure using magnetic resonance diffusion tensor imaging (DTI). Forty retired National Football League (NFL) players, ages 40-65, were matched by age and divided into two groups based on their AFE to tackle football: before age 12 or at age 12 or older. Participants underwent DTI on a 3 Tesla Siemens (TIM-Verio) magnet. The whole CC and five subregions were defined and seeded using deterministic tractography. Dependent measures were fractional anisotropy (FA), trace, axial diffusivity, and radial diffusivity. Results showed that former NFL players in the AFE <12 group had significantly lower FA in anterior three CC regions and higher radial diffusivity in the most anterior CC region than those in the AFE ≥12 group. This is the first study to find a relationship between AFE to RHI and later-life CC microstructure. These results suggest that incurring RHI during critical periods of CC development may disrupt neurodevelopmental processes, including myelination, resulting in altered CC microstructure.

Context: Anecdotal and qualitative evidence has suggested that some clinicians face pressure from coaches and other personnel in the athletic environment to prematurely return athletes to participation after a concussion. This type of pressure potentially can result in compromised patient care., Objective: To quantify the extent to which clinicians in the collegiate sports medicine environment experience pressure when caring for concussed athletes and whether this pressure varies by the supervisory structure of the institution's sports medicine department, the clinician's sex, and other factors., Design: Cross-sectional study., Setting: Web-based survey of National College Athletic Association member institutions., Patients or Other Participants: A total of 789 athletic trainers and 111 team physicians from 530 institutions., Main Outcome Measure(s): We asked participants whether they had experienced pressure from 3 stakeholder populations (other clinicians, coaches, athletes) to prematurely return athletes to participation after a concussion. Modifying variables that we assessed were the position (athletic trainer, physician) and sex of the clinicians, the supervisory structure of their institutions' sports medicine departments, and the division of competition in which their institutions participate., Results: We observed that 64.4% (n = 580) of responding clinicians reported having experienced pressure from athletes to prematurely clear them to return to participation after a concussion, and 53.7% (n = 483) reported having experienced this pressure from coaches. Only 6.6% (n = 59) reported having experienced pressure from other clinicians to prematurely clear an athlete to return to participation after a concussion. Clinicians reported greater pressure from coaches when their departments were under the supervisory purview of the athletic department rather than a medical institution. Female clinicians reported greater pressure from coaches than male clinicians did., Conclusions: Most clinicians reported experiencing pressure to prematurely return athletes to participation after a concussion. Identifying factors that are associated with variability in pressure on clinicians during concussion recovery can inform potential future strategies to reduce these pressures.

Background: Communication between coaches and athletes about concussion safety can reinforce or undermine a sport culture in which concussion under-reporting is often endemic., Method: This study tested a model in which self-reported coach communication about concussion safety was predicted by factors including concussion knowledge, attitudes and beliefs, sex of the coach, and sex of the team coached. Participants were 997 coaches of contact and collision sports teams competing in National Collegiate Athletic Association Division I, II, or III., Results: Concussion attitudes and beliefs were the strongest predictors of communication, and the small effect of knowledge on communication was transmitted nearly entirely through its effect on attitudes and beliefs. Much of the variability in communication was attributable to the sex of the coach and the sex of the team coached., Conclusions: These results serve as a starting point for the design of coach-targeted interventions that encourage communication about health and safety with athletes.

Concussions from sport present a substantial public health burden given the number of youth, adolescent and emerging adult athletes that participate in contact or collision sports. Athletes who fail to report symptoms of a suspected concussion and continue play are at risk of worsened symptomatology and potentially catastrophic neurologic consequences if another impact is sustained during this vulnerable period. Understanding why athletes do or do not report their symptoms is critical for developing efficacious strategies for risk reduction. Psychosocial theories and frameworks that explicitly incorporate context, as a source of expectations about the outcomes of reporting and as a source of behavioral reinforcement, are useful in framing this problem. The present study quantifies the pressure that athletes experience to continue playing after a head impact--from coaches, teammates, parents, and fans--and assesses how this pressure, both independently and as a system, is related to future concussion reporting intention. Participants in the study were 328 male and female athletes from 19 teams competing in one of seven sports (soccer, lacrosse, basketball, softball, baseball, volleyball, field hockey) at four colleges in the northeast region of the United States. Results found that more than one-quarter of the sample had experienced pressure from at least one source to continue playing after a head impact during the previous year. Results of a latent profile mixture model indicated that athletes who experienced pressure from all four of the measured sources were significantly more likely to intend to continue playing in the future than were athletes who had not experienced pressure from all sources, or only pressure from coaches and teammates. These findings underscore the importance of designing interventions that address the system in which athletes make decisions about concussion reporting, including athletes' parents, rather than focusing solely on modifying the individual's reporting cognitions., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Concussion from sport is increasingly recognized as a public health priority. In response, all states and the District of Columbia have enacted youth concussion legislation. This paper first examines key developments in concussion-related policy and legislation and then uses the findings from recent scientific studies to highlight the need to incorporate evolving scientific evidence into concussion legislation in order to better protect youth and adolescent athletes. Next, the paper discusses the framework of empirical health law research and why it should be applied in the case of concussion legislation. Finally, this paper argues that empirical health law research should be considered in any decision about whether legislation can help improve the health and safety of young players, a particularly vulnerable population whose unique needs have not yet been adequately addressed.

Objective: This study aimed to evaluate whether preseason concussion knowledge and reporting intention predicted in-season concussion reporting behavior., Design: Prospective cohort study., Setting: Collegiate athletic facility of each participating team., Participants: National Collegiate Athletic Association Division I men's ice hockey players in 1 conference of competition (n = 116)., Independent Variables: Intention to report symptoms of a "minor" concussion and concussion knowledge were assessed at preseason., Main Outcome Measures: Postseason recall of non-report of postimpact symptoms., Results: Preseason concussion knowledge was not significantly associated with in-season reporting behavior. Intention to report concussion symptoms was significantly related to in-season reporting behavior. There was a significant interaction between the number of different symptoms experienced and both preseason reporting intention and in-season reporting behavior., Conclusions: Evaluations of concussion education programs tend to measure concussion knowledge. The present findings suggest that reporting intention may be more strongly predictive of reporting behavior than concussion knowledge and should be included in evaluations of concussion effectiveness. New concussion education initiatives should consider targeting psychosocial constructs that increase reporting intention., Clinical Relevance: Sports medicine clinicians who are involved in evaluating concussion education programs should measure constructs other than just concussion knowledge. Intention, to report symptoms or to continue play while experiencing symptoms of a concussion, seems to be an important and feasible construct to include as part of proximal evaluations of education effectiveness.

Many states and sports leagues are instituting concussion policies aimed at reducing risk of morbidity and mortality; many include mandates about the provision of concussion education to youth athletes. However, there is limited evidence if educational materials provided under these typically vague mandates are in fact effective in changing concussion risk-related behavior or any cognition predictive of risk-related behavior. The purpose of this pilot randomized controlled study was to conduct a theory-driven evaluation of three publically available concussion education materials: two videos and one informational handout. Participants were 256 late adolescent males from 12 teams in a single league of ice hockey competition in the United States. Randomization of educational condition occurred at the team level. Written surveys assessing postimpact symptom reporting behavior, concussion knowledge, and concussion reporting cognitions were completed by participants immediately before receiving their educational intervention, 1 day after, and 1 month after. Results indicated no change in any measure over any time interval, with the exception of perceived underreporting norms. In one of the video conditions, perceived underreporting norms increased significantly 1 day after viewing the video. Possible content and viewing environment-related reasons for this increase are discussed. Across all conditions, perceived underreporting norms increased 1 month after intervention receipt, raising the possibility that late in the competitive season underreporting may be perceived as normative. The need for the development of theory-driven concussion education materials, drawing on best practices from health behavior scholars, is discussed., (© 2014 Society for Public Health Education.)

Background: Recent injury data for collegiate-level swimming and diving are limited. This study describes the epidemiology of men's and women's swimming and diving injuries reported by the National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP) during the 2009/2010 to 2013/2014 academic years., Methods: Injuries and athlete-exposure (AE) data reported within 9 men's and 13 women's swimming and diving programmes were analysed. Injury rates, injury rate ratios (IRR), and injury proportions by body site, diagnosis and mechanism were reported with 95% CIs., Results: The ISP captured 149 and 208 injuries for men's and women's swimming and diving, respectively, leading to injury rates of 1.54/1000 and 1.71/1000 AEs. Among females, divers had a higher injury rate (2.49/1000 AEs) than swimmers (1.63/1000 AEs; IRR=1.53; 95% CI 1.07 to 2.19). Injury rates for male divers (1.94/1000 AEs) and swimmers (1.48/1000 AEs) did not differ (IRR=1.33; 95% CI 0.85 to 2.31). Most injuries occurred to the shoulder, resulted in strains and were classified as overuse or non-contact. Female swimmers had a higher overuse injury rate (1.04/1000 AEs) than male swimmers (0.66/1000 AEs; IRR=1.58; 95% CI 1.14 to 2.19). Overuse injury rates for female divers (0.54/1000 AEs) and male divers (0.46/1000 AEs) did not differ (IRR=1.16; 95% CI 0.40 to 3.34). Injury rates in 2012/2013-2013/2014 were lower than those in 2009/2010-2011/2012 for women's swimming (IRR=0.70; 95% CI 0.52 to 0.95) and diving (IRR=0.56; 95% CI 0.30 to 1.08), respectively. No time trends existed for men's swimmers or divers., Conclusions: Shoulder, strain and overuse injuries were common in collegiate men's and women's swimming and diving. Female swimmers were more likely to suffer an overuse injury than male swimmers. In addition, divers may have higher injury rates than swimmers, although small reported numbers warrant additional research., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Objective: To determine the relationship between exposure to repeated head impacts through tackle football prior to age 12, during a key period of brain development, and later-life executive function, memory, and estimated verbal IQ., Methods: Forty-two former National Football League (NFL) players ages 40-69 from the Diagnosing and Evaluating Traumatic Encephalopathy using Clinical Tests (DETECT) study were matched by age and divided into 2 groups based on their age of first exposure (AFE) to tackle football: AFE <12 and AFE ≥12. Participants completed the Wisconsin Card Sort Test (WCST), Neuropsychological Assessment Battery List Learning test (NAB-LL), and Wide Range Achievement Test, 4th edition (WRAT-4) Reading subtest as part of a larger neuropsychological testing battery., Results: Former NFL players in the AFE <12 group performed significantly worse than the AFE ≥12 group on all measures of the WCST, NAB-LL, and WRAT-4 Reading tests after controlling for total number of years of football played and age at the time of evaluation, indicating executive dysfunction, memory impairment, and lower estimated verbal IQ., Conclusions: There is an association between participation in tackle football prior to age 12 and greater later-life cognitive impairment measured using objective neuropsychological tests. These findings suggest that incurring repeated head impacts during a critical neurodevelopmental period may increase the risk of later-life cognitive impairment. If replicated with larger samples and longitudinal designs, these findings may have implications for safety recommendations for youth sports., (© 2015 American Academy of Neurology.)

Concussions and subconcussive impacts sustained in American football have been associated with short- and long-term neurological impairment, but differences in head impact outcomes across playing positions are not well understood. The American Medical Society for Sports Medicine has identified playing position as a key risk factor for concussion in football and one for which additional research is needed. This study examined variation in head impact outcomes across primary football playing positions in a group of 730 National Collegiate Athletic Association Division I Football Championship Series athletes, using a self-report questionnaire. Although there were no significant differences between position groups in the number of diagnosed concussions during the 2012 football season, there were significant differences between groups in undiagnosed concussions (p=0.008) and "dings" (p<0.001); offensive linemen reported significantly higher numbers than most other positions. Significant differences were found between position groups in the frequencies of several postimpact symptoms, including dizziness (p<0.001), headache (p<0.001), and seeing stars (p<0.001) during the 2012 football season, with offensive linemen reporting significantly more symptoms compared to most other groups. There were also positional differences in frequency of returning to play while symptomatic (p<0.001) and frequency of participating in full-contact practice (p<0.001). Offensive linemen reported having returned to play while experiencing symptoms more frequently and participating in more full-contact practices than other groups. These findings suggest that offensive linemen, a position group that experiences frequent, but low-magnitude, head impacts, develop more postimpact symptoms than other playing positions, but do not report these symptoms as a concussion.

Background: In 2010, the National Collegiate Athletic Association (NCAA) adopted its Concussion Policy and Legislation, which applies to more than 450,000 collegiate athletes annually. To date, there has been no examination of school-level compliance with the NCAA Concussion Policy., Purpose: To examine whether stakeholders at NCAA schools report that their school has a concussion management plan and whether existing plans are consistent with the NCAA policy. Also examined were stakeholders' perceptions regarding concussion management at their institution and possible areas for improvement., Study Design: Cross-sectional study; Level of evidence, 3., Methods: Surveys were sent by e-mail to coaches, sports medicine clinicians, and compliance administrators at all 1066 NCAA member institutions. Surveys asked population-specific questions about institutional concussion management. Individuals (N=2880) from 907 unique schools participated in this survey., Results: Most respondents (n=2607; 92.7%) indicated their school had a concussion management plan. Most schools had all (82.1%) or some (15.2%) respondents indicate a concussion management plan was present. When asked to indicate all individuals who could have final responsibility for returning athletes to play after a concussion, 83.4% selected team doctor, 72.8% athletic trainer, 31.0% specialist physician, 6.8% coach, and 6.6% athlete. Most respondents (76.1%) indicated that their institution had a process for annual athlete concussion education; 91.2% required athletes to acknowledge their responsibility to report concussion symptoms. Nearly all respondents (98.8%) thought their school's concussion management plan protected athletes "well" or "very well." Top categories suggested for improvement included better coach education (39.7%), increasing sports medicine staffing (37.2%), and better athlete education (35.2%)., Conclusion: Although a large majority of respondents indicated that their school has a concussion management plan, improvement is needed. Compliance with specified components (eg, annual athlete education) lags behind the presence of the plan itself, and stakeholders had suggestions for areas in which improvements are needed. Increasing scientific evidence supporting the seriousness of concussion underscores the need for the NCAA to use its regulatory capabilities to ensure that athletes' brains are safe., (© 2014 The Author(s).)

The long-term consequences of repetitive head impacts have been described since the early 20th century. Terms such as punch drunk and dementia pugilistica were first used to describe the clinical syndromes experienced by boxers. A more generic designation, chronic traumatic encephalopathy (CTE), has been employed since the mid-1900s and has been used in recent years to describe a neurodegenerative disease found not just in boxers but in American football players, other contact sport athletes, military veterans, and others with histories of repetitive brain trauma, including concussions and subconcussive trauma. This article reviews the literature of the clinical manifestations of CTE from 202 published cases. The clinical features include impairments in mood (for example, depression and hopelessness), behavior (for example, explosivity and violence), cognition (for example, impaired memory, executive functioning, attention, and dementia), and, less commonly, motor functioning (for example, parkinsonism, ataxia, and dysarthria). We present proposed research criteria for traumatic encephalopathy syndrome (TES) which consist of four variants or subtypes (TES behavioral/mood variant, TES cognitive variant, TES mixed variant, and TES dementia) as well as classifications of 'probable CTE' and 'possible CTE'. These proposed criteria are expected to be modified and updated as new research findings become available. They are not meant to be used for a clinical diagnosis. Rather, they should be viewed as research criteria that can be employed in studies of the underlying causes, risk factors, differential diagnosis, prevention, and treatment of CTE and related disorders.

Opinion Statement: Chronic traumatic encephalopathy (CTE) is a unique neurodegenerative disease found in individuals with a history of repetitive head impacts. The neuropathology of CTE is increasingly well defined. Prospective, longitudinal studies with post-mortem neuropathologic validation as well as in vivo diagnostic techniques are needed in order to advance the understanding of CTE clinically. Given the large number of individuals who incur concussions and other forms of brain trauma, this is an important area for scientific and public health inquiry.

State concussion laws and sport-league policies are important tools for protecting public health, but also present implementation challenges. Both state laws and league policies often require athletes provide written acknowledgement of having received concussion-related information and/or of their responsibility to report concussion-related symptoms. This paper examines these requirements in two ways: an analysis of the variation in state laws and sport-league policies and a study of their effects in a cohort of collegiate football players., (© 2014 American Society of Law, Medicine & Ethics, Inc.)

This paper examines college athletes' perceived support for concussion reporting from coaches and teammates and its variation by year-in-school, finding significant differences in perceived coach support. It also examines the effects of perceived coach support on concussion reporting behaviors, finding that greater perceived coach support is associated with fewer undiagnosed concussions and returning to play while symptomatic less frequently in the two weeks preceding the survey. Coaches play a critical role in athlete concussion reporting., (© 2014 American Society of Law, Medicine & Ethics, Inc.)

Purpose: Athlete's report of concussion symptoms to coaching or medical personnel is an important component of concussion risk reduction. This study applies a model based on the Theory of Planned Behavior (TPB) to the prediction of concussive symptom underreporting among late adolescent and young adult male ice hockey players., Methods: Participants were members of an American Tier III Junior A ice hockey league (ages 18-21 years; male; n = 256). Twelve of 14 league teams and 97% of players within these teams agreed to participate. Written survey items assessed symptom reporting behavior, intention, perceived norms, self-efficacy, perceived outcomes of reporting, and concussion knowledge. Structural equation modeling was used to assess the significance of relationships hypothesized by the TPB-based model and the overall model fit. Data were collected in January 2013., Results: Results supported the fit of the TPB-based model in explaining reporting behavior; all model pathways were significant in the hypothesized direction. Of the perceived reporting outcomes assessed, those related to athletic performance were identified as most strongly associated with reporting intention., Conclusions: Results of this study suggest the importance of considering factors such as perceived outcomes of reporting, perceived norms, and self-efficacy, in addition to knowledge, when analyzing concussion underreporting among adolescent athletes. As concussion education for athletes becomes increasingly mandated, testing and applying psychosocial theories such as TPB may help increase program efficacy., (Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Background/aim: Despite concussion education being increasingly mandated by states and sports leagues, there has been limited evaluation of what education is in fact effective. The National Collegiate Athletic Association (NCAA) currently mandates that institutions provide concussion education, without specifying content or delivery. The present study evaluated the effectiveness of this general mandate, as enacted for male collegiate ice hockey teams within one conference of competition., Methods: In a prospective cohort design, 146 players from 6 male collegiate ice hockey teams in one Division 1 conference completed written surveys before and after receiving their institution-determined concussion education. Knowledge, attitudes, perceived norms and behavioural intention were assessed using validated measures. Education content and delivery was assessed by open-ended responses and consultation with team athletic trainers., Results: All teams received concussion education material; however, content and delivery varied. Rates of material recall differed by delivery format. Considering all teams together, there were no significant improvements in knowledge and only a very small decrease in intention to continue playing while experiencing symptoms of a concussion. Pre-education and post-education, there were significant between-team differences in attitudes towards concussion reporting and behavioural intention., Conclusions: The NCAA's general education mandate was divergently enacted; it did not significantly change the constructs of interest nor did it mitigate the pre-education team differences in these constructs. Existing educational materials should be evaluated, theory and evidence-driven materials developed, and mandates extended to, at a minimum, recommend materials found to be effective in changing concussion-reporting behaviour.

Objective: The goal of this study was to examine the clinical presentation of chronic traumatic encephalopathy (CTE) in neuropathologically confirmed cases., Methods: Thirty-six adult male subjects were selected from all cases of neuropathologically confirmed CTE at the Boston University Center for the Study of Traumatic Encephalopathy brain bank. Subjects were all athletes, had no comorbid neurodegenerative or motor neuron disease, and had next-of-kin informants to provide retrospective reports of the subjects' histories and clinical presentations. These interviews were conducted blind to the subjects' neuropathologic findings., Results: A triad of cognitive, behavioral, and mood impairments was common overall, with cognitive deficits reported for almost all subjects. Three subjects were asymptomatic at the time of death. Consistent with earlier case reports of boxers, 2 relatively distinct clinical presentations emerged, with one group whose initial features developed at a younger age and involved behavioral and/or mood disturbance (n = 22), and another group whose initial presentation developed at an older age and involved cognitive impairment (n = 11)., Conclusions: This suggests there are 2 major clinical presentations of CTE, one a behavior/mood variant and the other a cognitive variant.

Repetitive mild traumatic brain injury (mTBI), such as that experienced by contact-sport athletes, has been associated with the development of chronic traumatic encephalopathy (CTE). Executive dysfunction is believed to be among the earliest symptoms of CTE, with these symptoms presenting in the fourth or fifth decade of life. The present study used a well-validated self-report measure to study executive functioning in football players, compared to healthy adults. Sixty-four college and professional football players were administered the Behavior Rating Inventory of Executive Function, adult version (BRIEF-A) to evaluate nine areas of executive functioning. Scores on the BRIEF-A were compared to published age-corrected normative scores for healthy adults Relative to healthy adults, the football players indicated significantly more problems overall and on seven of the nine clinical scales, including Inhibit, Shift, Emotional Control, Initiate, Working Memory, Plan/Organize, and Task Monitor. These symptoms were greater in athletes 40 and older, relative to younger players. In sum, football players reported more-frequent problems with executive functioning and these symptoms may develop or worsen in the fifth decade of life. The findings are in accord with a growing body of evidence that participation in football is associated with the development of cognitive changes and dementia as observed in CTE.

Chronic traumatic encephalopathy is a progressive tauopathy that occurs as a consequence of repetitive mild traumatic brain injury. We analysed post-mortem brains obtained from a cohort of 85 subjects with histories of repetitive mild traumatic brain injury and found evidence of chronic traumatic encephalopathy in 68 subjects: all males, ranging in age from 17 to 98 years (mean 59.5 years), including 64 athletes, 21 military veterans (86% of whom were also athletes) and one individual who engaged in self-injurious head banging behaviour. Eighteen age- and gender-matched individuals without a history of repetitive mild traumatic brain injury served as control subjects. In chronic traumatic encephalopathy, the spectrum of hyperphosphorylated tau pathology ranged in severity from focal perivascular epicentres of neurofibrillary tangles in the frontal neocortex to severe tauopathy affecting widespread brain regions, including the medial temporal lobe, thereby allowing a progressive staging of pathology from stages I-IV. Multifocal axonal varicosities and axonal loss were found in deep cortex and subcortical white matter at all stages of chronic traumatic encephalopathy. TAR DNA-binding protein 43 immunoreactive inclusions and neurites were also found in 85% of cases, ranging from focal pathology in stages I-III to widespread inclusions and neurites in stage IV. Symptoms in stage I chronic traumatic encephalopathy included headache and loss of attention and concentration. Additional symptoms in stage II included depression, explosivity and short-term memory loss. In stage III, executive dysfunction and cognitive impairment were found, and in stage IV, dementia, word-finding difficulty and aggression were characteristic. Data on athletic exposure were available for 34 American football players; the stage of chronic traumatic encephalopathy correlated with increased duration of football play, survival after football and age at death. Chronic traumatic encephalopathy was the sole diagnosis in 43 cases (63%); eight were also diagnosed with motor neuron disease (12%), seven with Alzheimer's disease (11%), 11 with Lewy body disease (16%) and four with frontotemporal lobar degeneration (6%). There is an ordered and predictable progression of hyperphosphorylated tau abnormalities through the nervous system in chronic traumatic encephalopathy that occurs in conjunction with widespread axonal disruption and loss. The frequent association of chronic traumatic encephalopathy with other neurodegenerative disorders suggests that repetitive brain trauma and hyperphosphorylated tau protein deposition promote the accumulation of other abnormally aggregated proteins including TAR DNA-binding protein 43, amyloid beta protein and alpha-synuclein.

Chronic Traumatic Encephalopathy (CTE) is a neurodegenerative disease thought to be caused, at least in part, by repetitive brain trauma, including concussive and subconcussive injuries. It is thought to result in executive dysfunction, memory impairment, depression and suicidality, apathy, poor impulse control, and eventually dementia. Beyond repetitive brain trauma, the risk factors for CTE remain unknown. CTE is neuropathologically characterized by aggregation and accumulation of hyperphosphorylated tau and TDP-43. Recent postmortem findings indicate that CTE may affect a broader population than was initially conceptualized, particularly contact sport athletes and those with a history of military combat. Given the large population that could potentially be affected, CTE may represent an important issue in public health. Although there has been greater public awareness brought to the condition in recent years, there are still many research questions that remain. Thus far, CTE can only be diagnosed post-mortem. Current research efforts are focused on the creation of clinical diagnostic criteria, finding objective biomarkers for CTE, and understanding the additional risk factors and underlying mechanism that causes the disease. This review examines research to date and suggests future directions worthy of exploration.