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Social determinants of health (SDoH) are environmental and socioeconomic factors that indirectly or directly influence health. This study examined whether SDoH that might relate to health literacy or access to health care are associated with lifetime history of parent-reported concussion in school-aged children and adolescents in the United States. We hypothesized that lower parental education, living in poverty, and speaking a language other than English as the primary language in the home would be associated with a lower lifetime history of concussion. Participants were parents or caregivers of 34,077 children and adolescents (ages 5-17) from the 2021 National Survey of Children's Health. SDoH variables included primary language spoken at home, family income, parental level of education, and current health insurance. Univariable analyses assessed the individual association of each SDoH variable with lifetime history of concussion. A multivariable logistic regression was used to assess the combined association of SDoH variables and other demographic predictors with lifetime concussion history. In the univariable models, male gender, older age, sports participation, and having current health care coverage were associated with a higher lifetime history of concussion. Hispanic/Latino ethnicity, primary language spoken at home other than English, lower level of parental education, living in poverty, and Black or Asian race were associated with lower lifetime history of concussion. In a multivariable model, significant independent predictors of lower lifetime concussion history were lower level of parental education, not speaking English as the primary language at home, and identifying as Black or Asian. It is possible that lower parental education, living in poverty, and speaking a language other than English as the primary language spoken are factors relating to lower concussion-related health literacy. Lower health literacy might contribute to families being less likely to (i) recognize the symptoms of concussion and (ii) seek medical evaluation for the injury., (© The Author(s) 2025. Published by Mary Ann Liebert, Inc.)

Introduction: Children and adolescents with attention-deficit/hyperactivity disorder (ADHD) are more likely to report a lifetime history of concussion compared to those without ADHD. Prior studies have predominantly relied on surveys of youth who self-reported their ADHD status (as opposed to parent report), examined samples with relatively narrow age ranges, and focused on youth athletes. It is unclear if ADHD severity or ADHD medication influences the association between ADHD and greater lifetime history of concussion. We investigated the association between parent-reported ADHD, ADHD severity, and medication status with parent-reported lifetime concussion history in children and adolescents ranging in age from 5 to 17, sampled from the United States general population., Methods: Parent reported health data from 33,914 children and adolescents were selected from the 2021 National Survey of Children's Health. Lifetime history of concussion, current ADHD diagnosed by a healthcare provider, and, for those with current ADHD, ADHD severity (mild or moderate/severe), and current ADHD medication status (yes/no) were reported by parents. A Mantel-Haenszel analysis was used to assess the associations between ADHD and lifetime concussion history across five age groups (ages 5-7, 8-10, 11-13, 14-15, and 16-17). Additional Mantel-Haenszel analyses were used to assess the associations between lifetime history of concussion and ADHD severity as well as medication status across five age groups., Results: Overall, 6.2% of youth had a parent-reported history of concussion and 12.3% had parent-reported current ADHD. Twice as many youth with ADHD (10.6%) had a parent-reported history of concussion compared to youth without ADHD (5.6%). There were no differences in lifetime concussion history for those with mild (10.9%) versus moderate/severe ADHD (10.3%). Similarly, among those with ADHD, there were no differences in lifetime concussion history for those taking medication (9.9%) versus those not taking medication (11.6%)., Discussion: Consistent with previous literature, youth with ADHD had greater lifetime concussion history than youth without ADHD (approximately twice the prevalence in those with ADHD). Contrary to our hypotheses among youth with ADHD, parent-reported ADHD severity and current medication status were not associated with lifetime concussion history., Competing Interests: Grant Iverson serves or has served as a scientific advisor for NanoDX®, Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs. He has received past research support or funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc.). He has received research funding as a principal investigator from the National Football League, and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. Nathan Cook has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs. The remaining author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2025 Maietta, Iverson and Cook.)

We examined the association between social determinants of health and the likelihood of sustaining a concussion among adolescents. Participants in this cross-sectional study were 7164 high school students who completed the 2021 Adolescent Behaviors and Experiences Survey (52.7% girls; mean age = 16.0 years, SD = 1.2; age range 12-18 years). Logistic regression was used to determine which social determinants of health variables were associated with a self-reported history of concussion from playing a sport or being physically active over the past year. One in 10 adolescents (n = 716; 10.0% total; 11.8% of boys, 8.3% of girls) reported sustaining a concussion during the past year. Seven of 10 adolescents (70.3%) reported experiencing at least 1 of 8 negative social determinants of health. A multivariable logistic regression was statistically significant ( P  < .001), indicating that the negative social determinants of health were associated with having sustained a concussion during the past year; the model explained 12.5% (Nagelkerke R 2 ) of the variance in concussion. Controlling for all other predictors, sports participation (odds ratio [OR] = 3.72, medium effect), housing instability (OR = 3.25, small-medium effect) and limited English language proficiency (OR = 3.05, small-medium effect) were the strongest independent predictors of sustaining concussion within the past year. Adolescents who lived in a neighborhood where there is violence (OR = 1.78, small effect), who were bullied (OR = 1.57, very small effect), and who experienced food insecurity (OR = 1.36, very small effect) were more likely to have sustained a concussion. Research is needed to understand the nature of these determinant-injury associations. Whether social determinants of health are associated with specific treatment and rehabilitation needs, and time to recover following concussion, should be examined with prospective studies., Competing Interests: Declaration of Conflicting InterestsAs a general disclosure, Dr. Cook has a clinical and consulting practice in forensic neuropsychology involving individuals who have sustained concussions. Dr. Iverson serves or has served as a scientific advisor for NanoDx™, Sway Operations, LLC, and Highmark, Inc. He has received research funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc.). He has a clinical and consulting practice in forensic neuropsychology involving individuals who have sustained mild TBIs. Dr. Gaudet receives royalties from Oxford University Press.

Purpose: Our purpose was to represent a rare cohort of female collision sport athletes and investigate the association between sport type (collision, contact, and noncontact), symptoms, and performance on baseline neurocognitive assessments., Methods: We conducted a cross-sectional study using baseline computerized neurocognitive scores (Immediate Postconcussion Assessment and Cognitive Testing [ImPACT]) of 75,128 female high school student-athletes (age, 15.27 ± 1.05 yr) playing multiple sports. The dependent variables were verbal memory, visual memory, visual motor speed, reaction time, and total symptom score. The independent variable was sport type, categorized as collision, contact, noncontact, adjusted for the effect of the following covariables: age, concussion history, and comorbidities (learning disability, ADHD, psychiatric condition, headaches, migraines, speech therapy, special education, and repeating one of more years of school) using multivariable regression models., Results: Female collision sport athletes reported significantly higher symptoms (9.81 ± 12.63) at baseline compared with contact (5.78 ± 9.25) or noncontact (6.39 ± 9.74) sport athletes ( P < 0.001). Using noncontact sports as a reference, there was no significant association between collision sport participation and cognitive composite scores (verbal memory: β = -0.57, 95% confidence interval = -1.80 to 0.66, P = 0.38; visual memory: β = -0.83, 95% confidence interval = -2.46 to 0.79, P = 0.31; visual motor speed: β = -0.21, 95% confidence interval = -1.01, 0.59, P = 0.61; reaction time: β = 0.01, 95% confidence interval = -0.01 to 0.02, P = 0.29)., Conclusions: Participation in collision sports appears to be associated with baseline symptoms but not neurocognitive functioning among female adolescent athletes., (Copyright © 2024 by the American College of Sports Medicine.)

Objectives: To evaluate if the tackler correctly adhering, or not, to four different instructions of legal front-on one-on-one torso tackles altered the tackler and/or ball carrier peak inertial head kinematics., Design: Controlled laboratory study., Methods: Fifteen rugby-code players measured with three-dimensional optoelectronic motion capture performed two tackle instructions from the Australian National Rugby League coaching manual on under (Dominant National Rugby League) and over (Smother National Rugby League) the ball tackles, and two novel variants of these (under, Dominant, Torso Stick; over, Smother, Pop, Lock). A series of mixed general linear models identified if the tackler adhering (n = 455), or not (n = 139) to the tackle instructions altered peak inertial head kinematics., Results: The tackler's peak inertial head kinematics did not significantly change whether or not they adhered to each of the tackle instructions. When the tackler did adhere to the instructions, the ball carrier sustained a lower peak inertial head kinematics (p < 0.01) in the Smother National Rugby League tackle but higher peak inertial head kinematics in the Smother, Pop, Lock., Conclusions: The ball carriers' inertial head kinematics but not the tacklers were increased when the tackler adhered to this study's variants of the over and under the ball tackle instructions, suggesting that the tacklers were more effective in their tackle performance than the traditional tackle instructions when adhering to the tackle instruction. Greater adherence to the under the ball instructions suggests that the over the ball instruction is a more challenging technique to learn., Competing Interests: Declaration of interest statement Suzi Edwards declares that they have no conflict of interest. Andrew Gardner, Ph.D. has a clinical practice in neuropsychology involving individuals who have sustained sport-related concussion (including current and former athletes). He has been a contracted concussion consultant to Rugby Australia (2016–). He has received travel funding or been reimbursed by professional sporting bodies, and commercial organisations for discussing or presenting sport-related concussion research at meetings, scientific conferences, workshops, and symposiums. He has received research funding from the National Rugby League (NRL) for the Retired Players Brain Health research programme. Previous grant funding includes the NSW Sporting Injuries Committee, the Brain Foundation (Australia), an Australian–American Fulbright Commission Postdoctoral Award, a Hunter New England Local Health District, Research, Innovation and Partnerships Health Research & Translation Centre and Clinical Research Fellowship Scheme, and the Hunter Medical Research Institute (HMRI), supported by Jennie Thomas, and the HMRI, supported by Anne Greaves. He has served as a scientific advisor for hitIQ Ltd. Ross Tucker is a research consultant to World Rugby (Pty) Ltd, the governing body for Rugby Union globally. Ken Quarrie is employed as the senior sport scientist for New Zealand Rugby. Grant Iverson serves as a scientific advisor for NanoDx™ (formerly BioDirection, Inc.), Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including athletes). He has received research funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc.). He has received research funding as a principal investigator from the National Football League, and salary support as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. Gary Strangman has received pilot research funding from the Harvard Football Player's Health Study, funded through the National Football League Players Association., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by attention problems, excessive activity, and impulsivity - occurring in approximately 13% of children 12-17 years of age, and as many as 16% of older adolescents 18-22 years of age, with a greater prevalence in boys than girls. ADHD frequently co-occurs with specific learning disorder (LD), a neurodevelopmental disorder characterized by difficulties learning and using academic skills, such as reading, writing, and mathematics. Taken together, ADHD and/or LD are common among high school students and college students and can influence performance on computerized tests used in concussion management. However, normative data for widely used computer-based measures used in concussion management do not include reference samples with ADHD and/or LD. Previous research has documented the expected frequency of obtaining low scores on computer-based neuropsychological test measures among healthy, uninjured individuals, but few studies have examined the frequency of obtaining low scores in athletes with neurodevelopmental diagnoses, such as ADHD and/or LD. This study examined the frequency of low scores (i.e., multivariate base rates) on the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) for youth and young adults with self-reported ADHD and/or LD., Methods: The sample included 174,878 adolescent and young adult student-athletes who completed pre-season baseline neurocognitive assessments, who were assigned to the following independent groups: ADHD only ( n  = 45,215), LD only ( n  = 54,223), ADHD and LD ( n  = 45,737), No ADHD or LD ( n  = 47,684; "control athletes")., Results: Base rates of low scores were stratified by high school (e.g., 13-18) and collegiate age (e.g., 19-22) and sex. It was common for student athletes (all ages) with LD alone (i.e., 30-37%), or with both ADHD and LD (i.e., 24-31%), to obtain at least two low ImPACT composite scores, but not three low composite scores. However, it was relatively uncommon for control athletes (those without ADHD or LD) (i.e., 12-14%) or older athletes (ages 19-22) with ADHD (i.e., 14-15%) to obtain two (or more) low scores., Discussion: Having information relating to the base rates of low scores among uninjured athletes enhances the interpretation of ImPACT results among the broader population of student-athletes with and without neurodevelopmental disorders., Competing Interests: Philip Schatz, Ph.D. has previously served as a scientific advisor and consultant to ImPACT Applications, Inc. However, ImPACT Applications, Inc. was not involved in the study design, analysis, interpretation, the writing of this article, or the decision to submit it for publication. Nathan Cook, Ph.D. has a clinical and consulting practice in forensic neuropsychology involving individuals who have sustained mild TBIs. Grant Iverson, Ph.D. served as a scientific advisor for NanoDX®, Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including former athletes). He has received past research support or funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc.). He received royalties from the sales of one neuropsychological test (WCST-64). He has received research funding as a principal investigator from the National Football League, and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Schatz, Cuzzupe, Karr, Cook and Iverson.)

Objective: Prior studies have reported associations between childhood physical abuse and intimate partner violence (IPV). However, there has been limited literature examining the relationship between pediatric brain injuries and IPV-related brain injuries later in life. We examined the association between childhood brain injuries and brain injuries sustained from IPV in adulthood., Setting: Participants were recruited through Mass General Brigham's "Rally," social media, and information sheets distributed in locations likely to serve women in current or past abusive relationships (eg, domestic violence shelters, and IPV support programs)., Participants: Women who have experienced IPV with and without brain injury (n = 129), ages 19 to 69., Design: Retrospective, cross-sectional study design., Main Measures: We administered the Ohio State University Traumatic Brain Injury Identification Method and the Brain Injury Severity Assessment to assess brain injury history, and the Childhood Trauma Questionnaire (CTQ). A logistic regression was used to examine the association between pediatric brain injuries and IPV-related brain injuries, adjusting for childhood trauma, years of education, and age., Results: A majority of participants (64.3%) reported experiencing at least 1 IPV-related brain injury, and 30.2% experienced at least 1 childhood brain injury. Child abuse-related brain injuries occurred in 10.9% of the sample, whereas childhood brain injuries from other causes occurred in 19.4% of participants. Participants who sustained at least 1 childhood BI were significantly more likely to sustain a future IPV-related brain injury as an adult (OR = 4.652, P = .004). For each additional childhood BI sustained, participants were more likely to sustain an IPV-related BI (OR = 3.198, P = .005)., Conclusion: This study illustrates a high prevalence of childhood brain injuries among women who have experienced IPV and identifies an association between pediatric brain injuries and brain injuries due to partner violence in adulthood. Our findings speak to the urgency of increasing our understanding of childhood brain injuries and whether they or other related factors might confer an increased risk for brain injuries or possibly IPV later in life., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: To assess all-cause mortality and suicides after pediatric traumatic brain injury (pTBI)., Study Design: We conducted population-based historical cohort study using three nationwide registers from 1998 to 2018 in Finland. All patients that were the age of 0-17 at the time of the pTBI were included. The reference group consisted of children with ankle or wrist fractures. We used Kaplan-Meier and restricted mean survival time (RMST) analysis with 95% confidence intervals (CI) to compare all-cause mortality and suicides between groups., Results: After 20 years of follow-up, there were 479 deaths in the pTBI group (0.67% of 71,963) and 306 deaths in the reference group (0.47% of 64,848). In the pTBI group, 28.6% of the deaths occurred after the first follow-up year, compared to 2.6% in the reference group. In all-cause mortality, survival time was slightly less in the pTBI group with age and gender adjustment throughout the follow-up period [20-year RMST ratio: 0.995; CI (0.994-0.996)]. The leading manners of death were suicides (pTBI group = 28.4%; reference group = 45.5%) and traffic collisions (pTBI group = 37.4%; reference group = 20.8%). Age and gender-adjusted survival time was slightly less for those with suicide as a manner of death in the pTBI group [10-year RMST ratio: 0.999; CI (0.999-0.999); 20-year RMST ratio: 0.999; CI (0.998-0.999)]., Conclusions: Children and adolescents who sustained a TBI have slightly lower long-term survival time for all-cause mortality, most of which occurs during the first year following injury. There is no clinically meaningful difference in deaths by suicide between the two injury groups., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: The aim of this study was to assess whether a history of prior concussions, and especially multiple prior concussions, is associated with clinical recovery following a subsequent sport-related concussion among collegiate student athletes., Design: A naturalistic observational cohort study., Setting: Eleven National Collegiate Athletics Association Division III colleges., Participants: Collegiate athletes sustaining concussions from September 2014 through March 2020., Independent Variables: Participants were divided into 3 groups, athletes with: (1) no prior concussion history, (2) one prior concussion, and (3) 2 or more prior concussions., Main Outcome Measures: Survival analyses were used to compare time to return to school and sports among athletes with a history of 0, 1, or ≥2 prior concussions., Results: Among the 1132 college athletes, there were no statistically significant group differences between those with 0, 1, or ≥2 prior concussions in total time to return to school or sports. There was a statistically significant difference in the proportion of athletes with ≥2 prior concussions that had not fully returned to school, without accommodations, at 28 days (6.0%) compared to athletes with no prior concussions (2.2%; odds ratio = 2.80, 95% confidence interval 1.29-6.04)., Conclusions: In summary, concussion history was not associated with time to return to sports following a subsequent sport-related concussion in these college athletes. On average, athletes with prior concussions did not take longer to return to school, although a slightly greater proportion of college athletes with ≥2 prior concussions had not fully returned to school, without accommodations, by 28 days following injury., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: Career duration is often used as a metric of neurotrauma exposure in studies of elite athletes. However, as a proxy metric, career length may not accurately represent causal factors, and associations with health outcomes may be susceptible to selection effects. To date, relationships between professional American-style football (ASF) career length and postcareer health remain incompletely characterised., Methods: We conducted a survey-based cross-sectional cohort study of former professional ASF players. Flexible regression methods measured associations between self-reported career duration and four self-reported health conditions: pain, arthritis, mood and cognitive symptoms. We also measured associations between career duration and four self-reported ASF exposures: prior concussion signs and symptoms (CSS), performance enhancing drugs, intracareer surgeries and average snaps per game. Models were adjusted for age and race., Results: Among 4189 former players (52±14 years of age, 39% black, 34% lineman position), the average career length was 6.7±3.9 professional seasons (range=1-20+). We observed inverted U-shaped relationships between career duration and outcomes (all p<0.001), indicating that adverse health effects were more common among men with intermediate career durations than those with shorter or longer careers. Similar findings were observed for play-related exposures (eg, CSS and snaps)., Conclusions: Relationships between ASF career duration and subsequent health status are non-linear. Attenuation of the associations among longer career players may reflect selection effects and suggest career length may serve as a poor proxy for true causal factors. Findings highlight the need for cautious use of career duration as a proxy exposure metric in studies of former athletes., Competing Interests: Competing interests: ALB has received funding from the National Institute of Health/National Heart, Lung and Blood Institute, the National Football Players Association and the American Heart Association and receives compensation for his role as team cardiologist from the US Olympic Committee/US Olympic Training Centers, US Soccer, US Rowing, the New England Patriots, the Boston Bruins, the New England Revolution and Harvard University. GLI has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including former athletes). He has received past research support or funding from several test publishing companies, including ImPACT Applications, CNS Vital Signs and Psychological Assessment Resources (PAR). He receives royalties from the sales of one neuropsychological test (WCST-64). He has received research funding as a principal investigator from the National Football League, and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. He has received research funding from the Wounded Warrior Project. He acknowledges unrestricted philanthropic support from ImPACT Applications, the Mooney-Reed Charitable Foundation, the National Rugby League, Boston Bolts and the Schoen Adams Research Institute at Spaulding Rehabilitation. RDZ reported receiving royalties from Springer/Demos publishing for serving as coeditor of the text Brain Injury Medicine; serving on the scientific advisory board of Myomo, and onecare.ai; evaluating patients in the Massachusetts General Hospital Brain and Body–TRUST Programme, which is funded by the NFL Players Association and receiving grants from the NIH. MGW reported receiving grants from the NFL Players Association and the NIH during the conduct of the study. DPT serves on the Scientific Advisory Board for HitIQ and previously consulted for REACT Neuro. JDT serves as CEO of Mastery Development, Chief Health Innovation and Performance officer NESTRE Health and Performance, as Vice President of the Society for Sports Neuroscience, RG, HD, AJW and DM received grant funding from the NFL Players Association. No other disclosures were reported., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Concussions in contact sports are challenging for athletes, health professionals and sporting bodies to prevent, detect and manage. Design of interventions for primary prevention, early recognition of concussion and continuing to improve postconcussion management are essential for protecting athletes and promoting brain health. Over the last decade, there have been advancements in video technology for analysing head impact events and improvements in the clinical management of concussions. This study protocol describes how researchers, clinicians and staff from the Australasian National Rugby League (NRL) have brought these advancements together and developed a database of videos with head impact events and clinical outcomes. The intended outputs from this work will enhance the understanding of head impact events in NRL, from biomechanical and gameplay factors to concussion and return to play outcomes. Publishing this protocol increases the transparency of this large-scale effort to better identify head impacts and their relationship to concussions and player movement behaviour to contextualise these variables to generate new knowledge and support the reproducibility of these emerging findings. Between 2017 and 2023, over 5250 head contact cases were recorded in the database, from which >1700 head injury assessments were performed, and >600 concussions were diagnosed. Future studies using these data are planned to inform both primary and secondary injury prevention initiatives, such as risk analysis and prediction of game scenarios that result in concussion, as well as investigation of features and factors that help to inform the duration of recovery and return to play., Competing Interests: AG has a clinical practice in neuropsychology involving individuals who have sustained sport-related concussion (including current and former athletes). He has been a contracted concussion consultant to Rugby Australia. He is a member of the World Rugby Concussion Working Group, and a member of the Australian Football League Concussion Scientific Advisory Committee. He has received travel funding or been reimbursed by professional sporting bodies, and commercial organisations for discussing or presenting sport-related concussion research at meetings, scientific conferences, workshops and symposiums. Previous grant funding includes the NSW Sporting Injuries Committee, the Brain Foundation (Australia), an Australian-American Fulbright Commission Postdoctoral Award, a Hunter New England Local Health District, Research, Innovation and Partnerships Health Research & Translation Centre and Clinical Research Fellowship Scheme and the Hunter Medical Research Institute (HMRI), supported by Jennie Thomas, and the HMRI, supported by Anne Greaves. He is supported by a National Health and Medical Research Council (NHMRC) Investigator Grant. He acknowledges unrestricted philanthropic support from the Tooth Foundation, and the National Rugby League (NRL) for research in retired professional rugby league players. GI has been reimbursed by the government, professional scientific bodies and commercial organisations for discussing or presenting research related to mild traumatic brain injury and sport-related concussion at meetings, scientific conferences and symposiums. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including athletes). He has received research funding from several test publishing companies, including ImPACT Applications, CNS Vital Signs and Psychological Assessment Resources (PAR). He has received research funding from the National Football League. He has also received research funding from the Harvard Integrated Programme to Protect and Improve the Health of National Football League Players Association Members. He acknowledges unrestricted philanthropic support from ImPACT Applications, the Mooney-Reed Charitable Foundation, NRL, Boston Bolts, Heinz Family Foundation and Schoen Adams Research Institute at Spaulding Rehabilitation. PB was the past NRL chief medical officer (2015–2021) and initiated and developed the NRL injury surveillance bunker and NRL concussion rules. He is a past club medical officer (2000–2013) and current club medical officer with the Manly Sea Eagles NRL club. He also provides medical consultancy support to the Rugby League Players Association. SF is the NRL chief medical officer. JB has received research funding from World Rugby, the international governing body of rugby union. In addition, JB has received salary contributions and the coverage of travel costs from World Rugby. SE is an accredited sport scientist (ASpS2) and leads a tackle re-education programme that is partially funded by a NHMRC Ideas 2021 grant (202718). GF has previously received funding from World Rugby to attend research meetings and was a previous member of the Concussion in Sport expert panel. MG has received a Sports and Wellbeing Analytics/Cellbond Impact Solutions/Royal Academy of Engineering Senior Research Fellowship. PJ has no disclosures/conflicts of interest. BJ has secured research funding from World Rugby, Rugby Football Union, Scottish Rugby, Premiership Rugby, Rugby Football League, Catapult Sports, Prevent Biometrics, HitIQ, Leeds Rhinos Rugby League, Yorkshire Carnegie Rugby Union, Bath Rugby, Wasps Rugby. BJ is employed in a consultancy capacity by the Rugby Football League, and Premiership Rugby as their research lead. CRL serves as an honorary consultant neurologist to the NRL, providing a pro bono second opinion to current players regarding concussion assessment and management for the player’s club doctor. WMcD is Rugby Australia’s chief medical officer. SMcL has no disclosures/conflicts of interest. CO has a research fellowship that is part-funded by the Rugby Football League. GP has no disclosures/conflicts of interest. KLQ has been employed by New Zealand Rugby since 2000 and currently occupies the role of Chief Scientist, New Zealand Rugby. He was a member of World Rugby’s Scientific Committee from 2013 to 2024 and has contributed to various World Rugby working groups focussed on player welfare issues from 2011 to the time of publication. He has received funding for travel and accommodation to attend World Rugby’s medical meetings. OS and PS have no disclosures/conflicts of interest. DT has a PhD research programme that is part-funded by Leeds Rhinos rugby club. He also works as a medical doctor for multiple sports teams in the UK. TT is employed as the Senior Manager for Indigenous elite pathways at the NRL. He is also employed as a researcher by the University of Sydney through a 2021 NHMRC Ideas grant. DPT serves as a scientific advisor for HitIQ. He previously consulted for REACT Neuro. He has a consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including former athletes). He receives funding from Amgen and Football Research. CT has no disclosures/conflicts of interest. RT is a consultant to World Rugby. World Rugby is the governing body for the sport of Rugby Union and responsible for law changes in the sport. LVF is supported through research grant funding at Edith Cowan University. She has previously received project funding from several sports, health and government agencies including: Australian Football League; Australian Institute of Health and Welfare; Australian Institute of Sport; Combat Sport Commission Western Australia; Cricket Australia; Defence Science WA; Exercise & Sports Science Australia; Injury Matters; IOC; KidSafe WA; Rugby Australia; State Government of Victoria; VicSport., (Copyright © Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Prior studies examining small samples of symptomatic former professional football players suggest that earlier age of first exposure (AFE) to American football is associated with adverse later life health outcomes. This study examined a larger, more representative sample of former professional American football players to assess associations between AFE before age 12 (AFE < 12) and clinical outcomes compared with those who started at age 12 or older (AFE 12 +)., Methods: Former professional American football players who completed a questionnaire were dichotomized into AFE < 12 and AFE 12 + . AFE groups were compared on outcomes including symptoms of depression and anxiety, perceived cognitive difficulties, neurobehavioral dysregulation, and self-reported health conditions (e.g., headaches, sleep apnea, hypertension, chronic pain, memory loss, dementia/Alzheimer's disease, and others)., Results: Among 4189 former professional football players (aged 52 ± 14 years, 39% self-reported as Black), univariable associations with negligible effect sizes were seen with AFE < 12, depressive symptoms (p = 0.03; η 2  = 0.001), and anxiety-related symptoms (p = 0.02; η 2  = 0.001) only. Multivariable models adjusting for age, race, body mass index, playing position, number of professional seasons, and past concussion burden revealed no significant relationships between AFE < 12 and any outcome. Linear and non-linear models examining AFE as a continuous variable showed similar null results., Conclusions: In a large cohort of former professional American-style football players, AFE was not independently associated with adverse later life outcomes. These findings are inconsistent with smaller studies of former professional football players. Studies examining AFE in professional football players may have limited utility and generalizability regarding policy implications for youth sports., (© 2024. The Author(s).)

This review was designed to (1) determine the extent to which the clinical science on sport-related concussion treatment and rehabilitation has considered social determinants of health (SDoH) or health equity and (2) offer recommendations to enhance the incorporation of SDoH and health equity in concussion treatment research and clinical care. The Concussion in Sport Group consensus statement (2023) was informed by two systematic reviews examining prescribed rest or exercise following concussion and targeted interventions to facilitate concussion recovery. We examined 31 studies, including 2,698 participants, from those two reviews. Race ( k = 6; 19.4%) and ethnicity ( k = 4; 12.9%) of the study samples were usually not reported. Four studies examined ethnicity (i.e., Hispanic), exclusively as a demographic category. Five studies (16.1%) examined race as a demographic category. Three studies (9.7%) examined socioeconomic status (SES; measured as household income) as a demographic category/sample descriptor and one study (3.2%) examined SES in-depth, by testing whether the treatment and control groups differed by SES. Five studies examined an SDoH domain in a descriptive manner and four studies in an inferential/intentional manner. No study mentioned SDoH, health equity, or disparities by name. Many studies (61.3%) excluded participants based on demographic, sociocultural, or health factors, primarily due to language proficiency. The new consensus statement includes recommendations for concussion treatment and rehabilitation that rely on an evidence base that has not included SDoH or studies addressing health equity. Researchers are encouraged to design treatment and rehabilitation studies that focus specifically on underrepresented groups to determine if they have specific and unique treatment and rehabilitation needs, whether certain practical modifications to treatment protocols might be necessary, and whether completion rates and treatment adherence and response are similar.

Fear avoidance behaviour is associated with slow recovery from mild traumatic brain injury (mTBI). This study is a preliminary evaluation of graded exposure therapy (GET), which directly targets fear avoidance behaviour, for reducing post-concussion symptoms (PCS) and disability following mTBI. In a historical comparison design, we compared two groups from independent randomized trials. The GET + UC group (N = 34) received GET (delivered over 16 videoconference sessions) in addition to usual care (UC). The historical comparison group (N = 71) received UC only. PCS severity (Rivermead Post Concussion Symptoms Questionnaire; RPQ) and disability (World Health Organization Disability Assessment Schedule; WHODAS 2.0 12-item) were measured at clinic intake (M = 2.7, SD = 1.1 months after injury) and again at M = 4.9 (SD = 1.1) months after injury. Between-group differences were estimated using linear mixed effects regression, with a sensitivity analysis controlling for injury-to-assessment intervals. The estimated average change on the RPQ was -14.3 in the GET + UC group and -5.3 in the UC group. The estimated average change on the WHODAS was -5.3 in the GET + UC group and -3.2 in the UC group. Between-group differences post-treatment were -5.3 on the RPQ and -1.5 on the WHODAS. Treatment effects were larger in sensitivity analyses. Findings suggest that a randomized controlled trial is warranted.

Importance: Participation in American-style football (ASF) has been linked to chronic traumatic encephalopathy neuropathological change (CTE-NC), a specific neuropathologic finding that can only be established at autopsy. Despite being a postmortem diagnosis, living former ASF players may perceive themselves to have CTE-NC. At present, the proportion and clinical correlates of living former professional ASF athletes with perceived CTE who report suicidality are unknown., Objective: To determine the proportion, clinical correlates, and suicidality of living former professional ASF players with perceived CTE., Design, Setting, and Participants: A cross-sectional study within the Football Players Health Study at Harvard University was conducted from 2017 to 2020. Using electronic and paper surveys, this population-based study included former ASF players who contracted with a professional league from 1960 to 2020 and volunteered to fill out a baseline survey. Data for this study were analyzed from June 2023 through March 2024., Exposures: Data included demographics, football-related exposures (eg, position, career duration), and current health problems (anxiety, attention-deficit/hyperactivity disorder, depression, diabetes, emotional and behavioral dyscontrol symptoms, headache, hyperlipidemia, hypertension, low testosterone level, pain, sleep apnea, and subjective cognitive function)., Main Outcomes and Measures: The proportion of participants reporting perceived CTE. Univariable and multivariable models were used to determine clinical and suicidality correlates of perceived CTE., Results: Among 4180 former professional ASF players who volunteered to fill out a baseline survey, 1980 (47.4%) provided follow-up data (mean [SD] age, 57.7 [13.9] years). A total of 681 participants (34.4%) reported perceived CTE. Subjective cognitive difficulties, low testosterone level, headache, concussion signs and symptoms accrued during playing years, depressive/emotional and behavioral dyscontrol symptoms, pain, and younger age were significantly associated with perceived CTE. Suicidality was reported by 171 of 681 participants with perceived CTE (25.4%) and 64 of 1299 without perceived CTE (5.0%). After adjusting for established suicidality predictors (eg, depression), men with perceived CTE remained twice as likely to report suicidality (odds ratio, 2.06; 95% CI, 1.36-3.12; P < .001)., Conclusions and Relevance: This study found that approximately one-third of living former professional ASF players reported perceived CTE. Men with perceived CTE had an increased prevalence of suicidality and were more likely to have health problems associated with cognitive impairment compared with men without perceived CTE. Perceived CTE represents a novel risk factor for suicidality and, if present, should motivate the diagnostic assessment and treatment of medical and behavioral conditions that may be misattributed to CTE-NC.

Objective: To examine whether a personal history of migraines is associated with worse acute symptom burden after sport-related concussion (SRC)., Design: Retrospective cohort study., Setting: National Collegiate Athletic Association Division III collegiate programs., Participants: Collegiate athletes from a prospective concussion surveillance system between 09, 2014, and 01, 2023., Intervention: Preinjury migraines (yes/no) were self-reported by athletes., Main Outcome Measures: Post-Concussion Symptom Scale (PCSS) were collected within 3 days postinjury. Mann-Whitney U tests compared total PCSS scores and individual symptom scores between athletes with and without preinjury migraines. Chi-squared tests were used to compare proportions of athletes endorsing individual symptoms (ie, item score ≥1) between 2 groups. Multivariable regression analyzed potential predictors of PCSS scores., Results: Of 1190 athletes with SRC, 93 (7.8%) reported a preinjury history of migraines. No significant difference in total PCSS scores was found between athletes with and without preinjury migraines (22.0 ± 16.4 vs 20.5 ± 15.8, U = 48 719.0, P = 0.471). Athletes with preinjury migraines reported greater severity of "sensitivity to light" (1.59 ± 1.59 vs 1.23 ± 1.41, P = 0.040) and "feeling more emotional" (0.91 ± 1.27 vs 0.70 ± 1.30; P = 0.008) and were more likely to endorse "feeling more emotional" (45.2% vs 29.5%, P = 0.002). No differences were found across all other symptoms, including headaches (migraine = 87.1% vs no migraine = 86.3%, P = 0.835). In a multivariable model, a history of migraine was not a significant predictor of acute PCSS scores, but those with a history of psychological disorders (β = 0.12, P <0 .001) and greater number of days to symptom evaluation (β = 0.08, P = 0.005) had higher PCSS scores., Conclusions: Collegiate athletes with a pre-existing history of migraines did not have higher acute symptom burden after SRC., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Researchers and practitioners can detect cognitive improvement or decline within a single examinee by applying a reliable change methodology. This study examined reliable change through test-retest data from the English-language National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) normative sample., Method: Participants included adults (n = 138; age: M ± SD = 54.8 ± 20.0, range: 18-85; 51.4% men; 68.1% White) who completed test-retest assessments about a week apart on five fluid cognition tests, providing raw scores, age-adjusted standard scores (SS), and demographic-adjusted T-scores (T)., Results: The Fluid Cognition Composite (SS: ICC = 0.87; T-score: ICC = 0.84) and the five fluid cognition tests had good test-retest reliability (SS: ICC range = 0.66-0.85; T-score: ICC range = 0.64-0.86). The lower and upper bounds of 70%, 80%, and 90% confidence intervals (CIs) were calculated around change scores, which serve as cutoffs for determining reliable change. Using T-scores, 90% CI, and adjustment for practice effects, 32.3% declined on one or more tests, 9.7% declined on two or more tests, 36.6% improved on one or more tests, and 5.4% improved on two or more tests., Conclusions: It was common for participants to show reliable change on at least one test score, but not two or more test scores. Per an 80% CI, test-retest difference scores beyond these cutoffs would indicate reliable change: Dimensional Change Card Sort (SS ≥ 14/T ≥ 10), Flanker (SS ≥ 12/T ≥ 8), List Sorting (SS ≥ 14/T ≥ 10), Picture Sequence Memory (SS ≥ 19/T ≥ 13), Pattern Comparison (SS ≥ 11/T ≥ 8), and Fluid Cognition Composite (SS ≥ 10/T ≥ 7). The reliable change cutoffs could be applied in research or practice to detect within-person change in fluid cognition at the individual level., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Pre-injury migraines might be a risk factor for prolonged recovery after sport-related concussion (SRC). We sought to examine whether a pre-injury history of migraines is associated with worse recovery following SRC in collegiate athletes. Data were collected through a prospective concussion surveillance system in 11 National Collegiate Athletic Association (NCAA) Division III college athletic programs between September 2014 and March 2020. Our primary independent variable, pre-injury migraines, were self-reported by the athletes. Between those with and without migraines, the outcomes of days to return-to-learn (RTL) without academic accommodations and return-to-play (RTP) were compared using Mann-Whitney U tests. Each athlete's RTL and RTP status was dichotomized (i.e., returned vs. not returned) at various time points for RTL (i.e., 7/14/21/28 days) and RTP (i.e., 14/21/28/56 days). Chi-squared tests were performed to compare the proportions of RTL and RTP status between groups. Multivariable regressions analyzed potential predictors of RTL and RTP adjusting for age, gender, prior concussions, other health conditions, and symptom severity. Of 1409 athletes with an SRC, 111 (7.9%) had a pre-injury history of migraines. Compared with those without migraines, those with migraines had longer median (interquartile range [IQR]) days to RTL (migraines = 7.0 [3.0-12.3] vs. no migraines = 5.0 [2.0-10.0], U  = 53,590.5, p  = 0.022). No differences were found in RTP between the two groups (migraines = 16.0 [10.0-33.0] vs. nχo migraines 15.0 [11.0-23.0], U  = 38,545.0, p  = 0.408). Regarding RTL, significantly lower proportions of athletes in the migraine group had fully RTL, without accommodations, at ≤14 days (77.5% vs. 85.2%, χ 2  = 4.33, p  = 0.037), ≤21 days (85.3% vs. 93.0%, χ 2  = 7.99, p  = 0.005), and ≤28 days (88.2% vs. 95.6%, χ 2  = 10.60, p  = 0.001). Regarding RTP, a significantly lower proportion of athletes in the migraine group RTP at ≤28 days (72.0% vs. 82.7%, χ 2  = 5.40, p  = 0.020) and ≤56 days (84.0% vs. 93.0%, χ 2  = 8.19, p  = 0.004). In a multivariable model predicting RTL that was adjusted for age, gender, acute concussion symptoms, and other health variables (e.g., attention-deficit/hyperactivity disorder [ADHD], history of mental health difficulties), pre-injury history of migraine was associated with longer RTL (β = 0.06, p  = 0.030). In a multivariable model predicting RTP, pre-injury history of migraine was not associated with RTP (β = 0.04, p  = 0.192). In collegiate athletes, pre-injury migraine history was independently associated with longer RTL but not RTP. When comparing the proportions of those with successful RTP by days, significantly lower proportions of those with migraines showed successful RTP at ≤28 days and ≤56 days. Futures studies should study the generalizability of our findings in other school levels.

Objective: The United States Centers for Disease Control and Prevention (CDC) conducted the Adolescent Behavior and Experiences Survey (ABES) to examine disruption and adversity during the COVID-19 pandemic. We examined the association between social determinants of health (SDoH) and cognitive problems attributed to physical or mental health problems among high school students., Method: The ABES was an online survey. Perceived cognitive problems were assessed with the question: "Because of a physical, mental, or emotional problem, do you have serious difficulty concentrating, remembering, or making decisions?" A SDoH index was created by summing endorsements to 12 variables., Results: Participants were 6,992 students, age 14-18, with 3,294 boys (47%) and 3,698 girls (53%). Many adolescents reported experiencing cognitive problems (i.e., 45%), with girls (56%) more likely to report cognitive difficulties than boys (33%) [χ2(1) = 392.55, p < 0.001]. Having poor mental health was strongly associated with cognitive problems in both girls [81%, χ2(1, 3680) = 650.20, p < 0.001] and boys [67%, χ2(1, 3267) = 418.69, p < 0.001]. There was a positive, linear association between the number of SDoH experienced and reporting cognitive problems. Binary logistic regressions were used to identify predictors of cognitive difficulty for both boys and girls (e.g., being bullied electronically, experiencing food insecurity during the pandemic, being treated unfairly because of their race or ethnicity, and being in a physical fight)., Conclusions: A strikingly high proportion of adolescents reported experiencing problems with their cognitive functioning. After adjusting for current mental health problems, several SDoH remained associated with adolescents' reported cognitive difficulties, including experiencing racism, bullying, parental job loss, and food insecurity., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: Prior studies have investigated associations between gender, symptom resolution, and time to return to play following sport-related concussion (SRC). However, there is a notable gap in research regarding the association between gender and return to learn (RTL) in adolescents. Therefore, this study 1) compared the patterns of RTL between boys and girls who are high school student athletes, and 2) evaluated the possible association between gender and time to RTL after adjusting for covariates., Methods: A retrospective cohort study of a prospective surveillance program that monitored concussion recovery of athletes in high schools throughout the state of Maine between February 2015 and January 2023 was performed. The primary independent variable was gender, dichotomized as boys and girls. The primary outcome was time to RTL, defined by the number of days for an athlete to return to school without accommodations. Mann-Whitney U-tests were used to compare RTL between the boys and girls. Each athlete's RTL status was dichotomized (i.e., returned vs had not returned) at several time points following injury (i.e., 1, 2, 3, and 4 weeks), and chi-square tests were performed to compare the proportions who achieved RTL between groups. Multivariable linear regression analyses were performed to evaluate the predictive value of gender on RTL. Covariates included age, number of previous concussions, history of learning disability or attention-deficit disorder or attention-deficit/hyperactivity disorder, history of a psychological condition, history of headaches or migraines, initial Sport Concussion Assessment Tool (SCAT3/SCAT5) score, and days to evaluation., Results: Of 895 high school athletes, 488 (54.5%) were boys and 407 (45.5%) were girls. There was no statistically significant difference in median [IQR] days to RTL between genders (6.0 [3.0-11.0] vs 6.0 [3.0-12.0] days; U = 84,365.00, p < 0.375). A greater proportion of boys successfully returned to learn without accommodations by 3 weeks following concussion (93.5% vs 89.4%; χ2 = 4.68, p = 0.030), but no differences were found at 1, 2, or 4 weeks. A multivariable model predicting days to RTL showed that gender was not a significant predictor of RTL (p > 0.05). Longer days to evaluation (β = 0.10, p = 0.021) and higher initial SCAT3/SCAT5 scores (β = 0.15, p < 0.001) predicted longer RTL., Conclusions: In a cohort of high school athletes, RTL did not differ between boys and girls following SRC. Gender was not a significant predictor of RTL. Longer days to evaluation and higher initial symptom scores were associated with longer RTL.

Objective: Valid performance on preseason baseline neurocognitive testing is essential for accurate comparison between preseason and post-concussion test results. Immediate Post-Concussion and Cognitive Testing (ImPACT) is commonly used to measure baseline neurocognitive function in athletes. We examined the prevalence of invalid performance on ImPACT baseline testing and identified correlates of invalid performance. Method: The sample included 66,998 adolescents (ages 14-18, M  = 15.51 years, SD = 1.22) who completed ImPACT baseline tests between 2009 and 2019. Invalid performance was determined by the embedded validity indicators (EVI). Associations between invalid performance, demographic characteristics, and health conditions were assessed using chi-square tests and odds ratios (ORs). Results: Overall, 7.2% of adolescents had baseline tests identified as invalid by one or more of the EVIs. Individual validity indicators classified between 0.5% and 3.7% tests as invalid. Higher frequencies of invalid scores were observed among youth with neurodevelopmental, academic, and medical conditions. Youth who reported having learning disabilities ( n  = 3126), receiving special education ( n  = 3563), or problems with attention-deficit/hyperactivity disorder (ADHD; n  = 5104) obtained invalid baselines at frequencies of 16.4%, 16.0%, and 11.1%, respectively. Moreover, youth who reported receiving treatment for a substance use disorder ( n  = 311) or epilepsy ( n  = 718) obtained invalid baselines at frequencies of 17.0% and 11.1%, respectively. Conclusions: The base rate of invalid performance on ImPACT's EVIs was approximately 7%, consistent with prior research. Adolescents self-reporting neurodevelopmental conditions, academic difficulties, or a history of treatment for medical conditions obtained invalid baseline tests at higher frequencies. More research is needed to better understand invalid scores in youth with pre-existing conditions.

Primary Objective: We evaluated whether photobiomodulation with red/near infrared light applied transcranially via light emitting diodes (LED) was associated with reduced symptoms and improved cognitive functioning in patients with chronic symptoms following mild traumatic brain injury., Research Design: Participants (3 men, 6 women; 22-61 years-old) underwent a 6-week intervention involving 18 40-minute transcranial LED treatment sessions., Methods and Procedures: Reliable change indices were calculated for 10 neuropsychological test scores and 3 self-report questionnaires of subjective cognition, post-concussion symptoms, and depression at baseline and following treatment. Questionnaires were also administered after 2-week sham and at 1-month and 2-month follow-ups., Main Outcome and Results: Only 2 participants improved on neuropsychological testing. On questionnaires, 4 reported improved cognition, 5 reported improved post-concussion symptoms, and 3 reported improved depression. Significant improvement in 2 or more domains was reported by 4 participants and mostly maintained at both follow-ups., Conclusions: Most participants did not improve on neuropsychological testing. A minority self-reported improvement in symptoms, potentially explained by the intervention, psychiatric medication changes, placebo effects, or other factors. Selecting participants with different clinical characteristics, and dosing and delivery system changes, may produce different results. A study design accounting for placebo effects appears warranted in future trials.

Objective: Our objective was to determine whether there is an association between adverse childhood experiences (ACEs) and lifetime history of early childhood mild head or neck injury and concussion in a nationally representative US cohort., Setting and Design: This is a cross-sectional study using data from the Adolescent Brain Cognitive Development (ABCD) Study (data release 3.0), a prospective investigation of child brain development and health., Participants: There were 11 878 children aged 9 or 10 years at baseline, recruited from 21 school-based sites in the United States. After excluding children with missing questionnaires for the primary exposure variable and children with severe brain injuries involving more than 30-minute loss of consciousness, the final sample size was 11 230 children., Measures: The primary exposure variable was ACEs. We measured eight ACEs: sexual abuse, physical abuse, emotional neglect, parent domestic violence, parent substance use disorder, parental mental illness, parent criminal involvement, and parent divorce. The primary outcomes were head or neck injury and concussion, measured using the Ohio State University Traumatic Brain Injury Screen-Identification Method Short Form., Results: The sample ( N = 11 230) was 52% boys with a mean age of 9.9 years (SD = 0.62 years). The racial and ethnic makeup was reflective of national demographics. Having a higher overall ACE count was associated with higher odds of head or neck injury, with greater odds with more ACEs reported. Children with 2 ACEs had 24% greater odds of head or neck injury (AOR = 1.24, 95% confidence interval [CI] = 1.06-1.45) and 64% greater odds of concussion (AOR = 1.64, 95% CI = 1.18-2.22), and children with 4 or more ACEs had 70% greater odds of head or neck injury (AOR = 1.7, 95% CI = 1.14, 2.49) and 140% greater odds of concussion (AOR = 2.4, 95% CI = 1.15-4.47). The individual ACE categories of sexual abuse, parent domestic violence, parental mental illness, and parent criminal involvement were significantly associated with increased risk of head or neck injury and parental mental illness with increased risk of concussion., Conclusions and Relevance: ACEs are associated with early childhood mild head or neck injury and concussion and should be integrated in head injury prevention and intervention efforts., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To investigate whether involvement in litigation and performance validity test (PVT) failure predict adherence to treatment and treatment outcomes in adults with persistent symptoms after mild traumatic brain injury (mTBI)., Setting: Outpatient concussion clinics in British Columbia, Canada. Participants were assessed at intake (average 12.9 weeks postinjury) and again following 3 to 4 months of rehabilitation., Participants: Adults who met the World Health Organization Neurotrauma Task Force definition of mTBI. Litigation status was known for 69 participants ( n = 21 reported litigation), and 62 participants completed a PVT ( n = 13 failed the Test of Memory Malingering) at clinic intake., Design: Secondary analysis of a clinical trial (ClinicalTrials.gov #NCT03972579)., Main Measures: Outcomes included number of completed sessions, homework adherence, symptoms (Rivermead Post Concussion Symptoms Questionnaire), disability ratings (World Health Organization Disability Assessment Schedule 2.0), and patient-rated global impression of change., Results: We did not observe substantial differences in session and homework adherence associated with litigation or PVT failure. Disability and postconcussion symptoms generally improved with treatment. Involvement in litigation was associated with a smaller improvement in outcomes, particularly disability ( B = 2.57, 95% confidence interval [CI] [0.25-4.89], P = .03) and patient-reported global impression of change (odds ratio [OR] = 4.19, 95% CI [1.40-12.57], P = .01). PVT failure was not associated with considerable differences in treatment outcomes. However, participants who failed the PVT had a higher rate of missing outcomes (31% vs 8%) and perceived somewhat less global improvement (OR = 3.47, 95% CI [0.86-14.04]; P = .08)., Conclusion: Adults with mTBI who are in litigation or who failed PVTs tend to adhere to and improve following treatment. However, involvement in litigation may be associated with attenuated improvements, and pretreatment PVT failure may predict lower engagement in the treatment process., Competing Interests: Grant L. Iverson, PhD, serves as a scientific advisor for NanoDX, Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs. He has received research funding from several test publishing companies, including ImPACT Applications, Inc, CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc). He has received research funding as a principal investigator from the National Football League, and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. He acknowledges unrestricted philanthropic support from the Mooney-Reed Charitable Foundation, ImPACT Applications, Inc, the Heinz Family Foundation, National Rugby League, and the Schoen Adams Research Institute at Spaulding Rehabilitation. None of the aforementioned entities were involved in the study design, analysis, interpretation, the writing of this article, or the decision to submit it for publication. Dr Silverberg reports grants from the Canadian Institutes of Health Research, Canadian Foundation for Innovation, VGH+UBC Hospital Foundation, and WorkSafeBC, and clinical consulting fees from the National Hockey League and Major League Soccer, and expert testimony fees. Other authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

This study applied a reliable change methodology to the test-retest data from the Spanish-language NIH Toolbox Cognition Battery (NIHTB-CB) normative sample. Participants included Spanish-speaking adults ( n  = 48; 54.2% women, 100% Latinx) evaluated twice within one to two weeks on the Spanish-language NIHTB-CB, consisting of two crystallized and five fluid cognitive tests. Test-retest means, standard deviations, and intraclass correlations were used to calculate upper and lower bounds of 70, 80, and 90% confidence intervals (CIs) around change scores, with these bounds used as cutoffs for inferring reliable change. Cutoffs were calculated for raw scores, age-adjusted standard scores (SS; M  = 100, SD  = 15), and demographic-adjusted T-scores (T; M  = 50, SD  = 10), adjusting for age, gender, and education. Test-retest change scores on the Spanish-language NIHTB-CB exceeding the following cutoffs indicate reliable change based on an 80% CI (i.e., values exceeding these cutoffs indicate greater decline or greater improvement than 90% of the sample): Dimensional Change Card Sort (SS ≥ 15/T ≥ 11), Flanker (SS ≥ 13/T ≥ 10), List Sorting (SS ≥ 13/T ≥ 9), Picture Sequence Memory (SS ≥ 14/T ≥ 9), Pattern Comparison (SS ≥ 14/T ≥ 10), Picture Vocabulary (SS ≥ 8/T ≥ 6), Oral Reading (SS ≥ 7/T ≥ 5), Fluid Cognition Composite (SS ≥ 12/T ≥ 9), Crystallized Cognition Composite (SS ≥ 6/T ≥ 5), and Total Cognition Composite (SS ≥ 8/T ≥ 7). These cutoffs are one of few resources to interpret cognitive change at retest among Spanish-speaking patients and participants.

Background: The rugby league tackle has been identified as the game event with the greatest propensity for a clinically diagnosed concussion. This study aims to replicate the work conducted in professional rugby league and rugby union by examining Head Injury Assessment (HIA) events to determine the associated tackle characteristics that increase concussion risk in sub-elite rugby league players. This comparison between competition levels is important due to the less developed physiological and tackle proficiency characteristics of sub-elite rugby league players and the fewer resources available for an on-field diagnosis, compared to the elite level of the sport., Results: Tackles resulting in Head Injury Assessments (HIAs, n = 131) and 2,088 tackles that did not result in a head injury were identified and coded from one season of the 2019 Queensland Cup. The body position of both ball carrier and tackler, tackle height, and body contact areas were evaluated. The propensity for tacklers to undergo a head injury assessment was 1.49 HIAs per 1,000 tackles, equating to a 2.5-fold higher risk than that of the ball carrier (0.59 HIAs per 1,000 tackles). The risk for an HIA was 2.75-fold greater when the tackler was upright (2.89 HIAs per 1,000 tackles) compared to a bent-at-the-waist tackler (1.05 HIAs per 1,000 tackles). The greatest risk for the tackler and ball carrier sustaining an HIA occurred when the tackle height was high, with head-to-head contact having the greatest propensity for an HIA (44.37 HIAs per 1,000 tackles). HIA risk was also greater for both players when the ball carrier did not employ an evasion strategy (3.73 HIAs per 1,000 tackles)., Conclusions: The study replicates results from research in elite rugby league and rugby union. A combination of higher head contact/proximity and upright body position significantly increase an HIA risk. Tackler head position and ball carrier evasion behaviours also affect risk, suggesting that injury prevention strategies designed to reduce tackle height and improve tackle technique by focusing on head position, body position, and in a novel finding, ball carrier evasion, may reduce head injury risk in sub-elite rugby league players., (© 2024. The Author(s).)

There are no validated diagnostic criteria for traumatic encephalopathy syndrome (TES). During the early and middle 20th century, TES was described as a clinical condition that was experienced by some high-exposure boxers-and it was believed to reflect chronic traumatic brain injury. Consensus criteria for the diagnosis of TES were published in 2021. We applied the consensus criteria for TES retrospectively to cases of chronic brain damage in boxers described in articles published in the 20th century that were obtained from narrative and systematic reviews. The sample included 157 boxers identified in 21 articles published between 1929 and 1999. Two authors reviewed each case description and coded the criteria for TES. For the core clinical features, cognitive impairment was noted in 63.1%, and in 28.7% of cases the person's cognitive functioning appeared to be broadly normal. Neurobehavioral dysregulation was present in 25.5%. One third (34.4%) were identified as progressive, 30.6% were not progressive, and the course could not be clearly determined in 35.0%. In total, 29.9% met the TES consensus criteria, 28.0% did not, and 42.0% had insufficient information to make a diagnostic determination. TES, in the 20th century, was described as a neurological condition, not a psychiatric disorder-and this supports the decision of the 2021 consensus group to remove primary and secondary psychiatric diagnoses from being a core diagnostic feature. Future research is needed to determine whether, or the extent to which, cognitive impairment or neurobehavioral dysregulation described as characterizing TES are associated with chronic traumatic encephalopathy neuropathological change., Competing Interests: Grant Iverson, PhD, serves as a scientific advisor for NanoDX®, Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving persons who have sustained mild TBIs (including former athletes), and on the topic of suicide. He has received past research support or funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc.). He receives royalties from the sales of one neuropsychological test (WCST-64). He has received travel support and honoraria for presentations at conferences and meetings. He has received research funding as a principal investigator from the National Football League and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. Rudolph J. Castellani, MD, is a collaborator on a grant funded by the National Football League to study the spectrum of concussion, including possible long-term effects. He has a consulting practice in forensic neuropathology, including expert testimony, which has involved former athletes at amateur and professional levels, and sport organizations. Andrew J. Gardner, PhD, serves as a scientific advisor for hitIQ, Ltd. He has a clinical practice in neuropsychology involving persons who have sustained sport-related concussion (including current and former athletes). He has been a contracted concussion consultant to Rugby Australia since July 2016. He has received travel funding or been reimbursed by professional sporting bodies and commercial organizations for discussing or presenting sport-related concussion research at meetings, scientific conferences, workshops, and symposia. Previous grant funding includes the NSW Sporting Injuries Committee, the Brain Foundation (Australia), an Australian-American Fulbright Commission Postdoctoral Award, a Hunter New England Local Health District, Research, Innovation and Partnerships Health Research & Translation Centre and Clinical Research Fellowship Scheme, and the Hunter Medical Research Institute (HMRI), supported by Jennie Thomas, and the HMRI, supported by Anne Greaves. A.J.G. is supported by a National Health and Medical Research Council (NHMRC) Investigator Grant. He acknowledges unrestricted philanthropic support from the National Rugby League for research in former professional rugby league players., (© Grant L. Iverson et al., 2024; Published by Mary Ann Liebert, Inc.)

In 2021, an expert panel of clinician-scientists published the first consensus research diagnostic criteria for traumatic encephalopathy syndrome (TES), a clinical condition thought to be associated with chronic traumatic encephalopathy neuropathological change. This study evaluated the TES criteria in older adults and assessed associations between TES criteria and a history of repetitive head impacts. This cross-sectional, survey-based study examined the symptoms of TES, previous repetitive head impacts, and a variety of current health difficulties. To meet symptom criteria for TES, participants had to report progressive changes with memory, executive functioning, and/or neurobehavioral dysregulation. To meet the criterion for substantial exposure to repetitive head impacts via contact sports, participants reported at least 5 years of contact sport exposure (with 2+ years in high school or beyond). A sample of 507 older adults (mean age = 70.0 years, 65% women) completed the survey and 26.2% endorsed having one or more of the progressive core clinical features of TES. Those who had a significant history of contact sport exposure were not significantly more likely to meet TES criteria compared with those who did not (31.3% vs. 25.3%, p  = 0.46). In a binary logistic regression predicting TES status, current depression or anxiety (odds ratio [OR] = 12.55; 95% confidence interval [CI] = 4.43-35.51), history of psychiatric disorders (OR = 2.07, 95% CI = 1.22-3.49), male sex (OR = 1.87), and sleep problems (OR = 1.71, 95% CI = 1.01-2.91) were associated with meeting TES criteria. The sport exposure criterion, age, and current pain were not significantly associated with TES status ( p s > 0.05). A significant minority of participants with no history of neurotrauma endorsed symptoms consistent with TES (22.0% of men and 19.8% of women). Nearly 80% of neurotrauma naïve participants with clinically significant anxiety/depression met criteria for TES. In summary, approximately one in four older adults met the symptom criteria for TES, many of whom had no history of repetitive neurotrauma. Mental health problems and sleep issues were associated with TES, whereas having a history of repetitive head impacts in contact sports was not. These data suggest that the new consensus diagnostic criteria for TES may have low specificity and may carry a higher risk of misdiagnosing those with other physical and mental health conditions as having TES.

Aims: We applied the 2021 consensus criteria for both chronic traumatic encephalopathy neuropathological change and traumatic encephalopathy syndrome in a small case series of six former elite-level Australian rugby code players., Methods: Neuropathological assessment of these cases was carried out at the Sydney and Victorian Brain Banks. Clinical data were collected via clinical interviews and health questionnaires completed by the participants and/or their next of kin, and neuropsychological testing was conducted with participants who were capable of completing this testing., Results: All cases exhibited progressive cognitive impairment during life. Chronic traumatic encephalopathy neuropathological change was identified in four out of the six cases. However, coexisting neuropathologies were common, with limbic-predominant age-related TDP-43 encephalopathy and ageing-related tau astrogliopathy seen in all cases, intermediate or high Alzheimer's disease neuropathological change seen in four cases and hippocampal sclerosis seen in two of the six cases., Conclusion: The presence of multiple neuropathologies in these cases complicates clinical diagnostic efforts for traumatic encephalopathy syndrome. It will be important for further clinicopathological studies on larger groups to report all neuropathological comorbidities found in cases diagnosed with either chronic traumatic encephalopathy neuropathological change and/or traumatic encephalopathy syndrome., (© 2024 The Authors. Neuropathology and Applied Neurobiology published by John Wiley & Sons Ltd on behalf of British Neuropathological Society.)

Purpose: The objective was to determine the incidence of surgically treated chronic subdural hematoma (cSDH) within six months after head trauma in a consecutive series of head injury patients with a normal initial computed tomography (CT)., Methods: A total of 1941 adult patients with head injuries who underwent head CT within 48 h after injury and were treated at the Tampere University Hospital's emergency department were retrospectively evaluated from medical records (median age = 59 years, IQR = 39-79 years, males = 58%, patients using antithrombotic medication = 26%). Patients with no signs of acute traumatic intracranial pathology or any type of subdural collection on initial head CT were regarded as CT negative (n = 1573, 81%)., Results: Two (n = 2) of the 1573 CT negative patients received surgical treatment for cSDH. Consequently, the incidence of surgically treated cSDH after a normal initial head CT during a six-month follow-up was 0.13%. Both patients sustained mild traumatic brain injuries initially. One of the two patients was on antithrombotic medication (warfarin) at the time of trauma, hence incidence of surgically treated cSDH among patients with antithrombotic medication in CT negative patients (n = 376, 23.9%) was 0.27%. Additionally, within CT negative patients, one subdural hygroma was operated shortly after trauma., Conclusion: The extremely low incidence of surgically treated cSDH after a normal initial head CT, even in patients on antithrombotic medication, supports the notion that routine follow-up imaging after an initial normal head CT is not indicated to exclude the development of cSDH. Additionally, our findings support the concept of cSDH not being a purely head trauma-related disease., (© 2024. The Author(s).)

Objective: Adverse childhood experiences (ACEs) are associated with mental health and cognitive problems, and mental health problems are associated with perceived cognitive difficulties among adolescents. The unique contribution of ACEs to cognitive difficulties after adjusting for poor mental health is not well understood and represents the purpose of this study., Methods: The Adolescent Behaviors and Experiences Survey was conducted in 2021 with high school students in the United States. Cognitive difficulty was assessed with: 'Because of a physical, mental, or emotional problem, do you have serious difficulty concentrating, remembering, or making decisions?' Four ACEs were examined: sexual violence (lifetime and past 12 months), parental emotional abuse, and parental physical abuse. Students were asked about feeling sad or hopeless (past year), considering suicide (past year), and having poor mental health (past month). Binary logistic regressions examined the association between ACEs and cognitive problems, adjusting for mental health., Results: Participants were 6,945 students. Students reporting poor mental health were very likely to endorse difficulty concentrating, remembering, or making decisions (girls = 81% and boys = 67%). Cognitive difficulty was uncommon among students who denied poor mental health (girls = 17% and boys = 12%). For boys [ p  < 0.001; R 2  = 0.22] and girls [ p  < 0.001; R 2  = 0.31], after adjusting for mental health problems, independent predictors of cognitive difficulties included parental verbal abuse and physical abuse. For girls, lifetime forced sexual intercourse and sexual violence during the past year were also independently associated., Conclusion: ACEs are associated with perceived cognitive difficulty in both adolescent girls and boys, even after adjusting for poor mental health., Competing Interests: GI has received past research funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc.). He receives royalties from one neuropsychological test (WCST-64). The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Iverson, Cook and Iverson.)

Whether social determinants of health are associated with clinical outcome following concussion among adolescents is not well established. The present study examined whether neighborhood-level determinants are associated with clinical recovery time following concussion in adolescents. Participants included adolescent student athletes ( n  = 130; mean age = 16.6, standard deviation = 1.2; 60.8% boys, 39.2% girls) who attended one of nine selected high schools in Maine, USA. The Area of Deprivation Index (ADI), an indicator of neighborhood disadvantage was used to group high schools as either high or low in neighborhood disadvantage. Athletic trainers entered injury and recovery dates into an online surveillance application between September 2014 and January 2020. Chi-squared analyses and Kaplan-Meier survival analyses were used to compare the groups on two clinical outcomes: days to return to school and days to return to sports. Results of chi-squared tests did not reveal between-group differences in return to school at 21 or 28 days. However, groups differed in the percentage of adolescents who had returned to sports by 21 days (greater neighborhood disadvantage, 62.5%, lesser neighborhood disadvantage 82.0%, χ 2  = 4.96, p  = 0.03, odds ratio [OR] = 2.73, 95% confidence interval [CI], 1.11-6.74) and 28 days (greater neighborhood disadvantage, 78.6%, lesser neighborhood disadvantage 94.0%, χ 2  = 5.18, p  = 0.02, OR = 4.27, 95% CI, 1.13-16.16) following concussion. A larger proportion of adolescents attending schools located in areas of greater neighborhood disadvantage took more than 21 and 28 days to return to sports. These results indicate an association between a multi-faceted proxy indicator of neighborhood disadvantage and clinical outcome following concussion. Further research is needed to better characterize factors underlying group differences in time to return to sports and the interactions between neighborhood disadvantage and other correlates of clinical recovery following concussion.

Glial fibrillary acidic protein (GFAP) has become the most promising biomarker for detecting traumatic abnormalities on head computed tomography (CT) in patients with traumatic brain injury (TBI), but most studies have not addressed the potential added value of combining the biomarker with clinical variables that confer risk for intracranial injuries. The Scandinavian Guidelines for Initial Management of Minimal, Mild, and Moderate Head Injuries in Adults were the first clinical decision rules in the field with an incorporated biomarker, the S100 astroglial calcium-binding protein B (S100B), which is used in the Mild (Low Risk) group defined by the guidelines. Our aim was to evaluate the performance of the guidelines when S100B was substituted with GFAP. The sample ( N  = 296) was recruited from the Tampere University Hospital's emergency department between November 2015 and November 2016, and there were 49 patients with available GFAP results who were stratified in the Mild (Low Risk) group (thus patients undergoing biomarker triaging). A previously reported cutoff of plasma GFAP ≥140 pg/mL was used. Within the Mild (Low Risk) group ( n  = 49), GFAP sensitivity (with 95% confidence intervals in parentheses) for detecting traumatic CT abnormalities was 1.0 (0.40-1.00), specificity 0.34 (0.19-0.53), the negative predictive value (NPV) 1.0 (0.68-1.00), and the positive predictive value (PPV) 0.16 (0.05-0.37). The sensitivity and specificity of the modified guidelines with GFAP, when applied to all imaged patients ( n  = 197) in the whole sample, were 0.94 (0.77-0.99) and 0.20 (0.15-0.28), respectively. NPV was 0.94 (0.80-0.99) and PPV 0.18 (0.13-0.25). In the Mild (Low Risk) group, none of the patients with GFAP results below 140 pg/mL had traumatic abnormalities on their head CT. These findings were derived from a small patient subgroup. Future researchers should replicate these findings in larger samples and assess whether GFAP has added or comparable value to S100B in acute TBI management., Competing Interests: Dr. Grant Iverson serves as a scientific advisor for NanoDx™ (formerly BioDirection, Inc.), Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving persons who have sustained mTBIs. He acknowledges unrestricted philanthropic support from ImPACT Applications, Inc., the Mooney-Reed Charitable Foundation, the National Rugby League, and the Schoen Adams Research Institute at Spaulding Rehabilitation. The above entities were not involved in the study design, collection, analysis, interpretation of data, the writing of this article, or the decision to submit it for publication. Dr. Posti has received speaker's fees from Orion corporation and the Finnish Medical Association and a travel grant from Stryker Corporation. Dr. Henrik Zetterberg has served at scientific advisory boards and/or as a consultant for AbbVie, Acumen, Alector, Alzinova, ALZPath, Annexon, Apellis, Artery Therapeutics, AZTherapies, Cognito Therapeutics, CogRx, Denali, Eisai, Nervgen, Novo Nordisk, Optoceutics, Passage Bio, Pinteon Therapeutics, Prothena, Red Abbey Labs, reMYND, Roche, Samumed, Siemens Healthineers, Triplet Therapeutics, and Wave; has given lectures in symposia sponsored by Cellectricon, Fujirebio, Alzecure, Biogen, and Roche; and is a co-founder of Brain Biomarker Solutions in Gothenburg AB (BBS), which is a part of the GU Ventures Incubator Program (outside submitted work)., (© Mira Keski-Pukkila et al., 2024; Published by Mary Ann Liebert, Inc.)

Objective: To examine baseline neurocognitive functioning and symptom reporting among adolescents with self-reported autism., Method: Participants in this cross-sectional, observational study were 60,751 adolescents who completed preseason testing. There were 425 students (0.7%) who self-reported an autism spectrum disorder (ASD) diagnosis. Cognitive functioning was measured by Immediate Post-Concussion Assessment and Cognitive Testing and symptom ratings were obtained from the Post-Concussion Symptom Scale., Results: Groups differed significantly across all neurocognitive composites (p values <.002); effect size magnitudes for most differences were small, though among boys a noteworthy difference on visual memory and among girls differences on verbal memory and visual motor speed composites were noted. Among boys, the ASD group endorsed 21 of the 22 symptoms at a greater rate. Among girls, the ASD group endorsed 11 of the 22 symptoms at a greater rate. Some examples of symptoms that were endorsed at a higher rate among adolescents with self-reported autism were sensitivity to noise (girls: odds ratio, OR = 4.38; boys: OR = 4.99), numbness or tingling (girls: OR = 3.67; boys: OR = 3.25), difficulty remembering (girls: OR = 2.01; boys: OR = 2.49), difficulty concentrating (girls: OR = 1.82; boys: OR = 2.40), sensitivity to light (girls: OR = 1.82; boys: OR = 1.76), sadness (girls: OR = 1.72; boys: OR = 2.56), nervousness (girls: OR = 1.80; boys: OR = 2.27), and feeling more emotional (girls: OR = 1.79; boys: OR = 2.84)., Conclusion: Students with self-reported autism participating in organized sports likely experience a low degree of functional impairment, on average. If they sustain a concussion, their clinical management should be more intensive to maximize the likelihood of swift and favorable recovery., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Video surveillance has almost universally been employed by professional sports to identify signs of concussion during competition. This study examined associations between video-identified possible loss of consciousness (LOC), acute concussion evaluation findings, and recovery time in concussed professional rugby league players. Medical personnel and sideline video operators identified head impact events sustained during three seasons of National Rugby League (NRL) matches to determine the need for further medical evaluation. If a concussion was suspected, players were removed from play and underwent a Head Injury Assessment, including the Sports Concussion Assessment Tool, Fifth Edition (SCAT5). Video footage was later examined to identify signs of possible LOC (i.e., observed LOC, no protective action in the fall, and unresponsiveness or lying motionless). Possible LOC was identified in 99 of the 1706 head impact events (5.8%). The median duration of apparent unresponsiveness was 4.2 sec (M = 7.4, standard deviation [SD] = 12.8, interquartile range [IQR] = 2.5-6.6). In the 661 athletes for whom SCAT5 data were available, those with possible LOC endorsed more SCAT5 symptoms and performed worse on Maddocks questions, Standardized Assessment of Concussion (SAC) total scores, orientation, immediate recall, concentration, and delayed recall. For the 255 players with medically diagnosed concussions, SCAT5 data were available for 245. Concussed players with possible LOC performed significantly worse on Maddocks questions. However, there were no group differences in SCAT5 symptom endorsement, SAC total scores, orientation, immediate recall, concentration, delayed recall, or the modified version of the Balance Error Scoring System (mBESS) total errors. Further, the presence or absence of possible LOC was not associated with number of games missed or time to medical clearance for match play. The duration of possible LOC was not associated with the number of games missed or time to medical clearance for match play. According to video review in NRL players, brief LOC might be more common than previously thought. The present study reveals possible LOC is not predictive of missed games or time to recover following concussion.

We conducted a content analysis of the literature underlying the Centers for Disease Control and Prevention (CDC) Guideline on the Diagnosis and Management of Mild Traumatic Brain Injury Among Children (i.e., the "Guideline") to determine the extent to which social determinants of health (SDoH) were examined or addressed. The systematic review forming the basis for the Guideline included 37 studies addressing diagnosis, prognosis, and treatment/rehabilitation. We examined those studies to identify SDoH domains derived from the U.S. Department of Health and Human Services' Healthy People 2020 and 2030 websites. No study explicitly mentioned "social determinants of health," by name, and few studies addressed SDoH domains as a primary focus (ranging from 0% to 27% of studies across SDoH domains). The most frequently represented SDoH domains, described in an inferential or a descriptive manner, were Education Access and Quality (29.7% of studies), Social and Community Context (27.0% of studies), and Economic Stability (21.6% of studies). Health Care Access (13.5% of studies) was less well represented and no studies (0%) examined Neighborhood and Built Environment. In terms of the CDC clinical questions, SDoH were only examined as predictors of outcome (prognosis) and no studies examined SDoH in relation to diagnosis or treatment/rehabilitation. The Guideline includes some commentary on health literacy and socioeconomic status. Overall, social determinants of health are largely unrepresented as important or meaningful variables influencing the Guideline on the Diagnosis and Management of Mild Traumatic Brain Injury Among Children, or in the studies that informed the Guideline.

Graded exertion testing (GXT) is an important tool for concussion management, as it is used to personalize post-concussion exercise prescription and return athletes to sport. However, most GXT requires expensive equipment and in-person supervision. Our objective was to assess the safety and feasibility of the Mo ntreal V irtual E xertion (MOVE) protocol, a no-equipment, virtually compatible GXT, in healthy children and children with subacute concussion. The MOVE protocol consists of seven stages of bodyweight and plyometric exercises performed for 60 sec each. Twenty healthy (i.e., non-concussed) children completed the MOVE protocol virtually over Zoom Enterprise. Next, 30 children with subacute concussion (median: 31.5 days post-injury) were randomized to the MOVE protocol or Buffalo Concussion Treadmill Test (BCTT), which increases the incline or speed of the treadmill every minute until maximum exertion. Out of an abundance of caution, all concussed participants completed the MOVE protocol in an in-person clinical space. However, the test evaluator was stationed in a different room within the clinic and administered the MOVE protocol using Zoom Enterprise software to mimic telehealth conditions. Safety and feasibility outcomes were recorded throughout GXT, including heart rate, rate of perceived exertion (RPE), and symptom outcomes. No adverse events were recorded, and all feasibility criteria were successfully met in healthy youth and youth with concussion. Among concussed youth, increases in heart rate (MOVE: 82.4 ± 17.9 bpm, BCTT: 72.1 ± 23.0 bpm; t (28)  = 1.36, p  = 0.18), RPE (MOVE: 5.87 ± 1.92, BCTT: 5.07 ± 2.34, t (28)  = 1.02, p  = 0.32), and overall symptom presentation were similar between the MOVE and BCTT protocols. The MOVE protocol is a safe and feasible GXT in healthy youth and youth with subacute concussion. Future studies should assess the fully virtual administration of the MOVE in children with concussion, MOVE protocol tolerability in children with acute concussion, and whether the MOVE protocol can be used to guide individualized exercise prescription.

American-style football (ASF) players experience repetitive head impacts that may result in chronic traumatic encephalopathy neuropathological change (CTE-NC). At present, a definitive diagnosis of CTE-NC requires the identification of localized hyperphosphorylated Tau (p-Tau) after death via immunohistochemistry. Some studies suggest that positron emission tomography (PET) with the radiotracer [ 18 F]-Flortaucipir (FTP) may be capable of detecting p-Tau and thus establishing a diagnosis of CTE-NC among living former ASF players. To assess associations between FTP, football exposure, and objective neuropsychological measures among former professional ASF players, we conducted a study that compared former professional ASF players with age-matched male control participants without repetitive head impact exposure. Former ASF players and male controls underwent structural magnetic resonance imaging and PET using FTP for p-Tau and [ 11 C]-PiB for amyloid-β. Former players underwent neuropsychological testing. The ASF exposure was quantified as age at first exposure, professional career duration, concussion signs and symptoms burden, and total years of any football play. Neuropsychological testing included measures of memory, executive functioning, and depression symptom severity. P-Tau was quantified as FTP standardized uptake value ratios (SUVR) and [ 11 C]-PiB by distribution volume ratios (DVR) using cerebellar grey matter as the reference region. There were no significant differences in [ 18 F]-FTP uptake among former ASF players ( n  = 27, age = 50 ± 7 years) compared with control participants ( n  = 11, age = 55 ± 4 years), nor did any participant have significant amyloid-β burden. Among ASF participants, there were no associations between objective measures of neurocognitive functioning and [ 18 F]-FTP uptake. There was a marginally significant difference, however, between [ 18 F]-FTP uptake isolated to the entorhinal cortex among players in age-, position-, and race-adjusted models ( p  = 0.05) that may represent an area of future investigation. The absence of increased [ 18 F]-FTP uptake in brain regions previously implicated in CTE among former professional ASF players compared with controls questions the utility of [ 18 F]-FTP PET for clinical evaluation in this population.

Adolescents with ADHD have a greater lifetime history of concussion and experience concussion-like symptoms in the absence of a concussion, complicating concussion assessment and management. It is well established that individuals who experience greater acute symptoms following concussion are at risk for slower recovery and persistent symptoms. We examined whether youth with ADHD experience worse acute effects, within the first 72 h following concussion, compared to youth without ADHD. We hypothesized that youth with ADHD would perform worse on neurocognitive testing and endorse more severe symptoms acutely following injury, but the magnitude of change from pre injury to post injury would be similar for both groups, and thus comparable to baseline group differences. The sample included 852 adolescents with pre-injury and post-injury ImPACT results (within 72 h); we also conducted supplementary case-control analyses on a subset of youth with and without ADHD matched on demographics and pre-injury health history. For both samples, there were significant interaction effects for the Verbal Memory and Visual Motor Speed composites ( p  < 0.01, η 2 =.01-.07, small-medium effect), such that youth with ADHD showed a greater magnitude of diminished cognitive functioning from pre-injury to post-injury testing. There were no significant differences in the magnitudes of changes from pre injury to post injury with regard to overall symptom reporting (i.e., total symptom severity scores, total number of symptoms endorsed); however, there were group differences in endorsement rates for several individual symptoms. Further research is needed to determine whether such differential acute effects are associated with recovery time in youth with ADHD.

Objective: To develop new diagnostic criteria for mild traumatic brain injury (TBI) that are appropriate for use across the lifespan and in sports, civilian trauma, and military settings., Design: Rapid evidence reviews on 12 clinical questions and Delphi method for expert consensus., Participants: The Mild Traumatic Brain Injury Task Force of the American Congress of Rehabilitation Medicine Brain Injury Special Interest Group convened a Working Group of 17 members and an external interdisciplinary expert panel of 32 clinician-scientists. Public stakeholder feedback was analyzed from 68 individuals and 23 organizations., Results: The first 2 Delphi votes asked the expert panel to rate their agreement with both the diagnostic criteria for mild TBI and the supporting evidence statements. In the first round, 10 of 12 evidence statements reached consensus agreement. Revised evidence statements underwent a second round of expert panel voting, where consensus was achieved for all. For the diagnostic criteria, the final agreement rate, after the third vote, was 90.7%. Public stakeholder feedback was incorporated into the diagnostic criteria revision prior to the third expert panel vote. A terminology question was added to the third round of Delphi voting, where 30 of 32 (93.8%) expert panel members agreed that 'the diagnostic label 'concussion' may be used interchangeably with 'mild TBI' when neuroimaging is normal or not clinically indicated.', Conclusions: New diagnostic criteria for mild TBI were developed through an evidence review and expert consensus process. Having unified diagnostic criteria for mild TBI can improve the quality and consistency of mild TBI research and clinical care., (Copyright © 2023 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Introduction: Some ultra-high exposure boxers from the 20th century suffered from neurological problems characterized by slurred speech, personality changes (e.g., childishness or aggressiveness), and frank gait and coordination problems, with some noted to have progressive Parkinsonian-like signs. Varying degrees of cognitive impairment were also described, with some experiencing moderate to severe dementia. The onset of the neurological problems often began while they were young men and still actively fighting. More recently, traumatic encephalopathy syndrome (TES) has been proposed to be present in athletes who have a history of contact (e.g., soccer) and collision sport participation (e.g., American-style football). The characterization of TES has incorporated a much broader description than the neurological problems described in boxers from the 20th century. Some have considered TES to include depression, suicidality, anxiety, and substance abuse., Purpose: We carefully re-examined the published clinical literature of boxing cases from the 20th century to determine whether there is evidence to support conceptualizing psychiatric problems as being diagnostic clinical features of TES., Methods: We reviewed clinical descriptions from 155 current and former boxers described in 21 articles published between 1928 and 1999., Results: More than one third of cases (34.8%) had a psychiatric, neuropsychiatric, or neurobehavioral problem described in their case histories. However, only 6.5% of the cases were described as primarily psychiatric or neuropsychiatric in nature. The percentages documented as having specific psychiatric problems were as follows: depression = 11.0%, suicidality = 0.6%, anxiety = 3.9%, anger control problems = 20.0%, paranoia/suspiciousness = 11.6%, and personality change = 25.2%., Discussion: We conclude that depression, suicidality (i.e., suicidal ideation, intent, or planning), and anxiety were not considered to be clinical features of TES during the 20th century. The present review supports the decision of the consensus group to remove mood and anxiety disorders, and suicidality, from the new 2021 consensus core diagnostic criteria for TES. More research is needed to determine if anger dyscontrol is a core feature of TES with a clear clinicopathological association. The present findings, combined with a recently published large clinicopathological association study, suggest that mood and anxiety disorders are not characteristic of TES and they are not associated with chronic traumatic encephalopathy neuropathologic change., Competing Interests: GI serves as a scientific advisor for NanoDX®, Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including former athletes), and on the topic of suicide. He has received past research support or funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc.). He receives royalties from the sales of one neuropsychological test (WCST-64). He has received travel support and honorariums for presentations at conferences and meetings. He has received research funding as a principal investigator from the National Football League, and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. RC is a collaborator on a grant funded by the National Football League to study the spectrum of concussion, including possible long-term effects. He has a consulting practice in forensic neuropathology, including expert testimony, which has involved former athletes at amateur and professional levels, and sport organizations. AG serves as a scientific advisor for hitIQ, Ltd. He has a clinical practice in neuropsychology involving individuals who have sustained sport-related concussion (including current and former athletes). He has been a contracted concussion consultant to Rugby Australia since July 2016. He has received travel funding or been reimbursed by professional sporting bodies, and commercial organizations for discussing or presenting sport-related concussion research at meetings, scientific conferences, workshops, and symposiums. Previous grant funding includes the NSW Sporting Injuries Committee, the Brain Foundation (Australia), an Australian-American Fulbright Commission Postdoctoral Award, a Hunter New England Local Health District, Research, Innovation and Partnerships Health Research & Translation Centre and Clinical Research Fellowship Scheme, and the Hunter Medical Research Institute (HMRI), supported by Jennie Thomas, and the HMRI, supported by Anne Greaves. AG is supported by a National Health and Medical Research Council (NHMRC) Investigator Grant. He acknowledges unrestricted philanthropic support from the National Rugby League for research in former professional rugby league players. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Iverson, Kissinger-Knox, Huebschmann, Castellani and Gardner.)

Background: Most of moderate and severe pTBIs are managed conservatively, but in some cases neurosurgical interventions are needed. The incidence rates of acute pTBI neurosurgery vary considerably between countries and operation types. Our goal was to assess the incidence of acute pTBI neurosurgery in Finland., Methods: We conducted a retrospective Finnish register-based cohort study from 1998 to 2018. We included all patients that were 0 to 17 years of age at the time of the TBI. The incidence rates of patients with pTBI undergoing neurosurgery and the rates for specific operation types were calculated per 100,000 person-years. We compared the annual incidences with incidence rate ratios (IRR) with 95% confidence intervals (CI). We stratified patients to three age categories: (i) 0 to 3 years of age, (ii) 4 to 12 years of age, and (iii) 13 to 17 years of age., Results: The total number of neurosurgeries for acute pTBI during the study period was 386, and the cumulative incidence was 1.67 operations per 100,000 person-years. The cumulative incidence during the 21-year follow-up was highest at the age of 16 (IRR 4.78, CI 3.68 to 6.11). Boys had a 2.42-time higher cumulative incidence (IRR 2.35, CI 1.27 to 3.99) than girls (IRR 0.97, CI 0.35 to 2.20). The most common neurosurgery was an evacuation of an intracranial hemorrhage (n = 171; 44.3%)., Conclusion: The incidence of neurosurgeries for pTBIs has been stable from 1998 to 2018. The incidence was highest at the age of 16, and boys had higher incidence than girls., (© 2023. The Author(s).)

Clinical recovery after sport-related concussion varies as a function of pre-injury and acute factors. Whether, or the extent to which, concussion history is associated with clinical outcome after sport-related concussion is uncertain, because research has produced mixed findings. The present study aimed to assess whether a history of previous concussions was associated with prolonged clinical recovery after a subsequent sport-related concussion. The sample comprised 780 adolescent student athletes (mean age = 16.3, standard deviation = 1.3 years; 56.8% boys, 43.2% girls) whose school participated in the Maine Concussion Management Initiative (MCMI). Survival analyses were used to compare recovery times among adolescents with a history of 0, 1, or ≥2 previous concussions after a subsequent sport-related concussion. The two primary outcomes of interest were the number of days to return to school and sports. There were no statistically significant differences in total time to return to school and sports, or the proportion of adolescents who returned to school and sports at most intervals (e.g., 7, 14, 28 days), between those with 0, 1, or ≥2 previous concussions. A greater proportion of adolescents, however, with a history of ≥2 previous concussions remained out of sports at 28 days compared with those with no previous concussions (23.5% vs. 12.7%; odds ratio [OR] = 2.10, 95% confidence interval [CI] 1.18-3.73). Having sustained prior concussions was not associated with time to return to school after a subsequent sport-related concussion. A greater proportion of adolescents, however, with two or more previous concussions experienced a prolonged return to sports. Further research is warranted to identify risk factors for worse outcomes among the subset of adolescents with a history of multiple previous concussions who experience prolonged recoveries.

Introduction: We examined postmortem brain tissue from men, over the age of 50, for chronic traumatic encephalopathy neuropathologic change (CTE-NC). We hypothesized that (i) a small percentage would have CTE-NC, (ii) those who played American football during their youth would be more likely to have CTE-NC than those who did not play contact or collision sports, and (iii) there would be no association between CTE-NC and suicide as a manner of death., Methods: Brain tissue from 186 men and accompanying clinical information were obtained from the Lieber Institute for Brain Development. Manner of death was determined by a board-certified forensic pathologist. Information was obtained from next of kin telephone interviews, including medical, social, demographic, family, and psychiatric history. The 2016 and 2021 consensus definitions were used for CTE-NC. Two authors screened all cases, using liberal criteria for identifying "possible" CTE-NC, and five authors examined the 15 selected cases., Results: The median age at the time of death was 65 years (interquartile range = 57-75; range = 50-96). There were 25.8% with a history of playing American football and 36.0% who had suicide as their manner of death. No case was rated as definitively having "features" of CTE-NC by all five authors. Ten cases were rated as having features of CTE-NC by three or more authors (5.4% of the sample), including 8.3% of those with a personal history of playing American football and 3.9% of those who did not play contact or collision sports. Of those with mood disorders during life, 5.5% had features of CTE-NC compared to 6.0% of those who did not have a reported mood disorder. Of those with suicide as a manner of death, 6.0% had features of CTE-NC compared to 5.0% of those who did not have suicide as a manner of death., Discussion: We did not identify a single definitive case of CTE-NC, from the perspective of all raters, and only 5.4% of cases were identified as having possible features of CTE-NC by some raters. CTE-NC was very uncommon in men who played amateur American football, those with mood disorders during life, and those with suicide as a manner of death., Competing Interests: GI serves as a scientific advisor for NanoDX®, Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including former athletes), and on the topic of suicide. He has received research funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc.). He has received research funding as a principal investigator from the National Football League, and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. RC is subcontracted to the Lieber Institute for Brain Development to assist with brain examinations. He is a consultant on a grant from the National Football League. He has a consulting practice in forensic neuropathology, including expert testimony, some of which involves former contact sport athletes. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Iverson, Jamshidi, Fisher-Hubbard, Deep-Soboslay, Hyde, Kleinman, deJong, Shepherd, Hazrati and Castellani.)

Introduction: This systematic review examined whether race or ethnicity are associated with clinical outcomes (e.g., time to return to school/sports, symptom duration, vestibular deficits, and neurocognitive functioning) following sport-related concussion among child, adolescent, or college-aged student athletes. Additionally, this review assessed whether the existing literature on this topic incorporated or included broader coverage of social determinants of health., Methods: The online databases PubMed, MEDLINE ® , PsycINFO ® , CINAHL, Cochrane Library, EMBASE, SPORTDiscus, Scopus, and Web of Science were searched., Results: A total of 5,118 abstracts were screened and 12 studies met inclusion criteria, including 2,887 youth and young adults. Among the included articles, only 3 studies (25%) examined whether race and ethnicity were associated with outcomes following concussion as a primary objective. None of the studies assessed the association between social determinants of health and outcomes following concussion as a primary objective, although 5 studies (41.7%) addressed a social determinant of health or closely related topic as a secondary objective., Discussion: Overall, the literature to date is extremely limited and insufficient for drawing conclusions about whether race or ethnicity are categorically associated with outcomes from sport-related concussion, or more specifically, whether there are socioeconomic, structural, or cultural differences or disparities that might be associated with clinical outcome., Systematic Review Registration: identifier: PROSPERO, CRD42016041479, CRD42019128300., Competing Interests: AS has received research funding from the American Academy of Neurology, National Institute of Health, National Science Foundation, and the Russel Sage Foundation. GI serves as a scientific advisor for NanoDX®, Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including former athletes). He has received research funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc.). He has received research funding as a principal investigator from the National Football League and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Cook, Gaudet, Kissinger-Knox, Liu, Hunter, Norman, Saadi and Iverson.)

Objective: The tackle is the most injurious event in rugby league and carries the greatest risk of concussion. This study aims to replicate previous research conducted in professional men's rugby league by examining the association between selected tackle characteristics and head impact events (HIEs) in women's professional rugby league., Methods: We reviewed and coded 83 tackles resulting in an HIE and every tackle (6,318 tackles) that did not result in an HIE for three seasons (2018-2020) of the National Rugby League Women's (NRLW) competition. Tackle height, body position of the tackler and ball carrier, as well as the location of head contact with the other player's body were evaluated. Propensity of each situation that caused an HIE was calculated as HIEs per 1,000 tackles., Results: The propensity for tacklers to sustain an HIE was 6.60 per 1,000 tackles (95% CI: 4.87-8.92), similar to that of the ball carrier (6.13 per 1,000 tackles, 95% CI: 4.48-8.38). The greatest risk of an HIE to either the tackler or ball carrier occurred when head proximity was above the sternum (21.66 per 1,000 tackles, 95% CI: 16.55-28.35). HIEs were most common following impacts between two heads (287.23 HIEs per 1,000 tackles, 95% CI: 196.98-418.84). The lowest propensity for both tackler (2.65 per 1,000 tackles, 95% CI: 0.85-8.20) and ball carrier HIEs (1.77 per 1,000 tackles, 95% CI: 0.44-7.06) occurred when the head was in proximity to the opponent's shoulder and arm. No body position (upright, bent or unbalanced/off feet) was associated with an increased propensity of HIE to either tackler or ball carrier., Conclusions: In the NRLW competition, tacklers and ball carriers have a similar risk of sustaining an HIE during a tackle, differing from men's NRL players, where tacklers have a higher risk of HIEs. Further studies involving larger samples need to validate these findings. However, our results indicate that injury prevention initiatives in women's rugby league should focus on how the ball carrier engages in contact during the tackle as well as how the tackler executes the tackle., Competing Interests: MS is part-funded by Leeds Rhinos rugby league club. RT is a consultant to World Rugby Pty. World Rugby is the governing body for the sport of Rugby Union and responsible for law changes in the sport. BJ is employed by Leeds Rhinos, Rugby Football League and Premiership Rugby in a consultancy capacity. GLI serves as a scientific advisor for NanoDX® Sway Operations, LLC, and Highmark, Inc. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including former athletes). He has received research funding as a principal investigator from the National Football League, and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. He acknowledges unrestricted philanthropic support from ImPACT Applications, Inc., the Mooney-Reed Charitable Foundation, Boston Bolts, the National Rugby League, and the Schoen Adams Research Institute at Spaulding Rehabilitation. None of the above entities were involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication. AJG serves as a scientific advisor for HitIQ, Ltd. He has a clinical practice in neuropsychology involving individuals who have sustained sport-related concussion (including current and former athletes). He has been a contracted concussion consultant to Rugby Australia since July 2016. He has received travel funding or been reimbursed by professional sporting bodies, and commercial organisations for discussing or presenting sport-related concussion research at meetings, scientific conferences, workshops, and symposiums. Previous grant funding includes the NSW Sporting Injuries Committee, the Brain Foundation (Australia), an Australian-American Fulbright Commission Postdoctoral Award, a Hunter New England Local Health District, Research, Innovation and Partnerships Health Research & Translation Centre and Clinical Research Fellowship Scheme, and the Hunter Medical Research Institute (HMRI), supported by Jennie Thomas, and the HMRI, supported by Anne Greaves. He has current philanthropic support from the Nick Tooth Foundation. He acknowledges unrestricted philanthropic support from the National Rugby League (NRL). The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 McLeod, Tucker, Edwards, Jones, Page, Spiegelhalter, West, Iverson and Gardner.)

For over two decades, the Concussion in Sport Group has held meetings and developed five international statements on concussion in sport. This 6th statement summarises the processes and outcomes of the 6th International Conference on Concussion in Sport held in Amsterdam on 27-30 October 2022 and should be read in conjunction with the (1) methodology paper that outlines the consensus process in detail and (2) 10 systematic reviews that informed the conference outcomes. Over 3½ years, author groups conducted systematic reviews of predetermined priority topics relevant to concussion in sport. The format of the conference, expert panel meetings and workshops to revise or develop new clinical assessment tools, as described in the methodology paper, evolved from previous consensus meetings with several new components. Apart from this consensus statement, the conference process yielded revised tools including the Concussion Recognition Tool-6 (CRT6) and Sport Concussion Assessment Tool-6 (SCAT6, Child SCAT6), as well as a new tool, the Sport Concussion Office Assessment Tool-6 (SCOAT6, Child SCOAT6). This consensus process also integrated new features including a focus on the para athlete, the athlete's perspective, concussion-specific medical ethics and matters related to both athlete retirement and the potential long-term effects of SRC, including neurodegenerative disease. This statement summarises evidence-informed principles of concussion prevention, assessment and management, and emphasises those areas requiring more research., Competing Interests: Competing interests: OHA is a Senior Physiotherapist at University Hospitals Dorset NHS Foundation Trust (England) and is Para Football Physiotherapy Lead/Para Football Classification Lead at the Football Association (England). He also works on a consultancy basis with the Football Association as the squad physiotherapist to the England Cerebral Palsy Football squad and teaches a course on the Football Association’s Advanced Trauma and Medical Management in Football course on a consultancy basis. He has a Visiting Senior Lecturer position at the University of Portsmouth, England (unpaid). He sits on several disability sport committees, including Para Football Foundation as Medical Unit Co-Lead (unpaid), the International Federation of Cerebral Palsy Football as Medical and Sports Science Director (unpaid) and the International Blind Sports Association as Medical Committee member (unpaid). He has Associate Editor positions at the British Journal of Sports Medicine (unpaid) and BMJ Open Sports & Exercise Medicine (unpaid). He is also an Institutional Ethics Committee external member for World Rugby (unpaid) and co-chair of the Concussion in Para Sport Group (unpaid). CAB is an Associate Professor of PM&R Journal at Spaulding Rehabilitation Hospital/Harvard Medical School and Chief Medical Officer at Spaulding Rehabilitation Hospital. She receives grant funding from the US Center for Disease Control and Prevention and the US National Institute on Disability, Independent Living, and Rehabilitation Research. She serves on the Board of Directors of the US Olympic & Paralympic Committee (unpaid) as well as on the International Paralympic Committee Medical Committee (unpaid) and the IOC Medical & Scientific Commission (unpaid). She serves as an Associate Editor of the British Journal of Sports Medicine (unpaid) and the PM&R Journal (unpaid). SPB Current or past research funding from the National Institutes of Health; US Centers for Disease Control and Prevention; Department of Defence (DoD)—USA Medical Research Acquisition Activity, National Collegiate Athletic Association (NCAA); National Athletic Trainers’ Association Foundation; NFL/Under Armour/GE; Simbex and ElmindA. He has consulted for US Soccer (paid), US Cycling (unpaid), University of Calgary SHRed Concussions external advisory board (unpaid), medicolegal litigation and received speaker honorarium and travel reimbursements (including Concussion in Sport Group (CISG)) for talks given. He is the coauthor of Biomechanics of Injury (3rd Edition) and has a patent pending on Brain Metabolism Monitoring Through CCO Measurements Using All-Fiber-Integrated Super-Continuum Source (US Application No 17/164,490). He is/was on the editorial boards (all unpaid) for Journal of Athletic Training (2015 to present), Concussion (2014 to present), Athletic Training & Sports Health Care (2008 to present) and British Journal of Sports Medicine (2008–2019). RCC Senior Advisor NFL Head Neck & Spine Committee NOCSAE and Chair Scientific Advisory Committee Co-Founder, Medical Director Concussion Legacy Foundation Royalties Houghton Mifflin Harcourt Legal Expert Opinion. GAD is a member of the Scientific Committee of the Sixth International Conference on Concussion in Sport; an honorary member of the AFL Concussion Scientific Committee; Section Editor, Sport and Rehabilitation, Neurosurgery and has attended meetings organised by sport organisations including NFL, NRL, IIHF, IOC and FIFA; however has not received any payment, research funding or other monies from these groups other than for travel costs. JD is the co-founder and board member of CISG and Senior Advisor to BJSM. RJE is a paid consultant for the NHL and cochair of the NHL/NHLPA Concussion Subcommittee. He is also a paid consultant and chair of the Major League Soccer concussion committee and a consultant to the US Soccer Federation. He previously served as a neuropsychology consultant to Princeton University Athletic Medicine and EyeGuide. He is currently a co-principal investigator (PI) for a grant funded by the NFL (NFL-Long) through Boston Children’s Hospital. He occasionally provides expert testimony in matters related to mild traumatic brain injury (mTBI) and sports concussion and occasionally receives honoraria and travel support/reimbursement for professional meetings. CAE holds external peer-reviewed research funding from Canadian Institutes of Health Research, Canada Foundation for Innovation, IOC Medical and Scientific Committee, NFL Play Smart Play Safe Program and World Rugby. She is an Associate Editor of BJSM (unpaid) and has received travel and accommodation support for meetings where she has presented. She is an external advisory board member for HitIQ. NF-D International independent FIFA Concussion Advisory Group. GOTS Concussion Committee Innovation and Technology Panel, UK Department for Digital, Culture, Media and Sport. International Consensus Group on Concussion in Sports (CISG), NINDSCDE Sports Concussion CDE Subacute Subgroup (National Institutes of Health). IFAB Concussion Expert Group. Member of Swiss Neurology Society, Swiss Society for Clinical Neurophysiology, European Neuro-Ophthalmology Society and CISG. Editorial Board Member of Journal of Concussion, Journal of Science and Medicine in Football. GF has received travel expenses to attend academic meetings from World Rugby. He has also collaborated on research projects with World Rugby as chief or co-investigator. He is a previous associate editor of the British Journal of Sports Medicine. He has not received any other payments or support from any sporting or commercial bodies. CCG discloses the following: Grants/research support: HitIQ (2022–2023); NIH NINDS (R01 NS110757 2019–2024); NINDS (U54 NS121688 2021-2026); UCLA Brain Injury Research Center, UCLA Steve Tisch BrainSPORT programme, Easton Clinic for Brain Health. Clinical Consultant (provide clinical care to athletes): NBA, NFL-Neurological Care Program, NHL/NHLPA, Los Angeles Lakers Advisory Board (non-compensated): Major League Soccer, NBA and US Soccer Federation. Advisory Board (compensated): Highmark Interactive Medicolegal: One or two cases annually Speaker’s bureau: None. Stock shareholder: Highmark Interactive stock options (2018). Other financial or material support: book royalties—Blackwell/Wiley Publishing: prioritized. Neurological differential diagnosis. KMG has received grant funding from NFL for the NFL LONG study. He also serves on the NCAA Scientific Advisory Board in an unpaid capacity. BH works full time as a paid employee of the NCAA as Senior Vice President, Sport Science Institute, and as Chief Medical Officer. I serve as a volunteer advisory member for: US Football Medical Advisory Panel; CrashCourse by TeachAids; NBJA Youth Health & Wellness Working Group; External Advisory Board, DIAGNOSE CTE (Boston University). I am on the Board of Directors for the US Tennis Association, the Grand Slam Board; the International Tennis Integrity Agency and the Datalys Center. I am chair of the International Tennis Federation Sports Science & Medicine Commission. SAH is co-founder and senior advisor of the Sports Institute at UW Medicine (unpaid). Centers for Disease Control and Prevention and National Center for Injury Prevention and Control Board Pediatric Mild Traumatic Brain Injury Guideline Workgroup (unpaid). CISG (travel support). NCAA Concussion Safety Advisory Group (unpaid). Team Physician, Seattle Mariners. Former Team Physician, Seattle Seahawks. Occasional payment for expert testimony. Travel support for professional meetings. GLI serves as a scientific advisor for NanoDX, Sway Operations and Highmark. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mTBIs (including former athletes) and on the topic of suicide. He has received past research support or funding from several test publishing companies, including ImPACT Applications, CNS Vital Signs and Psychological Assessment Resources (PAR). He receives royalties from the sales of one neuropsychological test (WCST-64). He has received travel support and honorariums for presentations at conferences and meetings. He has received research funding as a PI from the NFL and subcontract grant funding as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of NFL Players Association Members. He has received research funding from the Wounded Warrior Project. He acknowledges unrestricted philanthropic support from ImPACT Applications, the Mooney-Reed Charitable Foundation, the National Rugby League, Boston Bolts and the Schoen Adams Research Institute at Spaulding Rehabilitation. JK declares the following affiliations: NBA. US Ski and Snowboard. US Olympic & Paralympic Committee. NHL Players’ Association. Major League Soccer Players’ Association. NFL Players’ Association. NeuroSync. Cognivue. JJL receives grant/research support from NIH, DoD and AMSSM. He is a member of the Scientific Advisory Board for Neuronasal, Highmark Innovations and Quadrant Biosciences. Minority stock options in Highmark Innovations and 360 Concussion Care. Expert consultant to NCAA. Consults with NFL and NHL teams on athlete care but does not receive any compensation from these organizations. He is on the Editorial Board of Journal of Head Trauma and Rehabilitation. DM Neuropsychologist and lawyer—legal practice in Medical Law. Legal representation provided to parties in personal injury legal proceedings. Former member of AFL Concussion Working Group—no remuneration. Past legal advisor to Cricket Australia and the AFL. Legal advisor to various professional sporting clubs. Past ARF concussion research funding received through the Florey Institute of Neuroscience & Mental Health. Member of the AFL Grievance Tribunal—no remuneration received. Legal advisor to private schools. Lectures (neuropsychology/law) to education providers—no remuneration. Cricket Victoria—former Director/Chair—no remuneration. Melbourne Grammar School—Audit & Risk Committee Member—no remuneration. CISG Board Member—no remuneration. Travel support to attend the 2022 CISG meeting. Abstained from discussions in the 2022 CISG consensus process in relation to ‘chronic traumatic encephalopathy, neuropathological change and trauatic encephalopathy syndrome'and 'potential long-term sequelae'. MM Sport and exercise medicine physician working in private consulting practice. Shareholder of Olympic Park Sports Medicine Centre in Melbourne. Ex-senior physician at the Hawthorn Football Club (AFL). Ex-Chief Executive Officer of the AFL Doctors Association. Research grants received from the Australian Football League, outside the submitted work. Travel support received from the Australian Football League, FIFA and the IOC to attend and present at international conferences. Member of the Scientific Committee for the Sixth International Conference on Concussion in Sport. Honorary member of the International CISG. Honorary member of the Australian Rugby Union Concussion Advisory Group. Independent Concussion Consultant for World Rugby. GTM discloses grants from the US DoD—TBI Endpoints Development Initiative (Grant no W81XWH-14-2-0176), TRACK-TBI Precision Medicine (Grant no W81XWH-18-2-0042) and TRACK-TBI NETWORK (Grant no W81XWH-15-9-0001); NIHNINDS—TRACK-TBI (Grant no U01NS086090) and the NFL Scientific Advisory Board—TRACK-TBI LONGITUDINAL. US Department of Energy supports GTM for a precision medicine collaboration. One Mind has provided funding for TRACK-TBI patients’ stipends and support to clinical sites. He has received an unrestricted gift from the NFL to the UCSF Foundation to support the research efforts of the TRACK-TBI NETWORK. GTM has also received funding from NeuroTruama Sciences to support TRACK-TBI data curation efforts. Additionally, Abbott Laboratories has provided funding for add-in TRACK-TBI clinical studies. MAM has received research funding to the Medical College of Wisconsin from the National Institutes of Health (NIH), Department of Veterans Affairs, US Centers for Disease Control and Prevention, DoD, NCAA, NFL and Abbott Laboratories. He receives book royalties from Oxford University Press. He serves as a clinical consultant to Milwaukee Bucks, Milwaukee Brewers and Green Bay Packers, and is Co-Director of the NFL Neuropsychology Consultants without compensation. He serves as a consultant for NeuroTrauma Sciences. He receives travel support and speaker honorariums for professional activities. MJM Chair, Ethics Expert Group, WADA (2021–2023) (paid). Member, International Boxing Association, Ethics and Integrity Committee, (2021–2022; resigned October 2022) (paid). Chair, Therapeutic Use Exemption Fairness Committee (2020 to present) (paid). Member, Steering Group, Sex Segregation in Sport, IAAF/World Athletics, (2019–2020) (unpaid). Member, International Ice Hockey Federation, Ethics and Integrity Committee (2019–2021) (paid). Member, IOC Consensus Statement Expert Group on Injuries in Children and Adolescents (2017) (unpaid). Member, Ethics Expert Group, WADA (2016–2021) (unpaid). Member, IOC Consensus Statement Expert Group on Pain Management (2016) (unpaid). WM is employed as the Chief Medical Officer of the NHL. JSP is an Editor of BJSM for which he receives a honorarium. He is an unpaid consultant to the World Rugby Concussion Advisory Group for which he also serves as an Independent Concussion Advisor (fee per consultation). Other unpaid positions include being medical advisor to South African Rugby, Co-chair of the Scientific Committee, 6th International Conference on Concussion in Sport (travel and accommodation subsidised), Board member of the CISG and a Scientific Advisory Board Member of EyeGuide. LKP CASEM Board Member, President-Elect 2022–2023 NIH R34 Grant for EPICC Study (Eye Problems In Concussed Children), Site PI. Speaker at various conferences. CISG member. Expert panellist for the Sixth International Conference on Concussion in Sport (travel and accommodation subsidised). MP declares the following: Consultant, Chief Medical Officer, Major League Soccer. Senior Advisor, NFL Head, Neck & Spine Committee. FA Research Task Force Committee member. UK Concussion Foundation Protocol Forum. US Soccer Medical Advisory Committee. CDC Concussion Consultant. CISG expert panel. NOCSAE Scientific Advisory Committee. IOC Mental Health Working Group. USOPC Mental Health Advisory Committee. Team Physician, US Soccer. Received funding for research; NCAA-CARE-DoD 2.0, ended 2020. He received honoraria and reimbursement for travel for speaking and conferences amended. He has written chapters for UpToDate and received royalties for the Netter’s Sports Medicine textbook. He has provided work as an expert for cases involving concussion, team physician and other sports medicine topics. KJS has received grant funding from the Canadian Institutes of Health Research, NFL Scientific Advisory Board, IOC Medical and Scientific Research Fund, World Rugby, Mitacs Accelerate, University of Calgary with funds paid to her institution and not to her personally. She is an Associate Editor of BJSM (unpaid), independent consultant to World Rugby and has received travel and accommodation support for meetings where she has presented. She led and coordinated the writing of the systematic reviews that informed the Sixth International Conference on Concussion in Sport and Amsterdam Consensus Statement, for which she received an educational grant to assist with the administrative costs associated with the writing of the reviews (with funds paid to her institution and not to her personally). She is a member of the AFL Concussion Scientific Committee (unpaid position) and Brain Canada (unpaid position). She works as a physiotherapy consultant and treats athletes of all levels of sport from grassroots to professional. MT is employed full-time as the CEO and Medical Director of ICHIRF—a paid post he has held since April 2015. Hon Medical Adviser to the Professional Riders Insurance Scheme (PRIS)—discretionary Honorarium. Member of the Premier League Head Injury Advisory Group—no remuneration. Director of ICHIRF Ireland—no remuneration. Honorary Medical Adviser to the Concussion Foundation—no remuneration. Member of the expert panel for the Department of Digital, Culture, Media and Sport review into concussion in amateur sport—no remuneration. Attendance at conferences or meetings as a guest speaker—reimbursement of travel expenses, complimentary registration and payment of hotel accommodation and meals by the organising committee. No stocks or options in any concussion-related company. No consultancies, board or editorial positions related to concussion. KOY is Editor-in-Chief of the journal Neuropsychology and receives an editorial stipend from the American Psychological Association. He is an unpaid consulting editor for the journals Archives of Clinical Neuropsychology and Journal of Head Trauma Rehabilitation. He is an unpaid member of the Scientific Advisory Committee for Brain Injury Canada. He is the chair of the Canadian Concussion Network, which is funded by a grant from the Canadian Institutes of Health Research (CIHR) to his institution; he is the principal applicant for the grant but receives no income from it. He is a PI on another grant from CIHR from which he derives no income. He is a co-investigator on research grants from CIHR, the US NIH, Brain Canada Foundation and NFL Scientific Advisory Board; he derives income only from the grant from the NIH. He serves as a member of a CIHR grant review panel for which he receives a small honorarium. He receives book royalties from Guilford Press and Cambridge University Press. He has received travel support and honorarium for presentations to multiple organisations. He serves or has served on the following committees/boards for which he receives honorarium: (1) Independent Data Monitoring Committee, Care for Post-Concussive Symptoms EffecCveness (CARE4PCS-2) Trial, National Institute for Child Health and Human Development; (2) Observational Study Monitoring Board, Approaches and Decisions in Acute Pediatric TBI (ADAPT) Trial, National Institute of Neurological Disorders and Stroke National Research Advisory Council; (3) National Pediatric Rehabilitation Resource Center, Center for Pediatric Rehabilitation: Growing Research, Education, and Sharing Science, Virginia Tech University., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Concern exists about possible problems with later-in-life brain health, such as cognitive impairment, mental health problems and neurological diseases, in former athletes. We examined the future risk for adverse health effects associated with sport-related concussion, or exposure to repetitive head impacts, in former athletes., Design: Systematic review., Data Sources: Search of MEDLINE, Embase, Cochrane, CINAHL Plus and SPORTDiscus in October 2019 and updated in March 2022., Eligibility Criteria: Studies measuring future risk (cohort studies) or approximating that risk (case-control studies)., Results: Ten studies of former amateur athletes and 18 studies of former professional athletes were included. No postmortem neuropathology studies or neuroimaging studies met criteria for inclusion. Depression was examined in five studies in former amateur athletes, none identifying an increased risk. Nine studies examined suicidality or suicide as a manner of death, and none found an association with increased risk. Some studies comparing professional athletes with the general population reported associations between sports participation and dementia or amyotrophic lateral sclerosis (ALS) as a cause of death. Most did not control for potential confounding factors (eg, genetic, demographic, health-related or environmental), were ecological in design and had high risk of bias., Conclusion: Evidence does not support an increased risk of mental health or neurological diseases in former amateur athletes with exposure to repetitive head impacts. Some studies in former professional athletes suggest an increased risk of neurological disorders such as ALS and dementia; these findings need to be confirmed in higher quality studies with better control of confounding factors., Prospero Registration Number: CRD42022159486., Competing Interests: Competing interests: GLI serves as a scientific advisor for NanoDX, Sway Operations and Highmark. He has a clinical and consulting practice in forensic neuropsychology, including expert testimony, involving individuals who have sustained mild TBIs (including former athletes), and on the topic of suicide. He has received past research support or funding from several test publishing companies, including ImPACT Applications, CNS Vital Signs and Psychological Assessment Resources. He receives royalties from the sales of one neuropsychological test (WCST-64). He has received travel support and honorariums for presentations at conferences and meetings. He has received research funding as a principal investigator from the National Football League (NFL), and subcontract grant funding as a collaborator from the Harvard Integrated Programme to Protect and Improve the Health of NFL Players Association Members. He has received research funding from the Wounded Warrior Project. He acknowledges unrestricted philanthropic support from ImPACT Applications, the Mooney-Reed Charitable Foundation, the National Rugby League, Boston Bolts and the Schoen Adams Research Institute at Spaulding Rehabilitation. RJC is a collaborator on a grant funded by the NFL to study the spectrum of concussion, including possible long-term effects. He has a consulting practice in forensic neuropathology, including expert testimony, which has involved former athletes at amateur and professional levels. JDC has provided expert epidemiological testimony in court cases on the long-term effects of concussions in sports. GMS is an owner of a multidisciplinary practice (managing patients with MSK pain disorders). He is a board member of Hockey Calgary (Calgary, Alberta, Canada) and Chair of the Alberta Association of Physiotherapy. He received funding for the administrative aspects of the writing of two of the systematic reviews that informed the consensus process. KJS has received grant funding from the CIHR, NFL Scientific Advisory Board, International Olympic Committee Medical and Scientific Research Fund, World Rugby, Mitacs Accelerate, University of Calgary, with funds paid to her institution and not to her personally. She is an Associate Editor of BJSM (unpaid), Independent consultant to World Rugby and has received travel and accommodation support for meetings where she has presented. She coordinated the writing of the systematic reviews that informed Amsterdam International Consensus on Concussion in Sport, for which she has received an educational grant to assist with the administrative costs associated with the writing of the reviews (with funds paid to her institution). She is a member of the AFL Concussion Scientific Committee (unpaid position), Brain Canada (unpaid positions) and Board member of the Concussion in Sport Group (CISG)(unpaid). She works as a physiotherapy consultant and treats athletes of all levels of sport from grass roots to professional. RJE is a paid consultant for the NHL and cochair of the NHL/NHLPA Concussion Subcommittee. He is also a paid consultant and chair of the Major League Soccer concussion committee, and a consultant to the US Soccer Federation. He previously served as a neuropsychology consultant to Princeton University Athletic Medicine and EyeGuide. He is currently a co-Principal Investigator for a grant funded by the NFL (NFL-Long) through Boston Children’s Hospital. He occasionally provides expert testimony in matters related to MTBI and sports concussion, and occasionally receives honoraria and travel support/reimbursement for professional meetings. JB serves as the Chairman of the Medical Advisory Committee of Pop Warrner Football and is a member of the NFL Head, Neck, and Spine Committee, NFLPA Mackey-White Health and Safety Committee and the NCAA Concussion Task Force, all without remuneration. He is a consultant for BrainLab and has provided expert testimony on TBI medicolegal cases. IKK is a professor at Ludwig-Maximilians-Universität Munich (paid position). She serves as European Editor at Journal of Neurotrauma (unpaid position) and as Vice President of the European Neurotrauma Organisation (unpaid position). She receives research grant funding from the National Institutes of Health, the European Research Council, the German Ministry for Research and Education. She receives funding for a research study on sport-related concussion from Abbott. The university hospital received donations for her research from the Schatt Foundation and Mary Ann Liebert. She receives royalties for book chapters published by Thieme Publishers. Her spouse is employee at Siemens and she thus holds stock options at Siemens and Siemens Healthineers. In-kind contribution: PhD students working under her supervision receive scholarships from the Villigst Foundation, the China Scholarship Council collaboration with Ludwig-Maximilians-University Munich and Fulbright. GM discloses grants from the United States Department of Defense—TBI End points Development Initiative (grant #W81XWH-14-2-0176), TRACK-TBI Precision Medicine (grant # W81XWH-18-2-0042) and TRACK-TBI NETWORK (grant # W81XWH-15-9-0001); NIH-NINDS–TRACK-TBI (grant #U01NS086090) and the NFL Scientific Advisory Board—TRACK-TBI LONGITUDINAL. The United States Department of Energy supports GM for a precision medicine collaboration. One Mind has provided funding for TRACK-TBI patients stipends and support to clinical sites. He has received an unrestricted gift from the NFL to the UCSF Foundation to support research efforts of the TRACK-TBI NETWORK. GM has also received funding from NeuroTruama Sciences to support TRACK-TBI data curation efforts. Additionally, Abbott Laboratories has provided funding for add-in TRACK-TBI clinical studies. MMcN has the following disclosures: (i) Chair, Ethics Expert Group, WADA (2021–23) (paid); (ii) Member, International Boxing Association, Ethics and Integrity Committee, (2021–22; resigned October 2022) (paid); (iii) Chair, Therapeutic Use Exemption Fairness Committee (2020–Present) (paid); (iv) Member, Steering Group, Sex Segregation in Sport, IAAF/World Athletics (2019–20) (unpaid); (v) Member, International Ice Hockey Federation, Ethics and Integrity Committee (2019–21) (paid); (vi) Member, IOC Consensus Statement Expert Group on Injuries in Children and Adolescents (2017) (unpaid); (vii) Member, Ethics Expert Group, WADA (2016–21) (unpaid) and (viii) Member, IOC Consensus Statement Expert Group on Pain Management (2016) (unpaid). JP is a sports and exercise medicine physician at Waterfall Sports Orthopaedic Surgery, Johannesburg, South Africa. He is Director of Sports Concussion South Africa and a Visiting Professor, Wits Sport and Health (WiSH), School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand. As an Editor of BJSM, he receives an honorarium and serves as a consultant (unremunerated) to World Rugby Concussion Advisory Group, South African Rugby, EyeGuide Scientific Advisory Board and the Union of European Football Associations. He is co-chair of the Scientific Committee, 6th International Conference on Concussion in Sport (unpaid) and a Board member of the Concussion in Sport Group (unpaid). RCC serves as a scientific advisor for the NFL's Head Neck and Spine Committee, VP and Chair of the Scientific Advisory Committee for the National Operating Committee on Standards for Athletic Equipment (NOCSAE), and as co-founder and Medical Director of the Concussion Legacy Foundation. He currently receives research support from the NINDS UNITE and Diagnose CTE grants. He has received travel support and honorariums for presentations at conferences and meetings. He receives royalties from Houghton Mifflin Harcourt publishing. He has a clinical and consulting practice in forensic neurology and neurosurgery, including expert testimony, especially individuals with traumatic brain and spinal cord injuries. He is a member of the National Collegiate Athletic Association Student-Athlete Concussion Injury Litigation Medical Science Committee., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)