Differences in sport-related concussion for female and male athletes in comparable collegiate sports: a study from the NCAA-DoD Concussion Assessment, Research and Education (CARE) Consortium

Sex differences in postconcussive symptom reporting in those with history of concussion: Findings from the federal interagency traumatic brain injury research (FITBIR) database

Objective: This study investigated influence of biological sex on postconcussive symptoms (PCS) following concussion using the Federal Interagency Traumatic Brain Injury Research (FITBIR) database. Method: All studies with publicly released data as of 4/7/21 that included both males and females, enough information to determine severity of injury consistent with concussion, a measure of PCS, and objective measures of neurocognitive functioning were used. This resulted in 6 studies with a total of 9890 participants (3206 females, 6684 males); 815 participants completed the Neurobehavioral Symptom Inventory (NSI), 471 completed the Rivermead Post-Concussion Symptoms Questionnaire (RPSQ), and 8604 completed the Sport Concussion Assessment Tool-3rd Edition (SCAT 3). Questionnaires were harmonized and the following symptom composite scores were computed: total score, somatic, cognitive, and affective. Data were analyzed using linear mixed-effects models. Results: Females endorsed higher total symptoms relative to males and that military personnel endorsed higher symptoms relative to civilians. Additionally, there was a small but significant interaction effect, such that female military personnel endorsed even higher symptoms than would be predicted by the main effects. Similar patterns were observed for somatic, cognitive, and affective symptom domains. Conclusions: Further understanding sex differences in PCS reporting is key to informing the most appropriate treatment options. Future work will need to examine whether sex differences in symptom reporting is due to sex differences in endorsement styles or genuine differences in symptom presentation, as well as the relationship between study population (e.g., military, civilian, sport) and sex on objective cognitive functioning and other functional outcomes.

Use of the concussion check protocol for concussion assessment in a female soccer team over two consecutive seasons in New Zealand

AIM

Address deficiencies in access to sports sideline medical care by using a Concussion Check Protocol (CCP) for non-medically-trained people.

METHOD

A prospective observational cohort study was undertaken on a single amateur female club-based soccer team over two consecutive years in New Zealand utilising a non-medically trained support person termed a Safety officer. CCP is an extension of the King-Devick test with features such as warning signs and symptoms of concussion built into the application. All players suspected of having a potential concussive injury were tested on the match sideline.

RESULTS

The study overall incidence of match-related concussions was 20.8 (95% CI: 11.8 to 36.6) per 1000 match-hrs, with mean missed-match duration of 31 (95% CI: 27.9 to 34.1) days. Twelve players over the study had a significantly slower post-injury KD (49.9 [44.3 to 64.1]s; χ2(1) = 11.0; p = 0.0009; z = -2.9; p = 0.0033; d = 0.30) and/or reported symptoms, compared with their own baseline (47.2 [44.3 to 64.1]s). CCP had an overall sensitivity of 100% (95% CI: 73.5% to 100.0%), specificity of 100% (95% CI: 69.2% to 100.0%) and positive predictive value (PPV) of 100% (84.6% to 100.0%).

CONCLUSION

Sideline use of CCP was undertaken successfully by non-medically trained people and provided a reliable platform for concussion identification.

Recovery duration and concussion severity in sport- and non-sport-related concussion among Pac-12 collegiate athletes: a retrospective cohort study

OBJECTIVES

To examine non-sport- and sport-related concussion severity, clinical care frequency and delayed reporting in relation to recovery duration among collegiate athletes.

DESIGN

Retrospective cohort study.

SETTING

Pac-12 varsity collegiate athletes.

PARTICIPANTS

461 collegiate male and female athletes PRIMARY AND SECONDARY OUTCOME MEASURES: The incidence of sport-related concussion (SRC) and non-sport-related concussion (NRC) were collected as well as times to recovery and return-to-play (RTP), symptom score and symptom severity and reported a loss of consciousness (LOC), retrograde amnesia (RGA) and post-traumatic amnesia (PTA) following concussion incidence.

RESULTS

Among 461 concussions, 388 (84%) occurred within sport and 73 (16%) occurred outside of sport. NRC, on average, required 3.5 more days to become asymptomatic (HR: 0.73, 95%confidence interval: 0.56 to 0.96, p=0.02) and 7 more days to RTP (HR: 0.64, 95% confidence interval: 0.49 to 0.85, p<0.01) compared with SRC. NRC were associated with an increase of 1.83 (p=0.07) symptoms reported at the time of diagnosis, an increase of 6.95 (p=0.06) in symptom severity and a higher prevalence of reported LOC (22% NRC vs. 3% SRC, p<0.001), PTA (15% NRC vs. 5% SRC, p<0.01) and RGA (10% NRC vs. 4% SRC, p=0.06), compared with SRC. There was no significant difference in clinical care (p=0.28) or immediate reporting (p=0.35) between NRC and SRC.

CONCLUSION

NRC were associated with greater severity and longer recovery duration when compared with SRC in a cohort of collegiate athletes.

The Interval Between Concussions Does Not Influence Time to Asymptomatic or Return to Play: A CARE Consortium Study

INTRODUCTION

The purpose of this study was to determine if the time interval between two concussive events influences the number of days to asymptomatic status, days to return to play, or performance on common post-concussion assessments following the second concussion.

METHODS

Data from 448 collegiate athletes and service academy cadets with two concussions (time between concussions: median 295.0 days [interquartile range: 125.0-438.2]), 40.0% female) were analyzed from Concussion Assessment Research and Education (CARE) Consortium institutions between 2014 and 2020. Days between concussions was the primary predictor variable. Primary outcome measures included time to asymptomatic and time to return to play following the second concussion. Secondary outcome measures included total number of symptoms, total symptom severity, Balance Error Scoring System total score, and Standardized Assessment of Concussion total score within 48 h of their second concussion.

RESULTS

Time between concussions did not significantly contribute to the multivariate time to asymptomatic (p = 0.390), time to return to play (p = 0.859), or the secondary outcomes (p-range = 0.165-0.477) models. Time to asymptomatic (p = 0.619) or return to play (p = 0.524) did not differ between same-season and different-season concussions. Sex significantly contributed to the return to play (p = 0.005) multivariate model. Delayed symptom onset and immediate removal from play/competition significantly contributed to the total number of symptoms (p = 0.001, p = 0.014) and symptom severity (p = 0.011, p = 0.022) multivariate models.

CONCLUSION

These results suggest that in a population with a large period between injuries, the time between concussions may not be relevant to clinical recovery.

Sport-related concussion knowledge and attitudes of staff working in English elite women's football: a survey-based study

BACKGROUND

Sport-related concussion (SRC) remains an injury of concern in sport, including football(soccer). There has been little investigation into SRC knowledge and attitudes of support staff working in the professional setting.

METHODS

An amended version of the Rosenbaum Concussion Knowledge and Attitudes Survey(RoCKAS) was distributed online to coaching staff, and medical and performance staff, working at clubs in the English Football Association Women's SuperLeague (WSL) and Championship. Completion of the survey generated two scores: concussion knowledge index (CKI) and concussion attitudes index (CAI).

RESULTS

Sixty-three completed surveys were returned. Eighteen respondents were coaching staff, and 45 were medical and performance staff. The median CKI in medical and performance staff was significantly greater than in coaching staff. There was no significant difference in CAIbetween coaching staff and medical and performance staff. There was no correlation between CKI and CAI across all staff.

CONCLUSION

Medical and performance staff working in elite women's football have greater knowledge of SRC than coaching staff. However, this does not always translate into safe behaviours on the field. Education should continue to be mandated across the professional game amongst support staff in order to maximise player welfare and enhance injury outcomes, whilst also reinforcing present SRC guidance.

Postinjury Outcomes After Non-Sport-Related Concussion: A CARE Consortium Study

CONTEXT

Concussion research has primarily focused on sport-related mechanisms and excluded non-sport-related mechanisms. In adult populations, non-sport-related concussions (non-SRCs) demonstrated worse clinical outcomes compared with sport-related concussions (SRCs); however, investigations of non-SRCs in college-aged patients are limited.

OBJECTIVES

To examine clinical outcomes in collegiate athletes with non-SRCs compared with SRCs and explore sex differences in outcomes among collegiate athletes with non-SRCs.

DESIGN

Prospective cohort study.

SETTING

Clinical setting.

PATIENTS OR OTHER PARTICIPANTS

A total of 3500 athletes were included (n = 555 with non-SRCs, 42.5% female) from colleges or universities and service academies participating in the National Collegiate Athletic Association Department of Defense Concussion Assessment, Research and Education (CARE) Consortium.

MAIN OUTCOME MEASURE(S)

Dichotomous outcomes (yes or no) consisted of immediate reporting, mental status alterations, loss of consciousness, posttraumatic amnesia, retrograde amnesia, motor impairments, delayed symptom presentation, and required hospital transport. Continuous outcomes were symptom severity, days with concussion symptoms, and days lost to injury. Data were collected within 24 to 48 hours of injury and at return to play. Adjusted relative risks (ARRs) compared the likelihood of dichotomous outcomes by mechanism and by sex within patients with non-SRCs. Multivariate negative binomial regressions were used to assess group differences in continuous variables.

RESULTS

Athletes with non-SRCs were less likely to report immediately (ARR = 0.73, 95% CI = 0.65, 0.81) and more likely to report delayed symptom presentation (ARR = 1.17, 95% CI = 1.03, 1.32), loss of consciousness (ARR = 3.15, 95% CI = 2.32, 4.28), retrograde amnesia (ARR = 1.77, 95% CI = 1.22, 2.57), and motor impairment (ARR = 1.45, 95% CI = 1.14, 1.84). Athletes with non-SRCs described greater symptom severity, more symptomatic days, and more days lost to injury (P < .001) compared with those who had SRCs. Within the non-SRC group, female athletes indicated greater symptom severity, more symptomatic days, and more days lost to injury (P < .03) than male athletes.

CONCLUSIONS

Athletes with non-SRCs had worse postinjury outcomes compared with those who had SRCs, and female athletes with non-SRCs had worse recovery metrics than male athletes. Our findings suggest that further investigation of individuals with non-SRCs is needed to improve concussion reporting and management.

Factors Influencing Time to Return to Learn Among NCAA Student-Athletes Enrolled in the Concussion Assessment, Research, and Education (CARE) Study

PURPOSE

The aim was to describe the demographic and post-injury factors that influence time to return to learn (RTL) among student-athletes enrolled in the Concussion Assessment, Research and Education (CARE) Consortium.

METHODS

A total of 47,860 student-athletes enrolled in the National Collegiate Athletic Association-Department of Defense (NCAA-DoD) CARE Consortium study from 2014 to 2020, with 1485 sport-related concussions (SRCs) analyzed in the present dataset. Demographic and post-injury characteristics were calculated using descriptive statistics, followed by Kaplan-Meier estimates to examine median time to return to normal academic performance (i.e., RTL) by sex (male, female), baseline psychiatric conditions (depression, anxiety) and/or learning disorder, NCAA division (I, II, III), SRC history (0, 1, 2, 3+), NCAA sport category (contact, limited contact, non-contact sport), and median difference in baseline/post-injury symptom severity scores (< 21, ≥ 21). Further, a multivariable zero-inflated negative binomial (ZINB) regression model was used to examine their association with RTL.

RESULTS

Overall, time to RTL (mean = 4.96 ± 8.24 days, median = 3.0 [interquartile range = 0.0, 6.0] days) was found to be influenced by several factors resulting in earlier trajectories. Notably, nearly 25% of the sample demonstrated immediate RTL (i.e., 0 days). Among student-athletes who did not immediately RTL, males demonstrated a decreased rate in RTL (rate = 0.79; 95% CI 0.66-0.96) compared to females. Further, student-athletes with a ≥ 21 change in symptom severity score (post-injury baseline) demonstrated a higher rate of RTL (rate = 1.47; 95% CI 1.21-1.79) compared to student-athletes with a symptom severity change score < 21. Lastly, male student-athletes demonstrated two times higher odds (odds ratio = 1.95; 95% CI 1.02-3.73) of immediate RTL compared to female student-athletes. No other covariates were associated with time to RTL.

CONCLUSION

Collectively, the present findings suggest a rapid return to the classroom following concussion. Specifically, males demonstrated higher odds of time to RTL, whereas those with greater differences in symptom severity resulted in a higher rate of time to RTL among those who did not immediately RTL. Ultimately, these findings support prior work emphasizing an individualized approach to SRC management.

Sex-Biased Expression and Response of microRNAs in Neurological Diseases and Neurotrauma

Neurological diseases and neurotrauma manifest significant sex differences in prevalence, progression, outcome, and therapeutic responses. Genetic predisposition, sex hormones, inflammation, and environmental exposures are among many physiological and pathological factors that impact the sex disparity in neurological diseases. MicroRNAs (miRNAs) are a powerful class of gene expression regulator that are extensively involved in mediating biological pathways. Emerging evidence demonstrates that miRNAs play a crucial role in the sex dimorphism observed in various human diseases, including neurological diseases. Understanding the sex differences in miRNA expression and response is believed to have important implications for assessing the risk of neurological disease, defining therapeutic intervention strategies, and advancing both basic research and clinical investigations. However, there is limited research exploring the extent to which miRNAs contribute to the sex disparities observed in various neurological diseases. Here, we review the current state of knowledge related to the sexual dimorphism in miRNAs in neurological diseases and neurotrauma research. We also discuss how sex chromosomes may contribute to the miRNA sexual dimorphism phenomenon. We attempt to emphasize the significance of sexual dimorphism in miRNA biology in human diseases and to advocate a gender/sex-balanced science.

Exploring the relationship between contraceptive medication use and concussion recovery in female collegiate athletes: a LIMBIC MATARS consortium investigation

OBJECTIVE

While recovery from concussion is variable, women are more likely to report symptoms, experience worse outcomes, and have longer recovery trajectories following concussion than men. Preliminary data suggest that hormonal fluctuations, specifically progesterone, may be associated with this variability. This study aimed to understand the effect of contraceptive medication on concussion recovery.

METHODS

A retrospective chart review using consensus-based common data elements was conducted at 11 NCAA institutions as part of the LIMBIC MATARS consortium. Participants included female collegiate athletes diagnosed with a concussion who did (n = 117) or did not report (n = 339) contraceptive medication use. Number of days between diagnosis and symptom resolution were compared using Mann-Whitney U tests. Self-reported diagnosis of attention deficit hyperactivity disorder, concussion history, anxiety, and depression was compared using Chi-squared tests.

RESULTS

The proportions of participants who did or did not take contraceptive medication were similar across covariates. Female athletes regardless of contraceptive medication use recovered similarly following a concussion.

CONCLUSIONS

Our findings suggest that contraceptive medication use did not significantly impact concussion recovery. Future prospective investigations should examine documentation practices and operationalize terminology for hormonal contraceptive medication to better understand their role on recovery from sport-related concussion in female collegiate athletes.

Placing the keystone: the LIMBIC Military and Tactical Athlete Research Study

OBJECTIVE

The LIMBIC Military and Tactical Athletic Research Study (MATARS) framework was established to confirm and extend understanding of concussion with initial studies driven by clinical data collected between 2015 and 2020 in a collegiate sports setting. The LIMBIC MATARS framework will be leveraged to apply gold-standard and innovative research designs to advance the science of concussion. This manuscript provides the background, methodology, and initial demographic data associated with the LIMBIC MATARS.

METHODS

Consensus-based common data elements were used to conduct a retrospective chart review, specific to collegiate athletes diagnosed with concussions between 2015 and 2020 at 11 universities.

RESULTS

A final sample of 1,311 (47.8% female) concussions were diagnosed during the five-year study period from athletes participating in a variety of National Collegiate Athlete Association (NCAA) sports. The LIMBIC MATARS demographic data, align with the NCAA and other pioneering multi-site concussion-related studies in terms of biological sex, race and ethnicity, and sport participation.

CONCLUSION

This pragmatic, methodological approach was used to address several a priori hypotheses related to concussion, align with other multi-site studies of concussion, and establish a consortium for future investigations.

Access to athletic trainers and sex as modifiers of time to reach clinical milestones after sport-related concussion in collegiate athletes

OBJECTIVE

Investigate whether an athlete's biological sex and exposure to a dedicated athletic trainer (AT) were related to clinical milestones after a sports-related concussion (SRC).

DESIGN

Retrospective chart review.

METHODS

Medical charts of collegiate athletes (n = 196 [70.9% female]) diagnosed with SRC were reviewed to extract: biological sex, dedicated AT exposure for their sport (yes/no), and time (days) to reaching clinical milestones (diagnosis, symptom resolution, unrestricted return to sport [RTS]). Mann-Whitney U tests were used to determine whether time to clinical milestones differed by sex, AT exposure, or their interaction. Proportions of same-day diagnoses and times to diagnosis, symptom resolution, and unrestricted RTS were evaluated with chi-squared and spearman's rank correlations, respectively.

RESULTS

There were no significant differences in times to reaching any clinical milestone by sex, AT exposure, or their interaction (ps > 0.05). Forty-three percent of participants were diagnosed on the day of their SRC. This did not differ by sex or AT exposure (ps > 0.29). Longer times to SRC diagnosis were associated with more days to symptom resolution (ρ = 0.236, p = 0.001) and unrestricted RTS (ρ = 0.223, p < 0.001).

CONCLUSIONS

Athlete sex and AT exposure were not associated with times to reach any clinical milestone; however, delayed diagnosis was associated with longer times to reach clinical recovery.

Sex Differences in Recovery Trajectories of Assessments for Sport-Related Concussion Among NCAA Athletes: A CARE Consortium Study

OBJECTIVES

The purpose of this study was to determine sex differences in recovery trajectories of assessments for sport-related concussion using Concussion Assessment, Research and Education (CARE) Consortium data.

METHODS

National Collegiate Athletic Association athletes (N = 906; 61% female) from sex-comparable sports completed a pre-season baseline assessment and post-sport-related concussion assessments within 6 h of injury, 24-48 h, when they initiated their return to play progression, when they were cleared for unrestricted return to play, and 6 months post-injury. Assessments included the Standardized Assessment of Concussion, Balance Error Scoring System, Brief Symptom Inventory-18, Immediate Post-concussion Assessment and Cognitive Testing (ImPACT), Sport Concussion Assessment Tool-3 symptom evaluation, Clinical Reaction Time, King-Devick test, Vestibular Ocular Motor Screen, 12-item Short-Form Health Survey, Hospital Anxiety and Depression Scale, and Satisfaction with Life Scale.

RESULTS

Only the Vestibular Ocular Motor Screen Total Symptom Score at the 24-48 h timepoint (p = 0.005) was statistically significantly different between sexes. Specifically, female athletes (mean = 60.2, 95% confidence interval [CI] 51.5-70.4) had higher Vestibular Ocular Motor Screen Total Symptom Scores than male athletes (mean = 36.9, 95% CI 27.6-49.3), but this difference resolved by the time of return-to-play initiation (female athletes, mean = 1.8, 95% CI 1.1-2.9; male athletes, mean = 4.1, 95% CI 1.5-10.9).

CONCLUSIONS

Sport-related concussion recovery trajectories for most assessments were similar for female and male National Collegiate Athletic Association athletes except for Vestibular Ocular Motor Screen symptoms within 48 h of sport-related concussion, which was greater in female athletes. Female athletes had a greater symptom burden across all timepoints, suggesting that cross-sectional observations may indicate sex differences despite similar recovery trajectories.

The 50 Most Cited Papers on Rugby since 2000 Reveal a Focus Primarily on Strength and Conditioning in Elite Male Players

We sought to conduct a bibliometric analysis and review of the most cited publications relating to rugby since 2000 in order to identify topics of interest and those that warrant further investigations. Clarivate Web of Science database was used to perform a literature search using the search term "rugby." The top 200 papers by citation count were extracted and reviewed for the inclusion criteria: all subjects were rugby players. The top 50 manuscripts were included for analysis of author, publication year, country of lead authors, institution, journal name and impact factor, topic, participant sex, and level of rugby. The total number of citations was 9,071 (average of 181.4 citations/article), with an average journal impact factor of 7.21; the top article was cited 407 times at the time of analysis. The most frequent publication was the Journal of Strength and Conditioning Research (26%), followed by the British Journal of Sports Medicine (20%) and the Journal of Sports Sciences (18%). Forty-eight (96%) of the manuscripts contained only male subjects, with 1 manuscript including females only and 1 manuscript containing mixed sexes. Thirty-three (66%) of the manuscripts focused on professional rugby players, with the next highest player group being mixed levels (10%). Twenty-eight (56%) concentrated on topics regarding strength and conditioning, 11 (22%) on injury, and 4 (8%) on physiology. Despite rugby being one of the most injurious sports and community players representing the largest component of the player pool, most of the top-cited rugby articles are cohort studies of professional male athletes focused on performance and strength and conditioning, noting the bias in research towards socially relevant topics that may not impact the majority of stakeholders and long-term health of rugby athletes. These findings highlight the need for further research among women and community athletes and on topics in injury prevention.

Estimating the Relationship Between the Symptom-Free Waiting Period and Injury Rates After Return-to-Play from Concussion: A Simulation Analysis Using CARE Consortium Data

BACKGROUND

A key component of return-to-play (RTP) from sport-related concussion is the symptom-free waiting period (SFWP), i.e., the period during which athletes must remain symptom-free before permitting RTP. Yet, the exact relationship between SFWP and post-RTP injury rates is unclear.

OBJECTIVE

We design computational simulations to estimate the relationship between the SFWP and rates of repeat concussion and non-concussion time-loss injury up to 30 days post-RTP for male and female collegiate athletes across 13 sports.

METHODS

We leverage N = 735 female and N = 1,094 male post-injury trajectories from the National Collegiate Athletic Association-Department of Defense Concussion Assessment, Research, and Education Consortium.

RESULTS

With a 6-day SFWP, the mean [95% CI] rate of repeat concussion per 1,000 simulations was greatest in ice hockey for females (20.31, [20.16, 20.46]) and American football for males (24.16, [24.05, 24.28]). Non-concussion time-loss injury rates were greatest in field hockey for females (153.66, [152.59, 154.74]) and wrestling for males (247.34, [246.20, 248.48]). Increasing to a 13-day SFWP, ice hockey for females (18.88, [18.79, 18.98]) and American football for males (23.16, [23.09, 24.22]) exhibit the greatest decrease in repeat concussion rates across all sports within their respective sexes. Field hockey for females (143.24, [142.53, 143.94]) and wrestling for males (237.73, [236.67, 237.90]) exhibit the greatest decrease in non-concussion time-loss injury rates. Males receive marginally smaller reductions in injury rates for increased SFWP compared to females (OR = 1.003, p ≤ 0.002).

CONCLUSION

Longer SFWPs lead to greater reductions in post-RTP injury rates for athletes in higher risk sports. Moreover, SFWPs should be tailored to sport-specific post-RTP injury risks.

Intersection of Race and Socioeconomic Status on Concussion Recovery among NCAA Student-Athletes: A CARE Consortium Study

PURPOSE

The objectives of this study are to 1) describe collegiate student-athlete (SA) race and household income and 2) evaluate time to normal academic performance (i.e., return to learn (RTL)), initiation of the return to play (iRTP) protocol, RTP protocol duration, and time to unrestricted RTP (URTP) after sustaining sport-related concussion (SRC).

METHODS

Data were collected between 2014 and 2020 by the Concussion Assessment, Research, and Education Consortium. Baseline data were used to characterize participant demographics ( N = 22,819) and post-SRC outcomes ( n = 5485 SRC) in time to RTL ( n = 1724) and RTP outcomes ( n = 2646) by race. Descriptive statistics and nonparametric tests examined differences across race by demographic and injury characteristics. Kaplan-Meier curves estimated median days to RTL, iRTP protocol, RTP protocol completion, and URTP by race and covariate measures. Multivariable Cox proportional hazards regression assessed the effect of race on risk of RTL and RTP recovery time points.

RESULTS

SA largely identified as White (75%) followed by Black (14%), multiracial (7%), and Asian (3%). More than half (53%) of all SA reported a household income of >$120,000, whereas 41% of Black SA reported a household income <$60,000. Race was not associated with relative risk of RTL or iRTP but was associated with RTP protocol completion and URTP. Non-Black/non-White SA were 17% less likely (adjusted hazard ratio = 0.83; 95% confidence interval = 0.71, 0.97) to complete the RTP protocol, and Black SA were 17% more likely (adjusted hazard ratio = 1.17; 95% confidence interval = 1.05, 1.31) to reach the URTP time point compared with White SA.

CONCLUSIONS

The present findings suggest collegiate SA enrolled in the Concussion Assessment, Research, and Education Consortium are primarily White and come from household incomes well above the US median. Race was not associated with RTL or iRTP but was associated with RTP protocol duration and total time to URTP. Clinicians should be conscientious of how their implicit or preconceived biases may influence SRC management among National Collegiate Athletic Association SA.

Sport-Specific Recovery Trajectories for NCAA Collegiate Athletes Following Concussion

The recovery trajectories of collegiate athletes with sport-related concussion (SRC) are well characterized in contact/collision sports but are less well understood in limited contact sports with lower risk, reducing the ability of clinicians to effectively manage the return-to-play (RTP) process. The current study investigated the time to asymptomatic and RTP across a broad range of male and female collegiate sports and sought to group sports by recovery intervals. Data from the Concussion Assessment, Research and Education (CARE) Consortium included 1049 collegiate athletes who sustained a SRC while participating in game or practice/training of their primary sport. Injury setting and subsequent clinical presentation data were obtained. Survival analysis using the Cox Proportional Hazard model estimated the median recovery times for each sport. Optimal univariate K-means clustering grouped sports into recovery categories. Across all sports, median time to asymptomatic following SRC ranged from 5.9 (female basketball) to 8.6 days (male wrestling). Median RTP protocol duration ranged from 4.9 days (female volleyball) to 6.3 days (male wrestling). Median total RTP days ranged from 11.2 days (female lacrosse) to 16.9 days (male wrestling). Sport clusters based on recovery differences in time to asymptomatic (3) and RTP protocol duration (2) were identified. The findings from this study of a large sample of more than 1000 NCAA collegiate athletes with SRC show there exists ranges in recovery trajectories. Clinicians can thus manage athletes with similar guidelines, with individualized treatment and recovery plans.

An Absence of Persistent Postural Stability Deficits Following a Sport Concussion in Collegiate Athletes

OBJECTIVE

The purpose of our study was to determine whether persistent postural stability deficits exist in athletes following sport concussion (SC) in comparison with preinjury (baseline) values using Sample Entropy (SampEn).

SETTING

Sports medicine clinic.

PATIENTS OR OTHER PARTICIPANTS

Participants consisted of 71 collegiate athletes (44 male, 27 female) with an average age of 19.9 ± 0.96 years who had a history of 1 concussion that occurred during their time as a collegiate athlete.

DESIGN

In our prospective, cohort design participants completed the Sensory Organization Test (SOT) at baseline, upon reporting symptom-free following a diagnosed SC, and upon establishing a new baseline prior to the start of the subsequent sport season.

MAIN OUTCOME MEASURES

The SOT's condition scores were calculated and analyzed in alignment with the manufacturer's instructions. SampEn was calculated in the anterior-posterior (AP) and medial-lateral (ML) directions from the center-of-pressure oscillations over the 20-second time series for each SOT condition. The SOT and SampEn outcome scores for each condition were analyzed with repeated-measures analyses of variance.

RESULTS

Significant main effects were observed for the SOT's conditions 3 ( F1.6, 114.8 = 7.83, P = .001, η2 = 0.10 [0.02-0.20]), 5 ( F1.8, 126.8 = 11.53, P < .001, η2 = 0.14 [0.04-0.25]), and 6 ( F1.9, 134.5 = 25.11, P < .001, η2 = 0.26 [0.14-0.37]), with significant improvements across time. Significant main effects were also observed for SampEn in the AP direction for conditions 3 ( F2, 140 = 7.59, P = .001, η2 = 0.10 [0.02-0.19]) and 6 ( F2, 140 = 6.22, P = .003, η2 = 0.08 [0.011-0.170]), with significant improvements across time.

CONCLUSIONS

Following a diagnosed SC, our results suggest that collegiate athletes returned if not exceeded baseline values at the symptom-free and new baseline assessments. The application of linear and nonlinear measures of postural stability following a SC yielded similar outcomes in conjunction with a baseline assessment. Our findings support the clinical utility of the baseline SC assessment when evaluating persisting balance deficits when using linear or nonlinear measures.

Some problems of research exploring sex differences in sport-related concussions: a narrative review

This narrative review scrutinizes research exploring sex-based differences in experiences of sport-related concussion. The article argues that the limitations of epidemiological studies identifying the greater incidence and severity of concussion among females require that these findings are read with caution. It secondly argues that the dominant explanations for these data are based on and extend historical tendencies to "other" female participation in sport and construct male experiences as the "norm". Finally, the article critiques policy recommendations related to these research findings, arguing that they are likely to embed rather than challenge sex inequality in sport, and that they are both impractical and unethical. While this commentary builds on a broader body of work advocating greater sex/gender equality in sports science research, the prominence of social concerns about concussions in sport makes the broader implications of the focus on sex and sport-related concussion particularly problematic and thus in need of redress.

Female Collegiate Athletes' Concussion Characteristics and Recovery Patterns: A Report from the NCAA-DoD CARE Consortium

Concussion has been described in the United States (US) collegiate student-athlete population, but female-specific findings are often underrepresented and underreported. Our study aimed to describe female collegiate student-athletes' initial injury characteristics and return to activity outcomes following concussion. Female collegiate student-athletes (n = 1393) from 30-US institutions experienced a concussion and completed standardized, multimodal concussion assessments from pre-injury through unrestricted return to play (uRTP) in this prospective, longitudinal cohort study. Initial injury presentation characteristics, assessment, and return to activity outcomes [<48-h (acute), return to learn, initiate return to play (iRTP), uRTP] were collected. We used descriptive statistics to report injury characteristics, return to activity outcomes, and post-injury assessment performance change categorization (worsened, unchanged, improved) based on change score confidence rank criteria across sport contact classifications [contact (n = 661), limited (n = 446), non-contact (n = 286)]. The median (25th to 75th percentile) days to return to learn was 6.0 (3.0-10.0), iRTP was 8.1 (4.8-13.8), and uRTP was 14.8 (9.9-24.0), but varied by contact classification. Across contact levels, the majority experienced worse SCAT total symptom severity (72.8-82.6%), ImPACT reaction time (91.2-92.6%), and BSI-18 total score (45.2-51.8%) acutely relative to baseline, but unchanged BESS total errors (58.0-60.9%), SAC total score (71.5-76.1%), and remaining ImPACT domains (50.6-66.5%). Our findings provide robust estimates of the typical female collegiate student-athlete presentation and recovery trajectory following concussion, with overall similar findings to the limited female collegiate student-athlete literature. Overall varying confidence rank classification was observed acutely. Our findings provide clinically-relevant insights for athletes, clinicians, researchers, and policymakers to inform efforts specific to females experiencing concussion.

Initial Mild Traumatic Brain Injury Characteristics and Recovery Patterns Among Females Across the United States Military Service Academies: A Report from the NCAA-DoD CARE Consortium

Mild traumatic brain injury (mTBI) has been described in the United States (US) military service academy cadet population, but female-specific characteristics and recovery outcomes are poorly characterized despite sex being a confounder. Our objective was to describe female cadets' initial characteristics, assessment performance, and return-to-activity outcomes post-mTBI. Female cadets (n = 472) from the four US military service academies who experienced a mTBI completed standardized mTBI assessments from pre-injury to acute initial injury and unrestricted return-to-duty (uRTD). Initial injury presentation characteristics (e.g., delayed symptoms, retrograde amnesia) and return-to-activity outcomes [i.e., return-to-learn, initiate return-to-duty protocol (iRTD), uRTD] were documented. Descriptive statistics summarized female cadets' injury characteristics, return-to-activity outcomes, and post-mTBI assessment performance change categorization (worsened, unchanged, improved) relative to pre-injury baseline using established change score confidence rank criteria for each assessment score. The median (interquartile range) days to return-to-learn (n = 157) was 7.0 (3.0-14.0), to iRTD (n = 412) was 14.7 (8.6-25.8), and to uRTD (n = 431) was 26.0 (17.7-41.8). The majority experienced worse SCAT total symptom severity (77.8%) and ImPACT reaction time (97.0%) acutely < 24-h versus baseline, but unchanged BESS total errors (75.2%), SAC total score (72%), BSI-18 total score (69.6%), and ImPACT verbal memory (62.3%), visual memory (58.4%), and visual motor speed (52.5%). We observed similar return-to-activity times in the present female cadet cohort relative to the existing female-specific literature. Confidence ranks categorizing post-mTBI performance were heterogenous and indicate multimodal assessments are necessary. Our findings provide clinically relevant insights to female cadets experiencing mTBI across the US service academies for stakeholders providing healthcare.

Association Between Symptom Cluster Endorsement at Initiation of a Graduated Return-to-Activity Protocol and Time to Return to Unrestricted Activity After Concussion in United States Service Academy Cadets

BACKGROUND

The endorsement of symptoms upon initiation of a graduated return-to-activity (GRTA) protocol has been associated with prolonged protocols. It is unclear whether there are specific symptom clusters affecting protocol durations.

PURPOSE

To describe the endorsement of specific concussion symptom clusters at GRTA protocol initiation and examine the association between symptom cluster endorsement and GRTA protocol duration.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This study was conducted among cadets enrolled at 3 US service academies. Participants completed an evaluation upon GRTA protocol initiation. Participants endorsing symptoms were binarized based on 6 symptom clusters (cognitive, emotional, insomnia, physical, sensitivity, and ungrouped). The primary outcome of interest was GRTA protocol duration based on symptom cluster endorsement severity. Prevalence rates were calculated to describe symptom cluster endorsement. Kaplan-Meier survival estimates and univariate and multivariable Cox proportional hazards regression models were calculated for all 6 symptom clusters to estimate GRTA protocol duration while controlling for significant covariates.

RESULTS

Data from 961 concussed participants were analyzed. Of these, 636 participants were asymptomatic upon GRTA protocol initiation. Among the 325 symptomatic participants, the physical symptom cluster (80%) was most endorsed, followed by the cognitive (29%), insomnia (23%), ungrouped (19%), sensitivity (15%), and emotional (9%) clusters. Univariate results revealed a significant association between endorsing cognitive (hazard ratio [HR], 0.79; p = .001), physical (HR, 0.84; p < .001), insomnia (HR, 0.83; p = .013), sensitivity (HR, 0.70; p < .001), and ungrouped (HR, 0.75; p = .005) symptom clusters and GRTA protocol duration. Endorsing physical (HR, 0.84; p < .001) and sensitivity (HR, 0.81; p = .036) clusters maintained a significant association with GRTA protocol duration in the multivariable models.

CONCLUSION

Participants endorsing physical or sensitivity symptom clusters displayed GRTA protocols prolonged by 16% to 19% compared with participants not endorsing that respective cluster after controlling for significant covariates.

Temporal Network Analysis of Neurocognitive Functioning and Psychological Symptoms in Collegiate Athletes After Concussion

Sport-related concussion (SRC) is associated with several post-injury consequences, including neurocognitive decrements and psychological distress. Yet, how these clinical markers interact with each other, the magnitude of their interrelationships, and how they may vary over time following SRC are not well understood. Network analysis has been proposed as a statistical and psychometric method to conceptualize and map the complex interplay of interactions between observed variables (e.g., neurocognitive functioning and psychological symptoms). For each collegiate athlete with SRC (n = 565), we constructed a temporal network as a weighted graph, with nodes, edges, and the set of weights associated with each edge at three time-points (baseline, 24-48 h post-injury, and asymptomatic), that graphically depicts the interrelated nature of neurocognitive functioning and symptoms of psychological distress throughout the recovery process. This graph shows that the inter-group relationships between neurocognitive functioning and symptoms of psychological distress were stronger at the 24-48 h time-point than at baseline or at the asymptomatic time-point. Further, all symptoms of psychological distress and neurocognitive functioning significantly improved from the 24-48 h time-point to asymptomatic status. The effect sizes of these changes ranged from 0.126 (small) to 0.616 (medium). This research suggests that significant improvements in symptoms of psychological distress appear necessary to drive related improvements in neurocognitive functioning and vice versa. Therefore, clinical interventions should consider the importance of managing psychological distress during the acute care of individuals with SRC to help ameliorate negative outcomes.

Comparison of Volleyball-Related Injuries at US Emergency Departments Between High School and Collegiate Athletes: A 10-Year NEISS Database Study

Background

There is a paucity of current data regarding the sport-specific injury patterns and epidemiological trends associated with volleyball.

Purpose

To provide an updated, comparative assessment of the epidemiology of volleyball-related injuries among female high school- and college-aged athletes and to characterize the burden of these injuries on emergency departments (EDs) across the United States.

Study Design

Descriptive epidemiological study.

Methods

Data were obtained from the National Electronic Injury Surveillance System for volleyball-related injuries between 2012 and 2021 in high school-aged (14-18 years) and college-aged (19-23 years) patients. Incidence, injury characteristics, incident locales, and dispositions were analyzed with weighted population statistics based on National Federation of State High School Associations and National Collegiate Athletic Association data as well as incidence rates and incidence rate ratios (IRRs) and 95% CIs.

Results

In total, an estimated 214,302 female athletes aged 14 to 23 years were evaluated in EDs across the United States with volleyball-related injuries between 2012 and 2021. Female college-aged athletes were nearly 3 times more likely to be evaluated with these injuries than their high school-aged counterparts, with incidence rates of 12.8 per 100 at-risk individuals among college-aged athletes and 4.3 per 100 at-risk individuals in high school-aged athletes (IRR, 0.338; 95% CI, 0.333-0.342). The ankle, head, and knee were most frequently injured, often involving strains/sprains, contusions, fractures, and concussions. The IRRs of nearly all injuries were higher among collegiate athletes, especially among knee (IRR, 4.56; 95% CI, 4.40-4.72) and shoulder (IRR, 5.07; 95% CI, 4.81-5.35) injuries.

Conclusion

Among volleyball-related injuries evaluated in EDs between 2012 and 2021, the incidence rates of injuries in college-aged athletes far surpassed those of their high school-aged peers irrespective of injury type or bodily location. While sprains and strains were the most frequent injuries, head injuries accounted for the second most common diagnosis in both groups, suggesting that clinicians should maintain a high index of suspicion for concussion when evaluating players.

Clinical recovery from concussion-return to school and sport: a systematic review and meta-analysis

OBJECTIVE

To define the time frames, measures used and modifying factors influencing recovery, return to school/learn (RTL) and return to sport (RTS) after sport-related concussion (SRC).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

8 databases searched through 22 March 2022.

ELIGIBILITY CRITERIA

Studies with diagnosed/suspected SRC and interventions facilitating RTL/RTS or investigating the time and modifying factors for clinical recovery. Outcomes included days until symptom free, days until RTL and days until RTS. We documented study design, population, methodology and results. Risk of bias was evaluated using a modified Scottish Intercollegiate Guidelines Network tool.

RESULTS

278 studies were included (80.6% cohort studies and 92.8% from North America). 7.9% were considered high-quality studies, while 23.0% were considered high risk of bias and inadmissible. The mean days until symptom free was 14.0 days (95% CI: 12.7, 15.4; I²=98.0%). The mean days until RTL was 8.3 (95% CI: 5.6, 11.1; I²=99.3%), with 93% of athletes having a full RTL by 10 days without new academic support. The mean days until RTS was 19.8 days (95% CI: 18.8, 20.7; I²=99.3%), with high heterogeneity between studies. Several measures define and track recovery, with initial symptom burden remaining the strongest predictor of longer days until RTS. Continuing to play and delayed access to healthcare providers were associated with longer recovery. Premorbid and postmorbid factors (eg, depression/anxiety, migraine history) may modify recovery time frames. Though point estimates suggest that female sex or younger age cohorts take longer to recover, the heterogeneity of study designs, outcomes and overlap in CIs with male sex or older age cohorts suggests that all have similar recovery patterns.

CONCLUSION

Most athletes have full RTL by 10 days but take twice as long for an RTS.

PROSPERO REGISTRATION NUMBER

CRD42020159928.

Primary and Secondary Risk Factors Associated With Concussion Symptom Clusters in Collegiate Athletes: Results From the NCAA-DoD Grand Alliance CARE Consortium

Background

There is a broad and diverse range of symptoms after a concussion, from irritability to nausea. This heterogeneity of symptoms is a challenge for clinicians managing the different presentations among injuries. Prior research has investigated the structure of postconcussive symptoms to determine if they can be grouped into clusters of related symptoms.

Purpose/Hypothesis

The purpose of this study was to identify symptom clusters during the acute phase after a sports-related concussion using exploratory factor analysis and to understand the relationship between risk factors for postconcussion symptoms (ie, demographics, injury characteristics, mental health, and sleep qualities) and different symptom clusters. We hypothesized that certain factors would be predictive of specific symptom clusters.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Collegiate athletes (N = 1104) from the Concussion, Assessment, Research, and Education (CARE) Consortium completed the Sport Concussion Assessment Tool-Third Edition symptom assessment tool 24 to 48 hours after concussion. Exploratory factor analysis was conducted on the symptom evaluation to determine symptom clusters 24 to 48 hours after concussion. Regression analysis was used to examine the effects of pre- and postinjury characteristics.

Results

Exploratory factor analysis revealed a 4-cluster structure for acute postconcussive symptoms that explained 62% of the variance in symptom reporting: vestibular-cognitive, migrainous, cognitive fatigue, and affective. Delayed reporting, less sleep before assessment, female sex, and being hurt outside of competition (during practice/training) was correlated with increased symptoms for 4 symptom clusters. Depression predicted higher vestibular-cognitive and affective symptoms. Amnesia was correlated with higher vestibular-cognitive and migrainous symptoms, whereas migraine history was associated with more migrainous and affective symptoms.

Conclusion

Symptoms can be grouped into 1 of 4 distinct clusters. Certain variables were associated with increased symptoms across multiple clusters and may be indicative of greater injury severity. Other factors (ie, migraine history, depression, amnesia) were associated with a more specific symptom presentation and may be mechanistically related to concussion outcomes and biological markers.

Reconceptualizing Recovery After Concussion: A Phenomenological Exploration of College Student Experiences

PURPOSE

Typical measures of recovery from concussion-such as symptom scales, neurocognitive testing, or exertion measures-may not capture individualized experiences of concussion. This report examines how college students with concussion interact with and consider their recovery.

METHOD

Sixteen college students who sustained concussions while in college completed 40- to 75-min semistructured interviews. All were enrolling to become mentors in a peer mentoring program for students with concussion. Questions addressed experiences as a college student with concussion, life changes following concussion, and role of peers in recovery. Using phenomenological reduction, analysis focused on the phenomenon of recovery and motivation for participation in a mentoring program.

RESULTS

Two main themes were found: (a) What Recovery Looks Like and (b) Gaining Perspective, Learning to Cope and Adapting to Change. Thirteen participants denied the label of "recovered" even though all had been deemed recovered and discharged from medical care. Instead, two subthemes emerged within What Recovery Looks Like: Ongoing Recovery and Reconceptualizing Recovery. Perceptions of recovery were influenced by effort, capacity, and resilience. In the second theme, students described strategies, resources, and supports used to cope with their injuries; most commonly used was emotion-focused coping.

CONCLUSIONS

College students with concussion consider recovery as an ongoing process rather than a dichotomized condition. Student experiences may not be reflected in commonly used symptom scales or objective assessments.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21084925.

Median Time to Return to Sports After Concussion Is Within 21 Days in 80% of Published Studies

PURPOSE

To perform a systematic review of the literature and evaluate the return to play (RTP) time frame after a concussion diagnosis. Our secondary purpose was to analyze and compare different prognostic variables affecting concussions, time to return to school, time to symptom resolution of concussive symptoms, and time each patient spent in the RTP protocol.

METHODS

A PubMed, Scopus, Medline, Embase, and Cochrane Library database literature review was performed in August 2022. The studies needed to report, in days, the length of time a patient/athlete was removed from play due to concussion management. The Risk of Bias in Non-Randomized Studies of Interventions tool was used for risk of bias for each study, and Methodological Index for Non-Randomized Studies criteria were used for quality assessment.

RESULTS

There were 65 studies included in the systematic review and a total of 21,966 patients evaluated. The RTP time intervals ranged from 1 to 1,820 days, with 80.7% of the median RTP time frames for each study within 21 days. Preconcussion risk factors for prolonged RTP included female sex, younger age, presence of psychiatric disorders, and history of previous concussion. Postconcussion risk factors included severe symptom scores at initial clinic visit, loss of consciousness, nonelite athletes, and delayed removal from competition. The most common sports resulting in concussion were contact sports, most commonly football and soccer. Median time to return to school was 3 to 23 days. Median time to symptom resolution ranged from 2 to 11 days. Median time in RTP protocol was 1 to 6 days.

CONCLUSIONS

Median time to return to sports after concussion is within 21 days in 80% of published studies.

LEVEL OF EVIDENCE

IV, systematic review of Level I to IV studies.

Cognitive and Behavioral Outcomes in Male and Female NCAA Soccer Athletes across Multiple Years: A CARE Consortium Study

PURPOSE

The purpose of this study was to determine changes in neurocognitive, psychosocial, and balance functioning in collegiate male and female soccer players across three consecutive years of baseline testing compared with a control group of noncontact athletes.

METHODS

Generalized estimating equations were used to compare changes in annual, preseason baseline measures of neurocognitive function, neurobehavioral and psychological symptoms, and postural stability between collegiate soccer players ( n = 75; 51 [68%] female soccer players) and noncontact athletes ( n = 210; 133 [63%] female noncontact athletes) across three consecutive years.

RESULTS

Among all participants, the group-time interaction was not significant for any outcome measures. Overall, soccer players reported lower (better) Brief Symptom Inventory 18 Depression ( P = 0.004, Exp(B) = 0.36, 95% confidence interval [CI] = 0.18-0.73), Global Severity Index ( P = 0.006, Exp(B) = 0.53, 95% CI = 0.33-0.84), and Post-Concussion Symptom Scale Symptom Severity ( P < 0.001, Exp(B) = 0.45, 95% CI = 0.22-0.95) scores than noncontact athletes. No other outcome measures were different between soccer players and noncontact athletes.

CONCLUSIONS

Among collegiate athletes, soccer players report similar or better psychosocial functioning and symptom scores than noncontact athletes. Importantly, neurocognitive functioning, neurobehavioral and psychological symptoms, and postural stability do not worsen over time in collegiate soccer players relative to their noncontact counterparts. Our findings suggest that despite possible exposure to repetitive head impacts, collegiate soccer players do not exhibit changes in observable function and symptoms across multiple seasons.

Baseline concussion assessment performance by sex in military service academy rugby players: findings from the CARE Consortium

BACKGROUND

Normative student-athlete concussion assessment data may not be appropriate for service academy members (SAMs), particularly rugby players, because of the uniqueness of their academic/military training environment. Having accurate baseline data for this population is important because of their high risk for concussion and frequent lack of assigned sports medicine professional. The primary purpose of this study was to characterise baseline performance on a concussion assessment battery, with secondary purpose to determine effect of sex and concussion history on these measures among SAM rugby players.

METHODS

601 rugby-playing SAMs (19.3±1.5 years, 37.9% female) completed baseline concussion assessments: the Sport Concussion Assessment Tool (SCAT) Symptom and Symptom Severity Checklist, Standard Assessment of Concussion (SAC) and a neuropsychological test (either ImPACT (Immediate Post Concussion Assessment and Cognitive Testing) or ANAM (Automated Neuropsychological Assessment Metrics)). Groups were compared using an independent samples t-test or Mann-Whitney U test. A 2 (sex) × 2 (concussion history) ANOVA was conducted to determine the effects of sex and concussion history on outcomes.

RESULTS

Women reported greater SCAT total symptoms (3.3 vs 2.8, p<0.001, r=0.143) and symptom severities (5.7 vs 4.3, p<0.001, r=0.139), and performed worse on ImPACT Visual Memory (79.3 vs 82.6, p=0.002, r=0.144) than men. Women performed better than men on SAC (28.0 vs 27.7, p=0.03, r=0.088), ImPACT Reaction Time Composite (0.59 vs 0.61, p=0.04, r=0.092) and ANAM Code Substitution Delayed (64.3 vs 61.5, p=0.04, d=0.433). Individuals with a history of concussion reported lower ImPACT Symptom Severity (2.6 vs 4.2, p=0.02, r=0.110). There was no interaction between concussion history and sex on outcomes.

CONCLUSIONS

These findings provide reference data for SAM rugby players on baseline assessments and to help in clinical decision-making when managing sports-related concussion in absence of baseline data.

Concussion Recovery in Children and Adolescents: A Retrospective Study

Background

Concussion is a common injury among children and adolescents, with a growing body of literature supporting a variety of diagnostic and treatment modalities. Recovery is variable and depends on multiple factors that can be evaluated through a clinic visit: a thorough history, physical examination, and use of the Post-concussion Symptom Scale (PCSS).

Purpose/Hypothesis

The purpose of this study was to evaluate factors associated with overall recovery from concussion in children and adolescents in the clinical setting. It was hypothesized that the presence of 1 of a number of pre- or postinjury characteristics will be associated with poor concussion recovery.

Study Design

Case-control study; Level of evidence, 3.

Methods

We conducted a retrospective chart review of adolescents and children aged 6 to 17 years with a diagnosis of concussion who were evaluated at a single sports medicine center between January 2015 and December 2019. Cases were categorized into recovered (PCSS <7) and poorly recovered (PCSS ≥7) cohorts based on the last PCSS scores during clinical follow-ups for concussion management.

Results

Of the 162 charts reviewed, 110 cases met inclusion criteria. Significant statistical differences were found between the recovered and poorly recovered cohorts regarding mean days from injury to last clinic visit, previous migraine diagnosis, and emergency room (ER) visit before the first clinic visit (P < .01 for all). Binary logistic regression analysis revealed that the most predictive factors associated with poorer recovery were having an ER visit before the first clinic evaluation (P = .01) and previous migraine diagnosis (P = .04).

Conclusion

While many factors may contribute to overall recovery from concussion in pediatric populations, our study suggested that a history of migraine and an ER visit before clinic evaluation may be associated with poor recovery of concussive symptoms.

Traumatic brain injury: progress and challenges in prevention, clinical care, and research

Traumatic brain injury (TBI) has the highest incidence of all common neurological disorders, and poses a substantial public health burden. TBI is increasingly documented not only as an acute condition but also as a chronic disease with long-term consequences, including an increased risk of late-onset neurodegeneration. The first Lancet Neurology Commission on TBI, published in 2017, called for a concerted effort to tackle the global health problem posed by TBI. Since then, funding agencies have supported research both in high-income countries (HICs) and in low-income and middle-income countries (LMICs). In November 2020, the World Health Assembly, the decision-making body of WHO, passed resolution WHA73.10 for global actions on epilepsy and other neurological disorders, and WHO launched the Decade for Action on Road Safety plan in 2021. New knowledge has been generated by large observational studies, including those conducted under the umbrella of the International Traumatic Brain Injury Research (InTBIR) initiative, established as a collaboration of funding agencies in 2011. InTBIR has also provided a huge stimulus to collaborative research in TBI and has facilitated participation of global partners. The return on investment has been high, but many needs of patients with TBI remain unaddressed. This update to the 2017 Commission presents advances and discusses persisting and new challenges in prevention, clinical care, and research.

In LMICs, the occurrence of TBI is driven by road traffic incidents, often involving vulnerable road users such as motorcyclists and pedestrians. In HICs, most TBI is caused by falls, particularly in older people (aged ≥65 years), who often have comorbidities. Risk factors such as frailty and alcohol misuse provide opportunities for targeted prevention actions. Little evidence exists to inform treatment of older patients, who have been commonly excluded from past clinical trials—consequently, appropriate evidence is urgently required. Although increasing age is associated with worse outcomes from TBI, age should not dictate limitations in therapy. However, patients injured by low-energy falls (who are mostly older people) are about 50% less likely to receive critical care or emergency interventions, compared with those injured by high-energy mechanisms, such as road traffic incidents.

Mild TBI, defined as a Glasgow Coma sum score of 13–15, comprises most of the TBI cases (over 90%) presenting to hospital. Around 50% of adult patients with mild TBI presenting to hospital do not recover to pre-TBI levels of health by 6 months after their injury. Fewer than 10% of patients discharged after presenting to an emergency department for TBI in Europe currently receive follow-up. Structured follow-up after mild TBI should be considered good practice, and urgent research is needed to identify which patients with mild TBI are at risk for incomplete recovery.

The selection of patients for CT is an important triage decision in mild TBI since it allows early identification of lesions that can trigger hospital admission or life-saving surgery. Current decision making for deciding on CT is inefficient, with 90–95% of scanned patients showing no intracranial injury but being subjected to radiation risks. InTBIR studies have shown that measurement of blood-based biomarkers adds value to previously proposed clinical decision rules, holding the potential to improve efficiency while reducing radiation exposure. Increased concentrations of biomarkers in the blood of patients with a normal presentation CT scan suggest structural brain damage, which is seen on MR scanning in up to 30% of patients with mild TBI. Advanced MRI, including diffusion tensor imaging and volumetric analyses, can identify additional injuries not detectable by visual inspection of standard clinical MR images. Thus, the absence of CT abnormalities does not exclude structural damage—an observation relevant to litigation procedures, to management of mild TBI, and when CT scans are insufficient to explain the severity of the clinical condition.

Although blood-based protein biomarkers have been shown to have important roles in the evaluation of TBI, most available assays are for research use only. To date, there is only one vendor of such assays with regulatory clearance in Europe and the USA with an indication to rule out the need for CT imaging for patients with suspected TBI. Regulatory clearance is provided for a combination of biomarkers, although evidence is accumulating that a single biomarker can perform as well as a combination. Additional biomarkers and more clinical-use platforms are on the horizon, but cross-platform harmonisation of results is needed. Health-care efficiency would benefit from diversity in providers.

In the intensive care setting, automated analysis of blood pressure and intracranial pressure with calculation of derived parameters can help individualise management of TBI. Interest in the identification of subgroups of patients who might benefit more from some specific therapeutic approaches than others represents a welcome shift towards precision medicine. Comparative-effectiveness research to identify best practice has delivered on expectations for providing evidence in support of best practices, both in adult and paediatric patients with TBI.

Progress has also been made in improving outcome assessment after TBI. Key instruments have been translated into up to 20 languages and linguistically validated, and are now internationally available for clinical and research use. TBI affects multiple domains of functioning, and outcomes are affected by personal characteristics and life-course events, consistent with a multifactorial bio-psycho-socio-ecological model of TBI, as presented in the US National Academies of Sciences, Engineering, and Medicine (NASEM) 2022 report. Multidimensional assessment is desirable and might be best based on measurement of global functional impairment. More work is required to develop and implement recommendations for multidimensional assessment. Prediction of outcome is relevant to patients and their families, and can facilitate the benchmarking of quality of care. InTBIR studies have identified new building blocks (eg, blood biomarkers and quantitative CT analysis) to refine existing prognostic models. Further improvement in prognostication could come from MRI, genetics, and the integration of dynamic changes in patient status after presentation.

Neurotrauma researchers traditionally seek translation of their research findings through publications, clinical guidelines, and industry collaborations. However, to effectively impact clinical care and outcome, interactions are also needed with research funders, regulators, and policy makers, and partnership with patient organisations. Such interactions are increasingly taking place, with exemplars including interactions with the All Party Parliamentary Group on Acquired Brain Injury in the UK, the production of the NASEM report in the USA, and interactions with the US Food and Drug Administration. More interactions should be encouraged, and future discussions with regulators should include debates around consent from patients with acute mental incapacity and data sharing. Data sharing is strongly advocated by funding agencies. From January 2023, the US National Institutes of Health will require upload of research data into public repositories, but the EU requires data controllers to safeguard data security and privacy regulation. The tension between open data-sharing and adherence to privacy regulation could be resolved by cross-dataset analyses on federated platforms, with the data remaining at their original safe location. Tools already exist for conventional statistical analyses on federated platforms, however federated machine learning requires further development. Support for further development of federated platforms, and neuroinformatics more generally, should be a priority.

This update to the 2017 Commission presents new insights and challenges across a range of topics around TBI: epidemiology and prevention (section 1 ); system of care (section 2 ); clinical management (section 3 ); characterisation of TBI (section 4 ); outcome assessment (section 5 ); prognosis (Section 6 ); and new directions for acquiring and implementing evidence (section 7 ). Table 1 summarises key messages from this Commission and proposes recommendations for the way forward to advance research and clinical management of TBI.

Head Trauma Exposure in Mixed Martial Arts

Combat sports training involves a high risk of head injury. Previously published research on head trauma exposure in MMA evaluated only the knockouts (KO), without calculating all head strikes. The aim of the research was to evaluate the total head trauma exposure during MMA competitions among male and female fighters. Two thousand four hundred and eighty-eight MMA fights from all numbered UFC events between 2000 and 2021 were analyzed. A database containing the results from officially published scorecards with information such as the outcome of a fight, its duration, number of strikes (significant and total amount of hits) depending on location and knockdowns was created. Additional video verification of the knockout technique was carried out. The athletes received an average of 2.41 significant head strikes out of a total of 6.30 head strikes per minute. Head strikes were more common in female fights than in male. Women executed more total and significant head strikes per minute than men. Head trauma caused the ending of 31.6% of all fights-more often in male fights (32.2%) than female (23.1%). It was the most common cause of knockouts-88.1%. Professional fights in mixed martial arts involve high exposure to head trauma. A careful evaluation of the risk involved in training in such a discipline is necessary to provide adequate prevention methods.

Epidemiology of sport-related concussion rates in female contact/collision sport: a systematic review

Objectives

To determine sport-related concussion (SRC) incidence rates in female contact/collision sport.

Design

Systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

Data sources

Four databases (PubMed, SportsDiscus, Web of Science, CINAHL) were searched for data from 2012 to 2021.

Eligibility criteria

Studies reporting SRC incidence rates or the number of concussions and athletic exposures (AEs) per 1000 participating events or hours in healthy female contact and collision sport athletes of any age were included.

Results

The search yielded 8438 non-duplicate articles. Following screening, 19 were included in the analysis (median quality score=70%), with 8 reporting match or training incidence rates. Studies were primarily from US high school and collegiate populations; data are reported for eight sports. Rugby union reported the highest match SRC rates (8.2-16.11 per 1000 AE hours), followed by Gaelic football (5.21 per 1000 AE hours) and soccer (2.08-4.04 per 1000 AE events). Where available, match SRC rates were substantially higher than training and overall SRC rates.

Conclusion

Female sports such as rugby union, Gaelic football and soccer present the highest risk for SRCs within the available data. Previous research indicates a potentially greater injury burden for female athletes experiencing SRCs than their male counterparts. Thus, future research should analyse concussion knowledge and return-to-play protocols in these sports. Future research should also prioritise exploration of the gap in SRC rates within amateur sports, and data should be presented specifically in the context of athletic exposures (match vs training).

Trial registration number

CRD42021281569.

Risk factors for prolonged recovery from concussion in young patients

Objectives

For young patients sustaining concussion, assessing recovery is vital in determining safe return to play. Identifying risk factors may aid clinicians in recognising patients at risk for prolonged recovery. The study objective is to identify risk factors for prolonged (>28 days) and extended (>90 days) recovery (defined as symptom duration) and analyse how these risk factors differ between the two groups.

Methods

We retrospectively analysed electronic health record data (n=4937) among patients aged 10–18 years collected at Nationwide Children’s Hospital Sports Medicine concussion clinics between 1 July 2012 and 30 June 2019. Data collected included patient demographics, comorbidities (eg, prior psychiatric diagnoses, prior concussions) and injury characteristics (eg, loss of consciousness, injury setting). We examined patient risk factors for prolonged (>28 days) and/or extended (>90 days) recovery using modified Poisson regression models.

Results

Factors associated with increased risk of prolonged recovery from concussion included prior concussions (adjusted risk ratio (ARR) 1.19, 95% CI 1.02 to 1.38) for two concussions (ARR 1.36, 95% CI 1.14 to 1.61), for >3, and higher initial symptom score (ARR 2.57, 95% CI 2.34 to 2.83) for postconcussion symptom (PCS) scores 21–60 (ARR 2.89, 95% CI 2.54 to 3.29), for PCS>60. Risk factors for extended recovery included history of concussion (ARR 1.50, 95% CI 1.09 to 2.06) for two concussions (ARR 1.75, 95% CI 1.17 to 2.62), for >3 and older age (15–18 years, ARR 1.11, 95% CI 1.05 to 1.18). Additionally, comorbid attention deficit hyperactivity disorder increased risk of prolonged recovery (ARR 1.14, 95% CI 1.01 to 1.29) while anxiety increased risk for extended recovery (ARR 1.47, 95% CI 1.10 to 1.95).

Conclusion

Overall, risk factors for prolonged recovery differ somewhat from risk factors for extended recovery. For patients who present to clinic with concussion, mental health is an important consideration which may impact the timeline for symptom recovery.

Under-representation of female athletes in research informing influential concussion consensus and position statements: an evidence review and synthesis

OBJECTIVE

We aimed to quantify the female athlete composition of the research data informing the most influential consensus and position statements in treating sports-related concussions.

DESIGN

We identified the most influential concussion consensus and position statements through citation and documented clinician use; then, we analysed the percentage of male and female athletes from each statement's cited research.

DATA SOURCES

We searched PubMed on 26 August 2021 with no date restrictions for English language studies using the terms 'concussion position statement' and 'concussion consensus statement.'

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Based on each statement having multiple statement editions, documented clinician use, and substantial citation advantages, we selected the National Athletic Trainers' Association (NATA, 2014), International Conference on Concussion in Sport (ICCS, 2017) and the American Medical Society for Sports Medicine (AMSSM, 2019). We extracted all cited studies from all three papers for assessment. For each paper analysing human data, at least two authors independently recorded female athlete participant data.

RESULTS

A total of 171 distinct studies with human participants were cited by these three consensus and position papers and included in the female athlete analyses (93 NATA; 13 ICCS; 65 AMSSM). All three statements documented a significant under-representation of female athletes in their cited literature, relying on samples that were overall 80.1% male (NATA: 79.9%, ICCS: 87.8 %, AMSSM: 79.4%). Moreover, 40.4% of these studies include no female participants at all.

CONCLUSION

Female athletes are significantly under-represented in the studies guiding clinical care for sport-related concussion for a broad array of sports and exercise medicine clinicians. We recommend intentional recruitment and funding of gender diverse participants in concussion studies, suggest authorship teams reflect diverse perspectives, and encourage consensus statements note when cited data under-represent non-male athletes.

The Role of Reported Affective Symptoms and Anxiety in Recovery Trajectories After Sport-Related Concussion

BACKGROUND

There is growing awareness and clinical interest in athletes with affective symptoms after sport-related concussion (SRC), as these symptoms may contribute to overall symptoms and represent a modifiable risk factor of longer recovery. However, evidence of their effects on the entire return-to-play (RTP) trajectory, particularly among women and men, is limited.

PURPOSE/HYPOTHESIS

To examine the relationship between affective symptom reporting and RTP progression after SRC among a cohort of Division 1 student-athletes. We hypothesized that those endorsing affective symptoms, specifically nervous-anxious symptoms, spend more time in RTP progression and recovery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Using SRC data from the Ivy League-Big Ten Epidemiology of Concussion Study among varsity athletes through February 2020, we identified the 4 affective symptoms from the Sport Concussion Assessment Tool symptom inventory. We modeled the relationship between a 4-category affective symptom variable and time to symptom resolution, RTP, and RTP progression, adjusting for nonaffective symptom prevalence and concussion history. Cox regressions were used to estimate hazard ratios for time to event outcomes, and linear regressions were used to evaluate mean differences for continuous outcomes.

RESULTS

Among 2077 student-athletes (men, 63.5%) with SRC symptoms, affective symptom prevalence was 47.6% and 44.3% in women and men, respectively, and nervous-anxious prevalence was 24.2% and 22.5%, respectively. When comparing women with and without co-occurring affective symptoms, rates of symptom resolution and RTP were significantly lower in those with affective symptoms, and women with nervous-anxious symptoms spent significantly longer in RTP progression. When comparing men with and without co-occurring affective symptoms, rates of symptom resolution and RTP were significantly lower in those with co-occurring affective symptoms, and affective symptoms were not associated with time in RTP progression.

CONCLUSION

Student-athletes with affective symptoms and nervous-anxious symptoms exhibited delayed clinical recovery and RTP timelines, particularly for time in RTP. Symptom prevalence and concussion history contributed to this; however, unmeasured confounding remains, as indicated by the poor model fit. This study motivates future work to explore affective symptoms and RTP timelines, considering anxiety and risk/protective factors over time.

Factors Associated With a Prolonged Time to Return to Play After a Concussion

BACKGROUND

Prognosticating recovery times for individual athletes with a concussion remains a challenge for health care providers. Several preinjury and postinjury factors have been proposed to be predictive of prolonged return-to-play (RTP) times, but the data in this area are still sparse.

PURPOSES

This study aimed to identify risk factors associated with prolonged recovery times and determine which are most predictive of prolonged recovery times in a head-to-head comparison.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

All concussions occurring between September 2017 and August 2020 at a single National Collegiate Athletic Association Division I institution were reviewed and included in this study. Preinjury modifiers including age, sex, sport, concussion history, and past medical problems were collected from the electronic medical records. Postinjury modifiers analyzed included initial and follow-up Sport Concussion Assessment Tool 5th Edition scores, vestibular evaluation findings, and eye tracking results.

RESULTS

A total of 159 athletes and 187 concussion cases were included. Preinjury factors that were correlated with prolonged RTP times included a history of concussions (P = .015), a history of migraines (P = .013), and whether an athlete participated in an individual sport (P = .009). Postinjury factors correlated with prolonged RTP times included the total number (P = .020) and severity (P = .023) of symptoms as well as abnormal Vestibular Ocular Motor Screening findings (P = .002). Overall, 6 different symptoms (balance problems, difficulty concentrating, light sensitivity, drowsiness, fatigue/low energy, and difficulty remembering) were significantly correlated with prolonged RTP times. The study also found that the number and severity of symptoms were additive in a dose-dependent fashion. On multivariable analysis of all these factors, a history of concussions was found to be the most predictive of prolonged RTP times, while participation in an individual sport had the largest effect on recovery times.

CONCLUSION

Several preinjury and postinjury risk factors were identified as being correlated with prolonged recovery times. Many of these risk factors were also found to be additive in nature. This information provides clinicians with a valuable tool in prognosticating and estimating recovery times for athletes. The study also revealed that athletes participating in individual sports had longer RTP times compared with athletes in team sports, which is a novel finding that requires further research.

Association Between Symptom Burden at Initiation of a Graduated Return to Activity Protocol and Time to Return to Unrestricted Activity After Concussion in Service Academy Cadets

BACKGROUND

Current consensus and position statements recommend that concussed patients be asymptomatic upon the initiation of the graduated return to activity (RTA) protocol. However, a significant number of concussed patients are beginning their RTA protocols while endorsing symptoms.

PURPOSE

To characterize symptom endorsement at the beginning of the RTA protocol and examine the association between symptom endorsement and RTA protocol duration in service academy cadets.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A prospective cohort study was conducted with cadets at 3 US service academies. Postconcussion symptom inventories were recorded upon the initiation of an RTA protocol. The Sport Concussion Assessment Tool Symptom Inventory was used to classify participants into 3 groups (0 symptoms, 1 symptom, and ≥2 symptoms) upon the initiation of the RTA protocol. The primary outcome of interest was RTA protocol duration. Kaplan-Meier survival estimates were calculated to estimate RTA protocol duration by symptom endorsement, sex, varsity status, academic break, and time to graduated RTA initiation. Univariate and multivariable Cox proportional hazards models were used to estimate the association between symptom endorsement at the initiation of the RTA protocol and RTA protocol duration (α < .05).

RESULTS

Data were analyzed from 966 concussed cadets (36% women). Headache (42%) and faintness/dizziness (44%) were the most commonly endorsed symptoms on the Sport Concussion Assessment Tool-Third Edition and the Brief Symptom Inventory-18, respectively. Univariate results revealed a significant association between endorsing ≥2 symptoms and RTA protocol duration. In the multivariable model, endorsing ≥2 symptoms maintained a statistically significant association with RTA protocol duration. Significant associations were observed between RTA protocol duration and nonvarsity status (27% longer), women (15% longer), academic breaks (70% longer), and time to the initiation of the RTA protocol (1.1% longer daily incremental increase) after controlling for covariates.

CONCLUSION

Symptom endorsement at the initiation of an RTA protocol was associated with RTA protocol duration. Cadets who had returned to preinjury baseline symptom burden or improved from baseline symptom burden and endorsed ≥2 symptoms at the initiation of the RTA protocol took longer to RTA.

Concussion in Women's Flat-Track Roller Derby

Concussions are common among flat-track roller derby players, a unique and under-studied sport, but little has been done to assess how common they are or what players can do to manage injury risk. The purpose of this study is to provide an epidemiological investigation of concussion incidence and experience in a large international sampling of roller derby players. Six hundred sixty-five roller derby players from 25 countries responded to a comprehensive online survey about injury and sport participation. Participants also responded to a battery of psychometric assessment tools targeting risk-factors for poor injury recovery (negative bias, social support, mental toughness) and players' thoughts and feelings in response to injury. Per 1,000 athletes, 790.98 concussions were reported. Current players reported an average of 2.2 concussions, while former players reported 3.1 concussions. However, groups were matched when these figures were corrected for differences in years of play (approximately one concussion every 2 years). Other frequent injuries included fractures in extremities and upper limbs, torn knee ligaments, and sprained ankles. We found no evidence that players' position, full-contact scrimmages, or flooring impacted number of concussions. However, neurological history and uncorrected vision were more influential predictors of an individual's number of concussions during roller derby than years of participation or age, though all four contributed significantly. These findings should assist athletes in making informed decisions about participation in roller derby, though more work is needed to understand the nature of risk.

Acute Physical and Mental Activity Influence on Concussion Recovery

INTRODUCTION

Physical activity (PA) and mental activity (MA) postconcussion has received renewed attention to improve concussion management; however, most protocols start after several days and do not assess the acute window. Therefore, the purpose of this study was to assess PA and MA in the first 48 h postconcussion on the time to symptom-free status and return to play.

METHODS

We recruited 78 NCAA Division I athletes (male, 51.3%; age, 19.6 ± 1.4 yr; height, 173.7 ± 11.5 cm; weight, 80.1 ± 23.2 kg) who were diagnosed with a sports-related concussion. Participants completed a 0-5 PA and MA scale daily until fully cleared for return to participation (mean, 15.1 ± 6.9 d). A quadratic model regression assessed PA and MA over the first 2 d (acute) postconcussion on to time to symptom-free status and return to play.

RESULTS

The overall model was significant for both time to symptom free (r2 = 0.27, P = 0.004) and return to play (r2 = 0.23, P = 0.019). Reported PA was the only significant predictor for time to symptom-free (P = 0.002) and return-to-participation (P = 0.006) day. Reported MA was not associated either outcome.

CONCLUSIONS

The primary finding of this study was that mild to moderate PA acutely postconcussion was associated with reduced time to symptom free and return to participation as opposed to either lower or higher levels of PA. Conversely, acute MA was not associated with recovery outcomes. These results further elucidate the role of postconcussion PA.

Optimizing Health and Athletic Performance for Women

PURPOSE OF REVIEW

The exponential growth of women participating in competitive sports throughout the years was made possible through several initiatives by the International Olympic Committee and the passage and implementation of Title IX as a federal law in the United States. However, this positive trend towards gender equity in sports has not transpired for women in medicine, especially in fields that care for elite athletes. This current review will discuss specific areas that can be tailored to help female athletes prevent injuries and optimize their athletic performance. We will also highlight how increased female team physician representation in sports may help optimize care for female athletes.

RECENT FINDINGS

Female athletes are considered high risk for certain conditions such as ACL tears, patellofemoral pain syndrome, bone stress injuries, sport-related concussions, and sexual violence in sport. Addressing factors specific to female athletes has been found to be valuable in preventing injuries. Strength and conditioning can optimize athletic performance but remains underutilized among female athletes. Although diversity in healthcare workforce has been found to be beneficial for multiple reasons, women remain underrepresented in sports medicine. Increasing female team physician representation may positively impact care for female athletes. Team physicians must understand the physiologic, biomechanical, and anatomic factors that are unique to female athletes in order to tailor injury prevention programs and optimize their athletic performance. Advocating for gender equity in sports medicine to advance representation of women in the field will increase workforce diversity and promote excellence in sports medicine care.

What Is the Evidence on Natural Recovery Over the Year Following Sports-Related and Non-sports-Related Mild Traumatic Brain Injury: A Scoping Review

Background: Treatment approaches often differ dependent upon whether a person experiences a sports-related or a non-sports-related mild traumatic brain injury. It remains unclear if recovery from these injuries is comparable or unique to context of the injury.

Objective: To identify knowledge gaps on self-reported outcomes and trajectories between sports- and non-sports-related mild traumatic brain injuries and how they are assessed in adults.

Methods: This scoping review used a systematic search of key electronic databases, including PubMed, SPORTDiscus, Embase, MEDLINE, and CINAHL for articles published in 1937 until March 10, 2021. Articles were included if they were available in English; full text published in a peer-reviewed journal; had a prospective or retrospective study design; reported data on mild TBI cases >16 years of age, and included data from at least two time points on self-reported outcomes within 12 months post-injury. A standardized data extraction spreadsheet was used to determine the participant characteristics, definitions, assessment methods, outcomes, and recovery time frames.

Results: Following removal of duplicates, the search strategy elicited 6,974 abstracts. Following abstract review, 174 were retained for full text review. Of the 42 articles that met inclusion criteria, 18 were sports related (15 in the USA and three in Canada) and 24 were general population studies (six in USA, three in Canada, three in Australasia, nine in Europe, two in Taiwan, and one in Morocco). Direct comparison in recovery trajectories between the sport and general population studies was difficult, given notable differences in methodology, definitions, types of outcome measures, and timing of follow-up assessments. Only one article reported on both sports-related and non-sports-related traumatic brain injuries separately at comparable timepoints. This study revealed no differences in recovery time frames or overall symptom burden.

Discussion: Whilst there is a clear benefit in researching specific subpopulations in detail, standardized outcome measures and follow-up time frames are needed across contexts to facilitate understanding of similarities and differences between sports- and non-sports-related mild traumatic brain injuries to inform clinical treatment.

The Natural History of Sport-Related Concussion in Collegiate Athletes: Findings from the NCAA-DoD CARE Consortium

BACKGROUND

Sport-related concussion is recognized as a significant injury with variable recovery rates.

OBJECTIVE

This study defined the acute natural history of sport concussion in male and female collegiate athletes participating in a broad array of sports.

METHODS

We conducted a prospective, longitudinal investigation among collegiate student athletes (n = 34,709) from 30 academic institutions. Primary outcomes included the time (days) from injury until initiation of a return to participation (RTP) protocol and time from injury until medical clearance for unrestricted RTP.

RESULTS

Concussed athletes (n = 1751, 19.2 years, 63.2% male) participating in 22 different sports began the RTP protocol in a median 6.4 (IQR 3.7-11.8) days. Time to initiate the RTP protocol was lengthened by less frequent post-injury assessments, greater initial post-injury symptom severity, limited contact sports participation, practice/training injuries, and three or more prior concussions. The median total RTP duration was 12.8 (IQR 8.7-20.1) days. Total RTP duration was shorter with ADHD medication usage, males, and greater assessment frequency; while greater initial post-injury symptom severity, practice-/training-related injuries, and three or more prior concussions had longer recoveries.

CONCLUSION

Although median recovery times are consistent with previous guidelines, it was not until 1 month post-injury that a preponderance of collegiate athletes were cleared to begin the RTP protocol (92%) or cleared for unrestricted sport participation (85%). Intrinsic and extrinsic factors had a small effect, altering recovery trajectories by up to 2 days, suggesting a largely unified approach to post-injury monitoring and management across all athletes. These data represent a shift from previous classification parameters of normal clinical recovery.

Clinical Recovery Timelines following Sport-Related Concussion in Men's and Women's Collegiate Sports

CONTEXT

Past work has identified sex differences in sport-related concussion (SRC) incidence and recovery time; however, few have examined sex differences in specific recovery trajectories: time to symptom resolution, return-to-academics, and return-to-athletic activity across collegiate sports.

OBJECTIVE

To examine sex differences in SRC recovery trajectories across a number of varsity sports with differing levels of contact.

DESIGN

Descriptive Epidemiology Study.

SETTING

College varsity and club sports.

PATIENTS OR OTHER PARTICIPANTS

SRCs sustained by student-athletes (N=1,974; 38.7% female) participating in Ivy League sports were tracked from 2013/14-2018/19.

INTERVENTION(S)

Athletic trainers collected concussive injury and recovery characteristics as part of the Ivy League-Big Ten Epidemiology of Concussion Study's surveillance system.

MAIN OUTCOME MEASURE(S)

Time to symptom resolution, return-to-academics, and return-to-limited and full athletic activity were collected. Survival analyses determined time from injury to each recovery outcome for males and females by sport. Peto tests compared recovery outcomes between males and female athletes and by sport.

RESULTS

The median time to symptom resolution overall was 9 days [IQR:4,18], return-to-academics was 8 days [IQR:3,15], return-to-limited activity was 12 days [IQR:8,23], and return-to-full activity was 16 days [IQR:10,29]. There were significant differences overall between sexes for median time to symptom resolution (males: 8 days [IQR:4,17], females: 9 days [IQR:5,20], p=0.029) and return-to-academics (males: 7 days [IQR:3,14], females: 9 days [IQR:4,17], p<.001), but not return to athletics (limited activity, p=0.107; full activity, p=0.578). Within-sport comparisons found that female lacrosse athletes had longer symptom resolution (p=0.030) and return to academics (p=0.035) compared to males, while male volleyball athletes took longer to return to limited (p=0.020) and full (p=0.049) athletic activity compared to females.

CONCLUSION

There were significant differences in recovery timelines between sexes. Females experienced longer symptom duration and time to return-to-academics compared to male athletes, but females and males presented similar timelines for return-to-athletics.