Self-reported Concussion Research Articles

Does Equestrian Helmet Type Affect Head Injury? A Study on Equestrian Helmet Use Among Collegiate Athletes.

To characterize helmet use, head injury risk, and to examine rider-related factors that influence these variables. Cross-sectional study. The University of Alabama at Birmingham Equestrian Sports Medicine Collaborative. In total, 357 equestrians competing at the collegiate level participated in this study. χ2 tests were used to evaluate potential associations between a rider's experience level, riding style, and use of helmet designed with MIPS with number of falls, past head injuries, and helmet use frequency. Data regarding helmet use and equestrian-related injuries were collected. χ2 analysis was used to determine potential associations. More than 50% of athletes reported falling off a horse during the course of 1 year. Head injuries occurred with high frequency. Concussion was the most frequently reported type. More than 50% of athletes with self-reported concussion denied receiving medical treatment. The risk of head injury was similar across helmet brands, and between helmets with Multi-Directional Impact Protection System (MIPS) and those without. Riders with the most experience were less likely to report sustaining a head injury than those with less experience. Contrary to current safety guidelines, 78% of equestrians said that they would not replace their helmet after every fall. Collegiate equestrians have a high risk of fall-related traumatic head injury. Despite this risk, they report helmet use practices that are not in line with current recommendations regarding helmet replacement. This suggests thatmany of the athletes are using protective equipment that does not adequately protect against head injury. Neither helmet brand nor liner type was associated with lower rate of head injury.

Spontaneous Headshake after a Kinematic Event (SHAAKE): Evaluating the Utility of a Potential New Sign in the Diagnosis of Concussion.

Background/Objectives: Diagnosing concussions is problematic, in part due to the invisible nature of concussion symptoms, in addition to personal and interpersonal factors that influence symptom reporting. As a result, observable signs of concussion can ensure concussions are identified and appropriately treated. Here, we define a potential novel sign, the spontaneous headshake after a kinematic event (SHAAKE) and evaluate its utility in the diagnosis of concussion. Methods: A cross-sectional survey study of 347 athletes (age 27, IQR: 25-29; 47.6% female; highest level of play: college-46.1%, high school-41.2%) identified whether SHAAKE occurred, the reasons underlying SHAAKEs, and its utility for self-reported concussion. Sensitivity and positive predictive value were calculated across all sports and these parameters, as well as estimates for specificity and negative predictive value leveraging published helmet sensor data, were calculated for football players. Results: The median number of times participants reported SHAAKE was 5 (IQR: 3-10), with 4 (IQR: 2-7) associated with a self-reported concussion. Overall, 84.9% of participants reported concussion symptoms as the most common reason for their SHAAKEs. Across all sports, SHAAKE had a sensitivity of 49.6% and positive predictive value 72.4% for diagnosing concussion. In football players, SHAAKE had a sensitivity of 52.3%, estimated specificity of 99.9%, positive predictive value of 91.9%, and estimated negative predictive value of 99.5% for diagnosing self-reported concussion. Conclusions: These results demonstrate that nearly three-quarters of athletes reported a SHAAKE associated with a self-reported concussion, which supports the potential for SHAAKE to be used as a concussion screening tool.

A retrospective evaluation of self-reported concussion history among male players drafted into professional Australian Rules Football

A retrospective evaluation of self-reported concussion history among male players drafted into professional Australian Rules Football

Reliable Change Indices for the Serial Administration of the Concussion Clinical Profiles Screening Tool.

The Concussion Clinical Profiles Screening Tool (CP Screen) self-report concussion symptom inventory is often administered at weekly intervals. However, 1-week reliable change indices (RCIs) for clinical cutoffs and the test-retest reliability of the CP Screen are unknown. To document RCI cutoff scores and 1-week test-retest reliability for each profile and modifier of the CP Screen for men and women. Case series. A large US university. One hundred seventy-three healthy college students. Participants completed 2 administrations of the CP Screen 7 days apart. The CP Screen items yielded 5 clinical profiles and 2 modifiers. Spearman ρ coefficients (rs), intraclass correlation coefficients (ICCs), single measures, and unbiased estimates of reliability (UERs) were used to assess test-retest reliability. Wilcoxon signed-rank tests assessed differences across time. Reliable change index values and cutoff scores are provided at 90%/95% CIs. All analyses were performed for the total sample and separately for men and women. Reliable change index cutoffs for clinically significant change (increase/decrease) at a 90% CI for men were as follows: ocular, vestibular >2/>4; anxiety/mood, cognitive/fatigue, and migraine >3/>3; sleep >4/>6; and neck >2/>2. Reliable change index cutoffs for clinically significant change (increase/decrease) at a 90% CI for women were as follows: anxiety/mood ≥2/≥4; cognitive/fatigue, migraine, ocular, vestibular, and sleep ≥3/≥3; and neck ≥1/≥1. Correlations for the CP Screen ranged from 0.51 (migraine) to 0.79 (anxiety/mood) for the total sample, from 0.48 (migraine) to 0.84 (vestibular) for men, and from 0.51 (migraine) to 0.77 (ocular) for women. Test-retest indices for each profile and modifier were moderate to good for the total sample (ICC, 0.64-0.82; UER, 0.79-0.90), men (ICC, 0.60-0.87; UER, 0.76-0.94), and women (ICC, 0.64-0.80; UER, 0.78-0.89). The CP Screen is reliable and stable across a 1-week interval, and established RCIs for men and women can help identify meaningful change throughout recovery.

Aerobic Exercise as an Intervention for Mild Traumatic Brain Injury: A Critically Appraised Topic.

As of 2020, the lifetime prevalence of at least one self-reported concussion is 24.6%. Athletic trainers in all settings work with patients who are at risk of sustaining a concussion or mild traumatic brain injury (mTBI) and developing persistent postconcussive symptoms. Aerobic exercise is emerging as an intervention for decreasing symptoms in patients who have sustained mTBI; however, the majority of research has been performed on pediatric patients. It is of interest whether aerobic exercise is an effective intervention for adult patients with mTBI. In adults who have sustained mTBI, does traditional therapy decrease symptoms more than aerobic exercise? Summary of Search: A systematic search of 4 databases was performed to answer this question. Three randomized controlled trials were identified that compared aerobic exercise to traditional therapy, which consists of physical and cognitive rest. Two studies found no significant differences in symptoms between the 2 groups while 1 study found decreased symptoms in the aerobic exercise group. The current evidence is clear that there is no decrease in mTBI symptoms with traditional therapy as compared withaerobic exercise, with 1 study showing decreased symptoms with aerobic exercise. Strength of Evidence: Based on the Center for Evidence-Based Medicine grades of evidence, the clinical bottom line is based on grade A evidence.

Summary of the Centers for Disease Control and Prevention's Self-reported Traumatic Brain Injury Survey Efforts.

Surveillance of traumatic brain injury (TBI), including concussion, in the United States has historically relied on healthcare administrative datasets, but these methods likely underestimate the true burden of TBI. The Centers for Disease Control and Prevention (CDC) has recently added TBI prevalence questions to several national surveys. The objective of this article is to summarize their recent efforts and report TBI prevalence estimates. Surveys. Adult and youth respondents to a series of national surveys. Recent nationally representative surveys with either 12-month or lifetime TBI prevalence questions were identified. For each data source, survey methodology, TBI definition, question wording, and prevalence estimates were examined. TBI prevalence varied depending on the question wording and data source. Overall 12-month prevalence of concussion/TBI among adults ranged from 2% to 12% while overall lifetime prevalence of concussion or TBI ranged from 19% to 29%. Overall 12-month prevalence of concussion/TBI among children and adolescents was 10% while 12-month prevalence of sports- and recreation-related concussion for youth ranged from 7% to 15%. Overall lifetime prevalence of TBI among youth ranged from 6% to 14%. Survey data based on self-reported concussions and TBIs resulted in larger prevalence estimates than would be expected based on traditional surveillance methods. Analyses of the various surveys shows that how the questions are asked and what terminology is used can notably affect the estimates observed. Efforts can be made to optimize and standardize data collection approaches to ensure consistent measurement across settings and populations.

A - 31 Relationship between Self-Reported Concussion History, Cognition, and Mood among Former Collegiate Athletes

Abstract Purpose Long-term concussion sequelae have been increasingly studied in former professional athletes, and less is known about those who participated in sport at the collegiate level. This study explores the relationship between concussion history and cognition/mood in former collegiate athletes in middle-to-later adulthood. Method 422 former collegiate athletes over age 50 (M = 61.5; 62% male) completed the College Level Aging Athlete Study (CLEAATS) including the Cognitive Function Instrument (CFI), Telephone Interview for Cognitive Status-Modified (TICSm), and self-report questionnaires including concussion history and current mood. Pearson correlations and multiple regression analyses examined the relationship between concussion history, subjective and objective cognitive status, and mood. Results 54% of the sample reported a history of concussion (M = 1.2, SD = 1.7). Number of concussions was marginally associated with subjective cognitive complaints (r = 0.13, p = 0.004) and depression (r = 0.14, p = 0.002), but not objective cognition (p = 0.39) or anxiety (p = 0.33). Regression models including demographic factors and mood were significant and explained 32% and 17% of the variance in subjective and objective cognition, respectively. Concussion history was not a significant predictor in either model, whereas depression (Β = -0.12) was associated with poorer subjective cognition only. Conclusions Concussion history was not associated with subjective or objective cognitive changes in former collegiate athletes. Although a very small relationship between concussion history and depression was found, depression was associated with more subjective cognitive complaints. This suggests mood symptoms have greater impact on subjective cognitive status than concussion history. These findings highlight the importance of considering the effect of current mood symptoms when evaluating former athletes who present with cognitive complaints.

The role of concussion history and biological sex on baseline concussion clinical profile symptoms in adolescent rugby players

BackgroundAccurate concussion monitoring requires access to preinjury baseline data. This is particularly important in adolescent athletes who have a high risk of concussion and are prone to prolonged recovery. As Rugby Union is governed by similar laws for men and women, it is also an ideal population to rigorously examine the impact of biological sex on concussion symptoms.AimsTo evaluate self-reported concussion symptoms at baseline in adolescent rugby union players, and examine if subtype-specific symptoms are affected by concussion history and biological sex.MethodsAdolescent rugby union players aged 16–18 years were recruited during the 2022–2023 playing season. Participants completed a series of questionnaires covering post-concussion symptoms, concussion clinical profiles, anxiety, depression and fear avoidance behaviours. Independent variables of interest in analysis were biological sex and concussion history.Results149 participants (75% male) were included. 42% (63/149) reported at least one previous concussion (average time since concussion: 18.7 months, range 1–72). Adolescents with a concussion history reported significantly higher scores than those with no history, across two clinical profiles (ocular and sleep), concussion symptom severity, and depression, all based on medium effect sizes (SMD 0.3–0.5). Females had significantly higher scores across cognitive/fatigue, ocular and sleep clinical profiles, concussion symptoms, anxiety and depression, each with large effect sizes (SMD > 0.5).ConclusionsConcussion history and sex are associated with higher baseline scores on specific concussion clinical profile, concussion symptom severity, and anxiety symptoms. These findings highlight the importance of considering baseline differences when interpreting post-injury clinical profile symptoms in adolescent rugby players. (Trial registration: ACTRN12622000931774).

University Club Sport Student-Athlete Concussion Profiles Differ by Sport and Sex

Athletes’ history of concussions is an important indicator of risk potential in organized sports. The purpose of this project was to explore differences by sport classification (contact vs. noncontact) and sex on concussion history among university club sports participants. This was a cross-sectional quality improvement study ( n = 593). The outcomes were self-reported answers to: (1) How many times have you been diagnosed with a concussion? and (2) How many times have you had your “bell rung”/“dinged”? Multivariable logistic regression models examined the association of contact club sport participation and sex on the history of concussion and prior experience of having their bell rung. Models were adjusted for age, race, participation in multiple sports, and years of participation in sports, and years in college. When compared to those in non-contact club sports, the adjusted odds of reporting ever having a concussion were 2.29 times higher for those participating in contact club sports (OR = 2.29; 95% CI: 1.49, 3.53). In the model for having a bell rung, those participating in a contact sport had 1.90 times greater odds of reporting having their bell rung in the past compared to those in noncontact sports (OR = 1.90; 95% CI: 1.25, 2.88). Whereas males and females did not differ in their self-reported concussion history, females had significantly lower odds of reporting having their bell rung in the past than males (OR = 0.46; 95% CI: 0.30, 0.69). Female athletes have a higher reporting of concussion incidence than that of male athletes. The use of terminology and variance in slang versus medical terms has the potential to affect reporting outcomes. Reporting of concussion incidents has the potential to be influenced by the nature of sport culture and sport participation in contact versus noncontact sports. Club sport athletes could benefit from tailored education related to concussions based on these results.

Optimizing Concussion Care Seeking: Connecting Care-Seeking Behaviors and Neurophysiological States Through Blood Biomarkers

Background: Timely and appropriate medical care after concussion presents a difficult public health problem. Concussion identification and treatment rely heavily on self-report, but more than half of concussions go unreported or are reported after a delay. If incomplete self-report increases exposure to harm, blood biomarkers may objectively indicate this neurobiological dysfunction. Purpose/Hypothesis: The purpose of this study was to compare postconcussion biomarker levels between individuals with different previous concussion diagnosis statuses and care-seeking statuses. It was hypothesized that individuals with undiagnosed concussions and poorer care seeking would show altered biomarker profiles. Study Design: Cohort study; Level of evidence, 3. Methods: Blood samples were collected from 287 military academy cadets and collegiate athletes diagnosed with concussion in the Advanced Research Core of the Concussion Assessment, Research and Education Consortium. The authors extracted each participant’s self-reported previous concussion diagnosis status (no history, all diagnosed, ≥1 undiagnosed) and whether they had delayed or immediate symptom onset, symptom reporting, and removal from activity after the incident concussion. The authors compared the following blood biomarkers associated with neural injury between previous concussion diagnosis status groups and care-seeking groups: glial fibrillary acidic protein, ubiquitin c-terminal hydrolase-L1 (UCH-L1), neurofilament light chain (NF-L), and tau protein, captured at baseline, 24 to 48 hours, asymptomatic, and 7 days after unrestricted return to activity using tests of parallel profiles. Results: The undiagnosed previous concussion group (n = 21) had higher levels of NF-L at 24- to 48-hour and asymptomatic time points relative to all diagnosed (n = 72) or no previous concussion (n = 194) groups. For those with delayed removal from activity (n = 127), UCH-L1 was lower at 7 days after return to activity than that for athletes immediately removed from activity (n = 131). No other biomarker differences were observed. Conclusion: Individuals with previous undiagnosed concussions or delayed removal from activity showed some different biomarker levels after concussion and after clinical recovery, despite a lack of baseline differences. This may indicate that poorer care seeking can create neurobiological differences in the concussed brain.

Concussion Exposure and Suicidal Ideation, Planning, and Attempts Among US High School Students.

Interest is growing in the association between repetitive concussions and mental health. However, studies on the relationship between concussion frequency and adverse mental health outcomes among female and male youth are lacking. To examine the association between self-reported concussion frequency and nonfatal suicidal behaviors among youth and to explore the possible interaction of biological sex. Retrospective cross-sectional survey. National Youth Risk Behavior Surveillance System. United States secondary school students (N = 28 442). Exposure variables were the frequency of self-reported sport- or recreation-related concussion in the previous 12 months (0, 1, ≥2). Outcome variables were feelings of self-reported sadness or hopelessness and suicidal ideation, planning, and attempts. Covariates were age, sex, race and ethnicity, bullying victimization, sexual orientation, and physical activity. Students who reported ≥2 concussions were at significantly greater odds of reporting suicidal attempts (adjusted odds ratio = 2.03; 95% CI = 1.43, 2.88) when compared with students reporting a single concussive event during the past 12 months. However, sex interactions revealed that this finding may have been driven by males; the strength of associations did not increase from single to multiple concussions among females. Our findings suggest that adolescents who reported concussion were at increased odds of reporting poor mental health and suicidal behaviors. Moreover, an increased number of concussive events may be associated with significantly greater odds of reporting suicidal attempts, particularly among males. Irrespective of sex, health care professionals should closely monitor mental health behaviors in adolescents with repetitive concussions, especially those that occur in close temporal proximity.

The Longitudinal Relationship Between Concussion History, Years of American Football Participation, and Alcohol Use Among Former National Football League Players: an NFL-LONG Study.

Investigate the relationships between concussion history and years of football participation (repetitive head impact proxy) with alcohol use across multiple decades in former professional football players. Participants (n= 348; mean age = 49.0 ± 9.4) completed health questionnaires in 2001 and 2019, which included self-reported concussion history and years of participation. Alcohol use frequency and amount per occasion were reported for three timepoints: during professional career, 2001, and 2019. Ordinal logistic regression models were fit to test associations of concussion history and years of participation with alcohol use at each timepoint. There were no significant associations between either concussion history or years of football participation with alcohol use (frequency and amount per occasion) at any timepoint. Effect estimates for concussion history and years of football participation with alcohol use were generally comparable across timepoints. Later life alcohol use by former American football players is not associated with concussion history or years of exposure to football.

Youth intentions to provide social support to a peer with a concussion

ABSTRACT Objectives 1) To describe demographic factors, concussion knowledge, attitudes, subjective norms, self-efficacy and intentions to provide social support to a peer with a concussion and 2) to examine if demographic factors and concussion knowledge are associated with components of the Theory of Planned Behavior. Methods The survey was completed between October 2018 and February 2019 by 200 youth (M = 15.30 years, SD = 1.52). Questions were designed for athletes and non-athletes and inquired about various types of social support. Data analysis included descriptive statistics, Wilcoxon Rank Sum Tests and Spearman’s Rank-Order Correlation Coefficients. Results More favorable attitudes and intentions to provide social support were observed among females (W = 2576, p ≤ 0.001; W = 2411, p ≤ 0.001), older youth (rho = 0.32, p ≤ 0.001; rho = 0.41, p ≤ 0.001) and those with higher concussion knowledge (rho = 0.29, p ≤ 0.001; rho = 0.22; p ≤ 0.001). Participating in sports with a high-risk of concussion was associated with lower attitudes and intentions to provide social support (W = 6677; p ≤ 0.001; W = 6721; p ≤ 0.001). Self-reported concussion history or knowing someone with a concussion history was not significantly associated with social support intentions. Conclusion This study identified characteristics of youth who had positive intentions to provide social support. These findings identify individuals who may model providing social support to a peer, as well as opportunities for future concussion education.

Self-reported concussions in Canada: A cross-sectional study.

Traumatic brain injuries (TBIs) are a major public health concern impacting the lives of many Canadians. Among all TBIs, concussions are the most common. However, to date, the incidence of concussions among the Canadian population, has remained unknown. To address this data surveillance gap, this study presents national estimates on the percentage of Canadians aged 12 years or older (excluding those living in the territories) who sustained one or more concussions in 2019. This study used data collected from the Traumatic Brain Injury Rapid Response (TBIRR) module of the 2020 Canadian Community Health Survey, a cross-sectional health survey. Descriptive statistics and logistic regressions were conducted to summarize the information in the TBIRR module. This study found that approximately 1.6% of Canadians aged 12 years or older reported sustaining one or more concussions in 2019. Age was significantly associated with concussion incidence after controlling for sex and annual household income, and the locations and activities surrounding respondents' most serious concussions varied by age group. Over one-third of respondents sustained multiple concussions. The results suggest that certain populations, particularly younger individuals, may be more affected by concussions. While circumstances surrounding concussions vary by age group, the most important contributing factors were sports or physical activities among youth and falls among the adult population. Monitoring concussions among the national population is an important activity in injury surveillance, as it can help evaluate the efficacy of injury prevention intervention and better understand knowledge gaps and the burden of this injury.

A-60 Gender and Age Differences on the Sway Medical Mobile Balance Test

Abstract Purpose To determine if performance on the Sway Medical Mobile Application Balance Test differs by age and gender. Methods Pre-season baseline data from 33,784 individuals (51.3% girls/women) between ages 12 and 22 (mean=16.8 years, SD=2.5), tested in the summer of 2022, without a self-reported concussion in the past 6 months, and without self-reported ADHD were examined. Three Spearman correlations were used to assess the association between balance scores and age for the total sample, and for the boys/men and girls/women groups separately. Twelve Mann-Whitney U tests were used to compare genders on balance scores within each age group (12, 13, 14, through 22-years-old) and for the total sample. A Bonferroni correction was used to adjust for multiple comparisons, and the level of significance was set at p=0.004. Results There was a positive correlation between higher (i.e., better) balance scores and older age for the total sample (r=.25, p<.001), and within the boys/men (r=.30, p<.001) and girls/women groups separately (r=.21, p<.001). For every age, there was a significant difference between boys/men and girls/women on balance test scores, with girls/women obtaining higher (i.e., better) balance scores than boys/men. Effect sizes for these differences ranged from small to medium (Hedge’s g=.29-.65). Conclusions There are age and gender-related differences on baseline Sway Medical Mobile Balance Test scores. Girls/women performed better on the balance testing compared to boys/men at all ages. Additionally, the balance scores improved throughout adolescence and generally plateaued in early adulthood (18-22-years-old).

A-36 Performance of Children with Attention Deficit/Hyperactivity Disorder on the Sway Medical Mobile Balance and Cognitive Tests

Abstract Purpose There is a recognized need for more research relating to preseason balance and cognitive testing, as part of a sport-related concussion medical management program, for middle school children. We examined if preseason baseline performance on the Sway Medical Mobile Balance and Cognitive Tests differs by self-reported ADHD diagnosis in 12- and 13-year-old children. Methods Data from 2,501 children (49.1% girls) between 12- and 13-years-old (mean=13.64 years, standard deviation=0.48), tested in 2022, without a self-reported concussion in the past 6 months, were examined. Mann-Whitney U tests were used to compare balance and four cognitive test scores between children with and without self-reported ADHD, stratified by gender, and significance was set at p<.01. Results There were no significant differences on balance testing for boys or girls with ADHD compared to those without ADHD. Boys with ADHD performed slightly slower on the Impulse Control (p=.001, Hedge’s g=.14) and Inspection Time (p=.002, g=.22) tests than boys without ADHD. Girls with ADHD performed slightly slower on the Reaction Time test (p=.001, g=.33) than girls without ADHD. No differences were found on the Memory test for girls or boys. Conclusions Middle school aged boys and girls with ADHD did not perform worse on balance testing and some of the cognitive tests compared to children without ADHD. There were small magnitude differences on timed tests of Impulse Control and Inspection Time for boys and Reaction Time for girls, with youth who self-reported having ADHD performing slower than youth without ADHD.

Effect of RISE Bundle implementation on school adoption of a student-centered return-to-learn program in Washington state.

Appropriate concussion care in school is vital for full recovery, but school return-to-learn (RTL) programs are lacking and vary in quality. Establishing student-centered RTL programs may reduce disparities in RTL care. To examine the effect of RISE Bundle (Return to Learn Implementation Bundle for Schools) implementation on high school adoption of a student-centered RTL program. A convenience sample of fourteen (4 rural and 10 urban) small and large Washington (WA) State public high schools were enrolled in a stepped-wedge study with baseline, end of study, and monthly measures over the 2021-2022 academic year. Schools identified an RTL champion who led RISE Bundle implementation in 6-week steps. Concussion knowledge and impact of RTL program on concussion care were examined. Ten schools (71.4%) successfully completed RISE Bundle implementation and established a functional RTL program. Self-reported concussion knowledge from RTL Champions increased post intervention. Establishing RTL programs facilitated provision of tailored accommodations, and perceived variation and inequities in RTL care were reduced. RISE Bundle implementation proved feasible, supported the establishment of a functional RTL program, and perceived to reduce disparities in concussion care in rural and urban WA State public high schools of varying sizes.

NZ-RugbyHealth Study: Current Postural Control Ability of Former Rugby Union and Non-contact Sport Players.

Players in contact sports frequently experience mild traumatic brain (concussion) injuries (TBI). While there are known disruptions to balance following acute head trauma, it is uncertain if sport-related concussion injuries have a lasting impact on postural control. To assess postural control in retired rugby players in comparison to retired non-contact sport players, and to evaluate any association with self-reported sport-related concussion history. Using a cross-sectional design, 75 players in the NZ-RugbyHealth study from three sports groups (44 ± 8years; 24 elite rugby, 30 community rugby, 21 non-contact sport) took part in this study. The SMART EquiTest® Balance Master was used to assess participant's ability to make effective use of visual, vestibular and proprioceptive information using standardised tests. Postural sway was also quantified using centre of pressure (COP) path length. The relationship among sports group, sport-related concussion history and postural control was evaluated using mixed regression models while controlling for age and body mass index. Limited significant differences in balance metrics were found between the sports groups. A statistically significant (p < 0.001) interaction indicated a relationship between COP path length and sport-related concussion history in the most challenging balance condition, such that path length increased as the number of previous sport-related concussions increased. There was some evidence for a relationship between sport-related concussion recurrence in sports players and postural stability in challenging balance conditions. There was no evidence of impaired balance ability in retired rugby players compared with non-contact sport athletes.

Traumatic brain injury history and baseline symptoms outweigh sex differences for risk of concussion in a sample of collegiate athletes

ABSTRACT Objective To test the hypothesis that a history of traumatic brain injury (TBI) prior to the collegiate pre-season is associated with risk for re-injury. We also investigate sex differences, cognitive functioning, and self-reported concussion symptoms and their associations with concussion risk. Methods A longitudinal cohort study consisting of collegiate athletes (n = 212) who completed consecutive preseason evaluations (P1 and P2) between 2012 and 2015, averaging 12.9 (SD = 4.2) months apart. Results There were 40 new concussions recorded between P1 and P2, 21 (53%) of which were among athletes who reported a lifetime history of mild TBI/concussion at P1. New P1-P2 concussions occurred in 24% of female athletes (n = 23) and 15% of male athletes (n = 17). History of TBI and female sex were significant predictors of new concussion between P1 and P2; however, in adjusted models, the inclusion of Impulse Control and PCSS Total symptom scores attenuated the effect of sex on the risk for new injury. Conclusion Collegiate athletes with a lifetime history of TBI had a significantly higher risk of sustaining a subsequent concussion. Pre-season emotional and somatic symptomology may contribute to incident concussion risk. The findings highlight the importance of considering lifetime head injury exposure and baseline symptomatology when interpreting sex differences and evaluating concussion risk.

Characterizing Factors Influencing Baseline Plasma Biomarkers for Sport-Related Concussion in Adolescents.

Abstract Developing objective measures to diagnose sport-related concussion (SRC) is a top priority, particularly in the pediatric context, given the vulnerability of the developing brain. While advances in SRC blood biomarkers are being made in adult populations, less data are available for adolescents. Clinical validation of blood biomarkers post-SRC will first require investigation in a healthy uninjured state. Further, rapid pubertal changes during adolescence may implicate possible interactions with circulating sex hormones and the menstrual cycle for females. This cross-sectional study aimed to characterize pre-injury plasma levels of glial fibrillary acidic protein (GFAP), neurofilament light (NF-L), ubiquitin C-terminal hydrolase-L1 (UCH-L1), total tau (T-tau), and phosphorylated tau-181 (P-tau-181), considering previous concussion, age, and sex in healthy adolescent sport participants. Possible associations with menstrual cycle phase and circulating sex hormone levels (i.e., progesterone, estradiol, testosterone) were also explored. Pre-injury blood samples were obtained from 149 healthy adolescents (48% female, ages 11-18) participating in a larger Surveillance in High Schools and Community Sports to Reduce Concussions and their Consequences (SHRed Concussions) multi-site longitudinal cohort study. Main outcomes were natural log (ln) transformed plasma GFAP, NF-L, UCH-L1, T-tau, and P-tau-181 concentrations, quantified on the Quanterix Simoa HD-X platform. Mixed-effects multi-variable linear regression was used to assess associations between biomarkers and self-reported previous concussion (yes/no), age (years), sex (male/female), objectively determined menstrual cycle phase (follicular/luteal), plasma progesterone, estradiol, and testosterone. Males had 19.8% lower UCH-L1 (β = -0.221, 95% confidence interval [CI; -0.396, -0.046]), 18.9% lower GFAP (β = -0.210, 95% CI [-0.352, -0.068]), and 21.8% higher P-tau-181 (β = 0.197, 95% CI [0.048, 0.346]) compared with females, adjusting for age and previous concussion. GFAP decreased 9.5% with each 1-year increase in age, adjusting for previous concussion and sex (β = -0.100, 95% CI [-0.152, -0.049]). No biomarkers were associated with a history of previous concussion. Exploratory investigations found no associations between biomarkers and menstrual cycle phase. Females displayed an age-adjusted negative association between T-tau and progesterone (β = -0.010, 95% CI [-0.018, -0.002]), whereas males had a negative age-adjusted association between UCH-L1 and testosterone (β = -0.020, 95% CI [-0.037, -0.002]). As such, age- and sex-specific reference intervals may be warranted for pediatric athlete populations prior to clinical validation of blood biomarkers for SRC. Additionally, hormonal associations highlight the need to consider puberty and development in adolescent studies. Overall, findings suggest these biomarkers are resilient to a history of previous concussion and menstrual cycle phase, supporting continued investigation in adolescent SRC.