A systematic review of sex differences in concussion outcome: What do we know?

Effects of mTBI with loss of consciousness on neurobehavioral symptoms, depression, and insomnia in former collegiate and NFL football athletes

OBJECTIVE

Considering that diagnostic decisions about mTBI are often predicated on clinical symptom criteria, it is imperative to determine which initial presentation features of mTBI have prognostic significance for identifying those at high risk for long-term functional impairment.

SETTING

Zoom interview Participants: Male, former NCAA Division I, and professional-level National Football League (NFL) athletes (n = 177) between the ages of 27 and 85 (M = 54.1, SD = 14.7).

DESIGN

Cross-sectional case-control. Main Measures: History of mild TBI, history of loss of consciousness (LOC), depression symptoms, insomnia, neurobehavioral symptoms.

RESULTS

Number of mTBI exposures did not predict neurobehavioral symptoms (B = 0.21, SE = 0.18, p = 0.23), but number of mTBI + LOC events did (B = 2.27, SE = 0.64, p = <.001). Further analysis revealed that the number of mTBI + LOC events predicted neurobehavioral symptoms indirectly through both depression (B = 0.85, 95% CI = [0.27, 1.52) and insomnia (B = 0.81, 95% CI = [0.3, 1.4]). Further, the direct effect of mTBI + LOC events on neurobehavioral symptoms became non-significant when depression and insomnia were added to the model (B = 0.78, SE = 0.45, p = 0.08).

CONCLUSIONS

Findings support LOC at time of injury as an important predictor of long-term outcomes. Additionally, results suggest depression and insomnia as potential mediators in the association between mTBI + LOC and neurobehavioral symptoms. These findings provide justification for early depression and insomnia symptom monitoring following mTBI + LOC.

Concussion Incidence, Mechanism, and Perspectives Among Australian Elite Surfers: Implications for Medical Support and Safety Protocols

OBJECTIVE

The primary objective was to investigate the incidence of concussion and the associated mechanisms of injury in elite Australian surfers. The secondary objective was to investigate the current perspectives and behaviors related to experiencing concussion in surfing.

DESIGN

A cross-sectional, retrospective, descriptive survey.

SETTING

Surfing Australia high-performance program.

PARTICIPANTS

Forty nationally identified elite Australian surfing athletes.

INTERVENTION

A retrospective survey collected information pertaining to participant demographics, concussion history, potential concussive symptoms, such as headache, neck pain, dizziness, or unusual fatigue, following a wipeout, and participants' perspectives on concussion.

MAIN OUTCOME MEASURES

Investigating concussion incidence among elite Australian surfers compared with potential undiagnosed concussive episodes.

RESULTS

Surfers with a history of diagnosed surfing-related concussion (DC) were compared with those with no history of a diagnosed surfing-related concussion (NDC). A total of 13 of 40 surfers had a DC, with "contact versus the water surface" identified as the primary mechanism. Both DC and NDC groups had a high frequency of concussive symptoms after a surfing wipeout with a total of 447 and 573 concussive symptom occurrences reported in the DC and NDC groups, respectively. Concern regarding the long-term impacts of concussion were reported in 25 of 40 surfers.

CONCLUSIONS

The number of concussive symptoms reported by surfers who had not previously been diagnosed with concussion suggests that concussion may be underreported and underdiagnosed in elite surfing. This underscores the need for increased medical support, education, and improved safety protocols.

Sex-dependent perturbations in risky choice behavior and prefrontal tyrosine hydroxylase levels induced by repetitive mild traumatic brain injury

Head trauma often impairs cognitive processes mediated within the prefrontal cortex (PFC), leading to impaired decision making and risk-taking behavior. Mild traumatic brain injury (mTBI) accounts for approximately 80 % of reported head injury cases. Most neurological symptoms of a single mTBI are transient; however, growing evidence suggests that repeated mTBI (rmTBI) results in more severe impairments that worsen with each subsequent injury. Although mTBI-induced disruption of risk/reward decision making has been characterized, the potential for rmTBI to exacerbate these effects and the neural mechanisms involved are unknown. Catecholamine neurotransmitters, dopamine (DA) and norepinephrine (NE), modulate PFC-mediated functions. Imbalances in catecholamine function have been associated with TBI and may underlie aberrant decision making. We used a closed head-controlled cortical impact (CH-CCI) model in rats to evaluate the effects of rmTBI on performance of a probabilistic discounting task of risk/reward decision making behavior and expression levels of catecholamine regulatory proteins within the PFC. RmTBI produced transient increases in risky choice preference in both male and female rats, with these effects persisting longer in females. Additionally, rmTBI increased expression of the catecholamine synthetic enzyme, tyrosine hydroxylase (TH), within the orbitofrontal (OFC) region of the PFC in females only. These results suggest females are more susceptible to rmTBI-induced disruption of risk/reward decision making behavior and dysregulation of catecholamine synthesis within the OFC. Together, using the CH-CCI model of rodent rmTBI to evaluate the effects of multiple insults on risk-taking behavior and PFC catecholamine regulation begins to differentiate how mTBI occurrences affect neuropathological outcomes across different sexes.

Vergence and accommodation deficits in paediatric and adolescent patients during sub-acute and chronic phases of concussion recovery

INTRODUCTION

Visual function deficits have been reported in adolescents following concussion. We compared vergence and accommodation deficits in paediatric and adolescent patients at a tertiary medical centre in the sub-acute (15 days to 12 weeks) and chronic (12 weeks to 1 year) phases of concussion recovery.

METHODS

The study included patients aged 7 to <18 years seen between 2014 and 2021, who had a binocular vision (BV) examination conducted within 15 days and 1 year of their concussion injury. Included patients had to have 0.10 logMAR monocular best-corrected vision or better in both eyes and be wearing a habitual refractive correction. BV examinations at near included measurements of near point of convergence, convergence and divergence amplitudes, vergence facility, monocular accommodative amplitude and monocular accommodative facility. Vergence and accommodation deficits were diagnosed using established clinical criteria. Group differences were assessed using nonparametric statistics and ANCOVA modelling.

RESULTS

A total of 259 patients were included with 111 in the sub-acute phase and 148 in the chronic phase of concussion recovery. There was no significant difference in the rates of vergence deficits between the two phases of concussion recovery (sub-acute = 48.6%; chronic = 49.3%). There was also no significant difference in the rates of accommodation deficits between the two phases of concussion recovery (sub-acute = 82.0%; chronic = 77.0%).

CONCLUSION

Patients in both the sub-acute and chronic phases of concussion recovery exhibited a high frequency of vergence and accommodation deficits, with no significant differences between groups. Results indicate that patients exhibiting vision deficits in the sub-acute phase may not resolve without intervention, though a prospective, longitudinal study is required to test the hypothesis.

Effects of repetitive subconcussive head trauma on the neuropsychological functioning and symptom reporting of high school athletes in high and low contact sports: Age and sex

OBJECTIVE

The present study was designed to assess the neuropsychological test performances of non-concussed female and male high school athletes of different ages in high and low contact sports.

METHOD

Large samples of 2,510 high school athletes in High Contact sports (e.g., football) and 1,437 in Low Contact sports (e.g., basketball) were examined. The participants were administered a baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) prior to their respective seasons.

RESULTS

Multivariate linear regression showed that the High Contact athletes had significantly poorer results than the Low Contact athletes in all four ImPACT Composite scores and the Total Symptom scores. No age differences were found, but in all three age groups, the High Contact athletes had lower Visual Motor Speed scores than the Low Contact athletes. No test score differences were noted between the females in the High and Low Contact groups, but the High Contact males had poorer Visual Motor Speed and Reaction Time than the Low Contact males.

CONCLUSIONS

The present results were consistent with prior studies of subconcussive head trauma, with High Contact athletes obtaining overall poorer neuropsychological test results than Low Contact athletes. More investigations in this age group seems is warranted.

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.

Pediatric Concussions in Contact Sports: A 10-Year Retrospective Analysis of Mechanisms and Associated Symptoms

Background

Concussions make up a significant proportion of sports injuries. This study aimed to describe the mechanisms of injury and associated symptoms of pediatric patients diagnosed with concussions (age range, 4-17 years) from contact sports.

Hypothesis

Mechanisms of injury would differ based on sex and age, with female athletes and younger athletes aged 4 to 11 years sustaining fewer concussions from player-to-player contact.

Study Design

Descriptive epidemiology study.

Methods

The National Electronic Injury Surveillance System was queried for all contact sport concussions presented to United States emergency departments. The sports analyzed included basketball, football, soccer, hockey, rugby, and lacrosse. Descriptive data, mechanisms of injury, and associated symptoms were analyzed for each sport. Differences in the number of concussions sustained by year and sport, the severity of the injury, and associated symptoms were compared using chi-square test, and differences in proportion were calculated for mechanisms of injury stratified by sex and age.

Results

A total of 12,602 youth athletes sustained concussions between 2012 and 2021. Most patients were male (78.5%), with a mean age of 13.48 years. Football concussions were the most common, with 45.32% of the concussions. The mechanism of injury was largely sport-specific, with player-to-player contact the most common overall. Older male athletes were more likely to have concussions from player-to-player contact, whereas younger athletes were more impacted by head-to-ground mechanisms. Symptom presentation was not sport-specific, and headache and dizziness were the most common presentation at 41.2% and 26.2%, respectively.

Conclusion

The most important overall mechanism of injury was player-to-player contact, especially in older male youth athletes, whereas younger athletes were more likely to be concussed due to head-to-ground injuries.

A PROGRESS-driven approach to cognitive outcomes after traumatic brain injury: A study protocol for advancing equity, diversity, and inclusion through knowledge synthesis and mobilization

Evidence syntheses for advancing equitable traumatic brain injury (TBI) research, policy, and practice presents formidable challenges. Research and clinical frameworks are currently not specific to equity, diversity, and inclusion considerations, despite evidence that persons with TBI live in societies in which power imbalances and systems of social dominance may privilege some people and marginalize others. The present protocol outlines a strategy for a research program, supported by the Canadian Institutes of Health Research, that explores the integration of PROGRESS-Plus parameters in research with the goal of advancing open-science databases and tools to improve our understanding of equity in cognitive and brain health outcomes in TBI. PROGRESS-Plus is a framework outlining social, economic, and cultural parameters that may influence health opportunities and outcomes (e.g., place of residence, race, occupation, gender, etc.). A multistep research program is proposed to support three objectives: (1) organizing existing data on TBI-induced changes in cognition and brain health into a template to facilitate future research, including research using machine learning techniques; (2) updating published evidence with a more rigorous approach to the consideration of PROGRESS-Plus parameters; and (3) mobilizing knowledge on the current state of evidence that is relevant, equitable, and accessible. This program facilitates partnerships with knowledge users across clinical, research, academic, and community sectors to address the three research objectives through a unifying workflow of exchange, synthesis, and knowledge mobilization. We anticipate that this global collaboration between topic experts and community leaders in equity in brain health will add significant value to the field of TBI by promoting equity-transformative advancements in knowledge synthesis, policy, and practice.

Measurement Invariance of the Neurobehavioral Symptom Inventory in Male and Female Million Veteran Program Enrollees Completing the Comprehensive Traumatic Brain Injury Evaluation

This study evaluated measurement invariance across males and females on the Neurobehavioral Symptom Inventory (NSI) in U.S. military veterans enrolled in the VA Million Veteran Program. Participants (N = 17,059; males: n = 15,450; females: n = 1,609) included Veterans who took part in the VA Traumatic Brain Injury (TBI) Screening and Evaluation Program and completed the NSI. Multiple-group confirmatory factor analyses investigated measurement invariance of the NSI 4-factor model. The configural (comparative fit index [CFI] = 0.948, root mean square error of approximation [RMSEA] = 0.060) and metric (CFI = 0.948, RMSEA = 0.058) invariance models showed acceptable fit. There was a minor violation of scalar invariance (Δχ2 = 232.50, p < .001); however, the degree of noninvariance was mild (ΔCFI = -0.002, Δ RMSEA = 0 . 000 ). Our results demonstrate measurement invariance across sex, suggesting that the NSI 4-factor model can be used to accurately assess symptoms in males and females following TBI. Findings highlight the importance of considering validity of measurement across study groups to increase confidence that a measure is interpreted similarly by respondents from different subgroups.

Identifying and Predicting Subgroups of Veterans With Mild Traumatic Brain Injury Based on Distinct Configurations of Postconcussive Symptom Endorsement: A Latent Class Analysis

OBJECTIVE

To identify distinct subgroups of veterans with mild traumatic brain injury (mTBI) based on configurations of postconcussive symptom (PCS) endorsement, and to examine predictors of subgroup membership.

SETTING

Outpatient Veterans Health Administration (VHA).

PARTICIPANTS

Veterans with clinician-confirmed mTBI who completed the Neurobehavioral Symptom Inventory (NSI), determined using the Comprehensive Traumatic Brain Injury Evaluation database. Individuals who tended to overreport symptoms were excluded via an embedded symptom validity scale.

DESIGN

Retrospective cohort study leveraging national VHA clinical data from 2012 to 2020. Latent class analysis (LCA) with a split-sample cross-validation procedure was used to identify subgroups of veterans. Multinomial logistic regression was used to examine predictors of subgroup membership.

MAIN MEASURES

Latent classes identified using NSI items.

RESULTS

The study included 72 252 eligible veterans, who were primarily White (73%) and male (94%). The LCA supported 7 distinct subgroups of veterans with mTBI, characterized by diverging patterns of risk for specific PCS across vestibular (eg, dizziness), somatosensory (eg, headache), cognitive (eg, forgetfulness), and mood domains (eg, anxiety). The most prevalent subgroup was Global (20.7%), followed by Cognitive-Mood (16.3%), Headache-Cognitive-Mood (H-C-M; 16.3%), Headache-Mood (14.2%), Anxiety (13.8%), Headache-Sleep (10.3%), and Minimal (8.5%). The Global class was used as the reference class for multinomial logistic regression because it was distinguished from others based on elevated risk for PCS across all domains. Female (vs male), Black (vs White), and Hispanic veterans (vs non-Hispanic) were less likely to be members of most subgroups characterized by lesser PCS endorsement relative to the Global class (excluding Headache-Mood).

CONCLUSION

The 7 distinct groups identified in this study distill heterogenous patterns of PCS endorsement into clinically actionable phenotypes that can be used to tailor clinical management of veterans with mTBI. Findings reveal empirical support for potential racial, ethnic, and sex-based disparities in PCS among veterans, informing efforts aimed at promoting equitable recovery from mTBI in this population.

More Than Skin Deep: Patient-Provider Racial and Ethnic Concordance and Discordance in Collegiate Athletics and Concussion Management

CONTEXT

There is strong evidence that racial and ethnic disparities exist in multiple arenas of health and wellness. The causes of racial and ethnic differences in health care are multidimensional; one factor that may affect injury/illness communication, interactions, and outcomes is patient-provider racial and ethnic concordance. At present, it is unclear what role patient-provider racial and ethnic concordance and discordance plays in facilitating concussion care for collegiate athletes.

OBJECTIVE

To investigate the presence of athlete-athletic trainer (AT) racial and ethnic concordance and discordance among diagnosed concussion cases and examine if racial and ethnic concordance and discordance influences time (in days) until diagnosis, symptom resolution, or return-to-sport clinical milestones in collegiate athletes.

DESIGN

Retrospective cohort study.

SETTING

Collegiate athletics.

PATIENTS OR OTHER PARTICIPANTS

A total of 694 concussion cases (38.6% [n = 268] sustained by women, 61.4% [n = 426] sustained by men) that occurred within the 2015-2016 through 2019-2020 sport seasons at 9 institutions.

MAIN OUTCOME MEASURE(S)

The number of days from the date of injury to diagnosis, symptom resolution, and return to sport and from the date of diagnosis to symptom resolution and return to sport.

RESULTS

Overall, 68.4% (n = 475) of concussion cases had patient-provider racial and ethnic concordance, and 31.6% (n = 219) were discordant. All concordant pairs included a White athlete and White AT. Time to diagnosis differed between the concordant and discordant groups (median [interquartile range] = 1 [0-2] versus 0 [0-1], respectively) only in the model adjusted for sex, sport type, and availability of an AT (odds ratio [95% CI] = 1.46 [1.07-1.85]). There were no other group differences.

CONCLUSIONS

One-third of concussion cases had athlete-AT racial and ethnic discordance. Although this group was diagnosed with a concussion 1 day sooner than the concordant group, no differences were observed for any concussion recovery milestones. These findings suggest that patient-provider racial and ethnic concordance may play a minor role in concussion recognition or reporting but not necessarily in the management and recovery thereafter.

The Prevalence and Influence of New or Worsened Neck Pain After a Sport-Related Concussion in Collegiate Athletes: A Study From the CARE Consortium

BACKGROUND

Neck pain in a concussion population is an emerging area of study that has been shown to have a negative influence on recovery. This effect has not yet been studied in collegiate athletes.

HYPOTHESIS

New or worsened neck pain is common after a concussion (>30%), negatively influences recovery, and is associated with patient sex and level of contact in sport.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Varsity-level athletes from 29 National Collegiate Athletic Association member institutions as well as nonvarsity sport athletes at military service academies were eligible for enrollment. Participants completed a preseason baseline assessment and follow-up assessments at 6 and 24 to 48 hours after a concussion, when they were symptom-free, and when they returned to unrestricted play. Data collection occurred between January 2014 and September 2018.

RESULTS

A total of 2163 injuries were studied. New or worsened neck pain was reported with 47.0% of injuries. New or worsened neck pain was associated with patient sex (higher in female athletes), an altered mental status after the injury, the mechanism of injury, and what the athlete collided with. The presence of new/worsened neck pain was associated with delayed recovery. Those with new or worsened neck pain had 11.1 days of symptoms versus 8.8 days in those without (P < .001). They were also less likely to have a resolution of self-reported symptoms in ≤7 days (P < .001). However, the mean duration of the return-to-play protocol was not significantly different for those with new or worsened neck pain (7.5 ± 7.7 days) than those without (7.4 ± 8.3 days) (P = .592).

CONCLUSION

This novel study shows that neck pain was common in collegiate athletes sustaining a concussion, was influenced by many factors, and negatively affected recovery.

Meta Data Analysis of Sex Distribution of Study Samples Reported in Summer Biomechanics, Bioengineering, and Biotransport Annual Conference Abstracts

The biased use of male subjects in biomedical research has created limitations, underscoring the importance of including women to enhance the outcomes of evidence-based medicine and to promote human health. While federal policies (e.g., the 1993 Revitalization Act and the 2016 Sex as a Biological Variable Act) have aimed to improve sex balance in studies funded by the National Institutes of Health (NIH), data on sex inclusivity in non-NIH funded research remain limited. The objective of this study was to analyze the trend of sex inclusion in abstracts submitted to the Summer Biomechanics, Bioengineering, & Biotransport Conference (SB3C) over 7 years. We scored every abstract accepted to SB3C, and the findings revealed that approximately 20% of total abstracts included sex-related information, and this trend remained stable. Surprisingly, there was no significant increase in abstracts, including both sexes and those with balanced female and male samples. The proportion of abstracts with balanced sexes was notably lower than those including both sexes. Additionally, we examined whether the exclusion of one sex from the corresponding studies was justified by the research questions. Female-only studies had a 50% justification rate, while male-only studies had only 2% justification. Disparity in sex inclusion in SB3C abstracts was apparent, prompting us to encourage scientists to be more mindful of the sex of the research samples. Addressing sex inclusivity in biomechanics and mechanobiology research is essential for advancing medical knowledge and for promoting better healthcare outcomes for everyone.

A literature review of outcome and treatment options after acquired brain injury: Suggestions for adult offenders using knowledge from the general population

BACKGROUND

Acquired brain injury (ABI) is a major health problem, often with negative effects on behaviour and mental health as well as cognition. Prevalence of ABI is exceptionally high among offenders and increases their re-offending risk. Information on risk factors for ABI and its outcomes among offenders that could guide effective treatment for them is, nevertheless, scarce and dispersed. However, there is a more substantial literature about the general population that could inform work with brain-injured offenders, especially when selecting for samples or subgroups with similar relevant characteristics, such as lower socio-economic status (SES), pre-injury lower tested intelligence score (<85) and pre-injury mental health problems.

AIMS

To explore brain injury data from non-offender samples of otherwise similar socio-economic and mental health and ability characteristics to offenders then, first, to describe their untreated outcomes and, secondly, outcomes after frequently used interventions in these circumstances, noting factors associated with their effectiveness.

METHOD

Three databases were systematically searched for the years 2010-2022; first, using terms for brain injury or damage and cognitive (dys)function, mental health or quality of life. Second, in a separate search, we used these terms and terms for interventions and rehabilitation. In the second review, studies were selected for clear, distinguishable data on age, sex, SES and lifestyle factors to facilitate inferences for offenders. A narrative analytical approach was adopted for both reviews.

RESULTS

Samples with characteristics that are typical in offender groups, including lower SES, lower pre-injury intelligence quotient (<85), prior cognitive impairments and prior mental health problems, had poorer cognitive and behavioural outcomes following ABI than those without such additional problems, together with lower treatment adherence. With respect to treatment, adequate motivation and self-awareness were associated with better cognitive and behavioural outcomes than when these were low or absent, regardless of the outcome measured.

CONCLUSIONS

More complex pre-injury mental health problems and social disadvantages typical of offenders are associated with poorer post-brain injury recovery. This paper adds to practical knowledge by bringing together work that follows specific outcome trajectories. Overall, succesful ABI-interventions in the general population that aim at pre-injury difficulties comparable to those seen among offenders, show that personalising injury-specific treatments and taking account of these difficulties, maximised positive outcomes.

Female RNA concussion (FeRNAC) study: assessing hormone profiles and salivary RNA in females with concussion by emergency departments in New Zealand: a study protocol

BACKGROUND

Females of reproductive age with concussion report a greater number of symptoms that can be more severe and continue for longer than age matched males. Underlying mechanisms for sex differences are not well understood. Short non-coding Ribonucleic Acids (sncRNAs) are candidate salivary biomarkers for concussion and have been studied primarily in male athletes. Female sex hormones influence expression of these biomarkers, and it remains unclear whether a similar pattern of sncRNA expression would be observed in females following concussion. This study aims to evaluate recovery time, the ratio of salivary sncRNAs and symptom severity across different hormone profiles in females presenting to emergency departments (ED) with concussion and, to investigate the presence of low energy availability (LEA) as a potential modifier of concussion symptoms.

METHODS

This prospective cohort study recruits participants from New Zealand EDs who are biologically female, of reproductive age (16-50 years) and with a confirmed diagnosis of concussion from an ED healthcare professional. Participants are excluded by ED healthcare professionals from study recruitment as part of initial routine assessment if they have a pre-diagnosed psychiatric condition, neurological condition (i.e., epilepsy, cerebral palsy) or more than three previously diagnosed concussions. Participants provide a saliva sample for measurement of sncRNA's, and online survey responses relating to hormone profile and symptom recovery at 7-day intervals after injury until they report a full return to work/study. The study is being performed in accordance with ethical standards of the Declaration of Helsinki with ethics approval obtained from the Health and Disability Ethics Committee (HDEC #2021 EXP 11655), Auckland University of Technology Ethics Committee (AUTEC #22/110) and locality consent through Wellington hospital research office.

DISCUSSION

If saliva samples confirm presence of sncRNAs in females with concussion, it will provide evidence of the potential of saliva sampling as an objective tool to aid in diagnosis of, and confirmation of recovery from, concussion. Findings will determine whether expression of sncRNAs is influenced by steroid hormones in females and may outline the need for sex specific application and interpretation of sncRNAs as a clinical and/or research tool.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) registration number ACTRN12623001129673.

New Insights Into Accelerometer-Measured Habitual Physical Activity and Sedentary Time During Early Recovery in Pediatric Concussion

PURPOSE

Concussion management is shifting away from a rest-is-best approach, as data now suggest that exercise-is-medicine for this mild brain injury. Despite this, we have limited data on habitual physical activity following concussion. Therefore, our objective was to quantify accelerometer-measured physical activity and sedentary time in children with concussion (within the first month of injury) and healthy controls. We hypothesized that children with concussion would be less active than their healthy peers.

METHODS

We performed a secondary analysis of prospectively collected accelerometer data. Our sample included children with concussion (n = 60, 31 females) and historical controls (n = 60) matched for age, sex, and season of accelerometer wear.

RESULTS

Children with concussion were significantly more sedentary than controls (mean difference [MD], 38.3 min/d, P = .006), and spent less time performing light physical activity (MD, -19.5 min/d, P = .008), moderate physical activity (MD, -9.8 min/d, P < .001), and vigorous physical activity (MD, -12.0 min/d, P < .001); these differences were observed from 8:00 AM to 9:00 PM. Sex-specific analyses identified that girls with concussion were less active and more sedentary than both boys with concussion (P = .010) and healthy girls (P < .010).

CONCLUSION

There is an activity deficit observed within the first month of pediatric concussion. Physical activity guidelines should address this while considering sex effects.

Association between days for concussion recovery and initial specialty clinic evaluation within 48 hours

BACKGROUND

Researchers have highlighted the importance of early access to concussion care within one week of injury in reducing recovery times. However, a persisting question for concussion researchers is "just how early is important?" The purpose of this study was to examine differences in recovery time as predicted by the number of days elapsed since injury (DSI) to initial evaluation among patients who had access to a specialty concussion clinic within seven days. We hypothesized that DSI group membership, even within seven days, would significantly predict risk of protracted recovery (i.e., beyond 21 days).

METHODS

In this archival study, retrospective data were gathered from electronic medical records between September 2020 to March 2022. Records of participants between ages 12-18, those diagnosed with a sports-related concussion based on initial clinic visit diagnosis by a medical provider and those who established care within seven days of injury at a large pediatric specialty concussion clinic were examined. Participants were divided into three DSI groups (patients seen in < 48 h: "acute", patients seen between 49 h < and < 96 h: "sub-acute", and patients seen between 97 < and < 168 h: "post-acute"). A general linear model was constructed to examine relationships between relevant concussion factors (e.g., Post Concussion Scale Score, neurodevelopmental history, psychiatric history, concussion history, migraine history, overall VOMS change score, cognitive testing, sex, age, race, and ethnicity) that were either significant in the preliminary analysis or in clinical judgement and recovery time. Adjusted odds ratios (OR) were derived from a binary logistic regression model, in which recovery time was normal (≤ 21 recovery days) or protracted (> 21 recovery days).

RESULTS

A total of 856 participants were eligible. Adolescents in the acute group (M = 15.12, SD = 8.04) had shorter recovery times in days compared to those in the sub-acute (M = 17.98, SD = 10.18) and post-acute (M = 21.12, SD = 10.12; F = 26.00, p < .001) groups. Further, participants in the acute (OR = 4.16) and sub-acute (OR = 1.37) groups who accessed specialty concussion clinics within 48 h were 4 times more likely to have a normal recovery and recovered approximately 6 days faster than the post-acute care group.

CONCLUSIONS

Earlier concussion care access predicted recovery times and was associated with lower risk for protracted recovery.

Representation of women in neuropsychology research prior to the COVID-19 pandemic

OBJECTIVE

Prior work has demonstrated that women have been historically underrepresented across various research fields, including neuropsychology. Given these disparities, the goal of this study was to systematically evaluate the inclusion of women as participants in neuropsychology research. The current study builds upon previous research by examining articles from eight peer-reviewed neuropsychology journals published in 2019.

METHOD

Empirical articles examining human samples were included in the current review if they were available in English. Eligible articles were examined to glean whether the main topic of the article was related to a gender issue, how gender was categorized, the gender distribution of the sample, whether gender was considered in analyses, whether gender was addressed in the discussion, and what age categories the study examined.

RESULTS

There was a relatively even distribution of men (51.76%) and women (48.24%) in neuropsychological research studies reviewed. There were twice as many studies that included only men compared to only women (16 vs. 8 studies), and nearly twice as many studies consisted of ≥ 75% men (16.6%) compared to ≥75% of women (8.5%). Gender-focused research was limited (3%). Furthermore, gender was frequently disregarded in analyses (58%) and often not addressed in the discussion (75%).

CONCLUSIONS

The current study highlights the limitations within neuropsychology related to the representation of women in research. Although it is encouraging that neuropsychological research is generally inclusive of women participants, future research should aim to more comprehensively investigate how gender may influence cognitive risk and resilience factors across different clinical presentations. Recommendations to begin addressing this challenge and to move toward more gender-equitable research are provided.

Exploring Interactions Between Traumatic Brain Injury History and Gender on Medical Comorbidities in Military Veterans: An Epidemiological Analysis in the VA Million Veteran Program

Epidemiological studies of medical comorbidities and possible gender differences associated with traumatic brain injury (TBI) are limited, especially among military veterans. The purpose of this study was to examine relationships between TBI history and a wide range of medical conditions in a large, national sample of veterans, and to explore interactions with gender. Participants of this cross-sectional epidemiological study included 491,604 veterans (9.9% TBI cases; 8.3% women) who enrolled in the VA Million Veteran Program (MVP). Outcomes of interest were medical comorbidities (i.e., neurological, mental health, circulatory, and other medical conditions) assessed using the MVP Baseline Survey, a self-report questionnaire. Logistic regression models adjusting for age and gender showed that veterans with TBI history consistently had significantly higher rates of medical comorbidities than controls, with the greatest differences observed across mental health (odds ratios [ORs] = 2.10-3.61) and neurological (ORs = 1.57-6.08) conditions. Similar patterns were found when evaluating men and women separately. Additionally, significant TBI-by-gender interactions were observed, particularly for mental health and neurological comorbidities, such that men with a history of TBI had greater odds of having several of these conditions than women with a history of TBI. These findings highlight the array of medical comorbidities experienced by veterans with a history of TBI, and illustrate that clinical outcomes differ for men and women with TBI history. Although these results are clinically informative, more research is needed to better understand the role of gender on health conditions in the context of TBI and how gender interacts with other social and cultural factors to influence clinical trajectories following TBI. Ultimately, understanding the biological, psychological, and social mechanisms underlying these comorbidities may help with tailoring TBI treatment by gender and improve quality of life for veterans with TBI history.

The influence of ADHD on recovery from sport concussion among collegiate athletes in the United States: LIMBIC MATARS consortium investigation

OBJECTIVE

The present study aimed to assess the potential influence of a diagnosis of ADHD on concussion recovery among collegiate athletes.

DESIGN

Retrospective and cross-sectional.

METHODS

Data were extracted retrospectively from medical records across LIMBIC MATARS member institutions (n = 11), representing 1,044 concussion cases among collegiate athletes. After exclusions, 406 concussions were included in our analysis (ADHD: n = 38, age = 20.2 ± 1.67 years, 18.4% female; No ADHD: n = 368, age = 19.8 ± 1.39 years, 40.1% female). Mann-Whitney U tests were used to compare days from injury to diagnosis, symptom resolution, and return to sport among athletes with and without ADHD.

RESULTS

No differences were observed for days from concussion until diagnosis (z = -0.33, p = 0.74), until days to symptom resolution (z = -1.30, p = 0.19), or days until return to sport (z = -0.68, p = 0.49); among concussion cases with or without a previously reported diagnosis of ADHD.

CONCLUSION

Our findings further expand the literature that suggests ADHD is not strongly associated with recovery trajectory following sport concussion in collegiate athletes. Future research should extend these findings to be inclusive of additional preexisting health conditions and moderating effects related to medication usage among diverse athlete levels.

Head Injury Due to Intimate Partner Violence: Injury Characteristics, Subacute Symptoms, and Receipt of Care

Women survivors of intimate partner violence (IPV) have increased risk of repetitive neurotrauma in their lifetime but have received less research focus compared with populations of athletes, veterans, and emergency department patients. The current study examined the importance of IPV as a contextual mechanism of injury, by comparing women survivors of IPV based on whether they experienced a head injury due to IPV or a head injury not due to IPV. The analyses involved archival data from in-person interviews conducted with women who received a protective order against an intimate partner in Kentucky from 2001 to 2004 (n = 641). Women were excluded if they reported no head injury history (n = 268), resulting in two groups compared based on a retrospective cohort design: 255 women with at least one self-reported IPV-related head injury (M = 33.8 ± 9.0 years old, range: 19-65; 87.5% White) and 118 women with self-reported head injuries due to reasons other than IPV (M = 32.2 ± 9.1 years old, range: 18-62; 89.0% White). Participants were compared on injury characteristics, lifetime physical and sexual IPV severity, subacute symptoms of head injury, and receipt of care for head injury. Compared with women with head injuries unrelated to IPV, women with IPV-related head injuries reported a higher number of lifetime head injuries (Mdn[range]: IPV-related = 3[1-515] vs. non-IPV-related = 1[1-13], p < 0.001, r = 0.51) and a higher number of head injuries involving loss of consciousness (Mdn[range]: IPV-related = 1[1-35] vs. non-IPV-related = 1[1-4], p < 0.001, r = 0.27), but lower rates of hospitalization (IPV-related = 56.1% vs. non-IPV-related = 73.7%, p = 0.001, odds ratio [OR] = 2.20 [95% confidence interval (CI): 1.36, 3.55]) and formal rehabilitation (IPV-related = 3.2% vs. non-IPV-related = 9.4%, p = 0.011, OR = 3.18 [1.24, 8.13]) following head injury. Women with IPV-related head injuries had greater lifetime severity of physical IPV (p < 0.001, d = 0.64 [0.41, 0.86]) and sexual IPV (p < 0.001, d = 0.38 [0.16, 0.60]). Women with IPV-related head injuries endorsed all symptoms at greater rates than women with non-IPV-related head injuries (ps < 0.001), including physical (e.g., headaches: OR = 3.15 [1.81, 5.47]; dizziness: OR = 2.65 [1.68, 4.16]), cognitive (e.g., trouble problem solving: OR = 2.66 [1.53, 4.64]; inattention: OR = 2.39 [1.52, 3.78]), and emotional symptoms (e.g., depression: OR = 7.39 [4.48, 12.20]; anxiety: OR = 4.60 [2.82, 7.51]). The total count of symptoms endorsed was higher for women with IPV-related head injury than women with head injuries unrelated to IPV (p < 0.001, d = 0.71 [0.49, 0.94]). When controlling for lifetime physical and sexual IPV, IPV-related head injury was independently associated with symptom count (β = 0.261, p < 0.001) and accounted for additional variance in symptom count (ΔR2 = 0.06, p < 0.001). Among women survivors of IPV, those reporting IPV-related head injuries reported greater subacute symptoms, but a lower likelihood of being hospitalized or receiving rehabilitative care. Women with self-reported IPV-related head injuries represent an underserved population that is often unevaluated following injury and may have many unmet care needs. Future studies should examine persistent symptoms following IPV-related head injuries and interventions that would be most beneficial for this population.

The association between symptom burden and processing speed and executive functioning at 4 and 12 weeks following pediatric concussion

OBJECTIVES

Symptoms and cognition are both utilized as indicators of recovery following pediatric concussion, yet their interrelationship is not well understood. This study aimed to investigate: 1) the association of post-concussion symptom burden and cognitive outcomes (processing speed and executive functioning [EF]) at 4 and 12 weeks after pediatric concussion, and 2) the moderating effect of sex on this association.

METHODS

This prospective, multicenter cohort study included participants aged 5.00-17.99 years with acute concussion presenting to four Emergency Departments of the Pediatric Emergency Research Canada network. Five processing speed and EF tasks and the Post-Concussion Symptom Inventory (PCSI; symptom burden, defined as the difference between post-injury and retrospective [pre-injury] scores) were administered at 4 and 12 weeks post-concussion. Generalized least squares models were conducted with task performances as dependent variables and PCSI and PCSI*sex interaction as the main predictors, with important pre-injury demographic and injury characteristics as covariates.

RESULTS

311 children (65.0% males; median age = 11.92 [IQR = 9.14-14.21 years]) were included in the analysis. After adjusting for covariates, higher symptom burden was associated with lower Backward Digit Span (χ2 = 9.85, p = .043) and Verbal Fluency scores (χ2 = 10.48, p = .033) across time points; these associations were not moderated by sex, ps ≥ .20. Symptom burden was not associated with performance on the Coding, Continuous Performance Test, and Color-Word Interference scores, ps ≥ .17.

CONCLUSIONS

Higher symptom burden is associated with lower working memory and cognitive flexibility following pediatric concussion, yet these associations were not moderated by sex. Findings may inform concussion management by emphasizing the importance of multifaceted assessments of EF.

Whole blood stimulation provides preliminary evidence of altered immune function following SRC

PURPOSE

To implement an approach combining whole blood immune stimulation and causal modelling to estimate the impact of sport-related concussion (SRC) on immune function.

METHODS

A prospective, observational cohort study was conducted on athletes participating across 13 university sports at a single academic institute; blood was drawn from 52 athletes, comprised of 22 athletes (n = 11 male, n = 11 female) within seven days of a physician-diagnosed SRC, and 30 healthy athletes (n = 18 female, n = 12 male) at the beginning of their competitive season. Blood samples were stimulated for 24 h under two conditions: (1) lipopolysaccharide (lps, 100ng/mL) or (2) resiquimod (R848, 1uM) using the TruCulture® system. The concentration of 45 cytokines and chemokines were quantitated in stimulated samples by immunoassay using the highly sensitive targeted Proximity Extension Assays (PEA) on the Olink® biomarker platform. A directed acyclic graph (DAG) was used as a heuristic model to make explicit scientific assumptions regarding the effect of SRC on immune function. A latent factor analysis was used to derive two latent cytokine variables representing immune function in response to LPS and R848 stimulation, respectively. The latent variables were then modelled using student-t regressions to estimate the total causal effect of SRC on immune function.

RESULTS

There was an effect of SRC on immune function in males following SRC, and it varied according to prior concussion history. In males with no history of concussion, those with an acute SRC had lower LPS reactivity compared to healthy athletes with 93% posterior probability (pprob), and lower R848 reactivity with 77% pprob. Conversely, in males with a history of SRC, those with an acute SRC had higher LPS reactivity compared to healthy athletes with 85% pprob and higher R848 reactivity with 82%. In females, irrespective of concussion history, SRC had no effect on LPS reactivity. However, in females with no concussion history, those with an acute SRC had higher R848 reactivity compared to healthy athletes with 86% pprob.

CONCLUSION

Whole blood stimulation can be used within a causal framework to estimate the effect of SRC on immune function. Preliminary evidence suggests that SRC affects LPS and R848 immunoreactivity, that the effect is stronger in male athletes, and differs based on concussion history. Replication of this study in a larger cohort with a more sophisticated causal model is necessary.

Genome-wide association study of traumatic brain injury in U.S. military veterans enrolled in the VA million veteran program

Large-scale genetic studies of traumatic brain injury (TBI) are lacking; thus, our understanding of the influence of genetic factors on TBI risk and recovery is incomplete. This study aimed to conduct a genome-wide association study (GWAS) of TBI in VA Million Veteran Program (MVP) enrollees. Participants included a multi-ancestry cohort (European, African, and Hispanic ancestries; N = 304,485; 111,494 TBI cases, 192,991 controls). TBI was assessed using MVP survey data and International Classification of Diseases (ICD) codes from the Veterans Health Administration's electronic health record. GWAS was performed using logistic regression in PLINK, and meta-analyzed in METAL. FUMA was used for post-GWAS analysis. Genomic structural equation modeling (gSEM) was conducted to investigate underlying genetic associations with TBI, and bivariate MiXeR was used to estimate phenotype specific and shared polygenicity. SNP-based heritability was 0.060 (SE = 0.004, p = 7.83×10-66). GWAS analysis identified 15 genome-wide significant (GWS) loci at p < 5×10-8. Gene-based analyses revealed 14 gene-wide significant genes; top genes included NCAM1, APOE, FTO, and FOXP2. Gene tissue expression analysis identified the brain as significantly enriched, particularly in the frontal cortex, anterior cingulate cortex, and nucleus accumbens. Genetic correlations with TBI were significant for risk-taking behaviors and psychiatric disorders, but generally not significant for the neurocognitive variables investigated. gSEM analysis revealed stronger associations with risk-taking traits than with psychiatric traits. Finally, the genetic architecture of TBI was similar to polygenic psychiatric disorders. Neurodegenerative disorders including Alzheimer's and Parkinson's disease showed much less polygenicity, however, the proportion of shared variance with TBI was high. This first well-powered GWAS of TBI identified 15 loci including genes relevant to TBI biology, and showed that TBI is a heritable trait with comparable genetic architecture and high genetic correlation with psychiatric traits. Our findings set the stage for future TBI GWASs that focus on injury severity and diversity and chronicity of symptom sequelae.

Medical Care Among Individuals with a Concussion in Ontario: A Population-based Study

BACKGROUND

Concussion affects 1.2% of the population annually; rural regions and children have higher rates of concussion.

METHODS

Using administrative health care linked databases, all residents of Ontario with a physician diagnosed concussion were identified using ICD-9 code 850 or ICD-10 code S06. Cases were tracked for 2 years for concussion-related health care utilization with relevant specialist physicians (i.e., neurology, otolaryngology, physiatry, psychiatry, ophthalmology). Billing codes, specialist codes, and time from index to visit were analyzed. Factors associated with increased specialist visits were also examined.

RESULTS

In total, 1,022,588 cases were identified between 2008 and 2014 with 2 years of post-concussion health care utilization available. Follow-up by physician within 3 days of injury occurred in only 14% of cases. Mean time between ED diagnosis and follow-up by a physician was 83.9 days, whereas for rural regions it was >100 days. About half of adults (51.9%) and children (50.3%) had at least 1 specialist visit following concussion. Mean time between injury and first specialist visit was 203.8 (SD 192.9) days for adults, 213.5 (SD 201.0) days for rural adults, and 276.0 (SD 202.6) days for children. There were 67,420 neurology visits, 70,404 psychiatry visits, 13,571 neurosurgery visits, 19,780 physiatry visits, 101,788 ENT visits, and 103,417 ophthalmology visits in the 2 years tracking period. Factors associated with more specialist use included age > 18 years, urban residence, and pre-injury psychiatric history.

CONCLUSIONS

There are discrepancies in post-concussion health care utilization based on age group and rural/urban residence. Addressing these risk factors could improve concussion care access.

Perceptions of personal control and treatment efficacy of sport-related concussions in collegiate athletes

OBJECTIVE

The purpose of this study was to examine healthy collegiate athletes' perceptions of personal control and beliefs regarding the treatment efficacy related to sport-related concussion (SRC) along with identifying factors that may be associated with these perceptions.

METHODS

This cross-sectional study included collegiate athletes (n = 956) between the age of 18-26 years. Participants completed a 10- to 15-min survey regarding their demographics, diagnosed SRC history, SRC knowledge, and Perceptions of Concussion Inventory for Athletes (PCI-A). Chi-squared analysis and multivariable logistic regressions were conducted to identify factors associated with the PCI-A outcomes of personal control and treatment efficacy perceptions.

RESULTS

24.2% of respondents reported higher perceptions of personal control, while 77.3% reported higher perceptions of treatment efficacy. The multivariable logistic regression revealed males had higher odds of greater perceptions of personal control (OR = 1.50; 95% CI: 1.10-2.03), while those with a history of diagnosed SRC had lower odds of having favorable treatment efficacy beliefs (OR: 0.69; 95% CI: 0.50-0.96).

CONCLUSIONS

This study established that collegiate athletes generally have lower perceptions of personal control and higher perceptions of treatment efficacy related to SRC recovery. Comprehensive SRC education should be expanded for individuals to understand that they have power over their own health outcomes and that SRC is a treatable injury.

Role of sex and gender in concussion outcome differences among patients presenting to the emergency department: a systematic review

OBJECTIVE

This systematic review aimed to identify research involving adults presenting to the emergency department (ED) with a concussion to document the reporting of sex and/or gender according to the Canadian Institutes of Health Research (CIHR) guidelines, the prevalence of sex and gender-based analysis (SGBA) and to summarise sex and/or gender-based differences in ED presentation, management and outcomes.

DESIGN

Systematic review.

METHODS

Electronic databases and grey literature were searched to identify studies that recruited adult patients with concussion from the ED. Two independent reviewers identified eligible studies, assessed quality and extracted data. A descriptive summary of the evidence was generated, and sex and/or gender reporting was examined for accuracy according to standardised criteria.

RESULTS

Overall, 126 studies were included in the analyses. A total of 80 (64%) studies reported sex and/or gender as demographic information, of which 51 (64%) included sex and/or gender in their analysis; however, 2 (3%) studies focused on an SGBA. Sex was more accurately reported in alignment with CIHR definitions than gender (94% vs 12%; p<0.0001). In total, 25 studies used an SGBA for outcomes of interest. Males and females experience different causes of concussion, 60% of studies documented that females had less frequent CT scanning while in the ED, and 57% of studies reported that postconcussion syndrome was more prevalent in females and women.

CONCLUSION

This systematic review highlighted that sex is reported more accurately than gender, approximately half of studies did not report either sex and/or gender as demographic information, and one-third of studies did not include SGBA. There were important sex and gender differences in the cause, ED presentation, management and outcomes of concussions.

PROSPERO REGISTRATION NUMBER

CRD42021258613.

The impact of the war in Ukraine on the reproductive health of female military personnel

OBJECTIVE

To explore the link between mental health, physical well-being, and reproductive system pathology in females who suffered war-related concussions.

METHODS

A study was conducted at the Kyiv Center of Reproductive and Perinatal Medicine with 715 participants. The group included 457 female military personnel with concussions (211 with post-concussive syndrome (PCS), 246 without), 208 women from occupied/deoccupied areas (103 with PCS, 105 without), and 50 civilians from safe zones. Average deployment time (mean ± standard deviation) was 60.26 ± 42.21 months, and trauma occurred 18.81 ± 9.221 months ago. Medical history and physical examinations were performed.

RESULTS

Female soldiers with PCS had a 1.3 times higher likelihood (P < 0.015) of experiencing longer menstrual periods. Painful menstruation was 1.47 times more frequent (P < 0.001), and heavy periods were 1.64 times more common (P < 0.003). Infertility duration in concussed women was 5.36 ± 0.13 years, whereas those with PCS experienced 1.29 times longer duration (6.02 ± 0.21 years) (P < 0.001) compared with women without PCS (4.69 ± 0.13 years). Among concussed soldiers, 69.27% had endometrial structural pathology, with PCS occurring 1.64 times more often (P < 0.001).

CONCLUSIONS

The health decline in female veterans and active-duty personnel extends beyond medical implications and has social significance. The well-being of these Ukrainian women affects the country's defense, demographic patterns, socio-political landscape, and social stability.

Early Moderate to Vigorous Physical Activity After Concussion Is Associated With Faster Symptom Resolution Time

CONTEXT

Early physical activity (PA) after concussion may promote symptom resolution. Prior studies have investigated exercise frequency/duration, yet precise PA intensity or volume required for optimal recovery requires further investigation. moderate to vigorous physical activity (MVPA) is beneficial for physical health. We investigated whether sedentary time, light activity time, MVPA time, or activity frequency in the weeks following concussion are associated with time to symptom resolution among adolescents.

DESIGN

Prospective cohort study.

METHODS

Adolescents 10-18 years of age were tested ≤14 days of concussion and followed until symptom resolution. At the initial visit, participants rated symptom severity and were provided wrist-worn activity trackers to monitor PA for the following week. PA behavior was categorized each day based on heart rate: sedentary (resting), light PA (50%-69% age-predicted max heart rate), and MVPA (70%-100% age-predicted max heart rate). Symptom resolution was defined as the date when participants reported cessation of concussion-like symptoms. Patients were not given specific PA instructions, though some may have received instructions from their physician.

RESULTS

Fifty-four participants were included in the study (54% female; mean age = 15.0 [1.8] y; initially assessed 7.5 [3.2] d after concussion). Female athletes recorded more sedentary time (900 [46] vs 738 [185] min/d; P = .01; Cohen d = 0.72), and less time in light PA (194.7 [64.5] vs 224 [55] min/d; P = .08; Cohen d = 0.48) and MVPA (23 [17] vs 38 [31] min/d; P = .04; Cohen d = 0.58) than male athletes. After adjusting for sedentary time, hours per day with >250 steps, sex, and initial symptom severity, more MVPA time was associated with faster symptom resolution time (hazard ratio = 1.016; 95% confidence interval, 1.001-1.032; P = .04).

CONCLUSION

Our findings offer preliminary insight into how varying PA intensities affect concussion recovery, as MVPA may be a higher intensity than what is typically prescribed in concussion care.

A Potential Role Exists for Nutritional Interventions in the Chronic Phase of Mild Traumatic Brain Injury, Concussion and Sports-Related Concussion: A Systematic Review

Mild traumatic brain injury (mTBI) represents a significant burden for individuals, economies, and healthcare systems worldwide. Recovery protocols focus on medication and physiotherapy-based interventions. Animal studies have shown that antioxidants, branched-chain amino acids and omega-3 fatty acids may improve neurophysiological outcomes after TBI. However, there appears to be a paucity of nutritional interventions in humans with chronic (≥1 month) symptomology post-mTBI. This systematic literature review aimed to consolidate evidence for nutrition and dietary-related interventions in humans with chronic mTBI. The review was registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42021277780) and conducted following the Preferred Reporting for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Three reviewers searched five databases (PubMed/MEDLINE, Web of Science, SPORTDiscus, CINAHL Complete and Cochrane), which yielded 6164 studies. Nine studies met the inclusion criteria. The main finding was the lack of interventions conducted to date, and a quality assessment of the included studies was found to be fair to good. Due to heterogeneity, a meta-analysis was not feasible. The six nutrition areas identified (omega-3 fatty acids, melatonin, Enzogenol®, MLC901, ketogenic diet and phytocannabinoids) were safe and well-tolerated. It was found that these nutritional interventions may improve cognitive failures, sleep disturbances, anxiety, physical disability, systolic blood pressure volume and sport concussion assessment tool scores following mTBI. Potential areas of improvement identified for future studies included blinding, reporting compliance, and controlling for confounders. In conclusion, further research of higher quality is needed to investigate the role of nutrition in recovery from mTBI to reduce the burden of chronic outcomes following mTBI.

The Toronto Concussion Study: a prospective investigation of characteristics in a cohort of adults from the general population seeking care following acute concussion, 2016-2020

Purpose

There is limited research regarding the characteristics of those from the general population who seek care following acute concussion.

Methods

To address this gap, a large cohort of 473 adults diagnosed with an acute concussion (female participants = 287; male participants = 186) was followed using objective measures prospectively over 16 weeks beginning at a mean of 5.1 days post-injury.

Results

Falls were the most common mechanism of injury (MOI) (n = 137, 29.0%), followed by sports-related recreation (n = 119, 25.2%). Male participants were more likely to be injured playing recreational sports or in a violence-related incident; female participants were more likely to be injured by falling. Post-traumatic amnesia (PTA) was reported by 80 participants (16.9 %), and loss of consciousness (LOC) was reported by 110 (23.3%). In total, 54 participants (11.4%) reported both PTA and LOC. Male participants had significantly higher rates of PTA and LOC after their injury compared to their female counterparts. Higher initial symptom burden was associated with a longer duration of recovery for both male and female participants. Female participants had more symptoms and higher severity of symptoms at presentation compared to male participants. Female participants were identified to have a longer recovery duration, with a mean survival time of 6.50 weeks compared to 5.45 weeks in male participants (p < 0.0001). A relatively high proportion of female and male participants in this study reported premorbid diagnoses of depression and anxiety compared to general population characteristics.

Conclusion

Although premorbid diagnoses of depression and/or anxiety were associated with higher symptom burden at the initial visit, the duration of symptoms was not directly associated with a pre-injury history of psychological/psychiatric disturbance. This cohort of adults, from the general population, seeking care for their acute concussion attained clinical and functional recovery over a period of 4-12 weeks.

BRCA1 heterozygosity promotes DNA damage-induced senescence in a sex-specific manner following repeated mild traumatic brain injury

Emerging evidence suggests cellular senescence, as a consequence of excess DNA damage and deficient repair, to be a driver of brain dysfunction following repeated mild traumatic brain injury (rmTBI). This study aimed to further investigate the role of deficient DNA repair, specifically BRCA1-related repair, on DNA damage-induced senescence. BRCA1, a repair protein involved in maintaining genomic integrity with multiple roles in the central nervous system, was previously reported to be significantly downregulated in post-mortem brains with a history of rmTBI. Here we examined the effects of impaired BRCA1-related repair on DNA damage-induced senescence and outcomes 1-week post-rmTBI using mice with a heterozygous knockout for BRCA1 in a sex-segregated manner. Altered BRCA1 repair with rmTBI resulted in altered anxiety-related behaviours in males and females using elevated zero maze and contextual fear conditioning. Evaluating molecular markers associated with DNA damage signalling and senescence-related pathways revealed sex-specific differences attributed to BRCA1, where females exhibited elevated DNA damage, impaired DNA damage signalling, and dampened senescence onset compared to males. Overall, the results from this study highlight sex-specific consequences of aberrant DNA repair on outcomes post-injury, and further support a need to develop sex-specific treatments following rmTBI.

Prognostic factors for persistent symptoms in adults with mild traumatic brain injury: an overview of systematic reviews

BACKGROUND

Mild traumatic brain injury (mTBI) is an increasing public health problem, because of its persistent symptoms and several functional consequences. Understanding the prognosis of a condition is an important component of clinical decision-making and can help to guide the prevention of persistent symptoms following mTBI. The prognosis of mTBI has stimulated several empirical primary research papers and many systematic reviews leading to the identification of a wide range of factors. We aim to synthesize these factors to get a better understanding of their breadth and scope.

METHODS

We conducted an overview of systematic reviews. We searched in databases systematic reviews synthesizing evidence about the prognosis of persistent symptoms after mTBI in the adult population. Two reviewers independently screened all references and selected eligible reviews based on eligibility criteria. They extracted relevant information using an extraction grid. They also rated independently the risk of bias using the ROBIS tool. We synthesized evidence into a comprehensive conceptual map to facilitate the understanding of prognostic factors that have an impact on persistent post-concussion symptoms.

RESULTS

From the 3857 references retrieved in a database search, we included 25 systematic reviews integrating the results of 312 primary articles published between 1957 and 2019. We examined 35 prognostic factors from the systematics reviews. No single prognostic factor demonstrated convincing and conclusive results. However, age, sex, and multiple concussions showed an affirmatory association with persistent post-concussion outcomes in systematic reviews.

CONCLUSION

We highlighted the need for a comprehensive picture of prognostic factors related to persistent post-concussion symptoms. We believe that these prognostic factors would guide clinical decisions and research related to prevention and intervention regarding persistent post-concussion symptoms.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020176676.

Investigating the Student in Returning to Learn After Concussion: A Systematic Review and Meta-Analysis

PURPOSE

Examine concussion effects on academic outcomes, including student perspectives.

METHODS

This study included a systematic review and meta-analysis examining post-concussion school attendance, academic performance, perceptions of academic difficulty, and accommodations for students in elementary through college settings. The analysis considered pre- and post-injury factors, along with injury factors that contribute to post-concussion academic outcomes.

RESULTS

The systematic review showed that students with concussion miss more school days and perceive higher levels of academic difficulty, but results about academic performance varied. Meta-analysis yielded small concussion effects on school absence and academic performance and moderate effects on perceptions of academic difficulty. Female sex, older age, history of migraine, prior concussions, severe or persistent symptoms, vestibular-ocular motor, and cognitive disruptions are risk factors, but these moderators were not identified in the meta-analysis due to lack of effect sizes.

IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY

This study confirmed negative concussion effects on academic absences, performance, and perceptions of academic difficulty. Identified contributing factors will guide future practices to support students returning to learn after concussion.

CONCLUSIONS

Negative impacts to academics from concussion may be amplified by complicating factors. Future investigations are needed to confirm risk factors and mitigating effects of early identification and post-injury supports.

The consideration of post-exercise impact on SCAT3 scores in athletes immediately following a head injury

METHODS

Symptoms were assessed immediately following completion of a rugby match (median 60 minutes). Players removed from the match for assessment due to a head hit were classified as head injured. Controls completed match without head hit.

RESULTS

209 players (67 female; 33 ± 13 years) participated with 80 experiencing a head injury. Symptom severity was significantly greater in head injured (26.2 ± 17.6) compared with controls (8.9 ± 11.5, P < 0.001). 21% of control players reporting >16 symptom severity, misclassifying them as suspected concussion. There were no significant sex differences. Factor analysis produced four symptom clusters of which Headache was most discriminatory between the head injured (median = 1.7) and controls (median = 0.0).

CONCLUSION

These findings demonstrate that exercise and contact during a game affect symptom assessment, increasing the likelihood of misclassifying players with suspected concussion. Factor characterization of symptoms associated with head injury using an exercised comparison group provides more useful discrimination. These results highlight the necessity for objective measures to diagnose concussions outside of symptom self-report.

Incidence of Remote Near-Point of Convergence in University Athletes After Sport-Related Concussion

OBJECTIVE

Near-point of convergence (NPC) testing is an attractive screening tool in the sport setting because it is rapid, requires few resources, and is easy to administer. Remote NPC has been reported after sport-related concussion (SRC), although the incidence among a university-aged population is not well defined. The purpose of the study was to examine the incidence of remote NPC after SRC in a cohort of Canadian interuniversity athletes.

DESIGN

Cross-sequential.

SETTING

University.

PARTICIPANTS

One hundred thirty-two university athletes [SRC, n = 68; musculoskeletal (MSK) injury, n = 64] were tested before the beginning of their competitive season and again after their injury.

INDEPENDENT VARIABLES

Healthy athletes measured preseason were compared with athletes after SRC or MSK injury using both longitudinal and cross-sectional designs.

MAIN OUTCOME MEASURES

Remote NPC (pass/fail), measured at 6 cm or greater, repeated 3 times.

RESULTS

After SRC, 22% of athletes failed their test postinjury (95% CI, 14%-33%). Comparatively, in the MSK group, 3% of athletes failed their test postinjury (95% CI, 1%-7%). A direct comparison of both injury groups yielded a mean 19% higher prevalence of failed NPC tests after SRC versus MSK injury (95% CI, 10%-30%). There seems to be no relationship between reported symptom burden and NPC performance after SRC.

CONCLUSION

Remote NPC occurs in approximately 1 of 5 athletes after SRC and is rarely observed after MSK injury.

Identifying prioritization criteria for patients with mtbi waiting for multidisciplinary rehabilitation services: A Delphi study

INTRODUCTION

Rehabilitation service providers must take into account prognostic factors when making clinical decisions, which includes using these factors as prioritization criteria. The goal of this study was to establish consensus on patient prioritization criteria based on prognostic factors related to persistent symptoms for patients with mild traumatic brain injury (mTBI) waiting for outpatient specialized rehabilitation services.

MATERIALS AND METHODS

We conducted a Delphi survey involving clinicians, researchers, decision makers, and patients. Before the survey, we presented the results of an overview of systematic reviews summarizing the evidence on prognostic factors related to post-concussion symptoms.

RESULTS

After two rounds, the 17 experts reached consensus on the inclusion of 12 prioritization criteria: acute stress disorder, anxiety and depression, baseline mental and physical health, functional impacts and difficulties in performing daily habits after the trauma, motivation to receive services, multiple concussions, prior neurological problems, PTSD, quality of sleep, return to work failures, somatic complaints, suicidal ideation.

CONCLUSION

Healthcare stakeholders must consider a wide range of factors to guide clinical decision-making, including about access to care and patient prioritization. This study shows that the Delphi technique can be used to reach consensus on such decisions regarding patients with mTBI who are waiting for outpatient specialized rehabilitation services.

Can quantitative susceptibility mapping help diagnose and predict recovery of concussion in children? An A-CAP study

BACKGROUND

Quantitative susceptibility mapping (QSM) is an MRI technique that is a potential biomarker for concussion. We performed QSM in children following concussion or orthopaedic injury (OI), to assess QSM performance as a diagnostic and prognostic biomarker.

METHODS

Children aged 8-17 years with either concussion (N=255) or OI (N=116) were recruited from four Canadian paediatric emergency departments and underwent QSM postacutely (2-33 days postinjury) using 3 Tesla MRI. QSM Z-scores within nine regions of interest (ROI) were compared between groups. QSM Z-scores were also compared with the 5P score, the current clinical benchmark for predicting persistent postconcussion symptoms (PPCS), at 4 weeks postinjury, with PPCS defined using reliable change methods based on both participant and parent reports.

RESULTS

Concussion and OI groups did not differ significantly in QSM Z-scores for any ROI. Higher QSM Z-scores within frontal white matter (WM) independently predicted PPCS based on parent ratings of cognitive symptoms (p=0.001). The combination of frontal WM QSM Z-score and 5P score was better at predicting PPCS than 5P score alone (p=0.004). The area under the curve was 0.72 (95% CI 0.63 to 0.81) for frontal WM susceptibility, 0.69 (95% CI 0.59 to 0.79) for the 5P score and 0.74 (95% CI 0.65 to 0.83) for both.

CONCLUSION

The findings suggest that QSM is a potential MRI biomarker that can help predict PPCS in children with concussion, over and above the current clinical benchmark, and thereby aid in clinical management. They also suggest a frontal lobe substrate for PPCS, highlighting the potential for QSM to clarify the neurophysiology of paediatric concussion.

Sex-specific differences in resting-state functional brain activity in pediatric concussion

Pediatric concussion has a rising incidence and can lead to long-term symptoms in nearly 30% of children. Resting state functional magnetic resonance imaging (rs-fMRI) disturbances are a common pathological feature of pediatric concussion, though no studies have explicitly examined sex-differences with respect to this outcome, precluding a sex-specific understanding of the functional neuropathology of pediatric concussion. Therefore, we performed a secondary data analysis of rs-fMRI data collected on children with concussion (n = 29) recruited from in a pediatric hospital setting, with greater than 12:1 matched control data accessed from the open-source ABIDE-II database. Seed-based and region of interest (ROI) analyses were used to examine sex-based rs-fMRI differences; threshold-free cluster enhancement (TFCE) and a family-wise error (FWE) corrected p-values were used to identify significantly different clusters. In comparing females with concussion to healthy females, groupwise differences were observed irrespective of seed selected. Notably, we observed (in order of largest effect) hypo-connectivity between the anterior cingulate cortex of the salience network and the thalamus and precuneus (TFCE = 1473.5, p-FWE < 0.001) and the cingulate gyrus (TFCE = 769.3, p-FWE = 0.009), and the seed (posterior cingulate cortex (PCC)) of the default mode network and the paracingulate gyrus (TFCE = 1275.7, p-FWE  < 0.001), occipital pole right (TFCE = 1045.0, p-FWE = 0.001), and sub-callosal cortex (TFCE = 844.9, p-FWE = 0.005). Hyper-connectivity was observed between the salience network seed and the cerebellum (TFCE = 1719.3, p-FWE < 0.001) and the PCC and the thalamus (TFCE = 1198.3, p-FWE < 0.001), cuneal cortex (1070.9, p-FWE = 0.001), and lateral occipital cortex left (TFCE = 832.8, p-FWE = 0.006). ROI analyses showed 10 and 5 significant clusters of hypo- and hyper-connectivity in females, respectively. Only one cluster of difference was found between males with concussion and healthy males on seed-based analyses, and 3 clusters on ROI analyses. There are alterations in rs-fMRI in females with concussion at one-month post-injury that are minimally present in males, which provides further evidence that recovery timelines in pediatric concussion may differ by sex.

Repeat subconcussion in the adult rat gives rise to behavioral deficits similar to a single concussion but different depending upon sex

Although concussions are a popular focus of neurotrauma research, subconcussions occur with higher frequency but are less well-studied. A subconcussion is an impact to the head that does not result in immediately diagnosable concussion but can result in later neurological consequences. Repeat subconcussions can produce behavioral impairments and neuropathology that is similar to or worse than those seen following a single concussion. The current study modified a previously established closed head injury model of concussion to create a subconcussion model and examines sex differences in behavioral responses to repeated subconcussion in the adult rat. Rats received a single concussion, single or repeat subconcussions, or no impact and behavior was monitored from 2 h through 31 days post-injury. A single concussion or repeat subconcussion resulted in deficits in locomotion, righting reflexes, and recognition memory. The degree of deficit induced by repeat subconcussions were either similar (righting reflexes) or greater/more persistent (locomotor deficits and recognition memory) than that of a concussion. Single subconcussion resulted in acute deficits that were mild and limited to righting reflexes and locomotion. Sex differences were observed in responses to repeat subconcussion: females showed greater deficits in righting reflexes, locomotion, and vestibular function, while males showed greater alterations in anxiety and depressive-like behavior. This study established a model of subconcussive impact where a single subconcussive impact resulted in minimal behavioral deficits but repeat subconcussions resulted in deficits similar to or worse than a single concussion. Our data also suggest sex differences in behavioral responses to both concussive and subconcussive impacts.

Altered connectivity of default mode and executive control networks among female patients with persistent post-concussion symptoms

OBJECTIVE

To examine the roles of the default mode network (DMN) and executive control network (ECN) in prolonged recovery after mild traumatic brain injury (mTBI), and relationships with indices of white matter microstructural injury.

METHODS

Seventeen mTBI patients with persistent symptoms were imaged an average of 21.5 months post-injury, along with 23 healthy controls. Resting-state functional magnetic resonance imaging (rs-fMRI) was used to evaluate functional connectivity (FC) of the DMN and ECN. Diffusion tensor imaging (DTI) quantified fractional anisotropy, along with mean, axial and radial diffusivity of white matter tracts.

RESULTS

Compared to controls, patients with mTBI had increased functional connectivity of the DMN and ECN to brain regions implicated in salience and frontoparietal networks, and increased white matter diffusivity within the cerebrum and brainstem. Among the patients, FC was correlated with better neurocognitive test scores, while diffusivity was correlated with more severe self-reported symptoms. The FC and diffusivity values within abnormal brain regions were not significantly correlated.

CONCLUSION

For female mTBI patients with prolonged symptoms, hyper-connectivity may represent a compensatory response that helps to mitigate the effects of mTBI on cognition. These effects are unrelated to indices of microstructural injury, which are correlated with symptom severity, suggesting that rs-fMRI and DTI may capture distinct aspects of pathophysiology.

Changes in ImPACT Cognitive Subtest Networks Following Sport-Related Concussion

OBJECTIVE

High school athletes are administered ImPACT at the start of the academic year or sport season and again after suspected concussion. Concussion management involves the comparison of baseline and post-injury cognitive scores with declines in scores providing evidence for concussive injury. A network framework may provide additional information about post-concussive cognitive changes and expand characterization of sport-related concussion (SRC) recovery.

DESIGN

Retrospective cohort study.

SETTING

High school.

PARTICIPANTS

High school athletes (n = 1553) were administered ImPACT at baseline (T1), post-SRC (T2 = 72 h of injury), and prior to return to play (T3 = within two weeks post-injury).

INDEPENDENT VARIABLES

ImPACT cognitive subtest scores.

MAIN OUTCOME MEASURES

Cognitive networks were calculated and compared over three time points. Centrality indices were calculated to determine the relative importance of cognitive variables within networks.

RESULTS

Network connectivity increased from T1 to T2 and remained hyperconnected at T3. There was evidence of network reorganization between T1 and T3. Processing speed was central within each network, and visual memory and impulsivity became more central over time.

CONCLUSIONS

The results suggest potential evidence of cognitive network change over time. Centrality findings suggest research specific to visual memory and impulse control difficulties during the post-concussion recovery period is warranted. Network analysis may provide additional information about cognitive recovery following SRC and could potentially serve as an effective means of monitoring persisting cognitive symptoms after concussion.

Beyond the medals: a cross-sectional study exploring retired elite female athletes' health

Objectives

Little is known about the impact of elite sport participation on long-term athlete health. We aimed to: (1) describe musculoskeletal, mental health, reproductive/endocrine and cardiovascular characteristics in retired elite female athletes and compare to the general population and (2) explore athletes' perceptions of their elite sport participation and its impact on health.

Methods

A 136-item online questionnaire was disseminated to Canadian elite female rowing and rugby athletes >18 years old, >2 years retired from elite competition. Matched general population data were obtained from Statistics Canada when available.

Results

Seventy-four (24% response rate) athletes (average age 45 (±9) years; retired 15 (±9) years) completed the questionnaire (30 rowing, 44 rugby athletes). During their career, 63 athletes (85%) experienced a hip/groin, knee, foot/ankle injury, or low back pain, with 42 (67%) reporting ongoing symptoms. Athletes 35-54 years reported worse knee symptoms and quality of life compared with the general population (symptom: p=0.197; d=1.15 [0.66, 1.63]; quality of life: p=0.312 d=1.03 [0.54, 1.51]) while other hip, knee and foot/ankle outcome scores were similar. Retired athletes had lower odds of anxiety (OR=0.155 [95% CI0.062 to 0.384]), greater lifetime/ever odds of amenorrhea (OR=6.10 [95%CI 2.67 to 13.96]) and gave birth when older (p<0.05). Fifty-nine (79%) recalled witnessing or experiencing at least one form of harassment/abuse during their career. Sixty athletes (81%) rated their current health as above average or excellent and 61 (82%) would compete at the same level again if given the choice.

Conclusion

These novel insights can inform future preventative efforts to promote positive elite sport-related outcomes for current, former and future female athletes.

Symptom Provocation Following Post-concussion Computerized Neurocognitive Testing and Its Relationship to Other Clinical Measures of Concussion

OBJECTIVE

The objective of this study was to document the prevalence of post-computerized neurocognitive test (post-CNT) increases in symptoms in athletes with sport-related concussion, and to examine the effect of post-CNT symptom increases on concussion neurocognitive and vestibular/ocular motor clinical outcomes.

METHODS

This was a retrospective analysis of medical records from a concussion specialty clinic. Two hundred and three athletes (M = 16.48 ± 1.97 years; 44% [90/203] female) completed a clinical visit for concussion within 30 days of injury (M = 7.73 ± 5.54 days). Computerized neurocognitive testing (the Immediate Post-concussion Assessment and Cognitive Testing: ImPACT), the Post-Concussion Symptom Scale (PCSS), and the Vestibular Ocular Motor Screening (VOMS) were the main outcome measures for the current study.

RESULTS

Sixty-nine percent (141/203) of the sample did not report significant increases in PCSS scores following post-concussion CNT and were classified into a No Provocation (NO PROV) group. Thirty-one percent (62/203) of participants did report a significant increase in symptoms following post-concussion CNT and were classified into a Provocation (PROV) group. Neurocognitive performance was similar between groups. However, the PROV group reported significantly higher scores on the VOMS symptom items than the NO PROV group.

CONCLUSIONS

The majority of adolescent athletes can complete a post-concussion CNT without experiencing significant increases in concussion symptoms. Individuals that report symptom increases from completing a post-concussion CNT are more likely to exhibit increased vestibular/ocular motor symptoms. These findings underscore the relationship between the clinical findings from both CNT and vestibular/ocular motor measures following concussion.

Characterizing Sex Differences in Clinical and Functional Outcomes Among Military Veterans with a Comprehensive Traumatic Brain Injury Evaluation (CTBIE): A Million Veteran Program (MVP) Study

Using a diverse sample of military Veterans enrolled in the VA's Million Veteran Program (N=14,378; n=1,361 females [9.5%]; all previously deployed), we examined sex differences on the Comprehensive Traumatic Brain Injury Evaluation (CTBIE), a structured traumatic brain injury (TBI) interview routinely administered within the VA. Confirmed TBI diagnoses were more frequent among males than females (65% vs. 58%). Additionally, when compared to females, a greater proportion of males with CTBIE-confirmed TBI histories experienced blast-related injuries and were employed. In contrast, a greater proportion of females reported experiencing falls, sustaining a TBI since deployment, and having more severe neurobehavioral symptoms (particularly affective-related symptoms). Results indicate that males and females experience differential clinical and functional outcomes in the aftermath of military TBI. Findings underscore the need to increase female representation in TBI research to increase understanding of sex-specific experiences with TBI and to improve the clinical care targeted to this vulnerable population.

Nutritional interventions to support acute mTBI recovery

When mild traumatic brain injury (mTBI) occurs following an impact on the head or body, the brain is disrupted leading to a series of metabolic events that may alter the brain's ability to function and repair itself. These changes may place increased nutritional demands on the body. Little is known on whether nutritional interventions are safe for patients to implement post mTBI and whether they may improve recovery outcomes. To address this knowledge gap, we conducted a systematic review to determine what nutritional interventions have been prescribed to humans diagnosed with mTBI during its acute period (<14 days) to support, facilitate, and result in measured recovery outcomes.

Methods

Databases CINAHL, PubMed, SPORTDiscus, Web of Science, and the Cochrane Library were searched from inception until January 6, 2021; 4,848 studies were identified. After removing duplicates and applying the inclusion and exclusion criteria, this systematic review included 11 full papers.

Results

Patients that consumed enough food to meet calorie and macronutrient (protein) needs specific to their injury severity and sex within 96 h post mTBI had a reduced length of stay in hospital. In addition, patients receiving nutrients and non-nutrient support within 24-96 h post mTBI had positive recovery outcomes. These interventions included omega-3 fatty acids (DHA and EPA), vitamin D, mineral magnesium oxide, amino acid derivative N-acetyl cysteine, hyperosmolar sodium lactate, and nootropic cerebrolysin demonstrated positive recovery outcomes, such as symptom resolution, improved cognitive function, and replenished nutrient deficiencies (vitamin D) for patients post mTBI.

Conclusion

Our findings suggest that nutrition plays a positive role during acute mTBI recovery. Following mTBI, patient needs are unique, and this review presents the potential for certain nutritional therapies to support the brain in recovery, specifically omega-3 fatty acids. However, due to the heterogenicity nature of the studies available at present, it is not possible to make definitive recommendations.

Systematic review registration

The systematic review conducted following the PRISMA guidelines protocol was registered (CRD42021226819), on Prospero.

Sex comparisons in neuropsychological functioning and reported symptoms following a sports-related concussion among high school athletes

The aim of this study was to compare the neuropsychological functioning and symptoms of female and male high school athletes following a single concussion during the school year. The baseline test scores of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) of 309 concussed athletes (169 females, 221 males) in varied sports were obtained. After a sport-related concussion, the athletes were re-administered the ImPACT, on the average, 7.25 days after the injury. MANCOVA compared the ImPACT baseline scores, post-concussion scores, and baseline-to-post-concussion changes of the female and male athletes, with p set at 0.01. The only significant sex comparison found females performing better on baseline visual motor speed (p < 0.001). Otherwise, no sex differences were found in baseline test scores, post-concussion scores, and baseline-to-post-concussion changes. The findings tentatively suggest that there are insignificant sex differences in the consequences of sport-related concussion after a week post-injury. Future studies on sex comparisons after a concussion are needed focusing on the acute and sub-acute phases of the recovery period.

Concussion Prone Scenarios: A Multi-Dimensional Exploration in Impact Directions, Brain Morphology, and Network Architectures Using Computational Models

While individual susceptibility to traumatic brain injury (TBI) has been speculated, past work does not provide an analysis considering how physical features of an individual's brain (e.g., brain size, shape), impact direction, and brain network features can holistically contribute to the risk of suffering a TBI from an impact. This work investigated each of these features simultaneously using computational modeling and analyses of simulated functional connectivity. Unlike the past studies that assess the severity of TBI based on the quantification of brain tissue damage (e.g., principal strain), we approached the brain as a complex network in which neuronal oscillations orchestrate to produce normal brain function (estimated by functional connectivity) and, to this end, both the anatomical damage location and its topological characteristics within the brain network contribute to the severity of brain function disruption and injury. To represent the variations in the population, we analyzed a publicly available database of brain imaging data and selected five distinct network architectures, seven different brain sizes, and three uniaxial head rotational conditions to study the consequences of 74 virtual impact scenarios. Results show impact direction produces the most significant change in connections across brain areas (structural connectome) and the functional coupling of activity across these brain areas (functional connectivity). Axial rotations were more injurious than those with sagittal and coronal rotations when the head kinematics were the same for each condition. When the impact direction was held constant, brain network architecture showed a significantly different vulnerability across axial and sagittal, but not coronal rotations. As expected, brain size significantly affected the expected change in structural and functional connectivity after impact. Together, these results provided groupings of predicted vulnerability to impact-a subgroup of male brain architectures exposed to axial impacts were most vulnerable, while a subgroup of female brain architectures was the most tolerant to the sagittal impacts studied. These findings lay essential groundwork for subject-specific analyses of concussion and provide invaluable guidance for designing personalized protection equipment.

Evaluation of an injury prevention programme (Prep-to-Play) in women and girls playing Australian Football: design of a pragmatic, type III, hybrid implementation-effectiveness, stepped-wedge, cluster randomised controlled trial

INTRODUCTION

Due to the increase in participation and risk of anterior cruciate ligament (ACL) injuries and concussion in women's Australian Football, an injury prevention programme (Prep-to-Play) was codesigned with consumers (eg, coaches, players) and stakeholders (eg, the Australian Football League). The impact of supported and unsupported interventions on the use of Prep-to-Play (primary aim) and injury rates (secondary aim) will be evaluated in women and girls playing community Australian Football.

METHODS AND ANALYSIS

This stepped-wedge, cluster randomised controlled trial will include ≥140 teams from U16, U18 or senior women's competitions. All 10 geographically separated clusters (each containing ≥14 teams) will start in the control (unsupported) phase and be randomised to one of five dates (or 'wedges') during the 2021 or 2022 season to sequentially transition to the intervention (supported Prep-to-Play), until all teams receive the intervention. Prep-to-Play includes four elements: a neuromuscular training warm-up, contact-focussed football skills (eg, tackling), strength exercises and education (eg, technique cues). When transitioning to supported interventions, study physiotherapists will deliver a workshop to coaches and player leaders on how to use Prep-to-Play, attend team training at least two times and provide ongoing support. In the unsupported phase, team will continue usual routines and may freely access available Prep-to-Play resources online (eg, posters and videos about the four elements), but without additional face-to-face support. Outcomes will be evaluated throughout the 2021 and 2022 seasons (~14 weeks per season).

PRIMARY OUTCOME

use of Prep-to-Play will be reported via a team designate (weekly) and an independent observer (five visits over the two seasons) and defined as the team completing 75% of the programme, two-thirds (67%) of the time.

SECONDARY OUTCOMES

injuries will be reported by the team sports trainer and/or players. Injury definition: any injury occurring during a football match or training that results in: (1) being unable to return to the field of play for that match or (2) missing ≥ one match. Outcomes in the supported and unsupported phases will be compared using a generalised linear mixed model adjusting for clustering and time. Due to the type III hybrid implementation-effectiveness design, the study is powered to detect a improvement in use of Prep-to-Play and a reduction in ACL injuries.

ETHICS AND DISSEMINATION

La Trobe University Ethics Committee (HREC 20488) approved. Coaches provided informed consent to receive the supported intervention and players provided consent to be contacted if they sustained a head or knee injury. Results will be disseminated through partner organisations, peer-reviewed publications and scientific conferences.

TRIAL REGISTRATION NUMBER

NCT04856241.