Sex differences in sport-related concussion long-term outcomes

Concussion history associated with adolescent psychological distress but not hazardous gambling: a cross-sectional study

BACKGROUND

Sustaining multiple concussions over one's lifetime may be associated with behavioral and mood changes beyond the acute phase of injury. The present cross-sectional study examined the relationship between concussion history, the incidence of current moderate-severe psychological distress, and lifetime adolescent hazardous gambling in high school students.

METHODS

Four-hundred fifty-nine high school students from southern Sweden (age: 16.81 ± 0.83, 58.2% male) completed a survey assessing concussion history (0,1,2…>8), psychological distress using the Kessler-6 scale, and lifetime hazardous gambling using the NODS-CLiP scale.

RESULTS

Participants who self-reported three or more concussions were more likely to endorse moderate-severe symptoms of psychological distress than those with no concussion history while controlling for covariates, OR = 2.71, 95% CI [1.19, 6.18]. In contrast, concussion history was not associated with hazardous gambling after controlling for confounding variables.

CONCLUSIONS

Self-reporting three or more concussions was associated with increased current psychological distress beyond the acute phase of injury among high school students. Adolescents who have sustained multiple concussions should undergo mental health evaluations beyond the acute phase of injury to identify and treat psychological distress, but probing for hazardous gambling may not be clinically relevant in this previously concussed adolescent population.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Examining the role of depression on the relationship between performance-based and self-reported cognitive functioning after sport-related concussion

OBJECTIVE

Little is known about the relationship between neuropsychological test performance, cognitive symptom reporting, and depressive symptoms after sport-related concussion. Accordingly, this cross-sectional study examined these relationships in collegiate athletes. It was hypothesized that depressive symptoms would moderate and mediate the relationship between performance-based and self-reported cognitive functioning after concussion.

METHODS

After sustaining a sport-related concussion, 110 collegiate athletes completed a neuropsychological battery, the Post-Concussion Symptoms Scale, and the Beck Depression Inventory-Fast Screen. Neuropsychological test performance, depressive symptoms, and their interactions were entered into distinct hierarchical linear regression analyses with self-reported cognition as the dependent variable to assess moderation. Mediation was analyzed using the PROCESS macro with 5000 bootstrap samples and a 95% confidence interval.

RESULTS

There was a significant interaction between the mean memory composite and depressive symptoms when predicting cognitive symptom reporting, p = 0.047. Simple effects tests revealed that for athletes who had a lower memory composite score, an increase in depressive symptoms led to an increase in self-reported cognitive dysfunction, p < 0.001, ηp2 = 0.11. Depressive symptoms partially mediated the relationship between the memory composite and cognitive symptom reporting, indirect effect = -0.26, 95%CI[-0.58,0.001], but this relationship was not found for any other neurocognitive domain.

CONCLUSIONS

For tests of memory, depressive symptoms moderated and partially mediated the relationship between performance-based and self-reported cognitive functioning after sport-related concussion. Athletes reporting high depressive symptoms and cognitive dysfunction may need more comprehensive evaluations to inform return-to-play decisions, and depression could be a treatment target for athletes who report high levels of cognitive dysfunction after concussion.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

A pilot study examining BDNF Val66Met polymorphism and biological sex: Relationships with baseline cognitive functioning in adolescent athletes

The purpose of this exploratory study was to examine interactive relationships between a common brain-derived neurotrophic factor (BDNF) polymorphism (Val66Met) and biological sex on cognitive functioning in a sample of healthy adolescent athletes. Participants included 82 student athletes (age: M = 12.85 years, SD = 1.13) who were involved in a clinically-based sports-concussion management program. Athletes completed the ImPACT computerized battery at baseline and provided buccal samples for determination of their BDNF genotype. Two-way ANOVAs were used to evaluate the effect of BDNF genotype (Met+ vs. Met-) and sex (male vs. female) on cognitive functioning (subgroup n's: Female/Met+ = 12, Female/Met- = 26, Male/Met+ = 12, Male/Met- = 32). ANOVAs revealed non-significant main effects for both BDNF genotype and sex across all four cognitive composites. However, there was a significant BDNF genotype by sex interaction for the visual-motor speed composite (p = .015; ηp2 = .073), such that female Met carriers demonstrated better performance than male Met carriers. In contrast, no differences were found on visual-motor speed performance between females and males without a Met allele. Although these results will need to be replicated using larger samples, our preliminary findings lend support to the view that the Met allele may be somewhat neuroprotective in healthy adolescent females.

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.

Associations of prior concussion severity with brain microstructure using mean apparent propagator magnetic resonance imaging

Magnetic resonance imaging (MRI) diffusion studies have shown chronic microstructural tissue abnormalities in athletes with history of concussion, but with inconsistent findings. Concussions with post-traumatic amnesia (PTA) and/or loss of consciousness (LOC) have been connected to greater physiological injury. The novel mean apparent propagator (MAP) MRI is expected to be more sensitive to such tissue injury than the conventional diffusion tensor imaging. This study examined effects of prior concussion severity on microstructure with MAP-MRI. Collegiate-aged athletes (N = 111, 38 females; ≥6 months since most recent concussion, if present) completed semistructured interviews to determine the presence of prior concussion and associated injury characteristics, including PTA and LOC. MAP-MRI metrics (mean non-Gaussian diffusion [NG Mean], return-to-origin probability [RTOP], and mean square displacement [MSD]) were calculated from multi-shell diffusion data, then evaluated for associations with concussion severity through group comparisons in a primary model (athletes with/without prior concussion) and two secondary models (athletes with/without prior concussion with PTA and/or LOC, and athletes with/without prior concussion with LOC only). Bayesian multilevel modeling estimated models in regions of interest (ROI) in white matter and subcortical gray matter, separately. In gray matter, the primary model showed decreased NG Mean and RTOP in the bilateral pallidum and decreased NG Mean in the left putamen with prior concussion. In white matter, lower NG Mean with prior concussion was present in all ROI across all models and was further decreased with LOC. However, only prior concussion with LOC was associated with decreased RTOP and increased MSD across ROI. Exploratory analyses conducted separately in male and female athletes indicate associations in the primary model may differ by sex. Results suggest microstructural measures in gray matter are associated with a general history of concussion, while a severity-dependent association of prior concussion may exist in white matter.

Differences in injury and concussion rates in a cohort of Canadian female and male youth Rugby Union: a step towards targeted prevention strategies

OBJECTIVE

To examine differences in match and training musculoskeletal injury and concussion rates and describe mechanisms of concussion while considering previous playing experience in female and male Canadian high school Rugby Union ('rugby') players.

METHODS

A 2-year prospective cohort study was completed in a high school league (n=361 females, 421 player-seasons; n=429 males, 481 player-seasons) in Calgary, Canada over the 2018 and 2019 rugby playing seasons. Baseline testing was completed at the start of each season and injury surveillance and individual player participation through session attendance was documented to quantify individual-level player exposure hours. Injury incidence rates (IRs) and incidence rate ratios (IRRs) were calculated using Poisson regression, offset by player exposure hours and clustered by team.

RESULTS

Overall match IR for females was 62% higher than males (overall IRR=1.62, 95% CI: 1.20 to 2.18) and the overall training IR was twice as high for females (overall IRR=2.15, 95% CI: 1.40 to 3.32). The female match concussion IR was 70% higher than the males (concussion IRR=1.70, 95% CI: 1.08 to 2.69). Females had a 75% greater tackle-related IR compared with males (IRR=1.75, 95% CI: 1.20 to 2.56). Additionally, female tacklers had a twofold greater rate of injury compared with male tacklers (IRR=2.17, 95% CI: 1.14 to 4.14). Previous playing experience was not associated with tackle-related injury or concussion IRs.

CONCLUSION

The rate of injury and concussion was significantly higher in females within this Canadian high school cohort. These results emphasise the need for development, implementation and evaluation of female-specific injury and concussion prevention strategies to reduce injury and concussion in female youth rugby.

Repeated mild traumatic brain injury causes sex-specific increases in cell proliferation and inflammation in juvenile rats

Childhood represents a period of significant growth and maturation for the brain, and is also associated with a heightened risk for mild traumatic brain injuries (mTBI). There is also concern that repeated-mTBI (r-mTBI) may have a long-term impact on developmental trajectories. Using an awake closed head injury (ACHI) model, that uses rapid head acceleration to induce a mTBI, we investigated the acute effects of repeated-mTBI (r-mTBI) on neurological function and cellular proliferation in juvenile male and female Long-Evans rats. We found that r-mTBI did not lead to cumulative neurological deficits with the model. R-mTBI animals exhibited an increase in BrdU + (bromodeoxyuridine positive) cells in the dentate gyrus (DG), and that this increase was more robust in male animals. This increase was not sustained, and cell proliferation returning to normal by PID3. A greater increase in BrdU + cells was observed in the dorsal DG in both male and female r-mTBI animals at PID1. Using Ki-67 expression as an endogenous marker of cellular proliferation, a robust proliferative response following r-mTBI was observed in male animals at PID1 that persisted until PID3, and was not constrained to the DG alone. Triple labeling experiments (Iba1+, GFAP+, Brdu+) revealed that a high proportion of these proliferating cells were microglia/macrophages, indicating there was a heightened inflammatory response. Overall, these findings suggest that rapid head acceleration with the ACHI model produces an mTBI, but that the acute neurological deficits do not increase in severity with repeated administration. R-mTBI transiently increases cellular proliferation in the hippocampus, particularly in male animals, and the pattern of cell proliferation suggests that this represents a neuroinflammatory response that is focused around the mid-brain rather than peripheral cortical regions. These results add to growing literature indicating sex differences in proliferative and inflammatory responses between females and males. Targeting proliferation as a therapeutic avenue may help reduce the short term impact of r-mTBI, but there may be sex-specific considerations.

Making the case for prophylactic use of betaine to promote brain health in young (15-24 year old) athletes at risk for concussion

Betaine supplementation in the context of human nutrition, athletic performance, and clinical therapy demonstrate that the osmolyte and methyl donor, betaine, is cytoprotective and beneficial to human health. These studies also demonstrate that betaine supplementation in healthy humans is straight-forward with no reported adverse effects. Here, we explore betaine uptake in the central nervous system (CNS) and contribute to evidence that betaine may be uniquely protective to the brain. We specifically describe the therapeutic potential of betaine and explore the potential implications of betaine on inhibition mediated by GABA and glycine neurotransmission. The influence of betaine on neurophysiology complement betaine's role as an osmolyte and metabolite and is consistent with clinical evidence of betaine-mediated improvements to cognitive function (reported in elderly populations) and its anti-convulsant properties. Betaine's therapeutic potential in neurological disorders including epilepsy and neurodegenerative diseases combined with benefits of betaine supplementation on athletic performance support the unique application of betaine as a prophylaxis to concussion. As an example, we identify young athletes (15-24 years old), especially females, for prophylactic betaine supplementation to promote brain health and resilience in a cohort at high risk for concussion and for developing Alzheimer's disease.

Are Sex Differences in Collegiate and High School Sports-Related Concussion Reflected in the Guidelines? A Scoping Review

Background: Sport-related concussion (SRC) is a common sport injury. Females are participating in sports at increasing rates, and there is growing awareness that female athletes may be more vulnerable to SRC. Objectives: We aimed to identify sex differences in epidemiology, clinical manifestation and assessment of SRC and examine how these relate to the 6th International Conference on Concussion in Sport (ICCS). Methods: We conducted a scoping review of the Medline database and identified 58 studies examining the effects of sex on SRC in collegiate and high school athletes that were written in English and published in a peer-reviewed journal between March 2012 and March 2022. Results: We found that female athletes suffer higher rates of concussion in sex-comparable sports, in particular soccer. Female athletes experience more somatic symptoms-headache/migraine/sleep disturbance-and may take longer to recover from concussion. Sex differences were also identified regarding some aspects of sideline concussion assessment with the Sport Concussion Assessment Tool. Conclusions: Females are at greater risk and experience SRC differently than males; this is mostly likely due to a combination of biomechanical factors, differences in neck musculature and hormonal and social factors. Sex differences are not widely addressed by the 6th ICSS, which informs many sports' concussion protocols.

Concussion History and the Emotional and Behavioral Dyscontrol Domains of Health-Related Quality of Life in College Students

CONTEXT

Injury or illness can affect individual perceptions of health status and health-related quality of life (HRQOL). Concussion can result in different symptoms, impairments, and functional limitations that have been found to lower HRQOL. Furthermore, concussion is known to influence the emotional and behavioral dyscontrol domains of HRQOL in pediatric populations; however, this has yet to be explored in other populations.

OBJECTIVE

To compare individuals with and those without a concussion history and (1) HRQOL and (2) the emotional and behavioral dyscontrol domains of HRQOL in college students.

DESIGN

Cross-sectional study.

SETTING

University laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

Of a total of 252 participants (155 women; age = 19.95 ± 1.53 years), 76 (30.2%) had a history of concussion and 176 (69.8%) did not. For participants with a history of concussion, the mean time since injury was 5.29 ± 2.77 years.

MAIN OUTCOME MEASURE(S)

The Patient-Reported Outcome Measures Information System (PROMIS) Global Health, version 1.1, and Quality of Life in Neurological Disorders Emotional and Behavioral Dyscontrol Short Form (Neuro-QOL).

RESULTS

No differences were seen between median scores in individuals with and those without a history of concussion in the PROMIS Physical Health (13.0 versus 14.0; P = .24), PROMIS Mental Health (12.0 versus 12.0; P = .99), and Neuro-QOL (16.0 versus 16.0; P = .47) scores. Additionally, when gender was controlled, the associations between a history of concussion and PROMIS Physical Health score (odds ratio [OR] = 1.04; 95% CI = 0.43, 2.52), PROMIS Mental Health score (OR = 0.66; 95% CI = 0.13, 3.25), and Neuro-QOL score (OR = 1.16; 95% CI = 0.66, 2.04) were not significant.

CONCLUSIONS

Preliminary findings suggested that the emotional and behavioral dyscontrol domains were not influenced by a concussion history of > 1 year in college-aged participants. Future researchers should continue to explore specific HRQOL domains affected by concussion as well as the influences of prior mental health conditions and behavioral dysfunction after a subsequent injury.

Existence ≠ adherence. Exploring barriers to best practice in sports-related concussion return to play (SRC-RTP) in Irish amateur female sport

OBJECTIVES

Sports-Related Concussion (SRCs) are of relevant risk and burden for female athletes. The following study aimed to explore potential barriers to return to play (RTP) best practice in coaches of amateur female athletes, and medical professionals who may treat and manage SRCs in amateur female athletes.

DESIGN

Qualitative, semi-structured, virtual interviews following a critical analysis framework.

METHODS

Twenty-five coaches, allied healthcare professionals (AHPs), and general practitioners (GPs) were recruited and interviewed using a convenience snowball sample. Data were transcribed verbatim and thematically analysed.

RESULTS

Three themes were identified following reflexive thematic analysis; biopsychosocial norms, stakeholder inaction, and practitioner effectiveness. The findings identify numerous factors which limit the uptake of best practice guidelines as endorsed by Irish national governing bodies (NGBs). Education, training, and implementation of these guidelines are lacking, with sub-standard or non-existent medical support and poor general injury and/or SRC attitudes providing further resistance to these measures.

CONCLUSION

Existence of SRC-RTP protocols does not equal adherence to such. Greater efforts are required to translate knowledge provided by the 6th Concussion Consensus statement. NGBs, league and club administrators, and educators need to better support coaches, practitioners and athletes in the implementation of these protocols in amateur female sport.

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

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

Cortical thickness and neurocognitive performance in former high-level female soccer and non-contact sport athletes

BACKGROUND

Long-term effects of playing soccer (football) on the brain structure and function of the brain are vividly debated. While some studies showed differences in neurocognitive performance and structural brain changes in retired male players, data on female players are scarce. The present study compares cortical thickness and neurocognitive performance in former high-level female soccer (SOC) and non-contact sport athletes (CON).

METHODS

3 T T1-weighted 3D MPRAGE MRI was performed, and vertex-wise cortical thickness was analyzed using FreeSurfer (v. 6.0.0). Neurocognitive performance in seven domains of SOC and CON was assessed. A multivariate linear model was used to analyze interactions with respect to heading frequency and a history of concussion.

RESULTS

SOC (n = 15, mean age 38.3 ± 5.1 years) and CON (n = 16, mean age 36.6 ± 5.8 years) had a similar cortical thickness and performed similarly in the neurocognitive tests except for verbal memory and psychomotor speed, where SOC performed significantly worse than CON. Moderate headers had a significantly larger cortical thickness than rare headers in the right inferior parietal region. Visual memory and cortical thickness were positively correlated in the group of frequent headers and negatively correlated in CON, but not in the other header groups.

PERSPECTIVE

In contrast to previous reports in male soccer players, female players did not reveal cortical thinning in comparison with control athletes, whereas neurocognitive profiles of female soccer players might not significantly differ from male athletes. Small sample sizes, subjective header assessment, and the case-control study design require a cautious interpretation.

Sport-related concussion disclosure in women's rugby-A social identity approach

Introduction

Sport-related concussion (SRC) is a risk of collision sports such as women's rugby. To support appropriate SRC diagnosis and management, an understanding of the factors that encourage SRC disclosure is necessary. To date, research has focused on ascertaining individual player knowledge and attitudes towards SRC disclosure.

Methods

We chose to investigate the potential influence of group identification effects by examining the role of social identity on SRC disclosure in elite women's rugby. Seventeen elite players from the United Kingdom and Ireland were interviewed and their transcripts thematically analysed.

Results

The data highlighted that the players shared a very strong social identity as women in rugby and were acutely aware that their experiences were different to their male counterparts. The shared social identity had both positive and negative implications for SRC disclosure. The players interviewed did not feel comfortable disclosing their symptoms to their coach and often felt that medical staff either did not listen to them or were unavailable to them. Mediators such as communication, trust in medical teams, perceived pressure, positive injury management experience, and player role models were identified.

Discussion

This research could be utilised to inform sport psychology interventions to enhance SRC disclosure in elite women's rugby.

Trajectories of Visual and Vestibular Markers of Youth Concussion

Visual and vestibular deficits, as measured by a visio-vestibular examination (VVE), are markers of concussion in youth. Little is known about VVE evolution post-injury, nor influence of age or sex on trajectory. The objective was to describe the time trend of abnormal VVE elements after concussion. Two cohorts, 11-18 years, were enrolled: healthy adolescents (n = 171) from a high school with VVE assessment before or immediately after their sport seasons and concussed participants (n = 255) from a specialty care concussion program, with initial assessment ≤28 days from injury and VVE repeated throughout recovery during clinical visits. The primary outcome, compared between groups, is the time course of recovery of the VVE examination, defined as the probability of an abnormal VVE (≥2/9 abnormal elements) and modeled as a cubic polynomial of days after injury. We explored whether probability trajectories differed by: age (<14 years vs. 14+ years), sex, concussion history (0 versus 1+), and days from injury to last assessment (≤28 days vs. 29+ days). Overall, abnormal VVE probability peaked at 0.57 at day 8 post-injury, compared with an underlying prevalence of 0.083 for uninjured adolescents. Abnormal VVE probability peaked higher for those 14+ years, female, with a concussion history and whose recovery course was longer than 28 days post-injury, compared with their appropriate strata subgroups. Females and those <14 years demonstrated slower resolution of VVE abnormalities. VVE deficits are common in adolescents after concussion, and the trajectory of resolution varies by age, sex, and concussion history. These data provide insight to clinicians managing concussions on the timing of deficit resolution after injury.

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.

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

Objectives

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

Design

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

Data sources

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

Eligibility criteria

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

Results

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

Conclusion

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

Trial registration number

CRD42021281569.

Social determinants of health associated with psychological distress stratified by lifetime traumatic brain injury status and sex: Cross-sectional evidence from a population sample of adults in Ontario, Canada

This study identified the social determinants of health (SDoH) associated with psychological distress in adults with and without a self-reported history of traumatic brain injury (TBI), stratified by sex. Data from the 2014–2017 cycles of the Centre for Addiction and Mental Health Monitor Survey, a representative survey of adults ≥18 years in Ontario, Canada, were analyzed (N = 7,214). The six-item version of the Kessler Psychological Distress Scale was used to determine moderate to severe psychological distress. Self-reported lifetime TBI was defined as a head injury resulting in a loss of consciousness for ≥5 minutes or at least one-night stay in the hospital (16.4%). Among individuals reporting a history of TBI, 30.2% of males and 40.1% of females reported psychological distress (p = 0.0109). Among individuals who did not report a history of TBI, 17.9% of males and 23.5% of females reported psychological distress (p<0.0001). Multivariable logistic regression analyses showed that the SDoH significantly associated with elevated psychological distress were similar between individuals with and without a history of TBI. This included unemployment, student, or ‘other’ employment status among both males and females; income below the provincial median and age 65+ among males; and rural residence among females. This study highlighted opportunities for targeted population-level interventions, namely accessible and affordable mental health supports for individuals with lower income. Notably, this study presented evidence suggesting adaptations to existing services to accommodate challenges associated with TBI should be explored, given the finite and competing demands for mental health care and resources.

Sex and gender differences in mild traumatic brain injury/concussion

The high incidence of concussions/mild traumatic brain injury and the significant number of people with persisting concussion symptoms as well as the concern for delayed, neurodegenerative effects of concussions makes them a major public health concern. There is much to learn on concussions with respect to pathophysiology as well as vulnerability and resiliency factors. The heterogeneity in outcome after a concussion warrants a more personalized approach to better understand the biological and psychosocial factors that may affect outcome. In this chapter we address biological sex and gender as they impact different aspects of concussion including incidence, risk factors and outcome. As well, this chapter will provide a more fulsome overview of intimate partner violence, an often-overlooked cause of concussion in women. Applying the sex and gender lens to concussion/mild traumatic brain injury is imperative for discovery of its pathophysiology and moving closer to treatments.

A window into eye movement dysfunction following mTBI: A scoping review of magnetic resonance imaging and eye tracking findings

Mild traumatic brain injury (mTBI), commonly known as concussion, is a complex neurobehavioral phenomenon affecting six in 1000 people globally each year. Symptoms last between days and years as microstructural damage to axons and neurometabolic changes result in brain network disruption. There is no clinically available objective biomarker to diagnose the severity of injury or monitor recovery. However, emerging evidence suggests eye movement dysfunction (e.g., saccades and smooth pursuits) in patients with mTBI. Patients with a higher symptom burden and prolonged recovery time following injury may show higher degrees of eye movement dysfunction. Likewise, recent advances in magnetic resonance imaging (MRI) have revealed both white matter tract damage and functional network alterations in mTBI patients, which involve areas responsible for the ocular motor control. This scoping review is presented in three sections: Section 1 explores the anatomical control of eye movements to aid the reader with interpreting the discussion in subsequent sections. Section 2 examines the relationship between abnormal MRI findings and eye tracking after mTBI based on the available evidence. Finally, Section 3 communicates gaps in our knowledge about MRI and eye tracking, which should be addressed in order to substantiate this emerging field.

Eye Movements in Mild Traumatic Brain Injury: Ocular Biomarkers

Mild traumatic brain injury (mTBI, or concussion), results from direct and indirect trauma to the head (i.e. a closed injury of transmitted forces), with or without loss of consciousness. The current method of diagnosis is largely based on symptom assessment and clinical history. There is an urgent need to identify an objective biomarker which can not only detect injury, but inform prognosis and recovery. Ocular motor impairment is argued to be ubiquitous across mTBI subtypes and may serve as a valuable clinical biomarker with the recent advent of more affordable and portable eye tracking technology. Many groups have positively correlated the degree of ocular motor impairment to symptom severity with a minority attempting to validate these findings with diffusion tract imaging and functional MRI. However, numerous methodological issues limit the interpretation of results, preventing any singular ocular biomarker from prevailing. This review will comprehensively describe the anatomical susceptibility, clinical measurement, and current eye tracking literature surrounding saccades, smooth pursuit, vestibulo-ocular reflex, vergence, pupillary light reflex, and accommodation in mTBI.

Examining how time from sport-related concussion to initial assessment predicts return-to-play clearance

OBJECTIVE

(i) To analyze data of adolescents who have sustained a sport-related concussion (SRC) through the use of Complete Concussion Management Inc. (CCMI) concussion database system; and (ii) to determine an optimal time to assess and manage an athlete with an SRC by prospectively analyzing data from CCMI concussion database system.

METHOD

A cohort of patients, ages 8-18 years, who sustained an SRC, assessed 30 days or less from injury and were treated at partnered CCMI clinics across Canada were prospectively followed. The primary outcome measure was recovery, defined as CCMI discharge, which includes an athlete having completed all return-to-school and return-to-play steps and passed the Gapski-Goodman test without symptom exacerbation.

RESULTS

1213 athletes (482 female) were included for analysis. Days between injury and initial assessment (p = 0.00), male sex (p = 0.00), and previous concussion history (p = 0.00) were significant predictors of time to discharge. A log-rank test revealed a significant difference (p = 0.00) in time to discharge with athletes assessed <10 days of injury discharged at a mean of 23.5 days (95% CI, 22.5, 24.5) and those assessed at day 10 to 30 were discharged at a mean of 37.1 days (95% CI, 33.7, 40.5). Athletes who were assessed at 0 to 9 days from injury were two times more likely to be discharged sooner compared to those athletes assessed 10 to 30 days from injury (HR 2.03, p = 0.00).

CONCLUSION

Time from SRC to initial assessment significantly predicted time to discharge, with those being evaluated earlier experiencing a faster discharge. The results aid in establishing recommended timelines for evaluation following an SRC in order to prevent or mitigate athletes experiencing a prolonged recovery and encourage timely access to care and a quicker return to life post-concussive injury.

Machine learning to predict sports-related concussion recovery using clinical data

OBJECTIVES

Sport-related concussions (SRCs) are a concern for high school athletes. Understanding factors contributing to SRC recovery time may improve clinical management. However, the complexity of the many clinical measures of concussion data precludes many traditional methods. This study aimed to answer the question, what is the utility of modeling clinical concussion data using machine-learning algorithms for predicting SRC recovery time and protracted recovery?

METHODS

This was a retrospective case series of participants aged 8 to 18 years with a diagnosis of SRC. A 6-part measure was administered to assess pre-injury risk factors, initial injury severity, and post-concussion symptoms, including the Vestibular Ocular Motor Screening (VOMS) measure, King-Devick Test and C3 Logix Trails Test data. These measures were used to predict recovery time (days from injury to full medical clearance) and binary protracted recovery (recovery time > 21 days) according to several sex-stratified machine-learning models. The ability of the models to discriminate protracted recovery was compared to a human-driven model according to the area under the receiver operating characteristic curve (AUC).

RESULTS

For 293 males (mean age 14.0 years) and 362 females (mean age 13.7 years), the median (interquartile range) time to recover from an SRC was 26 (18-39) and 21 (14-31) days, respectively. Among 9 machine-learning models trained, the gradient boosting on decision-tree algorithms achieved the best performance to predict recovery time and protracted recovery in males and females. The models' performance improved when VOMS data were used in conjunction with the King-Devick Test and C3 Logix Trails Test data. For males and females, the AUC was 0.84 and 0.78 versus 0.74 and 0.73, respectively, for statistical models for predicting protracted recovery.

CONCLUSIONS

Machine-learning models were able to manage the complexity of the vestibular-ocular motor system data. These results demonstrate the clinical utility of machine-learning models to inform prognostic evaluation for SRC recovery time and protracted recovery.

Associations between interpersonal violence victimisation and concussions among US college students

Interpersonal violence is common on college campuses and is associated with many adverse health outcomes; however, it remains unknown whether experiencing interpersonal violence victimisation is associated with concussions. The aim of this study was to estimate the associations between interpersonal violence, including emotional abuse, physical abuse and sexual assault, and concussions among a large, diverse sample of college students. We analysed cross-sectional data from the 2018-2019 national (US) Healthy Minds Study (N = 1,478). Multiple logistic regression analyses were conducted to estimate the association between interpersonal violence victimisation (any violence victimisation, emotional abuse, physical abuse and sexual assault) and concussion history (any concussion, diagnosed concussion and undiagnosed concussion), while adjusting for potential confounders. Analyses were conducted among the overall sample and separately by male and female participants. Results showed patterns of significant associations between interpersonal violence victimisation and concussions among the overall sample and among male and female participants. Among the overall sample, any interpersonal violence victimisation (adjusted odds ratio [AOR] 1.45, 95% confidence interval [CI] 1.13-1.88), emotional abuse (AOR 1.36, 95% CI 1.06-1.76), physical abuse (AOR 1.61, 95% CI 1.07-2.44) and sexual assault (AOR 2.17, 95% CI 1.44-3.26) were associated with higher odds of any concussion history. Sexual assault victimisation had the strongest association with any concussion history among male (AOR 1.96, 95% CI 1.04-3.71) and female (AOR 2.96, 95% CI 1.62-5.43) participants. These results expand on prior interpersonal violence and concussion research by showing an association with multiple victimisation measures among a large and diverse sample of college students. Medical professionals should screen for concussions among college students who experience emotional abuse, physical abuse and sexual assault to provide appropriate guidance. Information on the symptoms of concussions should be incorporated into campus violence awareness and prevention efforts.

Sex differences in acute and long-term brain recovery after concussion

Concussion is associated with acute disturbances in brain function and behavior, with potential long‐term effects on brain health. However, it is presently unclear whether there are sex differences in acute and long‐term brain recovery. In this study, magnetic resonance imaging (MRI) was used to scan 61 participants with sport‐related concussion (30 male, 31 female) longitudinally at acute injury, medical clearance to return to play (RTP), and 1‐year post‐RTP. A large cohort of 167 controls (80 male, 87 female) was also imaged. Each MRI session assessed cerebral blood flow (CBF), along with white matter fractional anisotropy (FA) and mean diffusivity (MD). For concussed athletes, the parameters were converted to difference scores relative to matched control subgroups, and partial least squares modeled the main and sex‐specific effects of concussion. Although male and female athletes did not differ in acute symptoms or time to RTP , all MRI measures showed significant sex differences during recovery. Males had greater reductions in occipital‐parietal CBF (mean difference and 95%CI: 9.97 ml/100 g/min, [4.84, 15.12] ml/100 g/min, z = 3.73) and increases in callosal MD (9.07 × 10⁻⁵, [−14.14, −3.60] × 10⁻⁵, z = −3.46), with greatest effects at 1‐year post‐RTP. In contrast, females had greater reductions in FA of the corona radiata (16.50 × 10⁻³, [−22.38, −11.08] × 10⁻³, z = −5.60), with greatest effects at RTP. These findings provide new insights into how the brain recovers after a concussion, showing sex differences in both the acute and chronic phases of injury.

Baseline SCAT Performance in Men and Women: Comparison of Baseline Concussion Screens Between 6288 Elite Men's and 764 Women's Rugby Players

OBJECTIVE

This study compared Sports Concussion Assessment Tool (SCAT) performance in elite male (6288 players) and female (764 players) rugby players, to determine whether reference limits used for the management and diagnosis of concussion should differ between sexes.

DESIGN

Cross-sectional census sample.

SETTING

Data from World Rugby's Head Injury Assessment management system were analyzed. This data set covers global professional rugby.

PARTICIPANTS

All professional players who underwent baseline SCAT testing as part of World Rugby's concussion management requirement formed the study cohort. Ten thousand seven hundred fifty-four SCAT assessments from 6288 elite male rugby players and 1071 assessments from 764 elite female players were analyzed.

INTERVENTION

Elite men and women rugby players are independent variables.

MAIN OUTCOME MEASURES

Sports Concussion Assessment Tool performance, including symptoms endorsed, cognitive submode performance, and balance performance.

RESULTS

Women endorsed significantly more symptoms, with greater symptom severity, than men (relative ratio 1.34, 95% confidence interval, 1.25-1.45 women vs men). Women outperformed men in cognitive submodes with the exception of immediate memory and delayed recall and made fewer balance errors than men during the modified Balance Error Scoring System. Clinical reference limits, defined as submode score achieved by the worst-performing 50% of the cohort, did not differ between men and women.

CONCLUSIONS

Women and men perform differently during SCAT baseline testing, although differences are small and do not affect either the baseline or clinical reference limits that identify abnormal test results for most submodes. The greater endorsement of symptoms by women suggests increased risk of adverse concussion outcomes and highlights the importance of accurate evaluation of any symptom endorsement at baseline.

Post-Concussion and Post-Traumatic Stress Symptoms after Pediatric Traumatic Brain Injury: Shared Vulnerability Factors?

Following pediatric traumatic brain injury (TBI), post-concussion symptoms (PCS) and post-traumatic stress symptoms (PTSS) occur commonly; however, it is unknown to what degree they overlap. The study examined PCS and PTSS persisting 7 weeks after injury in children and adolescents ages 8-15 years with TBI (n = 89) or extracranial injury (EI; n = 40) after vehicle collisions. TBI was divided into mild, complicated-mild/moderate, and severe groups. Parents retrospectively rated children's pre-injury symptoms and behavior problems, and children completed self-report measures after injury. PCS and PTSS total scores were significantly correlated in TBI and EI groups, respectively, for child (rs = 0.75; rs = 0.44), and adolescent (rs = 0.61; rs = 0.67) cohorts. Generalized linear models examined whether injury type and severity, age, sex, and pre-injury symptom ratings predicted PCS and PTSS total scores and factor scores. Specific PCS and PTSS factor scores were elevated in different TBI severity groups, with most frequent problems following mild or severe TBI. PCS did not differ by age; however, girls had more emotional symptoms than boys. Only PTSS were predicted by pre-injury externalizing behavior. Significant age by sex interactions indicated that adolescent girls had more total, avoidance, and hyperarousal PTSS symptoms than younger girls or all boys. PCS and PTSS significantly overlapped in both TBI and EI groups, highlighting shared persistent symptoms after injury. Shared vulnerability factors included female sex, milder TBI, and poorer pre-injury adjustment. Older age was a unique vulnerability factor for PTSS. Psychological health interventions after injury should be customized to address comorbid symptoms.

Differences in Adolescent Symptom Reporting Following Motor Vehicle Accident Versus Sport-Related Concussion

OBJECTIVE

To characterize potential differences in youth concussion sustained in motor vehicle accident (MVA) versus sport-related concussion (SRC), hypothesizing that youth who sustain concussion in a MVA would endorse higher initial and persistent symptom scores compared to those with SRC, despite similar injury severity levels.

METHODS

Participants age 12-18 who sustained a concussion (i.e., Glasgow Coma Scale = 13-15) in a MVA (n = 35) were matched with SRC participants (n = 35) by sex, age, and days since injury. ANCOVA comparing initial postconcussion total symptom scores between the MVA and SRC groups were performed. Chi-square analysis with injury group by recovery time was used to determine whether youth who sustained concussion from MVA were more likely to endorse symptoms persisting >30 days at 3 months postinjury, and ANCOVA compared 3-month total symptom scores.

RESULTS

On average, the MVA group reported significantly higher initial postconcussion and more frequent persistent symptom scores compared to the SRC group.

CONCLUSIONS

This is the first known study to examine context of injury in youth concussion while matching for injury severity, age, sex, and days since injury. Findings suggest the context of injury is an important clinical variable related to initial reporting of symptoms and endorsement of symptoms lasting more than 30 days. Tailored interventions that consider the context of injury may facilitate symptom resolution.

Developing Insights for Possible and Probable Acute Concussions Using Cluster Analysis

Few studies have analyzed the Sport Concussion Assessment Tool's (SCAT) utility among athletes whose concussion assessment is challenging. Using a previously published algorithm, we identified possible and probable concussions at <6 h (n = 393 males, n = 265 females) and 24-48 h (n = 323 males, n = 236 females) post-injury within collegiate student-athletes and cadets from the Concussion Assessment, Research, and Education (CARE) Consortium. We applied cluster analysis to characterize performance on the Standard Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and the SCAT symptom checklist for these athletes. Among the cluster sets that best separated acute concussions and normal performances, total symptom number raw score and change and post-traumatic migraine raw score and change score were the most frequent clustering variables across males and females at <6 h and 24-48 h. Similarly, total symptom number raw score and change score and post-traumatic migraine raw score and change score were most significantly different between clusters for males and females at <6 h and 24-48 h. Our results suggest that clinicians should focus on total symptom number, post-traumatic migraine symptoms, and cognitive-fatigue symptoms when assessing possible and probable concussions, followed by the SAC and BESS scores.

Association of Sex and Age With Mild Traumatic Brain Injury-Related Symptoms: A TRACK-TBI Study

IMPORTANCE

Knowledge of differences in mild traumatic brain injury (mTBI) recovery by sex and age may inform individualized treatment of these patients.

OBJECTIVE

To identify sex-related differences in symptom recovery from mTBI; secondarily, to explore age differences within women, who demonstrate poorer outcomes after TBI.

DESIGN, SETTING, AND PARTICIPANTS

The prospective cohort study Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) recruited 2000 patients with mTBI from February 26, 2014, to July 3, 2018, and 299 patients with orthopedic trauma (who served as controls) from January 26, 2016, to July 27, 2018. Patients were recruited from 18 level I trauma centers and followed up for 12 months. Data were analyzed from August 19, 2020, to March 3, 2021.

EXPOSURES

Patients with mTBI (defined by a Glasgow Coma Scale score of 13-15) triaged to head computed tomography in 24 hours or less; patients with orthopedic trauma served as controls.

MAIN OUTCOMES AND MEASURES

Measured outcomes included (1) the Rivermead Post Concussion Symptoms Questionnaire (RPQ), a 16-item self-report scale that assesses postconcussion symptom severity over the past 7 days relative to preinjury; (2) the Posttraumatic Stress Disorder Checklist for the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (PCL-5), a 20-item test that measures the severity of posttraumatic stress disorder symptoms; (3) the Patient Health Questionnaire-9 (PHQ-9), a 9-item scale that measures depression based on symptom frequency over the past 2 weeks; and (4) the Brief Symptom Inventory-18 (BSI-18), an 18-item scale of psychological distress (split into Depression and Anxiety subscales).

RESULTS

A total of 2000 patients with mTBI (1331 men [67%; mean (SD) age, 41.0 (17.3) years; 1026 White (78%)] and 669 women [33%; mean (SD) age, 43.0 (18.5) years; 505 (76%) White]). After adjustment of multiple comparisons, significant TBI × sex interactions were observed for cognitive symptoms (B = 0.76; 5% false discovery rate-corrected P = .02) and somatic RPQ symptoms (B = 0.80; 5% false discovery rate-corrected P = .02), with worse symptoms in women with mTBI than men, but no sex difference in symptoms in control patients with orthopedic trauma. Within the female patients evaluated, there was a significant TBI × age interaction for somatic RPQ symptoms, which were worse in female patients with mTBI aged 35 to 49 years compared with those aged 17 to 34 years (B = 1.65; P = .02) or older than 50 years (B = 1.66; P = .02).

CONCLUSIONS AND RELEVANCE

This study found that women were more vulnerable than men to persistent mTBI-related cognitive and somatic symptoms, whereas no sex difference in symptom burden was seen after orthopedic injury. Postconcussion symptoms were also worse in women aged 35 to 49 years than in younger and older women, but further investigation is needed to corroborate these findings and to identify the mechanisms involved. Results suggest that individualized clinical management of mTBI should consider sex and age, as some women are especially predisposed to chronic postconcussion symptoms even 12 months after injury.

Resilience and Sexuality After Concussion in Women

Background

Previous findings from our group show that in the acute (ie, 6–10 weeks) post-injury period, women with concussions have a 70% greater risk of sexual dysfunction than those with extremity injuries. There are currently limited treatment options for the clinical management of concussions. Resilience is a protective, modifiable psychological construct that has been shown to improve concussion-related sequelae. To date, however, no research has evaluated how resilience impacts sexuality outcomes after concussion in women.

Aim

Evaluate if resilience offers protection against negative sexuality outcomes in a cohort of reproductive, aged women with a concussion, seeking care in the Emergency Department of a Level-1 Trauma Center. We hypothesized that women with low resilience will be more likely to experience negative impacts on sexuality and that increasing levels of resilience will be associated with more positive sexuality outcomes.

Methods

Secondary data analyses.

Measures

Resilience was evaluated with the Resilience Scale (RS), and the Brain Injury Questionnaire for Sexuality (BIQS) was used for sexuality.

Results

Of the 299 participants recruited for the parent study, 80 with concussion had complete follow-up data and were included in these secondary analyses. Less than half (42.5%; n = 34) had low resilience (score≤130 on the RS), and the remaining 46 (57.5%) had high resilience (score>130 on the RS). In crude linear regression models, 1-unit increase in resilience was associated with a 4% increase in sexuality outcomes (β = 0.04, 95% CI:0.01, 0.05; P = .008). The effect estimate remained similar in post-concussion-symptom-adjusted models (β = 0.03, 95% CI:0.002, 0.06; P = .03). Mood-adjusted models showed a statistically significant interaction term (P < .0001). After stratifying by mood, findings showed that unit increases in resilience were associated with a 6% increase in sexuality outcomes for women in the high risk mood group (HADS score ≥11; PCS-adjusted β = 0.06, 95% CI:0.02, 0.11; P = .009).

Conclusion

Longitudinal studies are needed to evaluate how these improvements in resilience translate to patient recovery measures following concussion.

Anto-Ocrah M, Oktapodas Feiler M, Pukall C, et al. Resilience and Sexuality After Concussion in Women. Sex Med 2021;9:100297.

A Systematic Review of Strength and Conditioning Protocols for Improving Neck Strength and Reducing Concussion Incidence and Impact Injury Risk in Collision Sports; Is There Evidence?

The objective of this systematic literature review was to evaluate the evidence regarding the development of neck strength in reducing concussion and cervical spine injuries in adult amateur and professional sport populations. PubMed, CINAHL, Science Direct, and Web of Science databases were searched systematically. The criteria for inclusion in the review were as follows: (1) a human adult (≥18 or above); (2) involved in amateur, semi-professional, or professional sports; (3) sports included involved collisions with other humans, apparatus or the environment; (4) interventions included pre- and post-neck muscle strength measures or neck stability measures; (5) outcomes included effects on increasing neck strength in participants and/or injury incidence. Database searches identified 2462 articles. Following title, abstract, and full paper screening, three papers were eligible for inclusion. All of the papers reported information from male participants, two were focused on rugby union, and one on American football. Two of the included studies found a significant improvement in isometric neck strength following intervention. None of the studies reported any impact of neck strengthening exercises on cervical spine injuries. This review has shown that there is currently a lack of evidence to support the use of neck strengthening interventions in reducing impact injury risk in adult populations who participate in sport.

Neurocognitive performance and mental health of retired female football players compared to non-contact sport athletes

Background

Adverse long-term effects of playing football due to repetitive head impact exposure on neurocognition and mental health are controversial. To date, no studies have evaluated such effects in women.

Aims

To (1) compare neurocognitive performance, cognitive symptoms and mental health in retired elite female football players (FB) with retired elite female non-contact sport athletes (CON), and to (2) assess whether findings are related to history of concussion and/or heading exposure in FB.

Methods

Neurocognitive performance, mental health and cognitive symptoms were assessed using computerised tests (CNS-vital signs), paper pen tests (Category fluency, Trail-Making Test, Digit Span, Paced Auditory Serial Addition Test), questionnaires (Hospital Anxiety and Depression Scale, SF-36v2 Health Survey) and a symptom checklist. Heading exposure and concussion history were self-reported in an online survey and in a clinical interview, respectively. Linear regression was used to analyse the effect of football, concussion and heading exposure on outcomes adjusted for confounders.

Results

FB (n=66) performed similar to CON (n=45) on neurocognitive tests, except for significantly lower scores on verbal memory (mean difference (MD)=−7.038, 95% CI −12.98 to –0.08, p=0.038) and verbal fluency tests (MD=−7.534, 95% CI –13.75 to –0.46, p=0.016). Among FB weaker verbal fluency performance was significantly associated with ≥2 concussions (MD=−10.36, 95% CI –18.48 to –2.83, p=0.017), and weaker verbal memory performance with frequent heading (MD=−9.166, 95% CI –17.59 to –0.123, p=0.041). The depression score differed significantly between study populations, and was significantly associated with frequent heading but not with history of concussion in FB.

Conclusion

Further studies should investigate the clinical relevance of our findings and whether the observed associations point to a causal link between repetitive head impacts and verbal memory/fluency or mental health.

Sex-specific differences in resting-state functional connectivity of large-scale networks in postconcussion syndrome

Concussions are associated with a range of cognitive, neuropsychological and behavioral sequelae that, at times, persist beyond typical recovery times and are referred to as postconcussion syndrome (PCS). There is growing support that concussion can disrupt network-based connectivity post-injury. To date, a significant knowledge gap remains regarding the sex-specific impact of concussion on resting state functional connectivity (rs-FC). The aims of this study were to (1) investigate the injury-based rs-FC differences across three large-scale neural networks and (2) explore the sex-specific impact of injury on network-based connectivity. MRI data was collected from a sample of 80 concussed participants who fulfilled the criteria for postconcussion syndrome and 31 control participants who did not have any history of concussion. Connectivity maps between network nodes and brain regions were used to assess connectivity using the Functional Connectivity (CONN) toolbox. Network based statistics showed that concussed participants were significantly different from healthy controls across both salience and fronto-parietal network nodes. More specifically, distinct subnetwork components were identified in the concussed sample, with hyperconnected frontal nodes and hypoconnected posterior nodes across both the salience and fronto-parietal networks, when compared to the healthy controls. Node-to-region analyses showed sex-specific differences across association cortices, however, driven by distinct networks. Sex-specific network-based alterations in rs-FC post concussion need to be examined to better understand the underlying mechanisms and associations to clinical outcomes.

Sex Differences in Behavioral Sensitivities After Traumatic Brain Injury

Traumatic brain injury (TBI) is associated with high rates of post-injury psychiatric and neurological comorbidities. TBI is more common in males than females despite females reporting more symptoms and longer recovery following TBI and concussion. Both pain and mental health conditions like anxiety and post-traumatic stress disorder (PTSD) are more common in women in the general population, however the dimorphic comorbidity in the TBI population is not well-understood. TBI may predispose the development of maladaptive anxiety or PTSD following a traumatic stressor, and the impact of sex on this interaction has not been investigated. We have shown that white noise is noxious to male rats following fluid percussion injury (FPI) and increases fear learning when used in auditory fear conditioning, but it is unclear whether females exhibit a similar phenotype. Adult female and male rats received either lateral FPI or sham surgery and 48 h later received behavioral training. We first investigated sex differences in response to 75 dB white noise followed by white noise-signaled fear conditioning. FPI groups exhibited defensive behavior to the white noise, which was significantly more robust in females, suggesting FPI increased auditory sensitivity. In another experiment, we asked how FPI affects contextual fear learning in females and males following unsignaled footshocks of either strong (0.9 mA) or weaker (0.5 mA) intensity. We saw that FPI led to rapid acquisition of contextual fear compared to sham. A consistent pattern of increased contextual fear after TBI was apparent in both sexes across experiments under differing conditioning protocols. Using a light gradient open field task we found that FPI females showed a defensive photophobia response to light, a novel finding supporting TBI enhanced sensory sensitivity across modalities in females. General behavioral differences among our measures were observed between sexes and discussed with respect to interpretations of TBI effects for each sex. Together our data support enhanced fear following a traumatic stressor after TBI in both sexes, where females show greater sensitivity to sensory stimuli across multiple modalities. These data demonstrate sex differences in emergent defensive phenotypes following TBI that may contribute to comorbid PTSD, anxiety, and other neurological comorbidities.

Eye movement performance and clinical outcomes among female athletes post-concussion

BACKGROUND

Most post-concussion eye movement (EM) research involves predominantly male samples. We evaluated pro- (PRO; reflexive shift of visual attention to target) and anti- (ANTI; executive control of visual attention away from target) computer-based saccade task performance among female, collegiate athletes with recent concussion (CON) versus healthy-control athletes (HC). We evaluated the relationship between EM performance and post-concussion outcomes. We hypothesized ANTI performance would differ among CON and HC due to greater executive control demands, and that EM performance (both tasks) would be associated with clinical outcomes in CON.

METHODS

16 CON (assessed 4-10 days post-injury [M = 6.87, SD = 2.15 days]) and 16 age-matched HC athletes were recruited. General linear mixed modeling and Pearson's correlations were used.

RESULTS

On ANTI, CON demonstrated higher error rate [F(1,2863) = 12.650, p<.001] and shorter latency on error trials [F(1,469) = 5.976, p=.015] relative to HC. Multiple EM measures were associated with clinical outcomes: PRO duration predicted days to symptom remission (r=.44, p <.05); ANTI error rate was associated with symptom burden on the day of testing (r=.27, p <.05).

CONCLUSION

This study demonstrates promising utility of EM measures to detect cognitive control and sensorimotor effects of concussion among female athletes and their use as a prognostic indicators of recovery.

Sex as a Biological Variable in Preclinical Modeling of Blast-Related Traumatic Brain Injury

Approaches to furthering our understanding of the bioeffects, behavioral changes, and treatment options following exposure to blast are a worldwide priority. Of particular need is a more concerted effort to employ animal models to determine possible sex differences, which have been reported in the clinical literature. In this review, clinical and preclinical reports concerning blast injury effects are summarized in relation to sex as a biological variable (SABV). The review outlines approaches that explore the pertinent role of sex chromosomes and gonadal steroids for delineating sex as a biological independent variable. Next, underlying biological factors that need exploration for blast effects in light of SABV are outlined, including pituitary, autonomic, vascular, and inflammation factors that all have evidence as having important SABV relevance. A major second consideration for the study of SABV and preclinical blast effects is the notable lack of consistent model design—a wide range of devices have been employed with questionable relevance to real-life scenarios—as well as poor standardization for reporting of blast parameters. Hence, the review also provides current views regarding optimal design of shock tubes for approaching the problem of primary blast effects and sex differences and outlines a plan for the regularization of reporting. Standardization and clear description of blast parameters will provide greater comparability across models, as well as unify consensus for important sex difference bioeffects.

Quality of life of ice hockey players after retirement due to concussions

Background:

Sports-related concussion (SRC) is increasingly recognized as a potential health problem in ice hockey. Quality of life (QoL) in players retiring due to SRC has not been thoroughly addressed.

Materials & methods:

QoL using the Sports Concussion Assessment Tool 5th Edition, Impact of Event Scale-Revised and Short Form Health Survey was measured in Swedish ice hockey players who retired due to persistence of postconcussion symptoms or fear of attaining additional SRC.

Results:

A total of 76 players were assessed, on average of 5 years after their most recent SRC. Overall, retired players had a high burden of postconcussion symptoms and reduced QoL.

Conclusion:

Retired concussed ice hockey players have a reduced QoL, particularly those retiring due to postconcussion symptoms. Symptom burden should be continuously evaluated and guide the decision to retire.

Concussions sustained while playing ice hockey are increasingly recognized as a potential health problem. Long-term consequences for players retiring due to concussions have not been fully investigated. Therefore, we evaluated symptoms, quality of life and post-traumatic stress in former Swedish ice hockey players who retired due to postconcussion symptoms or to a fear of attaining additional concussions. We found that retired ice hockey players with a history of concussions had a low quality of life and high post-traumatic stress, particularly in players with a high symptom burden. We recommend that symptom burden should be continuously evaluated and guide the decision to retire.

Cognitive Ageing in Top-Level Female Soccer Players Compared to a Normative Sample from the General Population: A Cross-sectional Study

OBJECTIVE

There is an ongoing debate on the potential negative effect of contact sport participation on long-term neurocognitive performance due to inherent exposure to concussive and subconcussive head impacts. The aim of the present study was to investigate whether cognitive ageing is exacerbated in elite soccer players compared to the general population.

METHOD

Neurocognitive performance in 6 domains was compared between 240 elite soccer players and a normative sample from the general population (n = 585) using the computerised test battery CNS Vital Signs. We used two-way factorial ANOVA to analyse the interaction between age groups (15-19, 20-29, 30-39, 40-49 years) and study population (female soccer players vs. norm sample) in their effects on neurocognitive performance.

RESULTS

We found no significant interaction effect of age group and study population in five of six test domains. For processing speed, the effect of age was more pronounced in female soccer players (F = 16.89, p = .002). Further, there was a clear main effect of study population on neurocognitive performance with generally better scores in soccer players.

CONCLUSIONS

Elite female soccer players generally performed better than the norm sample on tests of cognitive function, and further, cognitive ageing effects were similar in elite soccer players and controls in all but one domain. A lifespan approach may facilitate insightful future research regarding questions related to long-term neurocognitive health in contact sport athletes.

Eye Movements, Dizziness, and Mild Traumatic Brain Injury (mTBI): A Topical Review of Emerging Evidence and Screening Measures

BACKGROUND AND PURPOSE

Eye movements may be adversely affected after mild traumatic brain injury (mTBI) and should be examined. The purpose of this topical review is to provide the clinician with the most up-to-date knowledge related to eye movement abnormalities, screening measures, and evidence related to exercise interventions that are designed to enhance outcomes in persons after mTBI.

SUMMARY OF KEY POINTS

Presence of eye misalignment such as tropias or phoria or symptoms with head/eye movements such as vestibulo-ocular reflex (VOR) × 1, saccades, or smooth pursuits may slow the person's recovery. Tools such as the Convergence Insufficiency Symptom Survey, the Vestibular/Ocular Motor Screening, the Pediatric Vestibular Symptom Questionnaire, and the Pediatric Visually Induced Dizziness questionnaire may aid in identifying visual concerns to target in the physical therapy intervention program. There is emerging evidence that vestibular rehabilitation enhances recovery in persons after mTBI.

RECOMMENDATIONS FOR CLINICAL PRACTICE

A thorough eye examination is highly recommended after mTBI to identify targeted areas for intervention.

No differences in tandem gait performance between male and female athletes acutely post-concussion

OBJECTIVES

To test whether 1) concussed athletes demonstrate slower tandem gait times compared to controls and 2) concussed female athletes display greater post-injury deficits than males.

DESIGN

Prospective longitudinal METHOD: Fifty concussed collegiate student-athletes (32% female, age=20.18±1.27 years) completed tandem gait tests during pre-season (Time 1) and acutely (<72hours) post-concussion (Time 2), and twenty-five controls (52% female, age=21.08±2.22 years) completed tandem gait at two time points, 1.96±0.46 days apart. Participants completed four single-task (ST) and dual-task (DT) trials. During DT trials, they simultaneously completed a cognitive assessment. The best ST and DT times were recorded, along with cognitive accuracy, and the change score between the two assessments was calculated. A positive change in tandem gait time was indicative of worsening performance. A 2×2 (group*sex) ANOVA was used to examine change between pre-injury and post-injury tests for ST/DT tandem gait time and DT cognitive accuracy.

RESULTS

The change in tandem gait time from Time 1 to Time 2 was significantly higher for the concussion group relative to controls during both ST (Concussion: 1.36±2.6 seconds, Controls: -1.16±0.8 seconds, p<0.001) and DT (Concussion: 1.70±3.8 seconds, Controls: -0.94±1.7 seconds, p=0.002) tandem gait. There were no interactions or main effects of sex for tandem gait time or cognitive accuracy.

CONCLUSIONS

There were no sex-specific differences in the change in tandem gait performance among concussed collegiate athletes or controls. However, all concussed participants, regardless of sex, performed significantly worse on tandem gait than male and female controls, who both improved between testing time points.

Symptom Burden and Profiles in Concussed Children with and without Prolonged Recovery

Although symptom burden and symptom profile severity are independent predictors of post-concussion symptom duration, few studies have examined their effects on prolonged recovery simultaneously. This study examined differences in symptom burden and symptom profile scores between concussed children with prolonged recovery and those with typical recovery. We conducted a retrospective case-control study of concussed children aged 10–18 years. Prolonged recovery was defined as symptom duration beyond 28 days post-injury. Symptom burden was measured as total symptom score (TSS) at injury. Symptom profiles included: (1) vestibular, (2) ocular, (3) cognitive/fatigue, (4) migraine, and (5) anxiety. A total of 4380 unique concussions sustained by 3777 patients were included; 80.3% white, 60.0% male, and 44.0% aged 13–15 years. The prolonged recovery group had a significantly higher TSS and greater number of symptoms than the typical recovery group (p < 0.001 and p < 0.001, respectively). The prolonged recovery group had significantly higher scores on all five symptom profiles, including vestibular (p < 0.001), ocular (p < 0.001), cognitive/fatigue (p < 0.001), migraine (p < 0.001) and anxiety (p < 0.001), than the typical recovery group, even after adjusting for number of symptoms and other covariates. Further studies using prospective cohort designs are needed to better understand the influence of symptom burden and profiles on pediatric concussion recovery.

Beyond Measures of Central Tendency: Novel Methods to Examine Sex Differences in Neuropsychological Performance Following Sports-Related Concussion in Collegiate Athletes

OBJECTIVE

The purpose of this study was to examine sex differences in neuropsychological functioning after sports-related concussion using several approaches to assess cognition: mean performance, number of impaired scores, and intraindividual variability (IIV).

METHOD

In the study, 152 concussed college athletes were administered a battery of neuropsychological tests, on average, 10 days post-concussion (SD = 12.75; Mdn = 4 days; Range = 0-72 days). Mean performance was evaluated across 18 individual neuropsychological variables, and the total number of impaired test scores (>1.5 SD below the mean) was calculated for each athlete. Two measures of IIV were also computed: an intraindividual standard deviation (ISD) score and a maximum discrepancy (MD) score.

RESULTS

Analyses of covariance revealed that, compared with males, females had significantly more impaired scores and showed greater variability on both IIV indices (ISD and MD scores) after adjusting for time since injury and post-concussive symptoms. In contrast, no significant effects of sex were found when examining mean neuropsychological performance.

CONCLUSION

Although females and males demonstrated similar mean performance following concussion, females exhibited a greater level of cognitive impairment and larger inconsistencies in cognitive performance than males. These results suggest that evaluating cognitive indices beyond mean neuropsychological scores may provide valuable information when determining the extent of post-concussion cognitive dysfunction.

The Potential Role of the Cervical Spine in Sports-Related Concussion: Clinical Perspectives and Considerations for Risk Reduction

Sports-related concussion (SRC) occurs due to biomechanical forces to the head or neck that can result in pathophysiological changes in the brain. The musculature of the cervical spine has been identified as one potential factor in reducing SRC risk as well as for underlying sex differences in SRC rates. Recent research has demonstrated that linear and rotational head acceleration, as well as the magnitude of force upon impact, is influenced by cervical spine biomechanics. Increased neck strength and girth are associated with reduced linear and rotational head acceleration during impact. Past work has also shown that overall neck strength and girth are reduced in athletes with SRC. Additionally, differences in cervical spine biomechanics are hypothesized as a critical factor underlying sex differences in SRC rates. Specifically, compared to males, females tend to have less neck strength and girth, which are associated with increased linear and rotational head acceleration. Although our ability to detect SRC has greatly improved, our ability to prevent SRC from occurring and decrease the severity of clinical outcomes postinjury is limited. However, we suggest, along with others, that cervical spine biomechanics may be a modifiable factor in reducing SRC risk. In this commentary, we review the role of the cervical spine in reducing SRC risk, and how this risk differs by sex. We discuss clinical considerations for the examination of the cervical spine and the potential clinical relevance for SRC prevention. Additionally, we provide suggestions for future research examining cervical spine properties as modifiable factors in reducing SRC risk. J Orthop Sports Phys Ther 2019;49(3):202-208. Epub 15 Jan 2019. doi:10.2519/jospt.2019.8582.