Preliminary Report: Localized Cerebral Blood Flow Mediates the Relationship between Progesterone and Perceived Stress Symptoms among Female Collegiate Club Athletes after Mild Traumatic Brain Injury

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A mini-review of the evidence for cerebrovascular changes following gender-affirming hormone replacement therapy and a call for increased focus on cerebrovascular transgender health

Gender-affirming hormone replacement therapy (gaHRT) is an important step for many in the gender diverse community, associated with increased quality-of-life and lower self-reported scores of depression and anxiety. However, considering the interactions that the involved sex hormones have on vasculature (with oestrogen and testosterone demonstrating vasodilatory and vasoconstricting properties, respectively), it is important for transgender healthcare research to examine how the manipulation of these hormones interact with cerebrovascular structure and functioning. There is a stark lack of research in this area. This mini-review outlines the research suggesting a vascular impact of these sex hormones using evidence from a range of cohorts (e.g., menopause, polycystic ovary syndrome) and discusses the work that has been done into cerebrovascular changes following gaHRT. Finally, recommendations for future research into cerebrovascular health in transgender cohorts following gaHRT are outlined.

Menstrual Cycle Patterns After Concussion in Adolescent Patients

OBJECTIVE

To describe menstrual cycle patterns in adolescents with concussion and investigate whether menstrual cycle phase at injury influenced postconcussion cycle pattern changes or concussion symptoms.

STUDY DESIGN

Data were collected prospectively from patients aged 13-18 years presenting to a specialty care concussion clinic for an initial visit (≤28 days postconcussion) and, if clinically indicated, at a follow-up visit 3-4 months postinjury. Primary outcomes included menstrual cycle pattern change since injury (change/no change), menstrual cycle phase at time of injury (calculated using date of last period before injury), and symptom endorsement and severity, measured by Post-Concussion Symptom Inventory (PCSI). Fisher exact tests were used to determine the association between menstrual phase at injury and change in cycle pattern. Multiple linear regression was used to determine whether menstrual phase at injury was associated with PCSI endorsement and symptom severity, adjusting for age.

RESULTS

Five hundred twelve postmenarchal adolescents were enrolled (age 15.2 ± 1.4 years), with 111 (21.7%) returning for follow-up at 3-4 months. Menstrual pattern change was reported by 4% of patients at initial visit and 10.8% of patients at follow-up. At 3-4 months, menstrual phase at injury was not associated with menstrual cycle changes (P = .40) but was associated with endorsement of concussion symptoms on the PCSI (P = .01).

CONCLUSIONS

At 3-4 months' postconcussion, 1 in 10 adolescents experienced a change in menses. Menstrual cycle phase at injury was associated with postconcussion symptom endorsement. Leveraging a large sample of postconcussion menstrual patterns, this study represents foundational data regarding potential menstrual cycle effects of concussion in female adolescents.

Concussion-related visual memory and reaction time impairment in college athletes improved after osteopathic manipulative medicine: a randomized clinical trial

CONTEXT

Concussion is an acute, transient disruption in brain function due to head injury. Previous studies suggest osteopathic manipulative medicine (OMM) improved recovery from concussion.

OBJECTIVES

The hypothesis was that new-onset impairments (NOI) of neurological functions identified by Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) will improve more so after OMM than after concussion-education.

METHODS

College athletes presenting to the outpatient academic healthcare center (AHCC) with concussion due to head injury within the preceding 2 weeks were recruited for this IRB-approved, randomized, single-blinded trial. Consented men and women were randomized into groups receiving two OMM treatments or two concussion-education sessions to control for social effects. Preseason, Baseline, ImPACT was compared to Post-Injury scores to determine NOI. Baseline, Post-Injury, and Post-Interventions ImPACTs were compared by analysis of variance (ANOVA, α≤0.05). Post-Injury correlations and mean changes in King-Devick (KD) scores were analyzed.

RESULTS

Post-Injury NOI were found in 77.8% (14/18) men and 85.7% (6/7) women, including ImPACT subscore indices for verbal and visual memory, processing speed (PS), and reaction time (RT). Of those with NOI, mean visual memory recovered by 50.0% following one and by 104.9% (p=0.032) following two OMM treatments in men and by 82.8% (p=0.046) following one treatment in women. Following two interventions, the mean RT in men receiving OMM improved by 0.10 more than education (p=0.0496). The effect sizes of OMM were large (Cohen's d=1.33) on visual memory and small (Cohen's d=0.31) on RT.

CONCLUSIONS

The NOI in visual memory and RT following concussion significantly improved in the OMM group compared to the education group. Integrating OMM utilizing physical exam and this treatment was a safe individualized approach in athletes with acute uncomplicated concussions. Further research is warranted to improve the utilization of OMM for individuals with concussion.

Altered Brain Functional Connectivity in Female Athletes Over the Course of a Season of Collision or Contact Sports

University athletes are exposed to numerous impacts to the body and head, though the potential cumulative effects of such hits remain elusive. This study examined resting-state functional connectivity (rsFC) of brain networks in female varsity athletes over the course of a season. Nineteen female university athletes involved in collision (N = 12) and contact (N = 7) sports underwent functional magnetic resonance imaging scans at both pre- and post-season. A group-level independent component analysis (ICA) was used to investigate differences in rsFC over the course of a season and differences between contact and collision sport athletes. Decreased rsFC was observed over the course of the season between the default mode network (DMN) and regions in the frontal, parietal, and occipital lobe (p false discovery rate, ≤0.05) driven by differences in the contact group. There was also a main effect of group in the dorsal attention network (DAN) driven by differences between contact and collision groups at pre-season. Differences identified over the course of a season of play indicate largely decreased rsFC within the DMN, and level of contact was associated with differences in rsFC of the DAN. The association between exposure to repetitive head impacts (RHIs) and observed changes in network rsFC supplements the growing literature suggesting that even non-concussed athletes may be at risk for changes in brain functioning. However, the complexity of examining the direct effects of RHIs highlights the need to consider multiple factors, including mental health and sport-specific training and expertise, that may potentially be associated with neural changes.

Chronic cerebral blood flow alterations in traumatic brain injury and sports-related concussions

PRIMARY OBJECTIVE

Traumatic brain injury (TBI) and sports-related concussion (SRC) may result in chronic functional and neuroanatomical changes. We tested the hypothesis that neuroimaging findings (cerebral blood flow (CBF), cortical thickness, and ¹H-magnetic resonance (MR) spectroscopy (MRS)) were associated to cognitive function, TBI severity, and sex.

RESEARCH DESIGN

Eleven controls, 12 athletes symptomatic following ≥3SRCs and 6 patients with moderate-severe TBI underwent MR scanning for evaluation of cortical thickness, brain metabolites (MRS), and CBF using pseudo-continuous arterial spin labeling (ASL). Cognitive screening was performed using the RBANS cognitive test battery.

MAIN OUTCOMES AND RESULTS

RBANS-index was impaired in both injury groups and correlated with the injury severity, although not with any neuroimaging parameter. Cortical thickness correlated with injury severity (p = 0.02), while neuronal density, using the MRS marker ((NAA+NAAG)/Cr, did not. On multivariate analysis, injury severity (p = 0.0003) and sex (p = 0.002) were associated with CBF. Patients with TBI had decreased gray (p = 0.02) and white matter (p = 0.02) CBF compared to controls. CBF was significantly lower in total gray, white matter and in 16 of the 20 gray matter brain regions in female but not male athletes when compared to female and male controls, respectively.

CONCLUSIONS

Injury severity correlated with CBF, cognitive function, and cortical thickness. CBF also correlated with sex and was reduced in female, not male, athletes. Chronic CBF changes may contribute to the persistent injury mechanisms in TBI and rSRC.

Traumatic brain injury in women across lifespan

Traumatic brain injury (TBI) is a leading cause of death and disability and a global public health challenge. Every year more than 50 million people suffer a TBI, and it is estimated that 50% of the global population will experience at least one TBI in their lifetime. TBI affects both men and women of all ages, however there is a male bias in TBI research as women have frequently been left out of the literature despite irrefutable evidence of male and female dimorphism in several posttraumatic measures. Women uniquely experience distinct life stages marked by levels of endogenous circulating sex hormones, as well as by physiological changes that are nonexistent in men. In addition to generalized sex-specific differences, a woman's susceptibility, neurological outcomes, and treatment success may vary considerably depending upon when in her lifespan she incurred a traumatic insult. How women impacted by TBI might differ from other women as a factor of age and physiology is not well understood. Furthermore, there is a gap in the knowledge of what happens when TBI occurs in the presence of certain sex-specific and sex-nonspecific variables, such as during pregnancy, with oral contraceptive use, in athletics, in cases of addiction and nicotine consumption, during perimenopause, postmenopause, in frailty, among others. Parsing out how hormone-dependent and hormone-independent lifespan variables may influence physiological, neurodegenerative, and functional outcomes will greatly contribute to future investigative studies and direct therapeutic strategies. The goal of this review is to aggregate the knowledge of prevalence, prognosis, comorbid risk, and response of women incurring TBI at differing phases of lifespan. We strive to illuminate commonalities and disparities among female populations, and to pose important questions to highlight gaps in the field in order to further the endeavor of targeted treatment interventions in a patient-specific manner.

Abcc8 (Sulfonylurea Receptor-1) Impact on Brain Atrophy after Traumatic Brain Injury Varies by Sex

Females have been understudied in pre-clinical and clinical traumatic brain injury (TBI), despite distinct biology and worse clinical outcomes versus males. Sulfonylurea receptor 1 (SUR1) inhibition has shown promising results in predominantly male TBI. A phase II trial is ongoing. We investigated whether SUR1 inhibition effects on contusional TBI differ by sex given that this may inform clinical trial design and/or interpretation. We studied the moderating effects of sex on post-injury brain tissue loss in 142 male and female ATP-binding cassette transporter subfamily C member 8 (Abcc8) wild-type, heterozygote, and knockout mice (12-15 weeks). Monkey fibroblast-like cells and mouse brain endothelium-derived cells were used for in vitro studies. Mice were injured with controlled cortical impact and euthanized 21 days post-injury to assess contusion, brain, and hemisphere volumes (vs. genotype- and sex-matched naïves). Abcc8 knockout mice had smaller contusion volumes (p = 0.012) and larger normalized contralateral (right) hemisphere volumes (nRHV; p = 0.03) after injury versus wild type. This was moderated by sex: Contusions were smaller (p = 0.020), nRHV was higher (p = 0.001), and there was less global atrophy (p = 0.003) in male, but not female, knockout versus wild-type mice after TBI. Less atrophy occurred in males for each copy of Abcc8 lost (p = 0.023-0.002, all outcomes). In vitro, sex-determining region Y (SRY) stimulated Abcc8 promoter activity and increased Abcc8 expression. Loss of Abcc8 strongly protected against post-traumatic cerebral atrophy in male, but not female, mice. This may partly be mediated by SRY on the Y-chromosome. Sex differences may have important implications for ongoing and future trials of SUR1 blockade.