Sex differences in outcome after mild traumatic brain injury

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

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

High-fat diet consumption negatively influences closed-head traumatic brain injury in a pediatric rodent model

Traumatic brain injury (TBI) is one of the most common causes of emergency room visits in children, and it is a leading cause of death in juveniles in the United States. Similarly, a high proportion of this population consumes diets that are high in saturated fats, and millions of children are overweight or obese. The goal of the present study was to assess the relationship between diet and TBI on cognitive and cerebrovascular outcomes in juvenile rats. In the current study, groups of juvenile male Long Evans rats were subjected to either mild TBI via the Closed-Head Injury Model of Engineered Rotational Acceleration (CHIMERA) or underwent sham procedures. The animals were provided with either a combination of high-fat diet and a mixture of high-fructose corn syrup (HFD/HFCS) or a standard chow diet (CH) for 9 days prior to injury. Prior to injury, the animals were trained on the Morris water maze for three consecutive days, and they underwent a post-injury trial on the day of the injury. Immediately after TBI, the animals' righting reflexes were tested. Four days post-injury, the animals were euthanized, and brain samples and blood plasma were collected for qRT-PCR, immunohistochemistry, and triglyceride assays. Additional subsets of animals were used to investigate cerebrovascular perfusion using Laser Speckle and perform immunohistochemistry for endothelial cell marker RECA. Following TBI, the righting reflex was significantly increased in TBI rats, irrespective of diet. The TBI worsened the rats' performance in the post-injury trial of the water maze at 3 h, p(injury) < 0.05, but not at 4 days post-injury. Reduced cerebrovascular blood flow using Laser Speckle was demonstrated in the cerebellum, p(injury) < 0.05, but not foci of the cerebral cortices or superior sagittal sinus. Immunoreactive staining for RECA in the cortex and corpus callosum was significantly reduced in HFD/HFCS TBI rats, p < 0.05. qRT-PCR showed significant increases in APOE, CREB1, FCGR2B, IL1B, and IL6, particularly in the hippocampus. The results from this study offer robust evidence that HFD/HFCS negatively influences TBI outcomes with respect to cognition and cerebrovascular perfusion of relevant brain regions in the juvenile rat.

The Uncoupling Effect of 17β-Estradiol Underlies the Resilience of Female-Derived Mitochondria to Damage after Experimental TBI

Current literature finds females have improved outcomes over their male counterparts after severe traumatic brain injury (TBI), while the opposite seems to be true for mild TBI. This begs the question as to what may be driving these sex differences after TBI. Estrogen is thought to be neuroprotective in certain diseases, and its actions have been shown to influence mitochondrial function. Mitochondrial impairment is a major hallmark of TBI, and interestingly, this dysfunction has been shown to be more severe in males than females after brain injury. This suggests estrogen could be playing a role in promoting "mitoprotection" following TBI. Despite the existence of estrogen receptors in mitochondria, few studies have examined the direct role of estrogen on mitochondrial function, and no studies have explored this after TBI. We hypothesized ex vivo treatment of isolated mitochondria with 17β-estradiol (E2) would improve mitochondrial function after experimental TBI in mice. Total mitochondria from the ipsilateral (injured) and contralateral (control) cortices of male and female mice were isolated 24 h post-controlled severe cortical impact (CCI) and treated with vehicle, 2 nM E2, or 20 nM E2 immediately before measuring reactive oxygen species (ROS) production, bioenergetics, electron transport chain complex (ETC) activities, and β-oxidation of palmitoyl carnitine. Protein expression of oxidative phosphorylation (OXPHOS) complexes was also measured in these mitochondrial samples to determine whether this influenced functional outcomes with respect to sex or injury. While mitochondrial ROS production was affected by CCI in both sexes, there were other sex-specific patterns of mitochondrial injury 24 h following severe CCI. For instance, mitochondria from males were more susceptible to CCI-induced injury with respect to bioenergetics and ETC complex activities, whereas mitochondria from females showed only Complex II impairment and reduced β-oxidation after injury. Neither concentration of E2 influenced ETC complex activities themselves, but 20 nM E2 appeared to uncouple mitochondria isolated from the contralateral cortex in both sexes, as well as the injured ipsilateral cortex of females. These studies highlight the significance of measuring mitochondrial dysfunction in both sexes after TBI and also shed light on another potential neuroprotective mechanism in which E2 may attenuate mitochondrial dysfunction after TBI in vivo.

Effects of Age, Sex, and Postconcussive Symptoms on Domain-Specific Quality of Life a Year After Mild Traumatic Brain Injury

OBJECTIVE

To identify the factors influencing longitudinal changes in patients' scores across 6 domains of the Quality of Life after Brain Injury (QOLIBRI) instrument 1 year after mild traumatic brain injury (mTBI).

DESIGN

This was a longitudinal cohort study.

PARTICIPANTS AND SETTING

Eligible patients with a new diagnosis of mTBI were recruited from the outpatient clinics of the neurosurgery departments of 3 teaching hospitals in Taipei City, Taiwan. In total, 672 patients participated in the baseline assessment. Postinjury follow-up was conducted at 6 and 12 months.

MAIN OUTCOME MEASURE

Six domains of the 37-item QOLIBRI: Cognition, Self, Daily Life and Autonomy, Social Relationships, Emotions, and Physical Problems.

RESULTS

Linear mixed-effects analyses revealed that, among patients younger than 60 years, the scores of the Cognition, Self, Daily Life and Autonomy, and Social Relationships domains significantly increased 6 months after injury; furthermore, their scores of the Cognition, Self, and Daily Life and Autonomy significantly increased 12 months after injury. By contrast, among patients 60 years and older, the scores of these domains reduced from baseline to 6 and 12 months. No significant sex-based difference was observed in the changes in scores of any QOLIBRI domain. At 6 and 12 months post-injury, the scores of the Cognition, Emotions, and Physical Problems domains were significantly higher for patients with postconcussive symptoms than for those without these symptoms.

CONCLUSIONS

Although multiple characteristics of patients significantly affected their baseline scores on the 6 domains of the QOLIBRI, only age and postconcussive symptoms were significantly associated with longitudinal changes in their scores 6 and 12 months after mTBI.

Perturbations in risk/reward decision making and frontal cortical catecholamine regulation induced by mild traumatic brain injury

Mild traumatic brain injury (mTBI) disrupts cognitive processes that influence risk taking behavior. Little is known regarding the effects of repetitive mild injury (rmTBI) or whether these outcomes are sex specific. Risk/reward decision making is mediated by the prefrontal cortex (PFC), which is densely innervated by catecholaminergic fibers. Aberrant PFC catecholamine activity has been documented following TBI and may underlie TBI-induced risky behavior. The present study characterized the effects of rmTBI on risk/reward decision making behavior and catecholamine transmitter regulatory proteins within the PFC. Rats were exposed to sham, single (smTBI), or three closed-head controlled cortical impact (CH-CCI) injuries and assessed for injury-induced effects on risk/reward decision making using a probabilistic discounting task (PDT). In the first week post-final surgery, mTBI increased risky choice preference. By the fourth week, males exhibited increased latencies to make risky choices following rmTBI, demonstrating a delayed effect on processing speed. When levels of tyrosine hydroxylase (TH) and the norepinephrine reuptake transporter (NET) were measured within subregions of the PFC, females exhibited dramatic increases of TH levels within the orbitofrontal cortex (OFC) following smTBI. However, both males and females demonstrated reduced levels of OFC NET following rmTBI. These results indicate the OFC is susceptible to catecholamine instability after rmTBI and suggests that not all areas of the PFC contribute equally to TBI-induced imbalances. Overall, the CH-CCI model of rmTBI has revealed time-dependent and sex-specific changes in risk/reward decision making and catecholamine regulation following repetitive mild head injuries.

Gender differences in female and male Australian football concussion injury: A prospective observational study of emergency department presentations

OBJECTIVE

To examine gender differences in Australian football (AF)-related concussion presentations to EDs in regional Australia.

METHODS

A prospective observational study of patients presenting to 1 of the 10 EDs in Western Victoria, Australia, with an AF-related concussion was conducted. Patients were part of a larger study investigating AF injuries over a complete AF season, including pre-season training and practice matches. Information regarding concussion injuries was extracted from patient medical records, including clinical features, concurrent injuries, mechanism and context of injury. Female and male data were compared with chi-squared and Fisher's exact tests. P < 0.05 was considered significant.

RESULTS

From the original cohort of 1635 patients with AF-related injuries (242 female and 1393 male), 231 (14.1%) patients were diagnosed with concussion. Thirty-eight (15.7%) females had concussions versus 193 (13.9%) males (P > 0.05). Females over the age of 16 were more likely to be concussed than males in the same age range (females n = 26, 68.4% vs males n = 94, 48.7%; P = 0.026). Neurosurgically significant head injury was rare (one case). Similar rates of concurrent injury were found between females 15 (39.5%) and males 64 (33.2%), with neck injury the single most common in 24 (10.3%) concussions. Sixty-nine patients (29%) were admitted for observation or to await the results of scans. The majority of concussions occurred in match play (87.9%). Females were more likely injured in contested ball situations (63.2% vs 37.3%; P < 0.05).

CONCLUSION

Concussion rates for community-level AF presentations to regional EDs were similar between genders. Serious head injury was rare, although hospital admission for observation was common. Concurrent injuries were common, with associated neck injury most often identified. Match play accounted for the majority of head injuries.

Sex differences in the extent of acute axonal pathologies after experimental concussion

Although human females appear be at a higher risk of concussion and suffer worse outcomes than males, underlying mechanisms remain unclear. With increasing recognition that damage to white matter axons is a key pathologic substrate of concussion, we used a clinically relevant swine model of concussion to explore potential sex differences in the extent of axonal pathologies. At 24 h post-injury, female swine displayed a greater number of swollen axonal profiles and more widespread loss of axonal sodium channels than males. Axon degeneration for both sexes appeared to be related to individual axon architecture, reflected by a selective loss of small caliber axons after concussion. However, female brains had a higher percentage of small caliber axons, leading to more extensive axon loss after injury compared to males. Accordingly, sexual dimorphism in axonal size is associated with more extensive axonal pathology in females after concussion, which may contribute to worse outcomes.

Applicability and clinical utility of the German rivermead post-concussion symptoms questionnaire in proxies of children after traumatic brain injury: an instrument validation study

BACKGROUND

The German Rivermead Post-Concussion Symptoms Questionnaire (RPQ) can be used to assess post-concussion symptoms (PCS) after traumatic brain injury (TBI) in adults, adolescents, and children.

METHODS

In this study, we examined the psychometric properties of the German RPQ proxy version (N = 146) for children (8-12 years) after TBI at the item, total and scale score level. Construct validity was analyzed using rank correlations with the proxy-assessed Post-Concussion Symptoms Inventory (PCSI-P), the Patient Health Questionnaire 9 (PHQ-9), and the Generalized Anxiety Disorder Scale 7 (GAD-7). Furthermore, sensitivity testing was performed concerning subjects' sociodemographic and injury-related characteristics. Differential item functioning (DIF) was analyzed to assess the comparability of RPQ proxy ratings for children with those for adolescents.

RESULTS

Good internal consistency was demonstrated regarding Cronbach's α (0.81-0.90) and McDonald's ω (0.84-0.92). The factorial validity of a three-factor model was superior to the original one-factor model. Proxy ratings of the RPQ total and scale scores were strongly correlated with the PCSI-P (ϱ = 0.50-0.69), as well as moderately to strongly correlated with the PHQ-9 (ϱ = 0.49-0.65) and the GAD-7 (ϱ = 0.44-0.64). The DIF analysis revealed no relevant differences between the child and adolescent proxy versions.

CONCLUSIONS

The German RPQ proxy is a psychometrically reliable and valid instrument for assessing PCS in children after TBI. Therefore, RPQ self- and proxy-ratings can be used to assess PCS in childhood as well as along the lifespan of an individual after TBI.

Nominal Differences in Acute Symptom Presentation and Recovery Duration of Sport-Related Concussion Between Male and Female Collegiate Athletes in the PAC-12

BACKGROUND

Sport-related concussion (SRC) is a heterogenous injury that often presents with varied symptoms and impairment. Recently, research has focused on identifying subtypes, or clinical profiles of concussion to be used in assessing and treating athletes with SRC. The purpose of this study was to investigate sex differences in clinical profiles, recovery duration, and initial symptom severity after SRC in a cohort of collegiate athletes in the Pacific-12 Conference (Pac-12).

METHODS

This prospective cohort study examined post-SRC symptoms, recovery, and return-to-play times using data from the Pac-12 CARE Affiliated Program and Pac-12 Health Analytics Program. Clinical profiles reported by student-athletes were defined by the number (> 50%) of specific symptoms frequently reported for each profile. Generalized linear mixed models were used to examine associations among sex, clinical profiles, time-to-recovery, and return-to-play times.

RESULTS

479 concussion incidents met inclusion criteria. The probabilities of initial presentation of each clinical profile, initial injury severity scores, and recovery times within a profile did not differ between sexes (p = 0.33-0.98). However, both males and females had > 0.75 probabilities of exhibiting cognitive and ocular profiles. Initial injury severity score was a strong nonlinear predictor of initial number of clinical profiles (p < 0.0001), which did not differ between sexes. The number of clinical profiles was also a nonlinear predictor of time-to-recovery (p = 0.03) and return-to-play times (p < 0.0001).

CONCLUSIONS

Initial symptom severity was strongly predictive of the number of acute clinical profiles experienced post-SRC. As the number of clinical profiles increased, time-to-recovery and time to return-to-play also increased. Factors other than sex may be better associated with acute symptom presentation post-concussion as no sex differences were found in reported clinical profiles or recovery. Understanding the number and type of clinical profiles experienced post-SRC may help inform concussion diagnostics and management.

Longitudinal Associations Between Persistent Post-Concussion Symptoms and Blood Biomarkers of Inflammation and CNS-Injury After Mild Traumatic Brain Injury

The aim of our study was to investigate the biological underpinnings of persistent post-concussion symptoms (PPCS) at 3 months following mild traumatic brain injury (mTBI). Patients (n = 192, age 16-60 years) with mTBI, defined as Glasgow Coma Scale (GCS) score between 13 and 15, loss of consciousness (LOC) <30 min, and post-traumatic amnesia (PTA) <24 h were included. Blood samples were collected at admission (within 72 h), 2 weeks, and 3 months. Concentrations of blood biomarkers associated with central nervous system (CNS) damage (glial fibrillary acidic protein [GFAP], neurofilament light [NFL], and tau) and inflammation (interferon gamma [IFNγ], interleukin [IL]-8, eotaxin, macrophage inflammatory protein-1-beta [MIP]-1β, monocyte chemoattractant protein [MCP]-1, interferon-gamma-inducible protein [IP]-10, IL-17A, IL-9, tumor necrosis factor [TNF], basic fibroblast growth factor [FGF]-basic platelet-derived growth factor [PDGF], and IL-1 receptor antagonist [IL-1ra]) were obtained. Demographic and injury-related factors investigated were age, sex, GCS score, LOC, PTA duration, traumatic intracranial finding on magnetic resonance imaging (MRI; within 72 h), and extracranial injuries. Delta values, that is, time-point differences in biomarker concentrations between 2 weeks minus admission and 3 months minus admission, were also calculated. PPCS was assessed with the British Columbia Post-Concussion Symptom Inventory (BC-PSI). In single variable analyses, longer PTA duration and a higher proportion of intracranial findings on MRI were found in the PPCS group, but no single biomarker differentiated those with PPCS from those without. In multi-variable models, female sex, longer PTA duration, MRI findings, and lower GCS scores were associated with increased risk of PPCS. Inflammation markers, but not GFAP, NFL, or tau, were associated with PPCS. At admission, higher concentrations of IL-8 and IL-9 and lower concentrations of TNF, IL-17a, and MCP-1 were associated with greater likelihood of PPCS; at 2 weeks, higher IL-8 and lower IFNγ were associated with PPCS; at 3 months, higher PDGF was associated with PPCS. Higher delta values of PDGF, IL-17A, and FGF-basic at 2 weeks compared with admission, MCP-1 at 3 months compared with admission, and TNF at 2 weeks and 3 months compared with admission were associated with greater likelihood of PPCS. Higher IL-9 delta values at both time-point comparisons were negatively associated with PPCS. Discriminability of individual CNS-injury and inflammation biomarkers for PPCS was around chance level, whereas the optimal combination of biomarkers yielded areas under the curve (AUCs) between 0.62 and 0.73. We demonstrate a role of biological factors on PPCS, including both positive and negative effects of inflammation biomarkers that differed based on sampling time-point after mTBI. PPCS was associated more with acute inflammatory processes, rather than ongoing inflammation or CNS-injury biomarkers. However, the modest discriminative ability of the models suggests other factors are more important in the development of PPCS.

Progesterone Levels in Adolescent Female Athletes May Contribute to Decreased Cognitive Performance During Acute Phase of Sports-Related Concussion

Although many outcome studies pertaining to sports-related concussion exist, female athletes with concussion remain an understudied group. We examined whether neurocognitive performance in adolescent females with sports-related concussion (SRC) is related to menstrual cycle-related hormone levels measured at one-week post-concussion, one-month post-concussion, or both. Thirty-eight female athletes, ages 14-18, were matched into two groups: SRC or healthy control. Self-reported symptom scores were higher among concussed females in the luteal phase, when progesterone levels are highest. Results suggest that progesterone levels may contribute to a heightened experience of symptoms during the acute phase of SRC, providing further evidence of a possible link between progesterone and symptom scores following concussion.

Exercise Intolerance After Mild Traumatic Brain Injury Occurs in All Subtypes in the Adult Population

Thematically grouped symptom clusters are present during the acute timeline of post-mild traumatic brain injuries (mTBI), representing clinical profiles called subtypes. Exercise intolerance has not been evaluated within the subtype classifications and, because guidelines support early submaximal aerobic exercise, further knowledge is required in regard to the exercise capabilities among the concussion subtypes. This cross-sectional study (n = 78) aimed to characterize the presence of exercise intolerance within the clinical subtypes and to explore performance on the Buffalo Concussion Treadmill Test (BCTT) in the adult subacute (2-12 weeks post-injury) mTBI population. All participants were evaluated using the BCTT to determine exercise tolerance. We first used the Neurobehavioral Symptom Inventory (NSI) questionnaire to assign each participant a primary subtype(s). To further explore all five subtypes (headache, cognitive, vestibular, ocular motor, and mood), participants were assessed using a multitude of thematically grouped assessments including self-reported questionnaires, clinical tests of vestibular and ocular motor function, balance function, and computerized cognitive testing. Thirty-seven (47%) subjects were exercise tolerant and 41 (53%) were exercise intolerant. There was no difference in the distribution of primary subtypes between the exercise tolerant and exercise intolerant groups. In addition, no significant differences were found between the exercise tolerant and exercise intolerant groups on other thematically grouped subtype assessments. The exercise intolerant group had a significantly higher resting heart rate (HR), lower percentage of age-predicted maximum HR achieved, lower Borg Rate of Perceived Exertion (RPE), and could walk on the treadmill for less time (lower duration) compared with the exercise tolerant group. The current findings suggest that exercise intolerance is common and pervasive across all five mTBI subtypes. A comprehensive mTBI assessment should include evaluation for exercise intolerance regardless of the primary clustering of symptoms and across patient populations. Therefore, early referral to physical therapists, athletic trainers, or medical clinics that can perform the BCTT may be helpful to initiate appropriate exercise prescriptions for patients with mTBI.

Traumatic brain injury screening and neuropsychological functioning in women who experience intimate partner violence

Objective: The potential for traumatic brain injury (TBI) to occur as the result of intimate partner violence (IPV) has received increased interest in recent years. This study sought to investigate the possible occurrence of TBI in a group of women who survived IPV and to measure the specific profile of cognitive deficits using standardized neuropsychological measures. Method: A comprehensive questionnaire about abuse history; neuropsychological measures of attention, memory and executive functioning; and measures of depression, anxiety and post-traumatic stress disorder were given to women who were IPV survivors, women who were sexual assault (SA) survivors, and a comparison group of women who did not experience IPV or SA. Results: Overall, rates of potential TBI, as measured by the HELPS brain injury screening tool, were high and consistent with previous studies. Consistent with potential TBI, lower scores were demonstrated on measures of memory and executive functioning compared to survivors of SA or those not exposed to violence. Importantly, significant differences on measures of memory and executive functioning remained, after controlling for measures of emotion. Of note, cognitive changes were highest among women who experienced non-fatal strangulation (NFS) compared to IPV survivors who did not. Conclusions: Rates of TBI may be high in women who survive IPV, especially those who survive strangulation. Better screening measures and appropriate interventions are needed as well as larger studies that look at social factors associated with IPV.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Heart Rate Variability in Concussed College Athletes: Follow-Up Study and Biological Sex Differences

Finding reliable biomarkers to assess concussions could play a pivotal role in diagnosis, monitoring, and predicting associated risks. The present study aimed to explore the use of heart rate variability (HRV) in the follow-up of concussions among college athletes and to investigate the relationships between biological sex, symptomatology, and HRV values at baseline and after a concussion. Correlations between measures were also analyzed. A total of 169 (55 females) athletes aged 16 to 22 years old completed baseline testing, and 30 (8 females) concussion cases were followed. Baseline assessment (T1) included psychosocial and psychological questionnaires, symptoms report, and four minutes of HRV recording. In the event of a concussion, athletes underwent re-testing within 72 h (T2) and before returning to play (T3). Baseline findings revealed that girls had higher %VLF while sitting than boys, and a small negligible correlation was identified between %HF and total symptoms score as well as %HF and affective sx. Post-concussion analyses demonstrated a significant effect of time × position × biological sex for %HF, where girls exhibited higher %HF at T3. These findings suggest disruptions in HRV following a concussion and underscore biological sex as an important factor in the analysis of HRV variation in concussion recovery trajectory.

The prevalence of persistent post-traumatic headache in adult civilian traumatic brain injury: a systematic review and meta-analysis on the past 14 years

ABSTRACT

The most recent prevalence estimate of post-traumatic headache (PTH) after traumatic brain injury (TBI) in veterans and civilians dates back to 2008. The prevalence was found to be 57.8%, with surprising higher rates (75.3%) in mild TBI when compared with those with moderate/severe TBI (32.1%). However, the revision of mild TBI diagnostic criteria and an historic peak of TBI in the elderly individuals attributed to the ageing population may lead to different results. Thus, we conducted a systematic review and meta-analysis to assess the updated prevalence of PTH during the past 14 years only in civilians. A literature search was conducted following PRISMA guidelines guided by a librarian. Screening, full-text assessment, data extraction, and risk of bias assessment were performed blindly by 2 raters. Meta-analysis of proportions using the Freeman and Tukey double arcsine method of transformation was conducted. Heterogeneity, sensitivity analysis, and meta-regressions were performed with the predictors: year of publication, mean age, sex, TBI severity, and study design. Sixteen studies were selected for the qualitative analysis and 10 for the meta-analysis. The overall prevalence estimate of PTH was 47.1%, (confidence interval = 34.6, 59.8, prediction intervals = 10.8, 85.4), being similar at different time points (3, 6, 12, and 36+ months). Heterogeneity was high, and none of the meta-regressions were significant. The overall prevalence of PTH after TBI over the past 14 years remains high even if assessed only in civilians. However, the prevalence rates attributed to mild and moderate/severe TBI were similar, differing significantly from previous reports. Efforts are needed to improve TBI outcomes.

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

OBJECTIVE

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

DESIGN

Systematic review.

METHODS

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

RESULTS

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

CONCLUSION

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

PROSPERO REGISTRATION NUMBER

CRD42021258613.

Early vs. delayed evaluation and persisting concussion symptoms during recovery in adults

Objective: Persisting concussion symptoms may adversely affect return to work and functioning in daily activities. This study compared adults who were initially evaluated < 30 days versus those evaluated ≥ 30 days following a concussion at a specialty concussion clinic to determine if delayed initial evaluation is associated with persisting symptoms during recovery. Method: Participants (N = 205) 18 years of age and older who sustained a concussion and presented to a North Texas Concussion Registry (ConTex) clinic were evaluated at two time points: initial clinical visit and three-month follow-up. Participants provided medical history, injury related information, and completed the Sport Concussion Assessment Tool-5 Symptom Evaluation, Generalized Anxiety Disorder 7-item scale (GAD-7), and Patient Health Questionnaire (PHQ-8). Participants were divided into two groups: early and delayed evaluation (±30 days post injury). Results: Number and severity of concussion symptoms were similar between both groups at their initial clinical visit. However, linear regression models showed that a delayed clinical evaluation was associated with a greater number and severity of concussion symptoms along with greater aggravation of symptoms from physical and cognitive activity at three-month follow-up. Conclusions: Individuals who sought care at specialty concussion clinics regardless of previous care 30 or more days following their injury reported more serious persisting concussion symptoms at three month follow-up than those who sought care sooner. Education to improve adults' recognition of concussions when they occur and obtaining earlier clinical evaluation may represent important opportunities in promoting better recovery and reducing persisting concussion symptoms.

The impact of patient sex on survival after unintentional trauma in Korea: a retrospective, observational, case-control study

OBJECTIVE

This study aimed to describe the relationship between sex and survival in patients experiencing unintentional trauma.

METHODS

This retrospective, national population-based observational, case-control study involved a cohort of Korean trauma patients who were transferred to an emergency department by a Korean emergency medical service from January 1 to December 31, 2018. Propensity score matching was used. The primary outcome was survival until hospital discharge.

RESULTS

Of 25,743 patients with severe unintentional trauma, 17,771 were male and 7,972 were female. Prior to propensity score matching, there was no significant difference in survival among male and female patients (92.6% vs. 93.1%, P=0.105). After using propensity score matching to adjust for confounders, there was still no sex difference in survival (male, 93.6% vs. female, 93.1%; P=0.270).

CONCLUSION

Survival after severe trauma was not influenced by the sex of the patient. Further studies with patients of reproductive age and a larger study population are needed to analyze the effects of sex on survival in patients with trauma.

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

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

Premorbid Risk Factors and Acute Injury Characteristics of Sport-Related Concussion Across the National Collegiate Athletic Association: Findings from the Concussion Assessment, Research, and Education (CARE) Consortium

BACKGROUND

Previous sport-related concussion research highlights post-injury characteristics that influence recovery trajectories; however, there is limited information regarding premorbid factors that affect sport-related concussion risk.

OBJECTIVE

We aimed to (a) compare premorbid demographic factors among a large cohort of collegiate student athletes who did or did not sustain a sport-related concussion and (b) assess differences in acute injury characteristics based on biological sex and contact level.

METHODS

We conducted a cohort study of university student athletes from 22 sports enrolled in the Concussion Assessment, Research, and Education (CARE) Consortium study from 2014 to 2021 (n = 1804 student athletes with sport-related concussions; n = 21,702 student athletes without sport-related concussions).

RESULTS

Statistical analyses indicated student athletes who self-identified as Black (odds ratio [OR] = 1.61; 95% confidence interval [CI] = 1.42, 1.81) or multiracial (OR = 1.32; 95% CI 1.10, 1.59) demonstrated greater odds of experiencing sport-related concussions than White-identifying student athletes. Additional findings suggest male athletes (OR = 1.47; 95% CI 1.20, 1.81) and contact sport student athletes (OR = 1.40; 95% CI 1.16, 1.70) may be at increased odds for sport-related concussions if they were previously diagnosed with attention deficit hyperactive disorder. Notable post-injury characteristics across sexes included differences in the incident loss of consciousness (male: 5.9%, female: 2.6%; p < 0.001), post-traumatic amnesia (male: 13.6%, female: 5.1%; p < 0.001), and retrograde amnesia (male: 6.8%, female: 2.8%; p < 0.001). A greater proportion of contact-sport student athletes experienced an altered mental status (52.7%) than limited contact (36.2%) and non-contact (48.6%) [p < 0.001]. Last, student athletes participating at lower contact levels were more likely to have a longer delay in removal from activity following injury (contact: 73.6 ± 322.2 min; limited contact: 139.1 ± 560.0 min; non-contact: 461.4 ± 1870.8 min; p = 0.005).

CONCLUSIONS

The present study provides contemporary pre- and post-sport-related concussion injury characteristics using a considerably sized cohort of collegiate student athletes. These findings support previous work suggesting sport-related concussion results in complex individualized clinical presentations, which may influence management strategies.

Thalamocortical Coherence Predicts Persistent Postconcussive Symptoms

The pathogenetic mechanism of persistent post-concussive symptoms (PCS) following concussion remains unclear. Thalamic damage is known to play a role in PCS prolongation while the evidence and biomarkers that trigger persistent PCS have never been elucidated. We collected longitudinal neuroimaging and behavior data from patients and rodents after concussion, complemented with rodents' histological staining data, to unravel the early biomarkers of persistent PCS. Diffusion tensor imaging (DTI) were acquired to investigated the thalamic damage, while quantitative thalamocortical coherence was derived through resting-state functional MRI for evaluating thalamocortical functioning and predicting long-term behavioral outcome. Patients with prolonged symptoms showed abnormal DTI-derived indices at the boundaries of bilateral thalami (peri-thalamic regions). Both patients and rats with persistent symptoms demonstrated enhanced thalamocortical coherence between different thalamocortical circuits, which disrupted thalamocortical multifunctionality. In rodents, the persistent DTI abnormalities were validated in thalamic reticular nucleus (TRN) through immunohistochemistry, and correlated with enhanced thalamocortical coherence. Strong predictive power of these coherence biomarkers for long-term PCS was also validated using another patient cohort. Postconcussive events may begin with persistent TRN injury, followed by disrupted thalamocortical coherence and prolonged PCS. Functional MRI-based coherence measures can be surrogate biomarkers for early prediction of long-term PCS.

Drosophila melanogaster as a model to study age and sex differences in brain injury and neurodegeneration after mild head trauma

Repetitive physical insults to the head, including those that elicit mild traumatic brain injury (mTBI), are a known risk factor for a variety of neurodegenerative conditions including Alzheimer's disease (AD), Parkinson's disease (PD), and chronic traumatic encephalopathy (CTE). Although most individuals who sustain mTBI typically achieve a seemingly full recovery within a few weeks, a subset experience delayed-onset symptoms later in life. As most mTBI research has focused on the acute phase of injury, there is an incomplete understanding of mechanisms related to the late-life emergence of neurodegeneration after early exposure to mild head trauma. The recent adoption of Drosophila-based brain injury models provides several unique advantages over existing preclinical animal models, including a tractable framework amenable to high-throughput assays and short relative lifespan conducive to lifelong mechanistic investigation. The use of flies also provides an opportunity to investigate important risk factors associated with neurodegenerative conditions, specifically age and sex. In this review, we survey current literature that examines age and sex as contributing factors to head trauma-mediated neurodegeneration in humans and preclinical models, including mammalian and Drosophila models. We discuss similarities and disparities between human and fly in aging, sex differences, and pathophysiology. Finally, we highlight Drosophila as an effective tool for investigating mechanisms underlying head trauma-induced neurodegeneration and for identifying therapeutic targets for treatment and recovery.

The influence of psychological flexibility on persistent post concussion symptoms and functional status after mild traumatic brain injury

PURPOSE

This study investigated the predictive role of psychological flexibility on long-term mTBI outcomes.

METHOD

Adults with mTBI (N = 147) completed a context specific measure of psychological flexibility, (AAQ-ABI), psychological distress, and mTBI outcomes at less than three months post injury (M = 6.02 weeks after injury) and 6 months later (N = 102). Structural equation modelling examined the mediating effects of psychological flexibility on psychological distress and mTBI outcomes at six months. The direct effect of psychological flexibility at less than three months on mTBI outcomes at six months was entered into the model, plus pre-injury and injury risk factors.

RESULTS

The theoretically derived model had good overall fit (χ2 = 1.42; p = 0.09; NFI = 0.95; TLI = 0.95; CFI = 0.98 and RMSEA = 0.06). Psychological flexibility at less than 3 months was directly significantly related to psychological distress and post-concussion symptoms at six months. Psychological flexibility at 6 months significantly mediated the relationship between psychological distress and functional disability but not post-concussion symptoms at six months post injury.

CONCLUSION

The exploratory findings suggest that a context specific measure of psychological flexibility assessed acutely and in the chronic phase of recovery may predict longer-term mTBI outcomes.Implications for RehabilitationPersistent post-concussion symptoms (PPCS) after mild traumatic brain injury (mTBI) can have a significant impact on wellbeing, functional status, and quality of life.In this study, psychological flexibility early in recovery, was associated with higher levels of psychological distress and more severe post-concussion symptoms six months later.Psychological flexibility at six months post-injury also mediated the relationship between psychological distress and functional disability.A context specific measure of psychological flexibility may predict poorer long-term outcomes following mTBI.

GABAA Receptor and Serotonin Transporter Expression Changes Dissociate Following Mild Traumatic Brain Injury: Influence of Sex and Estrus Cycle Phase in Rats

Mild traumatic brain injuries (mild TBIs) can affect both males and females, but females are more likely to report long-term psychological complications, including changes in mood and generalized anxiety. Additionally, reproductive cycle phase has been shown to affect mild TBI symptom expression within females. These variances may result from sex differences in mild TBI-induced alterations to neurotransmission in brain regions that influence mood and emotion, possibly mediated by sex steroids. The hippocampus and amygdala are implicated in stress responses and anxiety, and within these regions, gamma-aminobutyric acid (GABA) and serotonin modulate output and behavioral expression. Metabolites of progesterone can allosterically enhance GABAergic signaling, and sex steroids are suggested to regulate the expression of the serotonin transporter (SERT). To determine how mild TBI might alter GABA receptor and SERT expression in males and females, immunocytochemistry was used to quantify expression of the alpha-1 subunit of the GABA_A receptor (α1-GABA_A), SERT, and a neuronal marker (NeuN) in the brains of adult male and naturally-cycling female rats, both with and without mild TBI, 17 days after injury. Mild TBI altered the expression of α1-GABA_A in the amygdala and hippocampus in both sexes, but the direction of change observed depended on sex and reproductive cycle phase. In contrast, mild TBI had little effect on SERT expression. However, SERT expression differed between sexes and varied with the cycle phase. These findings demonstrate that regulation of neurotransmission following mild TBI differs between males and females, with implications for behavioral outcomes and the efficacy of therapeutic strategies.

Relationship Between Neighborhood Disadvantage and Mild Traumatic Brain Injury Symptoms

OBJECTIVE

To test the hypotheses that (1) higher neighborhood disadvantage is associated with greater injury-related symptom severity in civilians with mild traumatic brain injury (mTBI) and (2) neighborhood disadvantage remains predictive after controlling for other established predictors.

SETTING

Level 1 trauma center and affiliated academic medical center.

PARTICIPANTS

N = 171 individuals with mTBI.

DESIGN

Prospective cohort study.

MAIN MEASURES

Rivermead Post Concussion Symptoms Questionnaire (RPQ) total score assessed less than 24 hours and at 2 weeks, 3 months, and 6 months postinjury. Linear mixed-effects models were used to assess the relationship between predictor variables and mTBI-related symptom burden (RPQ score). Neighborhood disadvantage was quantified by the Area Deprivation Index (ADI), a composite of 17 markers of socioeconomic position (SEP) scored at the census block group level.

RESULTS

Individuals in the upper ADI quartile of the national distribution displayed higher RPQ symptoms than those in the lower 3 quartiles ( P < .001), with a nonsignificant ADI × visit interaction ( P = .903). In a multivariable model, the effect of ADI remained significant ( P = .034) after adjusting for demographics, individual SEP, and injury factors. Other unique predictors in the multivariable model were gender (gender × visit P = .035), health insurance type ( P = .017), and injury-related litigation ( P = .012).

CONCLUSION

Neighborhood disadvantage as quantified by the ADI is robustly associated with greater mTBI-related symptom burden throughout the first 6 months postinjury. That the effect of ADI remained after controlling for demographics, individual SEP, and injury characteristics implies that neighborhood disadvantage is an important, understudied factor contributing to clinical recovery from mTBI.

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

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

Age of first exposure to soccer heading: Associations with cognitive, clinical, and imaging outcomes in the Einstein Soccer Study

Introduction

The objective of this study is to assess the role of age at first exposure (AFE) to soccer heading as a predictor of known adverse associations of recent and longer-term heading with brain microstructure, cognitive, and behavioral features among adult amateur soccer players.

Methods

The sample included 276 active amateur soccer players (196 male and 81 female) aged 18-53 years old. AFE to soccer heading was treated as a binary variable, dichotomized at ≤ 10 years vs. >10 years old, based on a recently promulgated US Soccer policy, which bans heading for athletes ages 10 and under.

Results

We found that soccer players who began heading at age 10 or younger performed better on tests of working memory (p = 0.03) and verbal learning (p = 0.02), while accounting for duration of heading exposure, education, sex, and verbal intelligence. No difference in brain microstructure or behavioral measures was observed between the two exposure groups.

Discussion

The findings indicate that, among adult amateur soccer players, AFE to heading before age 10 compared to later start of heading, is not associated with adverse outcomes, and may be associated with better cognitive performance in young adulthood. Cumulative heading exposure across the lifespan, rather than early life exposure, may drive risk for adverse effects and should be the focus of future longitudinal studies to inform approaches to enhance player safety.

Incidence of concussions and helmet use in equestrians

OBJECTIVES

Equestrians have a high risk of concussions per hospital records. However, most concussions occur in private settings where concussions are not tracked. We determined concussion incidence by self-report, expressed per 1000 h of exposure, and determined helmet usage and concussion knowledge.

DESIGN

Descriptive epidemiological study.

METHODS

Equestrians were recruited using a snowball method of sampling in which enrolled participants recruited more equestrians. Participants completed a survey of equestrian experience and history of concussion, symptoms and provided estimates of hours spent in various equestrian activities. From these data, incidences of concussions were calculated. In addition, they answered questions regarding helmet usage and willingness to take risks when concussed.

RESULTS

210 participants (203 women) reported 27 ± 14 years of equine experience and 728 concussions, 3.47 ± 5.34 per person (0-55). Incidence while riding was 0.19/1000 h which was greater than the incidence while driving (0.02/1000 h) or handling horses (0.03/1000 h). Riders were helmeted at the time of injury 85% of the time. While concussion knowledge was high, most reported willingness to risk permanent injury by continuing to work with horses while injured.

CONCLUSIONS

To our knowledge this is the first study to document incidence of concussions in equestrians: incidence is higher while riding than during football or rugby training. Helmets were far more commonly worn at the time of concussion than reported in hospital data, suggesting that helmets effectively reduce concussions severe enough to warrant urgent medical care.

Reference Values of the Quality of Life after Brain Injury (QOLIBRI) from a General Population Sample in Italy

Traumatic brain injury (TBI) may affect the lives of the individuals concerned and their relatives negatively in many dimensions. Health-related quality of life (HRQoL) is a comprehensive and complex concept that can assess one's satisfaction with a broad range of areas of life and health. The Quality of Life after Traumatic Brain Injury (QOLIBRI) questionnaire is a TBI-specific measure for HRQoL which is used in research and health services worldwide. When evaluating self-reported HRQoL after TBI, reference values from a general population are helpful to perform clinically relevant evaluations and decisions about the condition of an affected person by comparing the patient scores with reference values. Despite the widespread use of the QOLIBRI, reference values have until now only been available for the Netherlands and the United Kingdom. The aim of this study was to validate the QOLIBRI for the general population in Italy and to provide reference values. An adapted form of the QOLIBRI was administered to 3298 Italians from a healthy general population using an online survey. Their scores were compared with those of 298 individuals post-TBI recruited within the international longitudinal observational cohort CENTER-TBI study in Italian hospitals, who completed the original questionnaire. The psychometric characteristics and the measurement invariance of the QOLIBRI were assessed. A regression analysis was performed to identify predictors relevant for HRQoL in the general population. Reference values were provided using percentiles. Measurement invariance analysis showed that the QOLIBRI captures the same HRQoL constructs in an Italian general population and Italian TBI sample from the observational Center-TBI study. Higher age, higher education and the absence of a chronic health condition were associated with higher QOLIBRI scores, suggesting better HRQoL. Reference values were provided for a general Italian population adjusted for age, sex, education and presence of chronic health conditions. We recommend using these for a better interpretation of the QOLIBRI score in clinical practice and research in Italy.

Influence of Sex and Muscarinic Activity on Memory Retrieval in Mouse Model of Traumatic Brain Injury

Traumatic brain injury (TBI) is a serious global risk factor leading to the onset of cognitive impairment and neurodegenerative diseases. Cognitive and memory impairment following a TBI is associated with the dysregulation of cholinergic neurotransmission in the brains of subjects. The extent of memory impairment following a TBI is linked with the sex of the subject. This study aimed to identify the sex-dimorphic role of muscarinic cholinergic modulation in neurological functioning and episodic memory retrieval in a mouse model of TBI. Balb/c mice were divided into four groups of males and four groups of females (i.e., Sham, TBI, TBI + Scopolamine 1 mg/kg, and TBI + Donepezil 1 mg/kg). After training with the Morris water maze test and fear conditioning, all groups were subjected to brain injury (7.84 × 10^-5 J impact force) except for the Sham mice. Following brain injury, scopolamine or donepezil was administered to the respective groups for 5 days. Acute scopolamine immediately after brain trauma showed a neuroprotective effect in the males only, while subchronic donepezil significantly impaired neurological functioning in both sexes. Subchronic scopolamine and donepezil treatment reversed the TBI-induced retrograde amnesia for spatial memory in male mice. Contextual fear memory retrieval was not affected by the TBI and treatments in both sexes. Thus, we concluded that the sex-dimorphic response of the muscarinic receptors in TBI-induced memory impairment depends on the type of memory. This study highlights the potential for therapeutic modalities in TBI subjects.

Female sex is independently associated with reduced inpatient mortality after endovascular repair of blunt thoracic aortic injury

BACKGROUND

Female sex has been associated with decreased mortality after blunt trauma, but whether sex influences the outcomes of thoracic endovascular aortic repair (TEVAR) for traumatic blunt thoracic aortic injury (BTAI) is unknown.

METHODS

In this retrospective study of a prospectively maintained database, the Vascular Quality Initiative registry was queried from 2013 to 2020 for patients undergoing TEVAR for BTAI. Univariate Student's t-tests and χ² tests were performed, followed by multivariate logistic regression for variables associated with inpatient mortality.

RESULTS

Of 806 eligible patients, 211 (26.2%) were female. Female patients were older (47.9 vs 41.8 years, P < .0001) and less likely to smoke (38.3% vs 48.2%, P = .044). Most patients presented with grade III BTAI (54.5% female, 53.6% male), followed by grade IV (19.0% female, 19.5% male). Mean Injury Severity Scores (30.9 + 20.3 female, 30.5 + 18.8 male) and regional Abbreviated Injury Score did not vary by sex. Postoperatively, female patients were less likely to die as inpatients (3.8% vs 7.9%, P = .042) and to be discharged home (41.4% vs 52.2%, P = .008). On multivariate logistic regression, female sex (odds ratio [OR]: 0.05, P = .002) was associated with reduced inpatient mortality. Advanced age (OR: 1.06, P < .001), postoperative transfusion (OR: 1.05, P = .043), increased Injury Severity Score (OR: 1.03, P = .039), postoperative stroke (OR: 9.09, P = .016), postoperative myocardial infarction (OR: 9.9, P = .017), and left subclavian coverage (OR: 2.7, P = .029) were associated with inpatient death.

CONCLUSIONS

Female sex is associated with lower odds of inpatient mortality after TEVAR for BTAI, independent of age, injury severity, BTAI grade, and postoperative complications. Further study of the influence of sex on postdischarge outcomes is needed.

Factors associated with the severity of traumatic brain injury

Introduction

Traumatic brain injury (TBI) is a defect in the brain function resulting from the action of external factors. The condition ranges from transient shifts in cellular ionic concentrations to total structural damage; the clinical symptoms can vary from brief confusion to death. The current classification system, based on the Glasgow Coma Scale (GCS), divides TBI into mild (GCS 14 to 15), moderate (GCS 9 to 13), and severe TBI (GCS 3 to 8). The leading causes of head injury in the population can be falls, motor vehicle collisions, blasts, and bullet injuries. The ultimate survival and neurologic outcome of the head trauma patient depend on the extent of TBI occurring at the time of injury. The aim of the study is to assess the factors associated with brain injury and their effect on its severity.

Method

A cross sectional, retrospective study including 469 adult patients with head injury was carried out in the emergency department of Baghdad teaching hospital between 1 October 2016 - 30 October 2017. Data of all the patients were entered and analyzed using the statistical package for social sciences (SPSS) software for Windows, version 24. The significance of correlation was assessed using a Chi-square test. Level of significance was set at ≤ 0.05. Final findings were presented in tables with an explanatory paragraph for each table using the MS. Office (Word 2013) for Windows.

Results

A total number of 469 patients were enrolled in this study with a mean age of 42.6 ± 13.7 years. The vast majority of the patients were males (383/469), which represented 81.7%. The male to female ratio was 4.45 to 1. The distribution of the patients according to their traumatic brain injury was 241 patients (51.4%) with mild, 99 (21.1%) with moderate and 129 (27.5%) with severe TBI. Associated injuries among the studied group were facial injuries in 133 (28.4%), skull fracture in 150 (32%), and thoracolumbar fracture in 51 (10.9%). The associated injuries were more frequent in the extremities - 112/469 (23.9%), combined injuries in 112 (23.9%), chest and abdomen injuries were reported in only 6% and 6.8%, respectively. The causes of injuries in the studied group were road traffic accidents (RTA), the most frequent mechanism - 37.1% of the cases, followed by fall from height (FFH) (23.9%), blast injury (16.8%), bullet injury (13%), while other mechanisms represented only (9.2%). There is a significant association reported with gender, where severe injuries were more frequent among males than females (P=0.014). All associated injuries were significantly associated with severe traumatic brain injury (P<0.05), also bullet injury was significantly associated with severe traumatic brain injury, followed by blast injury (P<0.001). Severe traumatic brain injury was significantly associated with the presence of clinical and radiographic findings (P<0.001).

Conclusion

The severity of TBI is significantly related to the type of the associated injury, mechanism of injury, clinical and radiological findings, and to the male gender, while it is not dependent on the age of the patient.

Sex predicts post-concussion symptom reporting, independently of fatigue and subjective sleep disturbance, in premorbidly healthy adults after mild traumatic brain injury

The relationship between sex and post-concussion symptom (PCS) reporting after mild traumatic brain injury (mTBI) is not well understood. Subjective sleep disturbance and fatigue impact PCS reporting after mTBI and show sex differences in the normal population. This study investigated whether sex had a relationship with PCS reporting after mTBI, independently of self-reported sleep disturbance and fatigue. Ninety-two premorbidly healthy adults in the post-acute period after mTBI completed the Rivermead Post-Concussion Symptoms Questionnaire, the Pittsburgh Sleep Quality Index, the Multidimensional Fatigue Inventory and measures of depression, anxiety and post-traumatic stress symptomatology. Females (n = 23) demonstrated higher levels of fatigue (p = .019) and greater psychological distress (p = .001) than males (n = 69), but equivalent levels of sleep disturbance (p = .946). Bootstrapping analyses were undertaken because PCS responses were not normally distributed. Female sex predicted greater PCS reporting (p = .001), independently of subjective sleep disturbance, fatigue, psychological distress and litigation status. The current findings support and extend previous work showing premorbidly healthy females are at higher risk of experiencing elevated PCS after mTBI than males in the post-acute period after mTBI. It may be beneficial for clinicians to be particularly sensitive to increased symptom reporting after mTBI in females, irrespective of sleep quality, fatigue or psychological status.

Molecular docking and molecular dynamics simulation study the mechanism of progesterone in the treatment of spinal cord injury

PURPOSE

Spinal cord injury can lead to incomplete or complete loss of voluntary movement and sensory function, leading to serious complications. Numerous studies have shown that progesterone exhibits strong therapeutic potential for spinal cord injury. However, the mechanism by which progesterone treats spinal cord injury remains unclear. Therefore, this article explores the mechanism of progesterone in the treatment of spinal cord injury by means of molecular docking and molecular dynamics simulation.

METHODS

We used bioinformatics to screen active pharmaceutical ingredients and potential targets, and molecular docking and molecular dynamics were used to validate and analysis by the supercomputer platform.

RESULTS

Progesterone had 3606 gene targets, spinal cord injury had 6560 gene targets, the intersection gene targets were 2355. GO and KEGG analysis showed that the abundant pathways involved multiple pathways related to cell metabolism and inflammation. Molecular docking showed that progesterone played a role in treating spinal cord injury by acting on BDNF, AR, NGF and TNF. Molecular dynamics was used to prove and analyzed the binding stability of active ingredients and protein targets, and AR/Progesterone combination has the strongest binding energy.

CONCLUSION

Progesterone promotes recovery from spinal cord injury by promoting axonal regeneration, remyelination, neuronal survival and reducing inflammation.

Enhanced education for adult patients with persistent post-concussion headaches: a randomized controlled trial

Aim & Patients

We conducted a randomized clinical trial to determine if an e-learning intervention can enhance recovery in adult patients with persistent post-concussion headaches (PPCH).

Materials & Methods

The intervention consisted of three e-learning modules administered at baseline, 6 and 12 weeks. Data were collected on symptoms, community integration, quality of life and healthcare utilization at baseline and 12-week follow-up. ANCOVA was conducted to compare changes.

Results

No statistically significant difference was observed on symptoms although we observed a trend toward reduced healthcare utilization and improved quality of life in the intervention group.

Conclusion

E-learning modules for patients experiencing PPCH warrant further investigation with data on participant compliance and measures focusing on simpler short-term outcomes.Clinical Trial Registration: NCT03391583 (ClinicalTrials.gov).

Repetitive soccer heading adversely impacts short-term learning among adult women

OBJECTIVES

To determine the impact of 12-month heading exposure on short-term learning.

DESIGN

A total of 105 active amateur soccer players, 45 women and 60 men, were administered an EMA-based test of working memory, a version of the two-back, once daily for 14 days.

METHODS

Heading exposure of the participants was assessed using "HeadCount", a validated structured questionnaire at the baseline visits. The short-term rate of learning of each individual is quantified by first fitting a quadratic model to the daily performance on the two-back test over a two-week period, then taking the instantaneous rate of the quadratic function at the 7th test. A linear regression model was used to test the association of heading exposure with rates of learning, including age, sex, years of education and history of concussion as covariates, as well as variables describing soccer play and heading within the two-week period. Sensitivity analyses were performed using different methods for quantifying the learning effects and different transformations on 12-month heading exposure.

RESULTS

Greater 12-month heading was associated with lower rates of learning among women (p = 0.008) but not among men (p = 0.74).

CONCLUSIONS

We have identified evidence for an adverse, albeit subclinical, effect of soccer heading on brain function among young adult players, which selectively affects women in our sample.

Neuro-Inflammation Modulation and Post-Traumatic Brain Injury Lesions: From Bench to Bed-Side

Head trauma is the most common cause of disability in young adults. Known as a silent epidemic, it can cause a mosaic of symptoms, whether neurological (sensory-motor deficits), psychiatric (depressive and anxiety symptoms), or somatic (vertigo, tinnitus, phosphenes). Furthermore, cranial trauma (CT) in children presents several particularities in terms of epidemiology, mechanism, and physiopathology-notably linked to the attack of an immature organ. As in adults, head trauma in children can have lifelong repercussions and can cause social and family isolation, difficulties at school, and, later, socio-professional adversity. Improving management of the pre-hospital and rehabilitation course of these patients reduces secondary morbidity and mortality, but often not without long-term disability. One hypothesized contributor to this process is chronic neuroinflammation, which could accompany primary lesions and facilitate their development into tertiary lesions. Neuroinflammation is a complex process involving different actors such as glial cells (astrocytes, microglia, oligodendrocytes), the permeability of the blood-brain barrier, excitotoxicity, production of oxygen derivatives, cytokine release, tissue damage, and neuronal death. Several studies have investigated the effect of various treatments on the neuroinflammatory response in traumatic brain injury in vitro and in animal and human models. The aim of this review is to examine the various anti-inflammatory therapies that have been implemented.

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.

Community reintegration of people with traumatic brain injury in South Africa

BACKGROUND

Traumatic brain injury (TBI) affects cognitive, behavioral and physical function, influencing community reintegration.

OBJECTIVES

To describe the level of community reintegration and the associated influencing factors post-TBI in South Africa.

METHODS

A cross-sectional analysis of patients living with TBI was done, using the Community Integration Questionnaire (CIQ), the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), and the Quality of Life after Brain Injury Overall Score (QOLIBRI-OS).

RESULTS

Of the 80 participants 54.0% presented with mild TBI. The median (IQR) score of the CIQ, WHODAS 2.0 and QOLIBRI-OS was 22 (7.5)/29, 31(18)/100 and 73 (45.5)/100. There was a moderate inverse relationship between the WHODAS 2.0 and CIQ scores (r = -0.68; p < 0.001) and a moderate positive correlation between the QOLIBRI-OS and CIQ scores (r = 0.54; p < 0.001). The WHODAS 2.0 scores also showed a strong inverse correlation with the QOLIBRI-OS scores (r = -0.76; p < 0.001).

CONCLUSION

The participants had high levels of functioning and low levels of disability, both of which were found to be in tandem with high CIQ scores and generally good quality of life. Post-TBI patients are capable of achieving good community integration provided they attain high levels of functioning.

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.

Persistent white matter vulnerability in a mouse model of mild traumatic brain injury

Background

Following one mild traumatic brain injury (mTBI), there is a window of vulnerability during which subsequent mTBIs can cause substantially exacerbated impairments. Currently, there are no known methods to monitor, shorten or mitigate this window.

Methods

To characterize a preclinical model of this window of vulnerability, we first gave male and female mice one or two high-depth or low-depth mTBIs separated by 1, 7, or 14 days. We assessed brain white matter integrity using silver staining within the corpus callosum and optic tracts, as well as behavioural performance on the Y-maze test and visual cliff test.

Results

The injuries resulted in windows of white matter vulnerability longer than 2 weeks but produced no behavioural impairments. Notably, this window duration is substantially longer than those reported in any previous preclinical vulnerability study, despite our injury model likely being milder than the ones used in those studies. We also found that sex and impact depth differentially influenced white matter integrity in different white matter regions.

Conclusions

These results suggest that the experimental window of vulnerability following mTBI may be longer than previously reported. Additionally, this work highlights the value of including white matter damage, sex, and replicable injury models for the study of post-mTBI vulnerability and establishes important groundwork for the investigation of potential vulnerability mechanisms, biomarkers, and therapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12868-022-00730-y.

Pregnancy After Concussion: A Clarion Call for Attention?

OBJECTIVE

Emerging research shows that women who sustain a mild traumatic brain injury, also termed concussion, have a higher risk of menstrual irregularities and sexual dysfunctions. However, no research exists on how these reproductive disruptions affect women's subsequent pregnancies. The objective of this study was to evaluate pregnancy outcomes after concussion in a cohort of reproductive-aged women (aged 18-45 years), 24 months post-injury. We hypothesized that, compared with their extremity-injured peers in the same cohort, women with concussion will have lower incidence of pregnancies.

SETTING

Emergency department of a level 1 trauma center.

PARTICIPANTS

Women of reproductive age (aged 18-45 years) seeking care for concussion or extremity injury.

DESIGN

Longitudinal cohort study that used data collected at 3 distinct time points: t0, baseline: an original cohort of 245 women recruited in January to July 2017 for exposure assessment; t1, 6(+4) weeks post-injury: evaluation of self-reported postinjury menstrual and sexual changes for subgroup analyses-data collected in March to September 2017 ( n = 135); t2, 24 months post-injury: March 2020 chart review for documentation of pregnancies/pregnancy-related events ( N = 245).

MAIN MEASURE

Poisson regression estimates used to model the incidence rate (IR) of pregnancies, comparing concussion with extremity injury.

RESULTS

We reviewed the charts of 254 women from the t0 cohort. After excluding 9 patients who were either deceased or missing relevant data, we had the 245 (96.5%) charts of 102 concussed and 143 extremity-injured study participants. After adjusting for race and obstetric history, women with concussion had 80% lower incidence of pregnancies than their extremity-injured peers (adjusted [adj] IR = 0.20; 95% CI: 0.07-0.59; P = .003). When we excluded women who were using birth control, the IR of pregnancy for women with concussions was 76% lower than for those who had sustained extremity injuries (adj IR = 0.24; 95% CI: 0.07-0.81; P = .02). Pregnancy incidence remained consistently lower for concussed women in additional sensitivity analyses excluding assault/domestic violence victims and those with a prior/new concussion at t0 and t2. Subgroup analyses of the 135 women who had experienced menstrual and/or sexual dysfunctions at t1 showed 84% reduced incidence of pregnancy for women with concussions compared with those who had sustained an extremity injury (adj IR = 0.16; 95% CI: 0.04-0.73; P = .02).

CONCLUSION AND RELEVANCE

Our study potentially serves as a clarion call to understand the long-term reproductive effects of female concussions.

Current Review of Traumatic Optic Neuropathy and Traumatic Brain Injury among Military Service Members

Traumatic optic neuropathy (TON) is a form of optic nerve damage that while rare in the general population, is commonly associated with traumatic brain injury (TBI). With increasingly high rates of TBI in the military community, our service members and veterans represent a population where traumatic optic neuropathy is prevalent. Parachute jumpers have been identified as a high-risk group for under-reported head injury and therefore many cases of TBI are easily overlooked. With recent insights into the limitations of the veteran's disability exam, we review the current understanding of TON and propose an updated protocol for TON evaluation. We also urge for development of safer helmet design to reduce and prevent further cases of TBI, mTBI, and TON in our military personnel.

Corticospinal Excitability and Inhibition Are Not Different between Concussed Males and Females

It has been consistently demonstrated that females report greater numbers of concussions in sex-comparable sports and take longer to recover from concussive symptoms than males. However, it is unknown if the neurophysiological consequences of concussion may contribute to these sex differences in concussion symptoms and recovery. The purpose of this study was to examine potential sex-related differences in neurophysiology in healthy and concussed individuals. Twenty-one (nine F) concussed individuals (20.9 ± 4.1 years; CONC) and twenty-one age-, sex-, height-, weight-, and activity-matched controls (21.2 ± 4.2 years; CONT) participated in the study. The CONC group reported to the lab within 72 h, 1-week, and 2-weeks post-injury and the CONT group followed a similar measurement schedule. Using transcranial magnetic stimulation, motor evoked potential (MEP) amplitude and cortical silent period (CSP) duration were measured from the first dorsal interosseous muscle to assess corticospinal excitability and inhibition, respectively. There were no significant differences across time (p ≥ 0.13) or between the CONC and CONT group in MEP amplitude (p = 0.72) or CSP duration (p = 0.54). Overall, males (119.08 ± 29.91 ms) had significantly longer CSP durations compared with females (101.24 ± 33.43 ms), indicating greater corticospinal inhibition in males, regardless of injury status (p = 0.04). An important and novel finding of this study was the lack of differences in these neurophysiological measures between males and females following concussion. To our knowledge, this is the first study to document greater corticospinal inhibition in males compared with females.

Repeated Mild TBI in Adolescent Rats Reveals Sex Differences in Acute and Chronic Behavioral Deficits

High school students who participate in contact sports are vulnerable to sustaining multiple concussions and exhibit deficits in cognitive function in both the acute and chronic phases and in emotional behavior in the chronic phase. Further, boys are more likely to suffer cognitive problems whereas girls tend to report depression and anxiety. The effects of repetitive mild TBI in adolescent (35-40-day old) male and female Sprague-Dawley rats on object location and spatial working memory (hippocampal-dependent) and object recognition memory (hippocampal-independent) at 1-and-4-weeks post-injury along with trait-dependent anxiety- and depressive-like behaviors at 5 weeks were examined. Compared to sham-injured rats, male brain-injured rats demonstrated significant impairment in both hippocampal-dependent and -independent memory tasks at both time points, whereas female brain-injured rats only exhibited impairment in these tests at the 4-week time point. In contrast, depressive-like behaviors were present in the forced swim test in only the female brain-injured animals at 5 weeks post-injury; anxiety-like behaviors were not evident in either male or female brain-injured animals. Histological analysis at 6 weeks after injury revealed that repeated mild TBI in male and female adolescent rats resulted in increased reactivity of astrocytes and microglia within the corpus callosum below the impact site and in the stratum oriens and stratum pyramidale of the CA2 region of the dorsal hippocampus. Together, these data are indicative of the differences in the temporal pattern of post-traumatic behavioral deficits between male and female animals and that female animals may be more likely to develop deficits in the chronic post-traumatic period.

Use of Novel Concussion Protocol With Infralow Frequency Neuromodulation Demonstrates Significant Treatment Response in Patients With Persistent Postconcussion Symptoms, a Retrospective Study

Introduction

Concussion is a growing public health concern. No uniformly established therapy exists; neurofeedback studies report treatment value. We use infralow frequency neuromodulation (ILF) to remediate disabling neurological symptoms caused by traumatic brain injury (TBI) and noted improved outcomes with a novel concussion protocol. Postconcussion symptoms (PCS) and persistent postconcussion symptoms (PPCS; >3 months post head injury) are designated timelines for protracted neurological complaints following TBI. We performed a retrospective study to explore effectiveness of ILF in PCS/PPCS and investigated the value of using this concussion protocol.

Method

Patients with PCS/PPCS seen for their first neurology office visit or received their first neurofeedback session between 1 August 2018 and 31 January 2021 were entered. Outcomes were compared following treatment as usual (TAU) vs. TAU with ILF neurotherapy (TAU+ILF). The study cohort was limited to PPCS patients; the TAU+ILF group was restricted further to PPCS patients receiving at least 10 neurotherapy sessions. Within the TAU+ILF group, comparisons were made between those who trained at least 10 sessions using concussion protocol (TAU+ILF+CP) and those who trained for at least 10 sessions of ILF regardless of protocol (TAU+ILF-CP).

Results

Among our resultant PPCS cohort (n = 59) leading persistent neurological complaints were headache (67.8%), memory impairment (57.6%), and brain fog (50.8%). PPCS patients in TAU+ILF+CP (n = 25) demonstrated greater net (p = 0.004) and percent (p = 0.026) improvement of symptoms compared to PPCS subjects in TAU (n = 26). PPCS patients in TAU+ILF-CP (n = 8) trended toward significant symptom improvements compared to TAU, and TAU+ILF+CP trended toward greater efficacy than TAU+ILF-CP.

Conclusion

PPCS patients who received TAU+ILF+CP demonstrated significantly greater improvement as a group when compared to TAU. When used as an integrative modality to treatment as usual in managing patients with PPCS, ILF neuromodulation with use of concussion protocol provided significant symptom improvements.

Prediction of Early Mortality Among Children With Moderate or Severe Traumatic Brain Injury Based on a Nomogram Integrating Radiological and Inflammation-Based Biomarkers

Inflammation-based scores have been increasingly used for prognosis prediction in neurological diseases. This study aimed to investigate the predictive value of inflammation-based scores combined with radiological characteristics in children with moderate or severe traumatic brain injury (MS-TBI). A total of 104 pediatric patients with MS-TBI were retrospectively enrolled and randomly divided into training and validation cohorts at a 7:3 ratio. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of prognosis in pediatric patients with MS-TBI. A prognostic nomogram was constructed, and its predictive performance was validated in both the training and validation cohorts. Sex, admission platelet-to-lymphocyte ratio, and basal cistern status from initial CT findings were identified as independent prognostic predictors for children with MS-TBI in multivariate logistic analysis. Based on these findings, a nomogram was then developed and its concordance index values were 0.918 [95% confidence interval (CI): 0.837-0.999] in the training cohort and 0.86 (95% CI: 0.70-1.00) in the validation cohort, which significantly outperformed those of the Rotterdam, Marshall, and Helsinki CT scores. The proposed nomogram, based on routine complete blood count and initial CT scan findings, can contribute to individualized prognosis prediction and clinical decision-making in children with MS-TBI.