Repetitive head-injury exposure and later-in-life cognitive and emotional outcomes among former collegiate football players: a CLEAATS investigation.

This study measured the relationship between head-injury exposure and later-in-life cognitive and emotional symptoms in aging collegiate football players who participated in the College Level Aging Athlete Study. Linear regressions examined the relationship between various head-injury exposure variables (head-injury exposure estimate [HIEE], number of diagnosed concussions, and symptomatic hits to the head) and subjective cognitive function, objective cognitive function, and emotional/mood symptoms. Additional regressions evaluated the impact of emotional symptoms on subjective cognitive decline and objective cognitive function. Participants (n = 216) were 50-87 years old (M = 63.4 [8.5]), 91% White, and well-educated (bachelor's/graduate degree = 92%). HIEE did not predict scores on cognitive or emotional/mood symptom measures (p's > .169). Diagnosed concussions had a small effect on depression symptoms (p = .002, b = 0.501, R2 = .052) and subjective cognitive symptoms (p = .002, b = 0.383, R2 = .051). An emotional symptom index had a stronger relationship (p < .001, b = 0.693, R2 = .362) with subjective cognitive functioning but no significant relationship with objective cognitive function (p = .052, b = -0.211, R2 = .020). Controlling for emotional symptoms, the relationship between concussions and subjective cognitive symptoms was attenuated (p = .078, R2 = .011). Findings suggested that head-injury exposure was not significantly related to cognitive or emotional/mood outcomes in former collegiate football players and highlighted the importance of current emotional/mood symptoms on subjective cognitive function.

A systematic review of pre-injury anxiety disorder and post-concussion outcomes in youth and young adult athletes.

Pre-injury anxiety disorder may be a risk factor for poor outcomes following sportsrelated concussion. A systematic review was performed to characterize the relationship between pre-injury anxiety disorder and post-concussion symptom presentation and recovery time after sports-related concussions among children, adolescents, and young adults. A PRISMA-compliant literature search was conducted in Ovid MEDLINE, PsycINFO, EMBASE, and Scopus for articles published up to 25 January 2024. The initial query yielded 1358 unique articles. Articles that analyzed the relationship between pre-injury anxiety disorder and post-concussion symptoms and recovery time were included. A final cohort of 11 articles was extracted, comprising a total of 8390 study participants, of whom 921 had a history of pre-injury anxiety disorder. Pre-injury anxiety disorder was associated with prolonged time to return to sports activity and an increased incidence of physical, emotional, cognitive, and sleep-related symptoms. While the results of this review suggest an association between pre-injury anxiety disorder and post-concussion symptoms and recovery time, future studies should be more stringent regarding standardized anxiety disorder definitions, longitudinal assessment of post-concussion symptoms, anxiety disorder subtypes, and anxiety treatment history.

Framing racial disparities within sports related concussion (SRC): an ecological framework for understanding biases and disparities in concussion care for black athletes.

Privilege and marginalization associated with racial background have been posited as contributors to why Black athletes face disparities within their care, treatment, and recovery from sport-related concussion (SRC). However, empirical findings have limited exploration on how disparate outcomes have emerged, and the interaction with systems of biases, power and disenfranchisement. To understand concussion care disparities, a qualitative content analysis was conducted in three phases: [I] identifying salient literature on racial differences for Black athletes with SRC (N = 29), [II] qualitative analysis of literature to determine salient topics, themes and patterns within the literature, and [III] constructing a novel ecological-systems framework that encapsulates the 'why' and 'how' related to psychosocial and sociocultural experiences of power, access, and biases for Black athletes. The content analysis yielded two patterns, where concussion care decisions are influenced by (1) biased, unconscious beliefs that posit Black athletes as uniquely invincible to injury and pain, and (2) inadequate access to concussion knowledge and resources, which both moderate SRC injury risk, diagnosis, recovery and outcomes. Ultimately, our novel framework provides a clear thread on how historical, macro-level policy and perceptions can impact micro-level clinical care and decision-making for Black athletes with SRC.

ASA-score is associated with 90-day mortality after complicated mild traumatic brain injury - a retrospective cohort study.

PURPOSE: This study explores the association of the American Society of Anesthesiologists (ASA) score with 90-day mortality in complicated mild traumatic brain injury (mTBI) patients, and in trauma patients without a TBI. METHODS: This retrospective study was conducted using a cohort of trauma patients treated at a level III trauma center in Stockholm, Sweden from January to December 2019. The primary endpoint was 90-day mortality. The population was identified using the Swedish Trauma registry. The Trauma and Injury Severity Score (TRISS) was used to estimate the likelihood of survival. Trauma patients without TBI (NTBI) were used for comparison. Data analysis was conducted using R software, and statistical analysis included univariate and multivariate logistic regression. RESULTS: A total of 244 TBI patients and 579 NTBI patients were included, with a 90-day mortality of 8.2% (n = 20) and 5.4% (n = 21), respectively. Deceased patients in both cohorts were generally older, with greater comorbidities and higher injury severity. Complicated mTBI constituted 97.5% of the TBI group. Age and an ASA score of 3 or higher were independently associated with increased mortality risk in the TBI group, with odds ratios of 1.04 (95% 1.00-1.09) and 3.44 (95% CI 1.10-13.41), respectively. Among NTBI patients, only age remained a significant mortality predictor. TRISS demonstrated limited predictive utility across both cohorts, yet a significant discrepancy was observed between the outcome groups within the NTBI cohort. CONCLUSION: This retrospective cohort study highlights a significant association between ASA score and 90-day mortality in elderly patients with complicated mTBI, something that could not be observed in comparative NTBI cohort. These findings suggest the benefit of incorporating ASA score into prognostic models to enhance the accuracy of outcome prediction models in these populations, though further research is warranted.

Plasma Biomarkers of Traumatic Brain Injury in Adolescents With Sport-Related Concussion.

Importance: Blood-based biomarkers may clarify underlying neuropathology and potentially assist in clinical management of adolescents with sport-related concussion (SRC). Objective: To investigate the association between SRC and plasma biomarkers in adolescents. Design, Setting, and Participants: Prospective cohort study in Canadian sport and clinic settings (Surveillance in High Schools and Community Sport to Reduce Concussions and Their Consequences study; September 2019 to November 2022). Participants were a convenience sample of 849 adolescent (ages 10-18 years) sport participants with blood samples. Data were analyzed from February to September 2023. Exposures: Blood collection and clinical testing preseason (uninjured) and post-SRC follow-ups (ie, ≤72 hours, 1 week, and biweekly until medical clearance to return to play [RTP]). Main Outcomes and Measures: Plasma glial fibrillary acidic protein (GFAP), ubiquitin c-terminal hydrolase-L1 (UCH-L1), neurofilament light (NfL), and total tau (t-tau) were assayed. Group-level comparisons of biomarker levels were conducted between uninjured and post-SRC intervals (postinjury day [PID] 0-3, 4-10, 11-28, and >28) considering age and sex as modifiers. Secondary analyses explored associations between biomarker concentrations and clinical outcomes (Sport Concussion Assessment Tool, Fifth Edition [SCAT5] symptom scores and time to RTP). Results: This study included 1023 plasma specimens from 695 uninjured participants (467 male participants [67.2%]; median [IQR] age, 15.90 [15.13-16.84] years) and 154 participants with concussion (78 male participants [51.0%]; median [IQR] age, 16.12 [15.31-17.11] years). Acute (PID 0-3) differences relative to uninjured levels were found for GFAP (female participants: 17.8% increase; ß = 0.164; 95% CI, 0.064 to 0.263; P = .001; male participants: 17.1% increase; ß = 0.157; 95% CI, 0.086 to 0.229; P < .001), UCH-L1 (female participants: 43.4% increase; ß = 0.361; 95% CI, 0.125 to 0.596; P = .003), NfL (male participants: 19.0% increase; ß = 0.174; 95% CI, 0.087 to 0.261; P < .001), and t-tau (female participants: -22.9%; ß = -0.260; 95% CI, -0.391 to -0.130; P < .001; male participants: -18.4%; ß = -0.203; 95% CI, -0.300 to -0.106; P < .001). Differences were observed for all biomarkers at PID 4 to 10, 11 to 28, and greater than 28 compared with uninjured groups. GFAP, NfL, and t-tau were associated with SCAT5 symptom scores across several PID intervals. Higher GFAP after 28 days post-SRC was associated with earlier clearance to RTP (hazard ratio, 4.78; 95% CI, 1.59 to 14.31; P = .01). Male participants exhibited lower GFAP (-9.7%), but higher UCH-L1 (21.3%) compared with female participants. Age was associated with lower GFAP (-5.4% per year) and t-tau (-5.3% per year). Conclusions and Relevance: In this cohort study of 849 adolescents, plasma biomarkers differed between uninjured participants and those with concussions, supporting their continued use to understand concussion neuropathology. Age and sex are critical considerations as these biomarkers progress toward clinical validation.

Levels of biomarkers associated with subconcussive head hits in mixed martial arts fighters.

Background: Concussion and the damage resulting from this event related to brain function have been widely studied; however, little is known about subconcussive impacts, especially in Mixed Martial Arts (MMA) fighters, which is a combat and full contact sport in which most blows are aimed at the head. Objective: This study aims to evaluate the biomarker levels associated with subconcussive hits to the head in MMA fighters. Methods: This is an exploratory study in which 30 male subjects (10 MMA fighters, 10 healthy individuals who practice muscle training, and 10 healthy sedentary individuals) aged between 18 and 32 years (25.4 ± 3.8) were evaluated. These individuals underwent blood collection to assess their Ubiquitin C-terminal hydrolase (UCH-L1), Glial Fibrillary Acidic Protein (GFAP) and Brain Derived Neurotrophic Factor (BDNF) levels before, immediately after and 72 hours after the sparring session (for the fighters) and were compared between groups. Results: Significant differences were found at baseline between active and healthy fighters in BDNF levels (p = 0.03). A significant reduction of BDNF levels were also observed between the post-immediate and 72h after the sparring session (p = 0.03). No differences were observed in the number or severity of symptoms reported by the fighters. Conclusion: Despite the exploratory approach, the findings of this study may help to understand the influence of repeated subconcussive hits to the head in MMA fighters, as well as to propose preventive interventions which can minimize the effects of the impact of hits, preserving fighters' neuronal integrity and function.

Clinician-Prioritized Measures to Use in a Remote Concussion Assessment: Delphi Study.

BACKGROUND: There is little guidance available, and no uniform assessment battery is used in either in-person or remote evaluations of people who are experiencing persistent physical symptoms post concussion. Selecting the most appropriate measures for both in-person and remote physical assessments is challenging because of the lack of expert consensus and guidance. OBJECTIVE: This study used expert consensus processes to identify clinical measures currently used to assess 5 physical domains affected by concussion (neurological examination, cervical spine, vestibular, oculomotor, or effort) and determine the feasibility of applying the identified measures virtually. METHODS: The Delphi approach was used. In the first round, experienced clinicians were surveyed regarding using measures in concussion assessment. In the second round, clinicians reviewed information regarding the psychometric properties of all measures identified in the first round by at least 15% (9/58) of participants. In the second round, experts rank-ordered the measures from most relevant to least relevant based on their clinical experience and documented psychometric properties. A working group of 4 expert clinicians then determined the feasibility of virtually administering the final set of measures. RESULTS: In total, 59 clinicians completed survey round 1 listing all measures they used to assess the physical domains affected by a concussion. The frequency counts of the 146 different measures identified were determined. Further, 33 clinicians completed the second-round survey and rank-ordered 22 measures that met the 15% cutoff criterion retained from round 1. Measures ranked first were coordination, range of motion, vestibular ocular motor screening, and smooth pursuits. These measures were feasible to administer virtually by the working group members; however, modifications for remote administration were recommended, such as adjusting the measurement method. CONCLUSIONS: Clinicians ranked assessment of coordination (finger-to-nose test and rapid alternating movement test), cervical spine range of motion, vestibular ocular motor screening, and smooth pursuits as the most relevant measures under their respective domains. Based on expert opinion, these clinical measures are considered feasible to administer for concussion physical examinations in the remote context, with modifications; however, the psychometric properties have yet to be explored. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/40446.

Differential neural mechanisms for movement adaptations following neuromuscular training in young female athletes with a history of sports-related concussion.

Sports-related concussion (SRC) in adolescent athletes is associated with an increased risk of subsequent lower extremity injury. Neuromuscular training (NMT) has shown promise for reducing lower extremity injuries following SRC, however, neural adaptations in response to changes in lower extremity biomechanics following NMT in athletes with a history of SRC (HxSRC) remains poorly understood. Therefore, the purpose of this study was to identify changes in neural activity associated with lower extremity movement adaptations following a six-week NMT intervention in athletes with a HxSRC. Thirty-two right-hand/foot-dominant female adolescent athletes (16 with self-reported HxSRC, 16 age- and anthropometrically-matched controls) completed a bilateral leg press task with 3D motion analysis during functional magnetic resonance imaging (fMRI). Movement adaptations were defined as a change in frontal and sagittal plane range of motion (ROM) during the fMRI bilateral leg press task. Significant pre- to post-NMT reductions were observed in the non-dominant (left) mean frontal plane ROM. Whole-brain neural correlate analysis revealed that increased cerebellar activity was significantly associated with reduced mean left-knee frontal ROM for matched controls. Exploratory within group analyses identified neural correlates in the postcentral gyrus for the HxSRC group which was associated with reduced mean left-knee frontal plane ROM. These distinct longitudinal changes provide preliminary evidence of differential neural activity associated with NMT to support knee frontal plane control in athletes with and without a HxSRC.

Subsequent musculoskeletal injury after concussion in National Football League players.

OBJECTIVE: To assess whether National Football League (NFL) players diagnosed with a concussion have an increased risk of injury after return to football. METHODS: A retrospective cohort study analysed the hazard of subsequent time-loss lower extremity (LEX) or any musculoskeletal injury among NFL players diagnosed with a concussion in 2015-2021 preseason or regular season games compared with: (1) all non-concussed players participating in the same game and (2) players with time-loss upper extremity injury. Cox proportional hazards models were adjusted for number of injuries and concussions in the prior year, player tenure and roster position. Additional models accounted for time lost from participation after concussion. RESULTS: There was no statistical difference in the hazards of LEX injury or any musculoskeletal injury among concussed players compared with non-concussed players, though concussed players had a slightly elevated hazard of injury (LEX injury: HR=1.12, 95% CI 0.90 to 1.41; any musculoskeletal injury: HR=1.08, 95% CI: 0.89 to 1.31). When comparing to players with upper extremity injuries, the hazard of injury for concussed players was not statistically different, though HRs suggested a lower injury risk among concussed players (LEX injury: HR=0.78, 95% CI: 0.60 to 1.02; any musculoskeletal injury: HR=0.82, 95% CI: 0.65 to 1.04). CONCLUSION: We found no statistical difference in the risk of subsequent injury among NFL players returning from concussion compared with non-concussed players in the same game or players returning from upper extremity injury. These results suggest deconditioning or other factors associated with lost participation time may explain subsequent injury risk in concussed players observed in some settings after return to play.

Concussions in Soccer.

The identification, management, and prevention of concussion across all competitive sports and athletic populations has been a notable topic of research over the last decade. Soccer is no exception, with over a billion participants worldwide. In soccer, 3 distinct subsets of head injuries are often the contributors to concussion: head-to-equipment, head-to-surface, and head-to-player collisions. Recognition of concussion is crucial, and ideally made on the sideline during competitive play. Recently updated screening tools include the SCAT6 and ChildSCAT6, which are widely utilized at all levels of play. Management of concussion is divided into on-field and in clinic management. Initial management includes removal from the field of play. There is increased emphasis on earlier incorporation of exercise prescription as a means to improve recovery in the concussed athlete. While few objective diagnostic tests exist to identify concussion, many are in development, most notably advanced imaging and biomarker modalities.

Efficacy of Computerized vs. Traditional Cognitive Interventions for the Treatment of Chronic mTBI Symptoms Among Service Members.

INTRODUCTION: Military service members (SMs) with mild traumatic brain injury (mTBI or concussion) frequently report cognitive and behavioral difficulties. Currently, military clinical guidelines recommend clinician-run, manualized cognitive rehabilitation (CR) to treat these symptoms; however, it is unclear whether this approach adequately addresses the unique needs of warfighters. Computerized cognitive training (CCT) programs represent an innovative, promising approach to treating cognitive difficulties; however, whether these programs can effectively remediate cognitive impairment in individuals with mTBI remains unclear. MATERIALS AND METHODS: A total of 65 SMs with a history of at least 1 diagnosed mTBI were recruited from a military hospital. Participants received 1 of 2 interventions: Clinician-run, manualized CR (Study of Cognitive Rehabilitation Effectiveness [SCORE]; n = 37), consisting of 60 total intervention hours over 6 weeks, or CCT (n = 28), in which participants trained with either a commercial CCT (n = 14) or noncommercial CCT (n = 14), for a total of 12 hours over 4 weeks. Participants were assessed pre- and postintervention, using a combination of self-report and objective outcome measures: Key Behaviors Change Inventory (KBCI), a self-report measure of functional difficulties; Paced Auditory Serial Addition Test (PASAT), an objective cognitive assessment that measures both information processing speed and sustained and divided attention; and Symbol Digit Modalities Test (SDMT), an objective cognitive assessment that measures information processing speed. RESULTS: Mixed ANOVA revealed no interaction effect between intervention type and time (pre- and postassessment) on the PASAT (P = .643, ηp2 = 0.003), SDMT (P = .423, ηp2 = 0.010), or KBCI (P = .434, ηp2 = 0.010); however, there was a significant within-group main effect (time) on all 3 outcome measures (PASAT P < .001, ηp2 = 0.54; SDMT P < .001, ηp2 = 0.25; and KBCI P = .001, ηp2 = 0.15). On average, participants showed improvement over baseline on the PASAT (SCORE delta = 6.98, SD = 7.25, P < .001; CCT delta = 7.79, SD = 6.45, P < .001), SDMT (SCORE delta = 4.62, SD = 8.82, P = .003; CCT delta = 6.58, SD = 10.81, P = .003), and KBCI (SCORE delta = -3.22, SD = 7.09, P = .009; CCT delta = -2.00, SD = 4.72, P = .033). Additional analysis comparing the relative effectiveness of the 2 different CCTs revealed that while training with either program resulted in improved performance on the PASAT (P < .001, ηp2 = 0.627), SDMT (P = .003, ηp2 = 0.286), and KBCI (P = .036, ηp2 = 0.158), there was no interaction effect of CCT program type and change over time for any measure (PASAT P = .102, ηp2 = 1.00; SDMT P = .317, ηp2 = 0.038; and KBCI P = .719, ηp2 = 0.005). CONCLUSIONS: We showed that CCT programs do not differ in efficacy compared to clinician-run, manualized CR for treating symptoms associated with mTBI; however, exploratory analyses suggest that each approach may have distinct advantages for treating specific symptoms. Additionally, we showed that the improvement in the CCT intervention did not differ between those who trained using the commercial program vs. those who trained with the noncommercial program.

Comparative Performance of Three Eye-Tracking Devices in Detection of Mild Traumatic Brain Injury in Acute Versus Chronic Subject Populations.

INTRODUCTION: Presently, traumatic brain injury (TBI) triage in field settings relies on symptom-based screening tools such as the updated Military Acute Concussion Evaluation. Objective eye-tracking may provide an alternative means of neurotrauma screening due to sensitivity to neurotrauma brain-health changes. Previously, the US Army Medical Research and Development Command Non-Invasive NeuroAssessment Devices (NINAD) Integrated Product Team identified 3 commercially available eye-tracking devices (SyncThink EYE-SYNC, Oculogica EyeBOX, NeuroKinetics IPAS) as meeting criteria toward being operationally effective in the detection of TBI in service members. We compared these devices to assess their relative performance in the classification of mild traumatic brain injury (mTBI) subjects versus normal healthy controls. MATERIALS AND METHODS: Participants 18 to 45 years of age were assigned to Acute mTBI, Chronic mTBI, or Control group per study criteria. Each completed a TBI assessment protocol with all 3 devices counterbalanced across participants. Acute mTBI participants were tested within 72 hours following injury whereas time since last injury for the Chronic mTBI group ranged from months to years. Discriminant analysis was undertaken to determine device classification performance in separating TBI subjects from controls. Area Under the Curves (AUCs) were calculated and used to compare the accuracy of device performance. Device-related factors including data quality, the need to repeat tests, and technical issues experienced were aggregated for reporting. RESULTS: A total of 63 participants were recruited as Acute mTBI subjects, 34 as Chronic mTBI subjects, and 119 participants without history of TBI as controls. To maximize outcomes, poorer quality data were excluded from analysis using specific criteria where possible. Final analysis utilized 49 (43 male/6 female, mean [x̅] age = 24.3 years, SD [s] = 5.1) Acute mTBI subjects, and 34 (33 male/1 female, x̅ age = 38.8 years, s = 3.9) Chronic mTBI subjects were age- and gender-matched as closely as possible with Control subjects. AUCs obtained with 80% of total dataset ranged from 0.690 to 0.950 for the Acute Group and from 0.753 to 0.811 for the Chronic mTBI group. Validation with the remaining 20% of dataset produced AUCs ranging from 0.600 to 0.750 for Acute mTBI group and 0.490 to 0.571 for the Chronic mTBI group. CONCLUSIONS: Potential eye-tracking detection of mTBI, per training model outcomes, ranged from acceptable to excellent for the Acute mTBI group; however, it was less consistent for the Chronic mTBI group. The self-imposed targeted performance (AUC of 0.850) appears achievable, but further device improvements and research are necessary. Discriminant analysis models differed for the Acute versus Chronic mTBI groups, suggesting performance differences in eye-tracking. Although eye-tracking demonstrated sensitivity in the Chronic group, a more rigorous and/or longitudinal study design is required to evaluate this observation. mTBI injuries were not controlled for this study, potentially reducing eye-tracking assessment sensitivity. Overall, these findings indicate that while eye-tracking remains a viable means of mTBI screening, device-specific variability in data quality, length of testing, and ease of use must be addressed to achieve NINAD objectives and DoD implementation.

Lifetime Psychotropic Medication Use Among Service Members and Veterans With and Without History of Mild Traumatic Brain Injury: A Pilot Study.

INTRODUCTION: Military Service Members, Veterans, and other patient populations who experience traumatic brain injury (TBI) may have increased risk of early neurodegenerative diseases relative to those without TBI history. Some evidence suggests that exposure to psychotropic medications may play a role in this association. The Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) prospective longitudinal study provides an ideal setting to examine the effects of psychotropic medication exposure on long-term neurological health of those with and without mild TBI history. In this study, we sought to develop and pilot test a self-report electronic survey instrument to measure participants' psychotropic medication histories for use across LIMBIC-CENC study sites. MATERIALS AND METHODS: We developed a new survey instrument measuring psychotropic medication history and fielded it among Service Members and Veterans enrolled in a single site of the LIMBIC-CENC study to evaluate response rates and patterns, and to compare survey responses to prescription data extracted from participants' Veterans Affair (VA) records. Descriptive statistics estimated survey respondents' lifetime psychotropic medication exposures by their TBI history and other demographic and clinical characteristics of interest. We also compared survey responses to participants' VA outpatient prescription records to estimate sensitivity and negative predictive values (NPVs) for participants' self-reported medication exposures relative to this single prescription data source. RESULTS: Among 310 Veterans enrolled at the study site, 249 completed the survey (response rate = 80%), of whom 248 also had VA health records and were included in the analysis. Most (69%) had a history of mild TBI. Over three-fourths of survey respondents (78%) reported ever having used prescription opioids, 26% reported benzodiazepines, 50% reported muscle relaxants, 42% reported antidepressants, 13% reported non-benzodiazepine sedative-hypnotics, 15% reported stimulants, 7% reported mood stabilizers, and 6% reported antipsychotics. Veterans with, versus without, a history of mild TBI were more likely to self-report psychotropic medication history as well as have confirmed receipt of VA prescriptions for each medication class. Using VA records as a criterion standard, the sensitivity of the survey for detecting VA prescriptions ranged from 19% to 84%, while the NPVs ranged from 64% to 97%. Sensitivity and NPVs were similar for participants with, versus without, mild TBI history. CONCLUSIONS: Service Members and Veterans may receive psychotropic medications from multiple sources over their lifetimes. Valid methods to examine and quantify these exposures among those with a history of TBI are important, particularly as we evaluate causes of neurodegenerative disorders in this population over time. The measurement of Veterans' lifetime psychotropic medication exposures using a self-report survey, in combination with health care records, holds promise as a valid approach, but further testing and refinement are needed.

Characterization of Mild Traumatic Brain Injury Cohort With Photophobia From the Defense and Veterans Eye Injury and Vision Registry.

INTRODUCTION: Photophobia is a common visual symptom following mild traumatic brain injury (mTBI), which can adversely affect the military readiness and performance of service members (SMs). We employed the Defense and Veterans Eye Injury and Vision Registry (DVEIVR) to identify and describe a cohort of SMs diagnosed with photophobia post-mTBI. The objective of this study was to characterize comorbid conditions and symptoms in an mTBI cohort with photophobia, to assess their co-occurrence, to describe the persistence of photophobia, and to assess the effectiveness of utilization of currently available International Statistical Classification of Diseases and Related Health Problems (ICD) codes in reporting photophobia in this cohort. MATERIALS AND METHODS: The DVEIVR database was searched to identify a cohort of SMs experiencing photophobia after mTBI. Photophobia and other potentially related conditions and symptoms, both coded and descriptive, which were abstracted directly from the medical records of SMs, were found within DVEIVR. The presence of the conditions and symptoms comorbid with photophobia was characterized on both patient and encounter levels. Analysis of co-occurrence of photophobia with these conditions or symptoms was performed on the encounter level using co-occur package in the statistical program R. Persistence of photophobia up to 1 year since the injury was assessed. The utilization of currently available ICD codes for photophobia was analyzed. RESULTS: A total of 639 SMs exhibiting photophobia after mTBI were identified in DVEIVR. Headaches, including migraines, were the most frequently experienced comorbidity affecting 92% of the SMs in the cohort. The second most frequent complaint was dizziness and/or vertigo (53%) followed by nausea (42%), blurry vision (31%), and irritation and discomfort in the eye (17%). In all, 20% of encounters with photophobia had a complaint of headaches, followed by 8.3% of photophobia encounters co-occurring with dizziness and vertigo, 5.7%-with nausea, 4.5%-with blurred vision, and 2.1%-with subjective sensations in the eye. All comorbidities co-occurred with photophobia at probabilities higher than by chance alone. The percentage of mTBI SMs experiencing photophobia declined to 20% at 30 days after the injury, 17% at 3 months, 12% at 6 months, and 7% at 12 months post-injury, respectively. The use of currently available ICD codes for photophobia was very low-only 27.1% of the cohort had at least 1 ICD code recorded in their medical records. CONCLUSIONS: The results of this study support the idea that there is a strong relationship between photophobia and headache after an mTBI. Additional research is warranted to better understand this relationship and its causes so that clinical management improves. The results of this study show a precipitous decline in the numbers of cases of photophobia after mTBI over the first 30 days and a longer-term persistence up to a year in a minority of cases, which is consistent with other research in this field. Various ICD codes, which are currently used to code for photophobia, along with other vision conditions, were not widely used to document photophobia symptoms. It is important to adopt a dedicated ICD code for photophobia to improve the surveillance, data collection, and analysis of this condition.

Neuroimaging and Clinical Findings in Healthy Middle-Aged Adults With Mild Traumatic Brain Injury in the PREVENT Dementia Study.

Importance: Traumatic brain injuries (TBI) represent an important, potentially modifiable risk factor for dementia. Despite frequently observed vascular imaging changes in individuals with TBI, the relationships between TBI-associated changes in brain imaging and clinical outcomes have largely been overlooked in community cases of TBI. Objective: To assess whether TBI are associated with and interact with midlife changes in neuroimaging and clinical features in otherwise healthy individuals. Design, Setting, and Participants: This cross-sectional analysis used baseline data from the PREVENT Dementia program collected across 5 sites in the UK and Ireland between 2014 and 2020. Eligible participants were cognitively healthy midlife adults aged between 40 and 59 years. Data were analyzed between January 2023 and April 2024. Exposure: Lifetime TBI history was assessed using the Brain Injury Screening Questionnaire. Main Outcomes and Measures: Cerebral microbleeds and other markers of cerebral small vessel disease (white matter hyperintensities [WMH], lacunes, perivascular spaces) were assessed on 3T magnetic resonance imaging. Clinical measures were cognition, sleep, depression, gait, and cardiovascular disease (CVD) risk, assessed using Computerized Assessment of Information Processing (COGNITO), Pittsburgh Sleep Quality Index, Center for Epidemiologic Studies Depression Scale, clinical interviews, and the Framingham Risk Score, respectively. Results: Of 617 participants (median [IQR] age, 52 [47-56] years; 380 female [61.6%]), 223 (36.1%) had a history of TBI. TBI was associated with higher microbleed count (ß = 0.10; 95% CI, 0.01-0.18; P = .03), with a dose-response association observed with increasing number of TBI events (ß = 0.05; 95% CI, 0.01-0.09; P = .03). Conversely, TBI was not associated with other measures of small vessel disease, including WMH. Furthermore, TBI moderated microbleed associations with vascular risk factors and clinical outcomes, such that associations were present only in the absence of TBI. Importantly, observations held when analyses were restricted to individuals reporting only mild TBI. Conclusions and Relevance: In this cross-sectional study of healthy middle-aged adults, detectable changes in brain imaging and clinical features were associated with remote, even mild, TBI in the general population. The potential contribution of vascular injury to TBI-related neurodegeneration presents promising avenues to identify potential targets, with findings highlighting the need to reduce TBI through early intervention and prevention in both clinical care and policymaking.

Sub-concussive head impacts from heading footballs do not acutely alter brain excitability as compared to a control group.

BACKGROUND: Repeated sub-concussive head impacts are a growing brain health concern, but their possible biomarkers remain elusive. One impediment is the lack of a randomised controlled human experimental model to study their effects on the human brain. OBJECTIVES: This work had two objectives. The first one was to provide a randomised controlled human experimental model to study the acute effects of head impacts on brain functions. To achieve this, this work's second objective was to investigate if head impacts from heading footballs acutely alter brain excitability by increasing corticospinal inhibition as compared to a control group. METHODS: In practised and unpractised young healthy adults, transcranial magnetic stimulation was used to assess corticospinal silent period (CSP) duration and corticospinal excitability (CSE) before and immediately after performing headings by returning 20 hand-thrown balls directed to the head (Headings; n = 30) or the dominant foot (Control; n = 30). Moreover, the Rivermead Post-Concussion Questionnaire (RPQ) was used to assess the symptoms of head impacts. Head acceleration was also assessed in subgroups of participants. RESULTS: The intervention lengthened CSP duration in both the Headings (6.4 ± 7.5%) and Control groups (4.6 ± 2.6%), with no difference in lengthening between the two groups. Moreover, CSE was not altered by the intervention and did not differ between groups. However, performing headings increased headaches and dizziness symptoms and resulted in greater head acceleration upon each football throw (12.5 ± 1.9g) as compared to the control intervention (5.5 ± 1.3g). CONCLUSIONS: The results suggest that head impacts from football headings do not acutely alter brain excitability as compared to a control intervention. However, the results also suggest that the present protocol can be used as an experimental model to investigate the acute effects of head impacts on the human brain.

Poor sleep and decreased cortical thickness in veterans with mild traumatic brain injury and post-traumatic stress disorder.

BACKGROUND: Poor sleep quality has been associated with changes in brain volume among veterans, particularly those who have experienced mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD). This study sought to investigate (1) whether poor sleep quality is associated with decreased cortical thickness in Iraq and Afghanistan war veterans, and (2) whether these associations differ topographically depending on the presence or absence of mTBI and PTSD. METHODS: A sample of 440 post-9/11 era U.S. veterans enrolled in the Translational Research Center for Traumatic Brain Injury and Stress Disorders study at VA Boston, MA from 2010 to 2022 was included in the study. We examined the relationship between sleep quality, as measured by the Pittsburgh Sleep Quality Index (PSQI), and cortical thickness in veterans with mTBI (n = 57), PTSD (n = 110), comorbid mTBI and PTSD (n = 129), and neither PTSD nor mTBI (n = 144). To determine the topographical relationship between subjective sleep quality and cortical thickness in each diagnostic group, we employed a General Linear Model (GLM) at each vertex on the cortical mantle. The extent of topographical overlap between the resulting statistical maps was assessed using Dice coefficients. RESULTS: There were no significant associations between PSQI and cortical thickness in the group without PTSD or mTBI (n = 144) or in the PTSD-only group (n = 110). In the mTBI-only group (n = 57), lower sleep quality was significantly associated with reduced thickness bilaterally in frontal, cingulate, and precuneus regions, as well as in the right parietal and temporal regions (ß = -0.0137, P < 0.0005). In the comorbid mTBI and PTSD group (n = 129), significant associations were observed bilaterally in frontal, precentral, and precuneus regions, in the left cingulate and the right parietal regions (ß = -0.0094, P < 0.0005). Interaction analysis revealed that there was a stronger relationship between poor sleep quality and decreased cortical thickness in individuals with mTBI (n = 186) compared to those without mTBI (n = 254) specifically in the frontal and cingulate regions (ß = -0.0077, P < 0.0005). CONCLUSIONS: This study demonstrates a significant relationship between poor sleep quality and lower cortical thickness primarily within frontal regions among individuals with both isolated mTBI or comorbid diagnoses of mTBI and PTSD. Thus, if directionality is established in longitudinal and interventional studies, it may be crucial to consider addressing sleep in the treatment of veterans who have sustained mTBI.

Optimizing Concussion Care Seeking: Using Machine Learning to Predict Delayed Concussion Reporting.

BACKGROUND: Early medical attention after concussion may minimize symptom duration and burden; however, many concussions are undiagnosed or have a delay in diagnosis after injury. Many concussion symptoms (eg, headache, dizziness) are not visible, meaning that early identification is often contingent on individuals reporting their injury to medical staff. A fundamental understanding of the types and levels of factors that explain when concussions are reported can help identify promising directions for intervention. PURPOSE: To identify individual and institutional factors that predict immediate (vs delayed) injury reporting. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This study was a secondary analysis of data from the Concussion Assessment, Research and Education (CARE) Consortium study. The sample included 3213 collegiate athletes and military service academy cadets who were diagnosed with a concussion during the study period. Participants were from 27 civilian institutions and 3 military institutions in the United States. Machine learning techniques were used to build models predicting who would report an injury immediately after a concussive event (measured by an athletic trainer denoting the injury as being reported "immediately" or "at a delay"), including both individual athlete/cadet and institutional characteristics. RESULTS: In the sample as a whole, combining individual factors enabled prediction of reporting immediacy, with mean accuracies between 55.8% and 62.6%, depending on classifier type and sample subset; adding institutional factors improved reporting prediction accuracies by 1 to 6 percentage points. At the individual level, injury-related altered mental status and loss of consciousness were most predictive of immediate reporting, which may be the result of observable signs leading to the injury report being externally mediated. At the institutional level, important attributes included athletic department annual revenue and ratio of athletes to athletic trainers. CONCLUSION: Further study is needed on the pathways through which institutional decisions about resource allocation, including decisions about sports medicine staffing, may contribute to reporting immediacy. More broadly, the relatively low accuracy of the machine learning models tested suggests the importance of continued expansion in how reporting is understood and facilitated.

The Influence of Induced Head Acceleration on Lower-Extremity Biomechanics during a Cutting Task.

Sports-related concussions are caused by one substantial impact or several smaller-magnitude impacts to the head or body that lead to an acceleration of the head, causing shaking of the brain. Athletes with a history of sports-related concussion demonstrate lower-extremity biomechanics during landing tasks that are conducive to elevated injury risk. However, the effect of head acceleration on lower-extremity biomechanics during landing tasks is unknown. Twenty participants were evenly separated into a vertical hopping group and a lateral hopping group. Participants performed several land-and-cut maneuvers before and after a hopping intervention. Vertical head acceleration (g) was measured via an accelerometer during the hopping interventions. Comparisons in head acceleration during the hopping tasks were made between groups. Additionally, kinematic and kinetic variables were compared pre- and post-intervention within groups as well as post-intervention between groups. The vertical hopping group demonstrated greater vertical head acceleration compared to the lateral hopping group (p = 0.04). Additionally, the vertical hopping group demonstrated greater knee abduction angles during landing post-intervention compared to the lateral hopping group (p < 0.000). Inducing head acceleration via continuous hopping had an influence on lower-extremity biomechanics during a landing task.