Association of Traumatic Brain Injury With Mortality Among Military Veterans Serving After September 11, 2001

Detecting Mild Traumatic Brain Injury after Combat Deployment: Agreement Between Veterans Health Administration Clinical System and LIMBIC-CENC Research Protocol

Identifying historical mild traumatic brain injury (TBI) is important for many clinical care reasons; however, diagnosing mild TBI is inherently challenging and utility of screening is unknown. This study compares a standardized research process to an established clinical process for screening and diagnosis of historical mild TBI during combat deployment in a military/Veteran cohort. Using validated instruments, the Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) prospective longitudinal study (PLS) screens for all potential concussive events (PCEs) and conducts structured concussion diagnostic interviews for each PCE. The Veterans Health Administration (VHA) systematically screens all Veterans with a post-9/11 combat deployment for historical TBI and offers a comprehensive TBI evaluation (CTBIE) for those who screen positive. This study evaluates the agreement between these two systems on both PCE and mild TBI identification during combat deployment and identifies features of Veterans who were negative clinically but positive in research. VHA TBI screen and CTBIE data were obtained from Veterans Affairs Informatics and Computing Infrastructure and linked to the LIMBIC-CENC PLS dataset. VHA screen positive for PCE was defined as a positive response for the first two VHA TBI screen questions of that query mechanism and immediate signs/symptoms of TBI. The PLS identified more positive PCE screens during combat deployment (86% vs. 41%) than the VHA PCE screen, and overall agreement was poor (kappa = 0.113). Participants had higher odds of being VHA negative/PLS positive on the PCE screen if they were of older age, female sex, had more years of military service, more months in combat deployment, officer rank, or <50% service-connected disability rating and lower odds if they had less education attainment, higher combat intensity, or higher Neurobehavioral Symptom Inventory scores. The LIMBIC-CENC PLS method also identified more Veterans with mild TBI during combat deployment compared with the VHA CTBIE (81% vs. 72%) with minimal overall agreement (kappa = 0.311). Participants had higher odds of being VHA negative/PLS positive for mild TBI diagnosis if they never married or were Air Force and had lower odds if they had higher combat intensity. The LIMBIC-CENC PLS research structured interview protocol identified higher rates of TBI than the VHA TBI assessment system both for positive PCE screens and positive mild TBI diagnosis during combat deployment. Agreement was far higher for TBI determinations compared with the PCE screening. Significant characteristics of PLS-positive/VHA-negative mismatches included demographic variables, military service variables, and current symptom levels. Further research is needed to better understand whether there is a clinical value to adjust the VHA TBI screening process and how these characteristics could be considered. Providers should be aware that some Veterans may have undocumented, positive mild TBI histories even if they underwent screening and/or CTBIE processes.

Traumatic Brain Injury in US Veterans: Prevalence and Associations With Physical, Mental, and Cognitive Health

OBJECTIVE

To examine the prevalence of traumatic brain injury (TBI) in the US veteran population, and physical, mental, and cognitive health conditions associated with TBI.

DESIGN

Retrospective cohort study.

SETTING

A nationally representative sample of US military veterans surveyed in 2019-2020.

PARTICIPANTS

Veterans with probable TBI (n=943; M=58.8 years, SD=16.4; 75.9% non-Hispanic White) and without probable TBI (n=3,033; M=63.3 years, SD=15.3; 78.6% non-Hispanic White) were categorized based on a 2-item modified Veterans Health Administration TBI screen or self-reported health professional diagnoses of concussion/TBI.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

Self-reported health professional-diagnosed physical and cognitive health conditions, disability with basic and instrumental activities of daily living (ADLs), positive screens for posttraumatic stress disorder (PTSD), major depressive disorder, anxiety disorder, alcohol use disorder, or drug use disorder, and current suicidal ideation or prior suicide attempts.

RESULTS

Among the full sample, 24.5% (95% confidence interval: 22.7, 26.3) had probable TBI. In adjusted analyses, probable TBI was independently associated with greater odds of rheumatoid arthritis (odds ratio [OR]=2.06), chronic pain (OR=1.87), kidney disease (OR=1.81), pulmonary disease (OR=1.74), arthritis (OR=1.65), migraine (OR=1.59), sleep disorders (OR=1.57), and osteoporosis or osteopenia (OR=1.51). Veterans with probable TBI also had higher odds of mild cognitive impairment (OR=4.53) and disability with ADLs (OR=2.18) and instrumental ADLs (OR=1.98), although ADL disability was explained by other physical health conditions. Probable TBI was associated with higher odds of probable current anxiety disorder (OR=2.82), major depressive disorder (OR=2.17), suicidal ideation (OR=1.78), PTSD (OR=1.72), drug use disorder (OR=1.54), and alcohol use disorder (OR=1.47).

CONCLUSIONS

Nearly 1-in-4 US veterans screen positive for probable TBI, which was associated with several physical and mental health conditions that adversely affect health and functioning. Results underscore the importance of multidisciplinary interventions that concurrently target the unique physical, mental, cognitive, and functional health needs of this population.

APOE4 and age affect the brain entorhinal cortex structure and blood arachidonic acid and docosahexaenoic acid levels after mild TBI

A reduction in the thickness and volume of the brain entorhinal cortex (EC), together with changes in blood arachidonic acid (AA) and docosahexaenoic acid (DHA), are associated with Alzheimer's disease (AD) among apolipoprotein E ε4 carriers. Magnetic Resonance Imaging (n = 631) and plasma lipidomics (n = 181) were performed using the LIMBIC/CENC cohort to examine the influence of ε4 on AA- and DHA-lipids and EC thickness and volume in relation to mild traumatic brain injury (mTBI). Results showed that left EC thickness was higher among ε4 carriers with mTBI. Repeated mTBI (r-mTBI) was associated with reduced right EC thickness after controlling for ε4, age and sex. Age, plus mTBI chronicity were linked to increased EC White Matter Volume (WMV). After controlling for age and sex, the advancing age of ε4 carriers with blast mTBI was associated with reduced right EC Grey Matter Volume (GMV) and thickness. Among ε4 carriers, plasma tau and Aβ40 were associated with mTBI and blast mTBI, respectively. Chronic mTBI, ε4 and AA to DHA ratios in phosphatidylcholine, ethanolamides, and phosphatidylethanolamine were associated with decreased left EC GMV and WMV. Further research is needed to explore these as biomarkers for detecting AD pathology following mTBI.

Emergency department visits at Veterans Health Administration hospitals related to alcohol intoxication: A ten-year retrospective

We sought to quantify and describe the volume of emergency department visits related to alcohol intoxication at the Veterans Health Administration (VHA), the largest healthcare system in the United States. This is a retrospective cohort study of patients with VHA emergency department visits for alcohol intoxication from 2010 to 2019 as identified via ICD-9/10 code and/or serum ethanol concentration >50 mg/dL. Encounters were identified and demographic and clinical data were acquired by automated query of the VHA Corporate Data Warehouse. Descriptive statistics and univariate analysis were performed. We identified 95,123 patients with a total of 251,310 emergency department visits. The annual number of visits increased over the study period, reaching 32,333 in 2019. Men aged 40-60 were the most common demographic group in the cohort (48% of all patients), and men made up a higher proportion of patients in the database (94%) than the VHA population overall (90%). A disproportionate number of visits (32%) came from the top 4.4% of most frequent visitors. Most of the emergency department visits in the database (68%) were associated with medical or psychiatric admission, or interfacility transfer for admission elsewhere. Patients in the cohort accounted for 1.3% of all VHA emergency department visits during the study period, a proportion that is somewhat smaller than what has been reported at non-VHA facilities, despite the high prevalence of addiction disorders in the VHA patient population. We submit that this lower-than-expected proportion of alcohol-related emergency department visits may be due to the access to primary and mental care which is afforded by VHA patient benefits.

Cognitive symptoms in veterans with migraine or traumatic brain injury: A Million Veteran Program study

OBJECTIVE

To examine the spectrum and severity of cognitive symptoms in veterans with migraine, traumatic brain injury (TBI), or both; and to evaluate the extent to which psychiatric conditions contribute to the relationship of migraine and TBI with cognitive symptoms.

BACKGROUND

Migraine contributes significantly to global disability, with veterans facing additional burdens due to high comorbidity of TBI and psychiatric conditions. Understanding the intersection of these conditions is crucial for improving veterans' health-care outcomes.

METHODS

This observational study used self-reported data from 338,217 veterans enrolled in the Million Veteran Program (MVP) to assess cognitive symptoms using the Medical Outcomes Study Cognitive Functioning Scale Revised (MOS-Cog-R) and psychiatric conditions in veterans with migraine only, TBI only, both, or neither.

RESULTS

Of the participants, 30,080/338,217 (8.9%) veterans reported migraine, 31,906/338,217 (9.4%) reported TBI, and 7828/338,217 (2.3%) reported both migraine and TBI. Veterans with only migraine or only TBI reported similar levels of cognitive symptoms (M = 74.19, standard deviation [SD] = 25.18; M = 73.87, SD = 24.98, respectively), which were substantially higher than veterans without these conditions (M = 62.52, SD = 27.90). Veterans with both conditions reported the most cognitive symptoms (M = 83.01, SD = 22.13) and psychiatric conditions (depression = 5041/7828 [64.4%], anxiety = 3735/7828 [47.7%], post-traumatic stress disorder = 4243/7828 [54.2%]). The association of migraine and TBI with cognitive symptoms persisted beyond the influence of psychiatric conditions (B = -2.20, standard error = -0.36, p < 0.001).

CONCLUSION

Veterans with migraine reported cognitive challenges analogous to veterans with TBI, indicating a need for careful attention to cognitive symptoms in veterans with migraine. Further, the associations of migraine and TBI with cognitive symptoms in veterans were not explained by psychiatric conditions. These findings encourage future research to elucidate the association between self-reported and objective cognitive symptoms and to identify factors, including environmental exposure and genetic influences, contributing to cognitive impairment to optimize the assessment and treatment of veterans with migraine.

Mortality Among Veterans Following Traumatic Brain Injury: A Veterans Administration Traumatic Brain Injury Model System Study

Few studies have examined long-term mortality following traumatic brain injury (TBI) in a military population. This is a secondary analysis of a prospective, longitudinal study that examines long-term mortality (up to 10 years) post-TBI, including analyses of life expectancy, causes of death, and risk factors for death in service members and veterans (SM/V) who survived the acute TBI and inpatient rehabilitation. Among 922 participants in the study, the mortality rate was 8.3% following discharge from inpatient rehabilitation. The mean age of death was 54.5 years, with death occurring on average 3.2 years after injury, and with an average 7-year life expectancy reduction. SM/V with TBI were nearly four times more likely to die compared with the U.S. general population. Leading causes of death were external causes of injury, circulatory disease, and respiratory disorders. Also notable were deaths due to late effects of TBI itself and suicide. Falls were a significant mechanism of injury for those who died. Those who died were also more likely to be older at injury, unemployed, non-active duty status, not currently married, and had longer post-traumatic amnesia, longer rehabilitation stays, worse independence and disability scores at rehabilitation discharge, and a history of mental health issues before injury. These findings indicate that higher disability and less social supportive infrastructure are associated with higher mortality. Our investigation into the vulnerabilities underlying premature mortality and into the major causes of death may help target future prevention, surveillance, and monitoring interventions.

Mortality among veterans with epilepsy: Temporal significance of traumatic brain injury exposure

OBJECTIVE

Epilepsy is associated with significant mortality risk. There is limited research examining how traumatic brain injury (TBI) timing affects mortality in relation to the onset of epilepsy. We aimed to assess the temporal relationship between epilepsy and TBI regarding mortality in a cohort of post-9/11 veterans.

METHODS

This retrospective cohort study included veterans who received health care in the Defense Health Agency and the Veterans Health Administration between 2000 and 2019. For those diagnosed with epilepsy, the index date was the date of first antiseizure medication or first seizure; we simulated the index date for those without epilepsy. We created the study groups by the index date and first documented TBI: (1) controls (no TBI, no epilepsy), (2) TBI only, (3) epilepsy only, (4) TBI before epilepsy, (5) TBI within 6 months after epilepsy, and (6) TBI >6 months after epilepsy. Kaplan-Meier estimates of all-cause mortality were calculated, and log-rank tests were used to compare unadjusted cumulative mortality rates among groups compared to controls. Cox proportional hazard models were used to compute hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

Among 938 890 veterans, 27 436 (2.92%) met epilepsy criteria, and 264 890 (28.22%) had a TBI diagnosis. Mortality was higher for veterans with epilepsy than controls (6.26% vs. 1.12%; p < .01). Veterans with TBI diagnosed ≤6 months after epilepsy had the highest mortality hazard (HR = 5.02, 95% CI = 4.21-5.99) compared to controls, followed by those with TBI before epilepsy (HR = 4.25, 95% CI = 3.89-4.58), epilepsy only (HR = 4.00, 95% CI = 3.67-4.36), and TBI >6 months after epilepsy (HR = 2.49, 95% CI = 2.17-2.85). These differences were significant across groups.

SIGNIFICANCE

TBI timing relative to epilepsy affects time to mortality; TBI within 6 months after epilepsy or before epilepsy diagnosis was associated with earlier time to death compared to those with epilepsy only or TBI >6 months after epilepsy.

Innovative outpatient treatment for veterans and service members and their family members

In 2009, Massachusetts General Hospital and the Red Sox Foundation launched Home Base, a nonprofit dedicated to providing care to veterans, service members, and their loved ones who struggle with the invisible wounds of war free of charge. Significant needs exist for mental health services in each of these populations, and a need for innovative approaches to address shortcomings in existing treatment models. Three inventive components of our programming are highlighted herein: a Veteran Outreach Team, which helps to engage patients in care, programming, and services specifically for family members, and an intensive outpatient substance use treatment program. More than 4,000 patients, 3,031 veterans and service members, and 1,025 family members have engaged in treatment at Home Base. Patients were asked to complete post-treatment self-measures, including a satisfaction questionnaire via an electronic data collection system. The vast majority of individuals who engaged in our treatment model were satisfied with the care they received (>92%) and would refer their peers to the Home Base program (>75%). Data from 78 individuals who completed the dual diagnosis services demonstrated large effect sizes in reductions in alcohol use and comorbid mental health symptoms. These data suggest that novel components to the standard outpatient mental health model might provide substantive benefits for the patients served. While internal data is prone to a lack of generalizability, these additional offerings help ameliorate patients' expressed shortcomings with existing models; present literature that describes the benefits that these additions provide is also reviewed. The lessons learned and limitations are discussed.

Suicide Attempts and Ideation Among Veterans/Service Members and Non-Veterans Over 5 Years Following Traumatic Brain Injury: A Combined NIDILRR and VA TBI Model Systems Study

OBJECTIVE

This study compared rates of suicide attempt (SA) and suicidal ideation (SI) during the first 5 years after traumatic brain injury (TBI) among veterans and service members (V/SMs) in the Veterans Affairs (VA) and the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) Model Systems National Databases to each other and to non-veterans (non-Vs) in the NIDILRR database.

SETTING

Twenty-one NIDILRR and 5 VA TBI Model Systems (TBIMS) inpatient rehabilitation facilities in the United States.

PARTICIPANTS

Participants with TBI were discharged from rehabilitation alive, had a known military status recorded (either non-V or history of military service), and successful 1-, 2-, and/or 5-year follow-up interviews completed between 2009 and 2021. The year 1 cohort included 8737 unique participants (8347 with SA data and 3987 with SI data); the year 2 (7628 participants) and year 5 (4837 participants) cohorts both had similar demographic characteristics to the year 1 cohort.

DESIGN

Longitudinal design with data collected across TBIMS centers at 1, 2, and 5 years post-injury.

MAIN OUTCOMES AND MEASURES

History of SA in past year and SI in past 2 weeks assessed by the Patient Health Questionnaire-9 (PHQ-9). Patient demographics, injury characteristics, and rehabilitation outcomes were also assessed.

RESULTS

Full sample rates of SA were 1.9%, 1.5%, and 1.6%, and rates of SI were 9.6%, 10.1%, and 8.7% (respectively at years 1, 2, and 5). There were significant differences among groups based on demographic, injury-related, mental/behavioral health, and functional outcome variables. Characteristics predicting SA/SI related to mental health history, substance use, younger age, lower functional independence, and greater levels of disability.

CONCLUSIONS

Compared with participants with TBI in the NIDILRR system, higher rates of SI among V/SMs with TBI in the VA system appear associated with risk factors observed within this group, including mental/behavioral health characteristics and overall levels of disability.

Risk of Adverse Outcomes Among Veterans Who Screen Positive for Traumatic Brain Injury in the Veterans Health Administration But Do Not Complete a Comprehensive Evaluation: A LIMBIC-CENC Study

OBJECTIVE

To examine whether post-9/11 veterans who screened positive for mild traumatic brain injury (mTBI) but did not complete a Comprehensive TBI Evaluation (CTBIE) were at higher risk of subsequent adverse events compared with veterans who screened positive and completed a CTBIE. Upon CTBIE completion, information assessed by a trained TBI clinician indicates whether there is mTBI history (mTBI+) or not (mTBI-).

SETTING

Veterans Health Administration (VHA) outpatient services.

PARTICIPANTS

A total of 52 700 post-9/11 veterans who screened positive for TBI were included. The follow-up review period was between fiscal years 2008 and 2019. The 3 groups studied based on CTBIE completion and mTBI status were: (1) mTBI+ (48.6%), (2) mTBI- (17.8%), and (3) no CTBIE (33.7%).

DESIGN

This was a retrospective cohort study. Log binomial and Poisson regression models adjusting for demographic, military, pre-TBI screening health, and VHA covariates examined risk ratios of incident outcomes based on CTBIE completion and mTBI status.

MAIN MEASURES

Incident substance use disorders (SUDs), alcohol use disorder (AUD), opioid use disorder (OUD), overdose, and homelessness documented in VHA administrative records, and mortality as documented in the National Death Index, 3 years post-TBI screen. VHA outpatient utilization was also examined.

RESULTS

Compared with the no CTBIE group, the mTBI+ group had 1.28 to 1.31 times the risk of incident SUD, AUD, and overdose, but 0.73 times the risk of death 3 years following TBI screening. The mTBI- group had 0.70 times the risk of OUD compared with the no CTBIE group within the same period. The no CTBIE group also had the lowest VHA utilization.

CONCLUSIONS

There were mixed findings on risk of adverse events for the no CTBIE group relative to the mTBI+ and mTBI- groups. Future research is needed to explore the observed differences, including health conditions and healthcare utilization, documented outside VHA among veterans who screen positive for TBI.

Comparison of Racial and Ethnic Mortality Disparities among Post-9/11 Veterans with and without Traumatic Brain Injury to the Total U.S. Adult Population

INTRODUCTION

The extent of racial/ethnic disparities and whether they are attenuated in the Veteran population compared to the total US population is not well understood. We aimed to assess racial/ethnic mortality disparities from all-cause, cardiovascular (CVD) and cancer among post-9/11 military Veterans with and without exposure to TBI, compared to the total US population.

METHODS

This cohort study included 2,502,101 US military Veterans (18,932,083 person-years) who served after 09/11/2001 with 3 or more years of care in the Military Health System (MHS); or had 3 or more years of care in the MHS and 2 or more years of care in the Veterans Health Administration. Mortality follow-up occurred from 01/01/2002 to 12/31/2020. Mortality rate ratios (MRR) from negative binomial regression models were reported for racial/ethnic groups compared to White non-Hispanic Veterans for all-cause, CVD and cancer mortality. Veteran MRR were compared to the total US population.

RESULTS

Mortality rates for Black Non-Hispanic Veterans were higher for all-cause (MRR = 1.21;95%CI: 1.13-1.29; p < 0.001), CVD (MRR = 1.78;95%CI: 1.62-1.96; p < 0.001) and cancer (MRR = 1.17;95%CI: 1.10-1.25; p < 0.001) than in White Non-Hispanic Veterans. Among Veterans with TBI, only Black Non-Hispanics had higher mortality than White Non-Hispanics and only for CVD (MRR = 1.32;95%CI: 1.12-1.54; p < 0.001), while CVD mortality was higher among Veterans without TBI (MRR = 1.77;95%CI: 1.63-1.93;p < 0.001). MRR for Black Non-Hispanics in the total US population, were consistently higher than those in the Veteran population for all-cause (MRR = 1.52;95%CI: 1.46-1.58; p < 0.001), CVD (MRR = 2.03;95%CI: 1.95-2.13; p < 0.001) and cancer (MRR = 1.26;95%CI: 1.22-1.30; p < 0.001).

CONCLUSION

This Veteran cohort experienced less racial/ethnic disparity in mortality than the total US population, especially among Veterans with TBI.

Divergent trends in accidental deaths since return from an Afghanistan/Iraq deployment among army soldiers

PURPOSE

Accidental death is a leading cause of mortality among military members and Veterans; however, knowledge is limited regarding time-dependent risk following deployment and if there are differences by type of accidental death.

METHODS

Longitudinal cohort study (N = 860,930) of soldiers returning from Afghanistan/Iraq deployments in fiscal years 2008-2014. Accidental deaths (i.e., motor vehicle accidents [MVA], accidental overdose, other accidental deaths), were identified through 2018. Crude and age-adjusted mortality rates, rate ratios, time-dependent hazard rates and trends postdeployment were compared across demographic and military characteristics.

RESULTS

During the postdeployment observation period, over one-third of deaths were accidental; most were MVA (46.0 %) or overdoses (37.9 %). Across accidental mortality categories (all, MVA, overdose), younger soldiers (18-24, 25-29) were at higher risk compared to older soldiers (40+), and females at lower risk than males. MVA death rates were highest immediately postdeployment, with a significant decreasing hazard rate over time (annual percent change [APC]: -6.5 %). Conversely, accidental overdose death rates were lowest immediately following deployment, with a significant increasing hazard rate over time (APC: 9.9 %).

CONCLUSIONS

Observed divergent trends in risk for the most common types of accidental deaths provide essential information to inform prevention and intervention planning for the immediate postdeployment transition and long-term.

Role of Deployment History on the Association Between Epilepsy and Traumatic Brain Injury in Post-9/11 Era US Veterans

BACKGROUND AND OBJECTIVES

Traumatic brain injury (TBI) is a well-established epilepsy risk factor and is common among service members. Deployment-related TBI, where combat/blast may be more common, may have different outcomes than nondeployment-related TBI. This work examined associations of all TBI exposures (not just combat), and epilepsy, while adjusting for comorbidities associated with epilepsy, among veterans by deployment status.

METHODS

The cohort included post-9/11 veterans with ≥2 years of care in both Veterans Health Administration and Defense Health Agency systems. We identified epilepsy using ICD-9/10-CM codes, antiseizure medication, and service-connected disability for epilepsy. We conducted a logistic regression model with interaction terms for conditions by deployment history that adjusted for demographics and military characteristics.

RESULTS

The cohort (n = 938,890) included post-9/11 veterans of whom 27,436 (2.92%) had epilepsy. Most veterans had a history of deployment (70.64%), referred to as "deployed." Epilepsy was more common among veterans who were never deployed ("nondeployed") (3.85% vs 2.54%). Deployed veterans were more likely to have had TBI, compared with the nondeployed veterans (33.94% vs 14.24%), but nondeployed veterans with moderate/severe TBI had higher odds of epilepsy compared with deployed veterans (adjusted odds ratio [aOR] 2.92, 95% CI 2.68-3.17 vs aOR 2.01, 95% CI 1.91-2.11). Penetrating TBI had higher odds of epilepsy among the deployed veterans (aOR 5.33, 95% CI 4.89-5.81), whereas the odds of epilepsy for mild TBI did not significantly differ by deployment status. Although most neurologic conditions were more prevalent among the nondeployed veterans, they were often associated with higher odds of epilepsy in the deployed veterans.

DISCUSSION

Deployment history had a significant differential impact on epilepsy predictors. As expected, penetrating TBI had a greater epilepsy impact among deployed veterans perhaps due to combat/blast. Some epilepsy predictors (moderate/severe TBI, multiple sclerosis, and Parkinson disease) had a stronger association in the nondeployed veterans suggesting a potential healthy warrior effect in which such conditions preclude deployment. Other neurologic conditions (e.g., brain tumor, Alzheimer disease/frontotemporal dementia) had a greater epilepsy impact in the deployed veterans. This may be attributable to deployment-related exposures (combat injury, occupational exposures). A better understanding of deployment effects is critical to provide targeted epilepsy prevention in veterans and military service members.

All-cause and cause-specific mortality rates after severe extremity injuries among previously deployed active duty service members

BACKGROUND

Previous research has shown that active duty military personnel who sustain extremity injuries while in service are at elevated risk for serious physical and psychological health issues that could affect their long-term functioning and quality of life yet longer-term mortality has not been studied in this population.

OBJECTIVE

To determine whether rates of all-cause and cause-specific mortality are elevated for active duty U.S. service members who sustained traumatic limb injuries in service, compared to the broader population of deploying service members. To assess differences in mortality rates between service members with traumatic limb injuries that did versus did not result in amputation.

DESIGN

Retrospective cohort study; archival Department of Defense deployment, personnel, medical, and death records were combined and analyzed. Standardized mortality ratios (SMR) adjusted for age, sex, and ethnoracial group, along with associated 95% confidence intervals (CIs), were calculated to directly compare all-cause and cause-specific mortality rates in each of the two injury groups to rates in the total study population.

SETTING

Not applicable.

PARTICIPANTS

Service members who deployed in support of the global war on terror between 2001 and 2016 were eligible for inclusion; the final sample included 1,875,206 individuals surveilled through 2019.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

All-cause and cause-specific mortality rates.

RESULTS

Overall, the number of deaths was over three times higher than expected among service members with amputations (SMR = 3.01; CI: 2.36-3.65), and nearly two times higher among those with serious limb injuries not resulting in amputation (SMR = 1.72; CI: 1.54-1.90) when compared to the larger study population. Rates for both internal and external causes of death were significantly elevated among those with limb injuries.

CONCLUSIONS

Long-term mortality rates are elevated among service members with traumatic limb injuries, though mortality patterns may differ based on whether the injury results in amputation. Although further research into causal mechanisms is needed, these results may inform the development of interventions to improve long-term health outcomes among injured military personnel.

Trends in Suicide Rates Among Post-9/11 US Military Veterans With and Without Traumatic Brain Injury From 2006-2020

This cohort study examines trends in suicide rates for veterans with and without traumatic brain injury compared with the US adult population.

Long-term risk of cardiovascular disease after traumatic brain injury: screening and prevention

Traumatic brain injury (TBI) is highly prevalent among individuals participating in contact sports, military personnel, and in the general population. Although it is well known that brain injury can cause neurological and psychiatric complications, evidence from studies on individuals exposed to a single or repetitive brain injuries suggests an understudied association between TBI and the risk of developing chronic cardiovascular diseases and risk factors for cardiovascular disease. Several studies have shown that people without pre-existing comorbidities who sustain a TBI have a significantly higher risk of developing chronic cardiovascular disease, than people without TBI. Similar observations made in military and professional American-style football cohorts suggest causal pathways through which modifiable cardiovascular risk factors might mediate the relationship between brain injury and chronic neurological diseases. A better understanding of cardiovascular disease risk after TBI combined with a proactive, targeted screening programme might mitigate long-term morbidity and mortality in individuals with TBI, and improve their quality of life.

Levels of Arachidonic Acid-Derived Oxylipins and Anandamide Are Elevated Among Military APOE ɛ4 Carriers With a History of Mild Traumatic Brain Injury and Post-Traumatic Stress Disorder Symptoms

Currently approved blood biomarkers detect intracranial lesions in adult patients with mild to moderate traumatic brain injury (TBI) acutely post-injury. However, blood biomarkers are still needed to help with a differential diagnosis of mild TBI (mTBI) and post-traumatic stress disorder (PTSD) at chronic post-injury time points. Owing to the association between phospholipid (PL) dysfunction and chronic consequences of TBI, we hypothesized that examining bioactive PL metabolites (oxylipins and ethanolamides) would help identify long-term lipid changes associated with mTBI and PTSD. Lipid extracts of plasma from active-duty soldiers deployed to the Iraq/Afghanistan wars (control = 52, mTBI = 21, PTSD = 34, and TBI + PTSD = 13) were subjected to liquid chromatography/mass spectrometry analysis to examine oxylipins and ethanolamides. Linear regression analyses followed by post hoc comparisons were performed to assess the association of these lipids with diagnostic classifications. Significant differences were found in oxylipins derived from arachidonic acid (AA) between controls and mTBI, PTSD, and mTBI + PTSD groups. Levels of AA-derived oxylipins through the cytochrome P450 pathways and anandamide were significantly elevated among mTBI + PTSD patients who were carriers of the apolipoprotein E E4 allele. These studies demonstrate that AA-derived oxylipins and anandamide may be unique blood biomarkers of PTSD and mTBI + PTSD. Further, these AA metabolites may be indicative of an underlying inflammatory process that warrants further investigation. Future validation studies in larger cohorts are required to determine a potential application of this approach in providing a differential diagnosis of mTBI and PTSD in a clinical setting.

Hypopituitarism After Mild Traumatic Brain Injury: A Case Report

Hypopituitarism is characterized by an underactive pituitary gland and may result in growth hormone deficiency, hypothyroidism, testosterone deficiency, and/or adrenal insufficiency. Traumatic brain injury (TBI) exposure is a known risk factor for hypopituitarism. However, patients with hypopituitarism secondary to TBI exposure may go undiagnosed because the signs and symptoms of hypopituitarism can be subtle. This case report describes a 40-year-old male US military veteran who endorsed fatigue, sexual dysfunction, and weight gain several years after experiencing multiple mild TBIs during his military service. He ultimately underwent a full neuroendocrine workup that revealed low testosterone in addition to previously diagnosed hypothyroidism with a resolution of symptoms after starting testosterone therapy.

Media-Induced War Trauma Amid Conflicts in Ukraine

War could be traumatic. War trauma could often lead to severe and sustained health consequences on people's physical and psychological health. War trauma is often prevalent in people who either participated in the war or lived near conflict zones, such as military professionals, refugees, and health workers. Advances in information and communication technologies, such as the speed, scale, and scope at which people worldwide could be exposed to the near-time happenings of the war, mean that an unprecedented number of people could face media-induced war trauma. Different from war experienced in person, which could be limited in scope and intensity, media-induced war trauma can be substantially more extensive and comprehensive-news reports on the war often cover all aspects and angles possible, possibly paired with disturbing, if not demoralizing, images, repeatedly 24/7. Although media-induced war trauma could have a profound influence on people's mental health, particularly factoring in the compounding challenges caused by the pandemic, there is a dearth of research in the literature. To shed light on this issue, in this article, we aim to examine the implications of media-induced war trauma on people's health and well-being. Furthermore, we discuss the duties and responsibilities of the media industry amid and beyond the current conflicts in Ukraine.

Blood-Based Biomarkers in Traumatic Brain Injury: A Narrative Review With Implications for the Legal System

Traumatic brain injury (TBI) is an increasingly recognized diagnosis with significant, and often costly, associated consequences. Yet, despite their increased recognition, TBIs remain underdiagnosed. This issue is especially prominent in the context of mild TBI (mTBI), where there often exists little to no objective evidence of brain injury. In recent years, considerable effort has been made to better define and interpret known objective markers of TBI, as well as identify and explore new ones. An area of particular interest has focused on research related to blood-based biomarkers of TBI. Advancements in our understanding of TBI-related biomarkers can make it possible to characterize the severity of TBI with greater accuracy, improve our understanding of staging within both the injury process and the recovery process, and help us develop quantifiable metrics representative of reversal and recovery from a brain injury following trauma. Proteomic and non-proteomic blood-based biomarkers are being studied extensively and have shown promise for these purposes. Developments in this realm have significant implications not only for clinical care but also for legislation, as well as civil and criminal litigation. Despite their substantial potential, most of these biomarkers are not yet ready for use within the clinical setting, and therefore, are not appropriate for use within the legal or policy-making systems at this time. Given that existing standardization for the accurate and reliable use of TBI biomarkers is currently insufficient for use within either the clinical or legal realms, such data can be vulnerable to misuse and can even result in the abuse of the legal system for unwarranted gain. Courts will need to carefully evaluate the information presented in their role as gatekeepers of the admissibility of scientific evidence within the legal process. Ultimately, the development of biomarkers should lead to improved clinical care following TBI exposure, coherent and informed laws surrounding TBI, and more accurate and just results in litigation surrounding TBI-related sequelae.

Racial and Ethnic Differences in Deaths by Suicide, Drug Overdose, and Opioid-Related Overdose in a National Sample of Military Members With Mild Traumatic Brain Injury, 1999-2019

OBJECTIVE

To examine racial and ethnic differences in suicide and drug and opioid-related overdose deaths among a population-based cohort of military service members who were diagnosed with a mild traumatic brain injury (mTBI) during military service.

DESIGN

Retrospective cohort.

SETTING

Military personnel receiving care within the Military Health System between 1999 and 2019.

PARTICIPANTS

In total, 356 514 military members aged 18 to 64 years, who received an mTBI diagnosis as their index TBI between 1999 and 2019, while on active duty or activated.

MAIN MEASURES

Death by suicide, death by drug overdose, and death by opioid overdose were identified using International Classification of Diseases, Tenth Revision (ICD-10) codes within the National Death Index. Race and ethnicity were captured from the Military Health System Data Repository.

RESULTS

Overall crude rates were 38.67 per 100 000 person-years for suicide; 31.01 per 100 000 person-years for drug overdose death; and 20.82 per 100 000 person-years for opioid overdose death. Crude and age-specific rates for military members who self-identified as Other were higher than all other racial/ethnic groups for all 3 mortality outcomes. Adjusting for age, suicide rates for those classified as Other were up to 5 times that of other racial/ethnic groups for suicide, and up to 11 and 3.5 times that of other race/ethnicity groups for drug and opioid overdose death, respectively.

CONCLUSION

Findings extend previous knowledge regarding risk for suicide and deaths by drug overdose among those with mTBI and highlight new important areas for understanding the impact of race and ethnicity on mortality. Methodological limitations regarding classification of race and ethnicity must be addressed to ensure that future research provides a better understanding of racial and ethnic disparities in suicide and drug overdose mortality among military members with TBI.

Neurotrauma: 2023 Update

2022 was a productive year for research in traumatic brain injury (TBI) and resultant neuropathology. After an extensive review, we present related studies and publications which we felt were of particular importance to the neuropathology community. First, 2022 was highlighted by important advancements in the diagnosis and, moreover, our understanding of chronic traumatic encephalopathy (CTE). Important publications include a pair concluding that CTE primarily concerns neuronal accumulation of phosphorylated tau (ptau), but that glial ptau accumulation often helps to facilitate diagnosis. In addition, a new large community study from Australia continues the indication that CTE is relatively uncommon in the community, and the first large-cohort study on brains of military personnel similarly demonstrates that CTE appears to be uncommon among service members and does not appear to explain high rates of neuropsychiatric sequelae suffered by the warfighter. The causation of CTE by impact-type TBI was supported by the application of the Bradford Hill criteria, within the brains of headbutting bovids, and interestingly within an artificial head model exposed to linear impact. Finally, a large-scale analysis of APOE genotypes contends that gene status may influence CTE pathology and outcomes. In experimental animal work, a study using mouse models provided important evidence that TDP-43 facilitates neurodegenerative pathology and is implicated in cognitive dysfunction following TBI, and another study using a swine model for concussion demonstrated that evidence that axonal sodium channel disruption may be a driver of neurologic dysfunction after concussion. Finally, we end with memoriam to Dr. John Q. Trojanowski, a giant of neurodegenerative research and an important contributor to the neurotrauma literature, who we lost in 2022.

Impact of gulf war toxic exposures after mild traumatic brain injury

Chemical and pharmaceutical exposures have been associated with the development of Gulf War Illness (GWI), but how these factors interact with the pathophysiology of traumatic brain injury (TBI) remains an area of study that has received little attention thus far. We studied the effects of pyridostigmine bromide (an anti-nerve agent) and permethrin (a pesticide) exposure in a mouse model of repetitive mild TBI (r-mTBI), with 5 impacts over a 9-day period, followed by Gulf War (GW) toxicant exposure for 10 days beginning 30 days after the last head injury. We then assessed the chronic behavioral and pathological sequelae 5 months after GW agent exposure. We observed that r-mTBI and GWI cumulatively affect the spatial memory of mice in the Barnes maze and result in a shift of search strategies employed by r-mTBI/GW exposed mice. GW exposure also produced anxiety-like behavior in sham animals, but r-mTBI produced disinhibition in both the vehicle and GW treated mice. Pathologically, GW exposure worsened r-mTBI dependent axonal degeneration and neuroinflammation, increased oligodendrocyte cell counts, and increased r-mTBI dependent phosphorylated tau, which was found to colocalize with oligodendrocytes in the corpus callosum. These results suggest that GW exposures may worsen TBI-related deficits. Veterans with a history of both GW chemical exposures as well as TBI may be at higher risk for worse symptoms and outcomes. Subsequent exposure to various toxic substances can influence the chronic nature of mTBI and should be considered as an etiological factor influencing mTBI recovery.

Chronic Traumatic Encephalopathy in the Brains of Military Personnel

BACKGROUND

Persistent neuropsychiatric sequelae may develop in military personnel who are exposed to combat; such sequelae have been attributed in some cases to chronic traumatic encephalopathy (CTE). Only limited data regarding CTE in the brains of military service members are available.

METHODS

We performed neuropathological examinations for the presence of CTE in 225 consecutive brains from a brain bank dedicated to the study of deceased service members. In addition, we reviewed information obtained retrospectively regarding the decedents' histories of blast exposure, contact sports, other types of traumatic brain injury (TBI), and neuropsychiatric disorders.

RESULTS

Neuropathological findings of CTE were present in 10 of the 225 brains (4.4%) we examined; half the CTE cases had only a single pathognomonic lesion. Of the 45 brains from decedents who had a history of blast exposure, 3 had CTE, as compared with 7 of 180 brains from those without a history of blast exposure (relative risk, 1.71; 95% confidence interval [CI], 0.46 to 6.37); 3 of 21 brains from decedents with TBI from an injury during military service caused by the head striking a physical object without associated blast exposure (military impact TBI) had CTE, as compared with 7 of 204 without this exposure (relative risk, 4.16; 95% CI, 1.16 to 14.91). All brains with CTE were from decedents who had participated in contact sports; 10 of 60 contact-sports participants had CTE, as compared with 0 of 165 who had not participated in contact sports (point estimate of relative risk not computable; 95% CI, 6.16 to infinity). CTE was present in 8 of 44 brains from decedents with non-sports-related TBI in civilian life, as compared with 2 of 181 brains from those without such exposure in civilian life (relative risk, 16.45; 95% CI, 3.62 to 74.79).

CONCLUSIONS

Evidence of CTE was infrequently found in a series of brains from military personnel and was usually reflected by minimal neuropathologic changes. Risk ratios for CTE were numerically higher among decedents who had contact-sports exposure and other exposures to TBI in civilian life than among those who had blast exposure or other military TBI, but the small number of CTE cases and wide confidence intervals preclude causal conclusions. (Funded by the Department of Defense-Uniformed Services University Brain Tissue Repository and Neuropathology Program and the Henry M. Jackson Foundation for the Advancement of Military Medicine.).