Service needs and neurobehavioral functioning following traumatic brain injury in U.S. military personnel.

OBJECTIVE: The purpose of this study was to (a) identify the prevalence and barriers of self-reported service needs in a military sample with and without traumatic brain injury (TBI), (b) evaluate the influence of the number of service needs on overall neurobehavioral functioning, and (c) examine the longitudinal trajectories of service needs over time. METHOD: Participants were 941 U.S. service members and veterans (SMVs) prospectively enrolled into four groups: uncomplicated mild TBI (MTBI; n = 455); complicated mild, moderate, severe, and penetrating TBI combined (STBI; n = 164); injured controls (IC, n = 138); and noninjured controls (NIC, n = 184). Participants completed a battery of neurobehavioral measures, as well as a self-reported service need interview, 12 or more month's postinjury. In addition, a longitudinal cohort (n = 553) was included using a subset of participants who had completed two or more evaluations. RESULTS: When examining the total number of self-reported service needs, there was a greater proportion of the MTBI and STBI groups that had a higher number of service needs compared to the NIC and IC groups (p < .001). In the MTBI and STBI groups, as the number of service needs increased, worse scores were found on all neurobehavioral measures. In the longitudinal cohort, the STBI group reported the highest number of service needs that persisted or developed over time (six needs), followed by the MTBI (three needs), IC (one need), and NIC (zero need) groups. CONCLUSIONS: These findings call for the need to enhance the provision of information given to service members and veterans following TBI regarding available services. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

High Lifetime Blast Exposure Using the Blast Exposure Threshold Survey Is Associated With Worse Warfighter Brain Health Following Mild Traumatic Brain Injury.

The purpose of this study was to extend previous research by examining the relationship between lifetime blast exposure and neurobehavioral functioning after mild TBI (MTBI) by (a) using a comprehensive measure of lifetime blast exposure, and (b) controlling for the influence of post-traumatic stress disorder (PTSD). Participants were 103 United States service members and veterans (SMVs) with a medically documented diagnosis of MTBI, recruited from three military treatment facilities (74.8%) and community-based recruitment initiatives (25.2%, e.g., social media, flyers). Participants completed a battery of neurobehavioral measures 12 or more months post-injury (Neurobehavioral Symptom Inventory, PTSD-Checklist PCLC, TBI-Quality of Life), including the Blast Exposure Threshold Survey (BETS). The sample was classified into two lifetime blast exposure (LBE) groups: High (n = 57) and Low (n = 46) LBE. In addition, the sample was classified into four LBE/PTSD subgroups: High PTSD/High LBE (n = 38); High PTSD/Low LBE (n = 19); Low PTSD/High LBE (n = 19); and Low PTSD/Low LBE (n = 27). The High LBE group had consistently worse scores on all neurobehavioral measures compared with the Low LBE group. When controlling for the influence of PTSD (using ANCOVA), however, only a handful of group differences remained. When comparing measures across the four LBE/PTSD subgroups, in the absence of clinically meaningful PTSD symptoms (i.e., Low PTSD), participants with High LBE had worse scores on the majority of neurobehavioral measures (e.g., post-concussion symptoms, sleep, fatigue). When examining the total number of clinically elevated measures, the High LBE subgroup consistently had a greater number of clinically elevated scores compared with the Low LBE subgroup for the majority of comparisons (i.e., four to 15 or more elevated symptoms). In contrast, in the presence of clinically meaningful PTSD symptoms (i.e., High PTSD), there were no differences between High versus Low LBE subgroups for all measures. When examining the total number of clinically elevated measures, however, there were meaningful differences between High versus Low LBE subgroups for those comparisons that included a high number of clinically elevated scores (i.e., six to 10 or more), but not for a low number of clinically elevated scores (i.e., one to five or more). High LBE, as quantified using a more comprehensive measure than utilized in past research (i.e., BETS), was associated with worse overall neurobehavioral functioning after MTBI. This study extends existing literature showing that lifetime blast exposure, that is largely subconcussive, may negatively impact warfighter brain health and readiness beyond diagnosable brain injury.

Convergent and Discriminant Validity of the Blast Exposure Threshold Survey in United States Military Service Members and Veterans.

The Blast Exposure Threshold Survey (BETS) is a recently developed and promising new self-report measure of lifetime blast exposure (LBE). However, there are no studies that have examined the psychometric properties of the BETS, which currently limits its clinical utility. The purpose of this study was to examine the convergent and discriminant validity of the BETS by comparing the BETS Generalized Blast Exposure Value (GBEV) to six variables hypothesized to be associated with LBE (i.e., single-item LBE, combat exposure, years in the military, number of combat deployments, and military occupation specialty [MOS]) and three variables hypothesized not to be associated with LBE (i.e., age at the time of injury, estimated pre-morbid Full-Scale Intelligence Quotient [FSIQ], and resilience). Participants were 202 United States service members and veterans prospectively enrolled from three military medical treatment facilities (68.7%) and via community recruitment initiatives (31.3%). Participants completed the BETS, Combat Exposure Scale (CES), Deployment Risk and Resiliency Inventory-2 Combat Experiences (DRRI-2 CE), Traumatic Brain Injury-Quality of Life Resilience scale, and a brief structured interview. For some analyses, participants were classified into two blast risk MOS groups: high (n = 89) and low (n = 94). The BETS GBEV was not significantly correlated with all three non-blast related variables (rs = 0.01 to rs = -0.12). In contrast, GBEV was significantly (p < 0.001) associated with all blast-related variables; single-item LBE (rs = 0.76), CES (rs = 0.58), number of combat deployments (rs = 0.53), DRRI-2 CE (rs = 0.48), and high blast risk MOS (r = 0.36, medium effect size). However, a stronger relationship was found between the blast-related variables and three modified GBEV scores when excluding some small weapons categories; single-item LBE (rs = 0.80-0.82), CES (rs = 0.64-0.67), number of combat deployments (rs = 0.56), DRRI-2 CE (rs = 0.51-0.53), and high blast risk MOS (r = 0.42-0.49, medium-large effect size). This is the first study to examine the psychometric properties of the BETS. Overall, these results offer support for the convergent and discriminant validity of the BETS. In order to ensure that the BETS can be confidently used as a valid and reliable measure of LBE, more research is needed to further examine the psychometric properties of the test, particularly with regard to the establishment of test-retest reliability.

Longitudinal health-related quality of life in military caregivers no longer providing care.

PURPOSE/OBJECTIVE: To examine health-related quality of life (HRQOL) in caregivers when providing care and no longer providing care to service members/veterans with traumatic brain injury. RESEARCH METHOD/DESIGN: Participants included 466 caregivers enrolled in a 15-year longitudinal study. During an annual follow-up evaluation, a subsample of caregivers self-identified as no longer providing care and were retained in the study as a No Longer Caregiving group (n = 48). Scores on HRQOL measures when providing care (baseline) and no longer providing care (follow-up) were examined. Scores on HRQOL measures were also compared with the remaining 418 caregivers (Caregiving group). RESULTS: The most frequent reasons for no longer caregiving were no longer being in a relationship with the SMV and the SMV had recovered/no longer required care. The No Longer Caregiving group at follow-up reported better scores on five measures compared to baseline, and three measures compared to the Caregiving group. There were no differences in the proportion of clinically elevated scores on HRQOL measures for the No Longer Caregiving group between baseline and follow-up. Compared to the Caregiving group, the No Longer Caregiving group reported a higher prevalence of clinical elevated scores on General Life Satisfaction at baseline and follow-up, and worse scores on Caregiving Relationship Satisfaction and the Couples Satisfaction Index at baseline. CONCLUSIONS/IMPLICATIONS: While some improvement in HRQOL was noted when caregivers were no longer providing care, many continued to report elevated scores. Services and supports are required for caregivers when providing care, but also when transitioning out of a caregiving role. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Risk factors for the presence and persistence of posttraumatic stress symptoms following traumatic brain injury in U.S. service members and veterans.

This study aimed to identify risk factors predictive of the presence and persistence of posttraumatic stress disorder (PTSD) symptom reporting following traumatic brain injury (TBI). Participants were 1,301 U.S. service members and veterans (SMVs) divided into four groups: uncomplicated mild TBI (mTBI; n = 543); complicated mild, moderate, severe, and penetrating TBI (n = 230); injured controls (n = 340); and noninjured controls (n = 188). We examined 25 factors related to demographic, injury-related, military-specific, treatment/health care need, and mental health/social support variables. Seven factors were statistically associated with the presence of DSM-IV-TR symptom criteria for PTSD: premorbid IQ, combat exposure, depression, social participation, history of mTBI, need for managing mood and stress, and need for improving memory and attention, p < .001 (51.3% variance). When comparing the prevalence of these risk factors in a longitudinal cohort (n = 742) across four PTSD trajectory groups (i.e., asymptomatic, improved, developed, persistent), a higher proportion of participants in the persistent PTSD group reported worse depression, a lack of social participation, and history of mTBI. Additionally, a higher proportion of participants in the persistent and developed PTSD groups reported the need for managing mood/stress and improving memory/attention. When considered simultaneously, the presence of ≥ 1 or ≥ 2 risk factors was associated with a higher proportion of participants in the developed and persistent PTSD groups, ps < .001. These risk factors may be useful in identifying SMVs at risk for the development and/or persistence of PTSD symptoms who may need intervention.

Extracellular vesicle neurofilament light is elevated within the first 12-months following traumatic brain injury in a U.S military population.

Traumatic brain injury (TBI) can be associated with long-term neurobehavioral symptoms. Here, we examined levels of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) in extracellular vesicles isolated from blood, and their relationship with TBI severity and neurobehavioral symptom reporting. Participants were 218 service members and veterans who sustained uncomplicated mild TBIs (mTBI, n = 107); complicated mild, moderate, or severe TBIs (smcTBI, n = 66); or Injured controls (IC, orthopedic injury without TBI, n = 45). Within one year after injury, but not after, NfL was higher in the smcTBI group than mTBI (p = 0.001, d = 0.66) and IC (p = 0.001, d = 0.35) groups, which remained after controlling for demographics and injury characteristics. NfL also discriminated the smcTBI group from IC (AUC:77.5%, p < 0.001) and mTBI (AUC:76.1%, p < 0.001) groups. No other group differences were observed for NfL or GFAP at either timepoint. NfL correlated with post-concussion symptoms (rs = - 0.38, p = 0.04) in the mTBI group, and with PTSD symptoms in mTBI (rs = - 0.43, p = 0.021) and smcTBI groups (rs = - 0.40, p = 0.024) within one year after injury, which was not confirmed in regression models. Our results suggest the potential of NfL, a protein previously linked to axonal damage, as a diagnostic biomarker that distinguishes TBI severity within the first year after injury.

Longitudinal trajectories and risk factors for persistent postconcussion symptom reporting following uncomplicated mild traumatic brain injury in U.S. Military service members.

OBJECTIVE: The purpose of this study was to examine individual postconcussion symptom [PCSx] trajectories following mild traumatic brain injury (MTBI), and to examine risk factors for persistent PCSx reporting. METHOD: Participants were 138 U.S. military service members and veterans (SMVs) prospectively enrolled in the Defense and Veterans Brain Injury Center, 15-Year Longitudinal TBI study. Participants were classified into three groups: uncomplicated MTBI (n = 54), injured controls (IC, n = 26), and non-injured controls (NIC, n = 58). Participants completed the Neurobehavioral Symptom Inventory, PTSD Checklist, and Traumatic Brain Injury Quality of Life at baseline (<8 months post-injury) and at follow-up (2-4 years post-injury). RESULTS: The prevalence of those who met DSM-IV-TR symptom criteria for Postconcussional Disorder (PCD) was high in all three groups (e.g., 44.8-63.0%) and did not significantly change from baseline to follow-up (all ps>.05). However, there was substantial variability in individual symptom trajectories over time. The majority of participants had symptom trajectories classified as either 'persistent' (∼32-55%) or 'asymptomatic' (∼30-36%), with a substantial minority classified as 'improved' (∼7-12%) or 'developed' (∼7-19%). Factors associated with 'persistent' PCD trajectories included cognitive complaints, PTSD, depression, anxiety, pain, and headaches at baseline; but not the presence/absence of MTBI. Factors associated with 'developed' PCD trajectories included PTSD and the number of lifetime exposures to blast. Conclusions: Reporting of 'new' PCSx over time was common in individuals with and without MTBI. It would be erroneous to assume uncritically that PCSx reported many years post-injury reflect only persistent symptomatology, or can be solely attributable to the direct consequences of a brain injury.