Altered lateralization of the cingulum in deployment-related traumatic brain injury: An ENIGMA military-relevant brain injury study.

Traumatic brain injury (TBI) in military populations can cause disruptions in brain structure and function, along with cognitive and psychological dysfunction. Diffusion magnetic resonance imaging (dMRI) can detect alterations in white matter (WM) microstructure, but few studies have examined brain asymmetry. Examining asymmetry in large samples may increase sensitivity to detect heterogeneous areas of WM alteration in mild TBI. Through the Enhancing Neuroimaging Genetics Through Meta-Analysis Military-Relevant Brain Injury working group, we conducted a mega-analysis of neuroimaging and clinical data from 16 cohorts of Active Duty Service Members and Veterans (n = 2598). dMRI data were processed together along with harmonized demographic, injury, psychiatric, and cognitive measures. Fractional anisotropy in the cingulum showed greater asymmetry in individuals with deployment-related TBI, driven by greater left lateralization in TBI. Results remained significant after accounting for potentially confounding variables including posttraumatic stress disorder, depression, and handedness, and were driven primarily by individuals whose worst TBI occurred before age 40. Alterations in the cingulum were also associated with slower processing speed and poorer set shifting. The results indicate an enhancement of the natural left laterality of the cingulum, possibly due to vulnerability of the nondominant hemisphere or compensatory mechanisms in the dominant hemisphere. The cingulum is one of the last WM tracts to mature, reaching peak FA around 42 years old. This effect was primarily detected in individuals whose worst injury occurred before age 40, suggesting that the protracted development of the cingulum may lead to increased vulnerability to insults, such as TBI.

Mechanisms of change in posttraumatic headache-related disability: A mediation model.

OBJECTIVE: To explore whether the association between change in headache management self-efficacy and posttraumatic headache-related disability is partially mediated by a change in anxiety symptom severity. BACKGROUND: Many cognitive-behavioral therapy treatments for headache emphasize stress management, which includes anxiety management strategies; however, little is currently known about mechanisms of change in posttraumatic headache-related disability. Increasing our understanding of mechanisms could lead to improvements in treatments for these debilitating headaches. METHODS: This study is a secondary analysis of veterans (N = 193) recruited to participate in a randomized clinical trial of cognitive-behavioral therapy, cognitive processing therapy, or treatment as usual for persistent posttraumatic headache. The direct relationship between headache management self-efficacy and headache-related disability, along with partial mediation through change in anxiety symptoms was tested. RESULTS: The mediated latent change direct, mediated, and total pathways were statistically significant. The path analysis supported a significant direct pathway between headache management self-efficacy and headache-related disability (b = -0.45, p < 0.001; 95% confidence interval [CI: -0.58, -0.33]). The total effect of change of headache management self-efficacy scores on change in Headache Impact Test-6 scores was significant with a moderate-to-strong effect (b = -0.57, p = 0.001; 95% CI [-0.73, -0.41]). There was also an indirect effect through anxiety symptom severity change (b = -0.12, p = 0.003; 95% CI [-0.20, -0.04]). CONCLUSIONS: In this study, most of the improvements in headache-related disability were related to increased headache management self-efficacy with mediation occurring through change in anxiety. This indicates that headache management self-efficacy is a likely mechanism of change of posttraumatic headache-related disability with decreases in anxiety explaining part of the improvement in headache-related disability.

Comparison of veterans affairs and NIDILRR traumatic brain injury model systems participants with disorders of consciousness.

OBJECTIVE: To characterize demographic, pre-injury, and outcome data within the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) and Veterans Affairs (VA) Traumatic Brain Injury Model Systems (TBIMS) cohorts with severe traumatic brain injury (TBI) with no command-following ability at time of admission to acute rehabilitation. DESIGN: Retrospective cohort. SETTING: NIDILRR and VA TBI Model Systems (TBIMS) centers. PARTICIPANTS: 396 NIDILRR and 72 VA participants without command-following ability who experienced TBI with subsequent Disorder of Consciousness (DoC). MAIN OUTCOME MEASURE: Pre-injury and injury characteristics, rehabilitation outcomes, and 1-year self-reported outcomes. RESULTS: VA TBIMS cohort included individuals who were active duty or had military service before their injury. The VA cohort were more likely to be re-hospitalized at 1-year follow-up or residing in a long-term care or rehab setting. The NIDILRR TBIMS cohort had higher FIM and DRS scores at rehabilitation discharge, while the VA participants saw longer lengths of stay and higher numbers of "violent" injury types. CONCLUSIONS: This study allows for a better understanding of the comparability between VA and NIDILRR DoC cohorts providing guidance on how veteran and civilian samples might be merged in future TBIMS studies to explore predictors of recovery from a DoC.

Research Letter: Long-Term Outcomes Following Cognitive Rehabilitation for Mild Traumatic Brain Injury: A 5-Year Follow-Up of a Cohort From the SCORE Randomized Clinical Trial.

OBJECTIVE: To examine the functioning of military service members 5 years after completing a randomized controlled trial (RCT) of cognitive rehabilitation for mild traumatic brain injury (mTBI). SETTING: Home-based telephonic interview and internet-based self-ratings. PARTICIPANTS: Sixty-nine of the 126 (55%) active-duty service members who were enrolled in a 4-arm RCT of cognitive rehabilitation 3 to 24 months after mTBI and were successfully contacted by phone 5 years later. Original and 5-year follow-up participants in each of 4 RCT treatment arms included: psychoeducation ( n = 32 original, n = 17 follow-up), computer ( n = 30 original, n = 11 follow-up), therapist-directed ( n = 30 original, n = 23 follow-up), integrated ( n = 34 original, n = 18 follow-up). DESIGN: Inception cohort evaluated 5 years after completion of an RCT of cognitive rehabilitation. MAIN MEASURES: Postconcussion symptoms (Neurobehavioral Symptom Inventory total score), psychological distress (Symptom Checklist-90-revised Global Severity Index score), and functional cognitive/behavioral symptoms (Key Behaviors Change Inventory total average score). RESULTS: Participants' postconcussive symptoms and psychological distress improved at the 5-year follow-up. Functional cognitive/behavioral symptoms were not significantly improved, but therapeutic gains were maintained across time, to 5 years after completing the RCT. CONCLUSION: In this sample of military personnel, postconcussive symptoms and psychological distress significantly improved from posttreatment to 5 years after cognitive rehabilitation, regardless of treatment arm. Functional cognitive/behavioral symptoms significantly improved with treatment while treatment gains were maintained at the 5-year follow-up. Replication of these results with a larger sample and interim data between 18 weeks and 5 years post-treatment is needed.

The management and rehabilitation of post-acute mild traumatic brain injury.

DESCRIPTION: In June 2021, the U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DoD) approved a joint clinical practice guideline for the management and rehabilitation care for those who have symptoms in the post-acute period following mild traumatic brain injury (mTBI). This synopsis describes some of the clinically important recommendations. METHODS: In January 2020, VA and DoD leaders assembled a joint VA/DoD guideline development team of multidisciplinary clinical stakeholders that developed key questions, systematically searched and evaluated the literature, created two 1-page algorithms, and refined 19 recommendations using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The process closely conformed to the National Academy of Medicine's tenets for trustworthy clinical practice guidelines. RECOMMENDATIONS: This synopsis describes clinically important recommendations for the management and rehabilitation of mTBI. Outpatient primary care providers are the target audience for this synopsis and guideline. The current recommendations are an update from the 2016 VA/DoD Clinical Practice Guidelines for the Management of Concussion-Mild Traumatic Brain Injury.

Persistent posttraumatic headaches and functioning in veterans: Injury type can matter.

OBJECTIVE: To characterize the relationship between head trauma types (blast injury, blunt injury, combined blast+blunt injury) with subsequent headache presentations and functioning. BACKGROUND: Posttraumatic headaches (PTHs), the most common sequelae of traumatic brain injury (TBI), are painful and disabling. More than 400,000 veterans report having experienced a TBI, and understanding the predictors of PTHs may guide treatment developments. METHODS: This study used a nested-cohort design analyzing baseline data from a randomized clinical trial of cognitive behavioral therapy for PTH (N = 190). Participants had PTH (from blast and/or blunt head trauma) and symptoms of posttraumatic stress disorder (PTSD). The Structured Diagnostic Interview for Headache-Revised and Ohio State University Traumatic Brain Injury Identification Method were used to phenotype headaches and head injury histories, respectively. RESULTS: Individuals with persistent PTHs after a combined blast and blunt head trauma were more likely (OR =3.45; 95% CI [1.41, 8.4]) to experience chronic (vs. episodic) PTHs compared with the blunt trauma only group (23/33, 70% vs. 26/65, 40%, respectively); and they were more likely (OR =2.51; 95% CI [1.07, 5.9]) to experience chronic PTH compared with the blast trauma only group (44/92, 48%). There were no differences between head injury type on headache-related disability, depression symptoms, or severity of PTSD symptoms. CONCLUSION: The combination of blast and blunt injuries was associated with headache chronicity, but not headache disability. Considering the refractory nature of chronic headaches, the potential added and synergistic effects of distinct head injuries warrant further study.

Demographic and Mental Health Predictors of Arrests Up to 10 Years Post-Traumatic Brain Injury: A Veterans Affairs TBI Model Systems Study.

OBJECTIVE: Examine rates and predictors of arrests in Veterans and Service Members (V/SM) who received inpatient rehabilitation for traumatic brain injury (TBI). SETTING: Veterans Administration (VA) Polytrauma Rehabilitation Centers. PARTICIPANTS: A total of 948 V/SM drawn from the VA TBI Model Systems cohort with arrest data up to 10 years post-TBI. DESIGN: Longitudinal cohort study; secondary analysis of pre-TBI characteristics predicting post-TBI arrests. MAIN MEASURES: Disclosure of arrests pre-TBI and up to10 years post-TBI. RESULTS: Thirty-six percent of the sample had been arrested prior to their TBI; 7% were arrested post-TBI. When considering all variables simultaneously in a multivariate model, pre-TBI mental health treatment (adjusted odds ratio [aOR] = 4.30; 95% confidence interval [CI]: 2.03-9.14), pre-TBI heavy alcohol use (aOR = 3.04; CI: 1.08-8.55), and number of follow-up interviews (aOR = 2.05; CI: 1.39-4.50) were significant predictors of post-TBI arrest. CONCLUSION: Arrest rates of V/SM prior to TBI were consistent with rates of arrest for people of similar ages in the United States. Post-TBI rates were lower for V/SM than published rates of post-TBI arrests in civilians with TBI. As part of rehabilitation planning for V/SM with TBI, providers should assess for preinjury mental health services and alcohol misuse to (1) identify those who may be at risk for postinjury arrests and (2) provide relevant resources and/or supports.

Health Phenotypes and Neurobehavioral Symptom Severity Among Post-9/11 Veterans With Mild Traumatic Brain Injury: A Chronic Effects of Neurotrauma Consortium Study.

OBJECTIVE: To evaluate whether neurobehavioral symptoms differ between groups of veterans with mild traumatic brain injury (mTBI) classified by health characteristics. PARTICIPANTS: A total of 71 934 post-9/11 veterans with mTBI from the Chronic Effects of Neurotrauma Consortium Epidemiology warfighter cohort. DESIGN: Cross-sectional analysis of retrospective cohort. MAIN MEASURES: Health phenotypes identified using latent class analysis of health and function over 5 years. Symptom severity measured using Neurobehavioral Symptom Inventory; domains included vestibular, somatic, cognitive, and affective. RESULTS: Veterans classified as moderately healthy had the lowest symptom burden while the polytrauma phenotype group had the highest. After accounting for sociodemographic and injury characteristics, polytrauma phenotype veterans had about 3 times the odds of reporting severe symptoms in each domain compared with moderately healthy veterans. Those veterans who were initially moderately healthy but whose health declined over time had about twice the odds of severe symptoms as consistently healthier Veterans. The strongest associations were in the affective domain. Compared with the moderately healthy group, veterans in other phenotypes were more likely to report symptoms substantially interfered with their daily lives (odds ratio range: 1.3-2.8). CONCLUSION: Symptom severity and interference varied by phenotype, including between veterans with stable and declining health. Ameliorating severe symptoms, particularly in the affective domain, could improve health trajectories following mTBI.

Reason to doubt the ICHD-3 7-day inclusion criterion for mild TBI-related posttraumatic headache: A nested cohort study.

BACKGROUND: Posttraumatic headache is difficult to define and there is debate about the specificity of the 7-day headache onset criterion in the current definition. There is limited evidence available to guide decision making about this criterion. METHOD: A nested cohort study of 193 treatment-seeking veterans who met criteria for persistent headache attributed to mild traumatic injury to the head, including some veterans with delayed headache onset up to 90 days post-injury, was undertaken. Survival analysis examined the proportion of participants reporting headache over time and differences in these proportions based on sex, headache phenotype, and mechanism of injury. RESULT: 127 participants (66%; 95% CI: 59-72%) reported headache onset within 7 days of head injury and 65 (34%) reported headache onset between 8 days and 3 months after head injury. Fourteen percent of participants reported pre-existing migraine before head injury, and there was no difference in the proportion of veterans with pre-existing migraine based on headache onset. Headache onset times were not associated with sex, headache phenotype, or mechanism of injury. There were no significant differences in proportion of veterans with headache onset within 7 days of head injury based on headache phenotype (70% migraine onset within 7 days, 70% tension-type headache within 7 days, 56% cluster headache within 7 days; p ≥ .364). Similar findings were observed for head injury (64% blast, 60% blunt; p = .973). There were no significant differences observed between headache onset groups for psychiatric symptoms (Posttraumatic Stress Disorder Checklist for DSM-5 = 1.3, 95% CI = -27.5, 30.1; Patient Health Questionnaire-9 Item = 3.5, 95% CI = -6.3, 3.7; Generalized Anxiety Disorder Screener = 6.5, 95% CI = -2.7, 15.6). CONCLUSIONS: Although most of the sample reported headache onset within 7 days of head injury, one-third experienced an onset outside of the diagnostic range. Additionally, veterans with headache onset within 7 days of head injury were not meaningfully different from those with later onset based on sex, headache phenotype, or mechanism of head injury. The ICHD-3 diagnostic criteria for 7-day headache onset should be expanded to 3 months. CLINICALTRIALS.GOV IDENTIFIER: NCT02419131.

Self-reported Participation Restrictions Among Male and Female Veterans With Traumatic Brain Injury in Veterans Health Administration Outpatient Polytrauma Programs.

OBJECTIVES: To identify areas of most restricted self-reported participation among veterans with traumatic brain injury (TBI), explore associations among participation restriction and clinical characteristics, and examine differences in participation restrictions by sex. DESIGN: Retrospective cross-sectional design. SETTING: National VA Polytrauma System of Care outpatient settings. PARTICIPANTS: Veterans with a confirmed TBI event (N=6065). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE(S): Mayo-Portland Participation Index (M2PI), a 5-point Likert-type scale with 8 items. Total score was converted to standardized T score for analysis. RESULTS: The sample consisted of 5679 male and 386 female veterans with ≥1 clinically confirmed TBI events (69% white; 74% with blast exposure). The M2PI items with greatest perceived restrictions were social contact, leisure, and initiation. There were no significant differences between men and women on M2PI standardized T scores. Wilcoxon rank-sum analyses showed significant differences by sex on 4 items: leisure, residence, employment, and financial management (all P<.01). In multinomial logistic regression on each item controlling for demographics, injury characteristics, and comorbidities, female veterans had significantly greater relative risk for part-time work and unemployment on the employment item and significantly less risk for impairment on the residence and financial management item. CONCLUSIONS: There was no significant difference between men and women. Veterans on M2PI standardized T scores, which masks differences in response patterns to individual items. Clinical teams should be encouraged to discuss perceived restrictions with patients and target these areas in treatment planning. Future work is needed to investigate the psychometric properties of the M2PI by biological sex.

Posttraumatic Stress Disorder Symptoms Contribute to Staff Perceived Irritability, Anger, and Aggression After TBI in a Longitudinal Veteran Cohort: A VA TBI Model Systems Study.

OBJECTIVE: To examine the relationship between staff perceived irritability, anger, and aggression and posttraumatic stress disorder (PTSD) in veterans with traumatic brain injury (TBI) of all severity levels. DESIGN: Longitudinal cohort design. SETTING: Veterans Affairs Polytrauma Transitional Rehabilitation Programs. PARTICIPANTS: Veterans and service members with TBI of all severity levels enrolled in the Veterans Affairs Polytrauma Rehabilitation Centers' Traumatic Brain Injury Model System national database (N=240). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Univariable and multivariable logistic regression modeling was used to examine the association between irritability, anger, and aggression and potential risk factors, including PTSD symptoms. Irritability, anger, and aggression was measured as a single construct using an item from the Mayo-Portland Adaptability Inventory-4 that was rated by program staff at admission and discharge from the inpatient rehabilitation program. PTSD symptoms were assessed using the PTSD Checklist-Civilian Version. RESULTS: PTSD symptoms uniquely predicted program staff-rated irritability, anger, and aggression at discharge even after controlling for severity of TBI, age, male sex, education, and annual earnings. The model explained 19% of the variance in irritability, anger, and aggression. CONCLUSIONS: When TBI severity and PTSD symptoms were considered simultaneously in a sample of veterans, only PTSD symptoms predicted staff-rated irritability, anger, and aggression. Given the negative outcomes linked with irritability, anger, and aggression, veterans may benefit from assessment and treatment of PTSD symptoms within rehabilitation settings.

The Management of Stroke Rehabilitation: A Synopsis of the 2019 U.S. Department of Veterans Affairs and U.S. Department of Defense Clinical Practice Guideline.

Description: In June 2019, the U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DoD) approved an update of the joint clinical practice guideline for rehabilitation after stroke. This synopsis summarizes the key recommendations from this guideline. Methods: In February 2018, the VA/DoD Evidence-Based Practice Work Group convened a joint VA/DoD guideline development effort that included clinical stakeholders and stroke survivors and conformed to the National Academy of Medicine (formerly the Institute of Medicine) tenets for trustworthy clinical practice guidelines. The guideline panel identified key questions, systematically searched and evaluated the literature, and developed 2 algorithms and 42 key recommendations using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. Stroke survivors and their family members were invited to share their perspectives to further inform guideline development. Recommendations: The guideline recommendations provide evidence-based guidance for the rehabilitation care of patients after stroke. The recommendations are applicable to health care providers in both primary care and rehabilitation. Key features of the guideline are recommendations in 6 areas: timing and approach; motor therapy; dysphagia; cognitive, speech, and sensory therapy; mental health therapy; and other functions, such as returning to work and driving.

Self-efficacy predicts response to cognitive rehabilitation in military service members with post-concussive symptoms.

This study examined whether self-efficacy differentiated treatment responders from non-responders in a trial of cognitive rehabilitation (CR) for postconcussive symptoms. 126 service members with mild TBI seen on average 9.5 months since injury completed one of four cognitive rehabilitation treatments for 6 weeks. The four treatment arms were: (1) Psychoeducation control, (2) Self-administered computerized CR, (3) Interdisciplinary CR, and (4) Interdisciplinary CR integrated with CBT. Outcome was assessed across time (baseline, and 6, 12, and 18 weeks post-treatment) for three domains: psychological (Symptom Checklist-90-Revised; SCL-90-R), cognitive (Paced Auditory Serial Addition Test; PASAT), and functional/behavioural (Key Behaviors Change Inventory; KBCI). Mixed model ANOVAs tested for self-efficacy differences across time in treatment responders versus non-responders, as defined by reliable change indices. A significant interaction was found on the SCL-90 such that responders had increasing self-efficacy with respect to psychological symptoms across four time points, whereas non-responders' self-efficacy did not change. Perceived self-efficacy at the beginning of treatment was associated with treatment engagement within the psychological domain for responders only, suggesting a mediating role in treatment outcome. Overall, results suggest that increasing patients' level of self-efficacy may be important for successful treatment of psychological distress in those with remote concussion.

Traumatic Brain Injury Severity, Comorbidity, Social Support, Family Functioning, and Community Reintegration Among Veterans of the Afghanistan and Iraq Wars.

OBJECTIVE: To examine the association between traumatic brain injury (TBI) severity; social, family, and community reintegration outcomes; and return to work status among post-9/11 veterans in Department of Veterans Affairs (VA) care. DESIGN: Retrospective observational cohort study. SETTING: Mail/online survey fielded to a national sample of veterans. PARTICIPANTS: Sample of post-9/11 veterans with at least 3 years of VA care stratified according to TBI severity and comorbidities who completed and returned surveys (N=2023). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Deployment Risk and Resilience Inventory-2 family functioning and social support subscales; Military to Civilian Questionnaire; and employment status. RESULTS: Bivariate analyses revealed that veterans with every classification of TBI severity reported significantly more difficulty on social, family, and community reintegration outcomes than those with no TBI. In the fully adjusted model, veterans with unclassified and moderate/severe TBI reported significantly more difficulty with community reintegration and were less likely to be employed relative to those with no TBI; those with unclassified TBI also reported significantly more difficulty with family functioning. Veterans with mild TBI also reported significantly more difficulty with community reintegration. CONCLUSIONS: This study provides insight into long-term outcomes associated with TBI in post-9/11 veterans and suggests that exposure to TBI has a negative effect on social and family functioning, community reintegration, and return to work even after controlling for comorbidity, deployment experiences, and sociodemographic characteristics. Additional research is required to explicate what appears to be complex interactions among TBI severity, psychosocial well-being, combat exposures, and socioeconomic resources in this population.

Long-term physical and mental health outcomes associated with traumatic brain injury severity in post-9/11 veterans: A retrospective cohort study.

OBJECTIVES: To examine long-term outcomes of self-reported physical and mental health among Post-9/11 Veterans stratified by traumatic brain injury (TBI) severity, we hypothesized that more severe TBI would be associated with significantly poorer outcomes. METHODS: A prospective longitudinal survey of physical and mental health status was conducted with a national cohort of Post-9/11 Veterans. We then used generalized linear models (GLM) to assess the unique contribution of TBI severity on long-term outcomes after controlling for socio-demographic characteristics, comorbidity phenotypes, and deployment experiences. RESULTS: TBI of any severity was associated with significantly poorer outcomes relative to the No TBI group. However, the manifestation of these outcomes identified in our study differed meaningfully by TBI severity level. CONCLUSIONS: Veterans with any TBI exposure experience poorer long-term outcomes than those with no TBI even when covariates are considered. In particular, measures of somatization, PTSD symptom distress, and depression indicate pervasive and long-term health concerns among individuals with TBI. Additional research is required to fully explicate what appear to be complex relationships among TBI severity, physical and mental well-being, combat exposures, and socioeconomic resources in this population.

Pain and chronic mild traumatic brain injury in the US military population: a Chronic Effects of Neurotrauma Consortium study.

PRIMARY OBJECTIVES: To describe the association between mild traumatic brain injury (mTBI) and pain intensity and pain interference outcomes while accounting for potential confounders and mediators including environmental factors and comorbidities in a cohort of US Veterans of the Iraq and Afghanistan wars. RESEARCH DESIGN: Cross-sectional snapshot of baseline data from a prospective, longitudinal study. METHODS: Effects of mTBI on pain intensity and pain interference were compared between participants with or without mTBI exposure. Data were analysed using covariate-adjusted regression analyses as well as structural equation modelling (SEM) methods to assess the robustness of findings across different modelling assumptions. As results of the two approaches were consistent with respect to the overall association between mTBI exposure and pain, the results focus primarily on the SEM findings. RESULTS: The mTBI exposed group reported significantly greater indices of post-traumatic stress disorder (PTSD), depression, anxiety and sleep disturbance. After accounting for other factors, mTBI exposure was significantly, but indirectly associated with the pain interference and pain intensity outcomes. CONCLUSIONS: mTBI is strongly associated with pain intensity and pain interference in this sample. However, the effect appears to be mediated by other common mTBI comorbidities: PTSD, depression, anxiety and sleep disturbance.

Chronic Effects of Neurotrauma Consortium (CENC) multicentre study interim analysis: Differences between participants with positive versus negative mild TBI histories.

OBJECTIVES: Compare characteristics and outcomes of combat-exposed military personnel with positive versus negative mild traumatic brain injury (mTBI) histories. SETTING: Recruitment was from registration lists and ambulatory clinics at four veterans administration hospitals. PARTICIPANTS: Consented veterans and service members completing initial evaluation by September 2016 (n = 492). DESIGN: Observational with cross-sectional analyses. MAIN MEASURES: Multimodal assessments including structured interviews, record review, questionnaires, neuroendocrine labs and neurocognitive and sensorimotor performance. RESULTS: In unadjusted comparisons to those absent lifetime mTBI, the mTBI positive group (84%) had greater combat exposure, more potential concussive events, less social support and more comorbidities, including asthma, sleeping problems and post-traumatic stress disorder. They also fared worse on all sensory and pain symptom scores and self-reported functional and global outcomes. They had poorer scores on Wechsler Adult Intelligence Scale-IV coding (processing speed), TMT-B (visual-motor integration and executive function) and two posturography subtests, but were otherwise equal to TBI negative participants on neurocognitive and sensorimotor testing and neuroendocrine levels. CONCLUSIONS: Although differences in characteristics exist which were not adjusted for, participants with historical mTBI have greater symptomatology and life functioning difficulties compared with non-TBI. Performance measures were less dissimilar between groups. These findings will guide further research within this accruing cohort.

Is balance performance reduced after mild traumatic brain injury?: Interim analysis from chronic effects of neurotrauma consortium (CENC) multi-centre study.

OBJECTIVES: Determine if mild traumatic brain injury (mTBI) history is associated with balance disturbances. SETTING: Chronic Effects of Neurotrauma Consortium (CENC) centres. PARTICIPANTS: The CENC multi-centre study enrols post-9/11 era Service Members and Veterans with combat exposure. This sample (n = 322) consisted of enrolees completing initial evaluation by September 2016 at the three sites conducting computerized dynamic post-urography (CDP) testing. DESIGN: Observational study with cross-sectional analyses using structural equation modelling. MAIN MEASURES: Comprehensive structured interviews were used to diagnose all lifetime mild traumatic brain injuries (mTBIs). The outcome, Sensory Organization Test (SOT), was measured on CDP dual-plate force platform. Other studied variables were measured by structured interviews, record review and questionnaires. RESULTS: The overall positive/negative mTBI classification did not have a significant effect on the composite equilibrium score. However, the repetitive mTBI classification showed lower scores for participants with ≥ 3 mTBI versus 1-2 lifetime mTBIs. For repetitive mTBI, pain interference acted as a mediator for the indirect effect, and a direct effect was evident on some sensory condition equilibrium scores. CONCLUSION: These findings show that repeated mTBI, partially mediated by pain, may lead to later balance disturbances among military combatants. Further study of CDP outcomes within this accruing cohort is warranted.

Predictors of Satisfaction With Life in Veterans After Traumatic Brain Injury: A VA TBI Model Systems Study.

OBJECTIVE: To identify predictors of satisfaction with life in Veterans 1 year after traumatic brain injury (TBI). SETTING: The VA TBI Model Systems (TBIMS) project includes 5 Veterans Affairs (VA) Polytrauma Rehabilitation Centers. PARTICIPANTS: Veterans enrolled in the VA TBIMS study who completed the Satisfaction With Life Scale at year 1 follow-up. The sample is largely male (96%) and Caucasian (72%), with a median age of 27 years upon enrollment. DESIGN: Prospective observational cohort study measuring including demographics (eg, education), preinjury variables (eg, mental health history and employment), and military variables (eg, injury during deployment and injury during active duty status). MAIN OUTCOME MEASURE: Satisfaction With Life Scale. RESULTS: Multivariate regression analyses revealed that age, marital status, preinjury employment status, preinjury mental health history, and active duty status at the time of injury were significant predictors of life satisfaction at year 1 follow-up. CONCLUSIONS: Results of this study suggest that satisfaction with life in Veterans with TBI is mediated by several factors that might inform rehabilitation interventions and discharge recommendations. Preinjury variables and active duty status (a unique aspect of the Veteran population) influence life satisfaction at 1 year postinjury. Limitations and future clinical implications will be discussed.

Predictors of Employment Outcomes in Veterans With Traumatic Brain Injury: A VA Traumatic Brain Injury Model Systems Study.

OBJECTIVES: To examine the length of time to return to work (RTW) among service members and veterans (SM/V) with traumatic brain injury (TBI) and to identify variables predictive of RTW. SETTING: Department of Veterans Affairs Polytrauma Rehabilitation Centers (VA PRC). PARTICIPANTS: SM/V enrolled in the VA PRC Traumatic Brain Injury Model Systems database who were of 18 to 60 years of age and admitted with the diagnosis of TBI. DESIGN: Prospective observational cohort study. MAIN OUTCOME MEASURES: Employment status at 1-year postinjury follow-up; Time to Employment (ie, number of days it took to RTW) as documented during 1-year postinjury follow-up. RESULTS: The final sample (n = 293) included male (96%) SM/V with severe TBI (69%). Approximately 21% of the sample participants were employed at 1 year postinjury. Younger individuals who self-identified as nonminority returned to work sooner. Significant associations were observed for time to employment for cause of injury and injury severity. CONCLUSIONS: Few SM/V with moderate to severe TBI returned to work at 1 year postinjury. Predictors such as younger age at the time of injury, minority status, and severity of TBI affected time to and probability of RTW. Findings from this study have important implications for rehabilitation planning and service delivery across the continuum of recovery.