Health Outcomes Associated With Military Deployment: Mild Traumatic Brain Injury, Blast, Trauma, and Combat Associations in the Florida National Guard

Health Conditions and Treatment Utilization Among Older Male Veterans Incarcerated in Prisons

BACKGROUND

More than 50,000 older male veterans incarcerated in prisons are expected to return to their communities and utilize the Veterans Health Administration (VHA) and community healthcare systems. To support the continuity of healthcare and overall successful community reentry of older incarcerated veterans, an understanding of their health profiles and treatment utilization while in correctional care is needed.

OBJECTIVE

To assess the health status of older male veterans incarcerated in state prisons and explore demographic, military, and VHA-related factors associated with medical conditions, disabilities, behavioral conditions, and medical and behavioral treatment utilization.

DESIGN/PARTICIPANTS

Cross-sectional observational study of 880 male veterans aged 50 + incarcerated in state prisons using data from the 2016 Bureau of Justice Statistics Survey of Prison Inmates.

MAIN MEASURES

Veteran status, self-report health status, and treatment utilization since prison admission. Prevalence rates for conditions and treatment utilization were calculated. Logistic regression models were used to examine the association of characteristics with conditions and treatment utilization.

KEY RESULTS

Among the 880 older male veterans in state prisons, the majority reported having a current medical condition (79.3%) or disability (61.6%), almost half had history of a mental health condition (44.5%), and more than a quarter (29%) had a substance use disorder. Compared to White veterans, Black veterans were less likely to report a disability or mental health condition. Few demographic, military, and VA-related characteristics were associated with medical or behavioral conditions or treatment utilization.

CONCLUSION

Our results suggest that the VHA and community healthcare systems need to be prepared to address medical and disability conditions among the majority of older male veterans who will be leaving prison and returning to their communities. Integrated medical and behavioral healthcare delivery models may be especially important for these veterans as many did not receive behavioral health treatment while in prison.

Military and Nonmilitary TBI Associations with Hearing Loss and Self-Reported Hearing Difficulty among Active-Duty Service Members and Veterans

OBJECTIVE

Identify associations between self-reported history of military and nonmilitary traumatic brain injury (TBI) on hearing loss and hearing difficulty from the Noise Outcomes in Servicemembers Epidemiology (NOISE) study.

STUDY DESIGN

Cross-sectional.

SETTING

Multi-institutional tertiary referral centers.

PATIENTS

Four hundred seventy-three Active-Duty Service members (ADSM) and 502 veterans.

EXPOSURE

Self-reported history of no TBI, military TBI only, nonmilitary TBI only, both military and nonmilitary TBI.

MAIN OUTCOME MEASURES

Pure-tone hearing thresholds, Speech Recognition In Noise Test (SPRINT), Hearing Handicap Inventory for Adults (HHIA), and Speech, Spatial and Qualities of Hearing Scale (SSQ)-12.

RESULTS

25% (120/473) of ADSM and 41% (204/502) of veterans self-reported a TBI. Military TBI was associated with poorer hearing thresholds in all frequency ranges in veterans (adjusted mean difference, 1.8 dB; 95% confidence interval [CI], 0.5-3.0; 3.3, 0.8-5.8; 5.1; 1.7-8.5, respectively), and in the high frequency range in ADSM (mean difference, 3.2 dB; 95% CI, 0.1-6.3). Veterans with military TBI only and nonmilitary TBI only had lower odds of correctly identifying speech in noise than veterans with no TBI (odds ratio [OR], 0.78; 95% CI, 0.72-0.83; 0.90; 0.84-0.98). ADSM with a military TBI (OR, 5.7; 95% CI, 2.6-12.5) and veterans with any TBI history (OR, 2.5; 95% CI, 1.5-4.3; OR, 2.2; 95% CI, 1.3-3.8; OR, 4.5; 95% CI, 2.1-9.8) were more likely to report hearing difficulty on HHIA. SSQ-12 results corroborated HHIA findings.

CONCLUSIONS

Military TBI was associated with poorer hearing thresholds in veterans and ADSM, and poorer SPRINT scores in veterans. Military TBI was associated with poorer self-perceived hearing ability in ADSM. All types of TBI were associated with poorer self-perceived hearing ability in veterans, although the strength of this association was greatest for military TBI.

The Effect of Concussion Mechanism of Injury on Sleep Problems in Active Duty Service Members Following Deployment

INTRODUCTION

Sleep disruption is pervasive in the military and is generally exacerbated during deployment, partially due to increases in operational tempo and exposure to stressors and/or trauma. In particular, sleep disruption is a commonly reported symptom following deployment-related traumatic brain injury (TBI), though less is known about the prevalence of sleep disturbance as a function of whether the TBI was induced by high-level blast (HLB) or direct impact to the head. TBI assessment, treatment, and prognosis are further complicated by comorbidity with posttraumatic stress disorder (PTSD), depression, and alcohol misuse. Here, we examine whether concussion mechanism of injury is associated with differences in the prevalence of self-reported sleep disturbance following deployment in a large sample of U.S. Marines while accounting for probable PTSD, depression, and alcohol misuse.

MATERIALS AND METHODS

This was a retrospective cohort study of active duty enlisted Marines with a probable concussion (N = 5757) who completed the Post-Deployment Health Assessment between 2008 and 2012. Probable concussion was defined as endorsement of a potentially concussive event with corresponding loss or alteration of consciousness. The presence of concussion-related sleep problems was assessed with a dichotomous item. Probable PTSD, depression, and alcohol misuse were assessed using the Primary Care PTSD Screen, the Patient Health Questionnaire-2, and the Alcohol Use Identification Test-Concise, respectively. Logistic regression models investigated the effects of mechanism of injury (HLB vs. impact), PTSD, depression, and alcohol misuse on the presence of sleep problems, adjusting for sex and pay grade. The study was approved by the Naval Health Research Center Institutional Review Board.

RESULTS

Approximately 41% of individuals with a probable deployment-related concussion reported sleep problems following the event; 79% of concussed individuals reporting both HLB and probable PTSD reported sleep problems. All main effects were significantly associated with sleep disturbance in adjusted models. PTSD showed the strongest association with sleep disturbance (adjusted odds ratio [AOR] = 2.84), followed by depression (AOR = 2.43), HLB exposure (AOR = 2.00), female sex (AOR = 1.63), alcohol misuse (AOR = 1.14), and pay grade (AOR = 1.10). A significant HLB × PTSD interaction emerged (AOR = 1.58), which suggests that sleep disturbance was elevated among those with both HLB-induced (vs. impact-induced) concussions and presence (vs. absence) of PTSD. No other significant interactions emerged.

CONCLUSION

To our knowledge, this is the first study to examine the prevalence of concussion-related sleep complaints following deployment as a function of the mechanism of injury in individuals with and without probable PTSD and depression. Individuals with HLB-induced concussion were twice as likely to report sleep problems as those with an impact-induced concussion. Future work should examine these effects longitudinally with validated measures that assess greater precision of exposure and outcome assessment (e.g., blast intensity and type of sleep disturbance).

Associations between health-related behaviors and self-reported cognitive symptoms in U.S. military personnel injured on deployment

Health behaviors may be core contributors to cognition and mental health following mild traumatic brain injury (TBI). The aims of the present study examined: (1) whether health behaviors including sleep duration, alcohol use, and physical activity differed in injured military personnel with and without deployment-related mild TBI history and (2) the relative contributions of health behaviors and deployment-related mild TBI history to self-reported cognitive, posttraumatic stress disorder (PTSD), and depressive symptoms. Participants included 3076 military personnel injured on deployment participating in the Wounded Warrior Recovery Project, an ongoing web-based study. Military personnel with deployment-related mild TBI history reported similar rates of physical activity and levels of alcohol problems as those without, but were less likely to report receiving the recommended duration of sleep. When adjusting for demographic and injury variables, all three health behaviors were associated with cognitive, PTSD, and depressive symptoms. Alcohol problems demonstrated significant but small effects across all outcomes measures (ηp2=.01) whereas physical activity was associated with slightly larger effects albeit still within the small range (ηp2=.02-0.04). Duration of sleep bordered a medium effect for cognitive symptoms (ηp2=.05) and was in the medium range for PTSD and depressive symptoms (ηp2=.06). Although deployment-related mild TBI history was significant in all models, effect sizes were small (ηp2=.01). Findings from the present study provide support that health behaviors have stronger effects with regard to cognitive, PTSD, and depressive symptoms compared to deployment-related mild TBI history in military personnel and, given their modifiable nature, may represent treatment targets in this population.

Post-Traumatic Headache: A Review of Prevalence, Clinical Features, Risk Factors, and Treatment Strategies

Post-traumatic headache (PTH) is a common and debilitating consequence of mild traumatic brain injury (mTBI) that can occur over one year after the head impact event. Thus, better understanding of the underlying pathophysiology and risk factors could facilitate early identification and management of PTH. There are several factors that could influence the reporting of PTH prevalence, including the definition of concussion and PTH. The main risk factors for PTHs include a history of migraines or headaches, female gender, younger age, greater severity of the head injury, and co-occurring psychological symptoms, such as anxiety and depression. PTH clinical profiles vary based on onset, duration, and severity: tension-type headache, migraine headaches, cervicogenic headache, occipital neuralgia, and new daily persistent headache. Pharmacological treatments often consist of analgesics and non-steroidal anti-inflammatory drugs, tricyclic antidepressants, or antiepileptic medication. Cognitive behavioral therapy, relaxation techniques, biofeedback, and physical therapy could also be used for PTH treatment. Our work highlighted the need for more rigorous studies to better describe the importance of identifying risk factors and patient-centered treatments and to evaluate the effectiveness of the existing treatment options. Clinicians should consider a multidisciplinary approach to managing PTH, including pharmacotherapy, cognitive behavioral therapy, and lifestyle changes.

Multispectral optoacoustic tomography (MSOT): Monitoring neurovascular changes in a mouse repetitive traumatic brain injury model

BACKGROUND

Evidence suggests that mild TBI injuries, which comprise > 75% of all TBIs, can cause chronic post-concussive symptoms, especially when experienced repetitively (rTBI). rTBI is a major cause of cognitive deficit in athletes and military personnel and is associated with neurovascular changes. Current methods to monitor neurovascular changes in detail are prohibitively expensive and invasive for patients with mild injuries.

NEW METHOD

We evaluated the potential of multispectral optoacoustic tomography (MSOT) to monitor neurovascular changes and assess therapeutic strategies in a mouse model of rTBI. Mice were subjected to rTBI or sham via controlled cortical impact and administered pioglitazone (PG) or vehicle. Oxygenated and deoxygenated hemoglobin were monitored using MSOT. Indocyanine green clearance was imaged via MSOT to evaluate blood-brain-barrier (BBB) integrity.

RESULTS

Mice subjected to rTBI show a transient increase in oxygenated/total hemoglobin ratio which can be mitigated by PG administration. rTBI mice also show BBB disruption shortly after injury and reduction of oxygenated/total hemoglobin in the chronic stage, neither of which were affected by PG intervention.

COMPARISON WITH EXISTING METHODS

MSOT imaging has the potential as a noninvasive in vivo imaging method to monitor neurovascular changes and assess therapeutics in mouse models of rTBI. In comparison to standard methods of tracking inflammation and BBB disruption, MSOT can be used multiple times throughout the course of injury without the need for surgery. Thus, MSOT is especially useful in research of rTBI models for screening therapeutics, and with further technological improvements may be extended for use in rTBI patients.

Prevalence and correlates of self-reported cognitive difficulties in deployment-injured U.S. military personnel

Cognitive difficulties typically resolve within days to weeks following mild traumatic brain injury (mTBI); however, a sizable proportion of individuals continue to report cognitive symptoms months to years later that are often associated with posttraumatic stress disorder (PTSD) and depression to a greater degree than a history of mTBI. The current study sought to evaluate the prevalence of self-reported cognitive difficulties as well as the relative contributions of demographic, injury-related, and mental health variables in a large study of U.S. military personnel injured during deployment since 2001. Slightly fewer than half (42.0%) of participants reported elevated cognitive difficulties compared with a normative population; however, this was driven primarily by those who screened positive for PTSD or depression. Hierarchical linear regression revealed that various demographic and injury factors, including lower educational attainment, retired or separated military status, enlisted rank, and a history of deployment-related mTBI, were associated with more self-reported cognitive difficulties, f² = 0.07. Screening positive for PTSD or depression accounted for 32.1% of the variance in self-reported cognitive symptoms, f² = 0.63, whereas injury variables, including a history of deployment-related mTBI, albeit significant in the model, accounted for 1.6%. The current findings add to the growing body of literature underscoring the importance of screening for and treating mental health conditions in injured military personnel.

Health symptoms after war zone deployment-related mild traumatic brain injury: contributions of mental disorders and lifetime brain injuries

PRIMARY OBJECTIVE

To gain a better understanding of the complex relationship between combat deployment-related mild traumatic brain injury (mTBI) and persistent post-concussive symptoms (PPCSs), taking into consideration a wide range of potentially mediating and confounding factors.

RESEARCH DESIGN

Cross-sectional.

METHODS AND PROCEDURES

Subjects were 613 U. S. military Veterans and Service Members who served during operations Enduring Freedom, Iraqi Freedom, or New Dawn (OEF/OIF/OND) and completed a structured interview of mental disorders and a battery of questionnaires. Hierarchical binary logistic regression analyses were used to test the hypotheses.

MAIN OUTCOMES AND RESULTS

After accounting for mental disorders, lifetime mTBIs outside of OEF/OIF/OND deployment, medical conditions, and injury/demographic characteristics, deployment-related mTBI continued to be associated with several PPCSs (headaches, sleep disturbance, and difficulty making decisions). Deployment-related mTBI was also associated with two symptoms not normally associated with mTBI (nausea/upset stomach and numbness/tingling).

CONCLUSIONS

After adjusting for a wide range of factors, OEF/OIF/OND deployment-related mTBI was still associated with PPCSs on average 10 years after the injury. These findings suggest that mTBI sustained during OEF/OIF/OND deployment may have enduring negative health effects. More studies are needed that prospectively and longitudinally track health and mental health outcomes after TBI.

The 3 levels of HIV stigma in the United States military: perspectives from service members living with HIV

Background

Epidemiological surveillance data indicate that a majority of HIV-infected in the United States (U.S.) military are African-Americans and men who have sex with men. There is limited research about barriers to HIV prevention among military service members and the unique factors that contribute to HIV stigma.

Methods

A convenience sample of 30 U.S. service members were recruited from an infectious disease clinic. In depth interviews were conducted and data analyzed using a thematic coding process.

Results

Two broad categories were identified: 1) Outcomes of HIV Stigma: Fear of Rejection, Shame, and Embarrassment; and 2) Strategies for combating stigma which include increasing HIV education and prevention resources. Military policies and institutional culture regarding sexuality were found to contribute to stigma.

Conclusions

Participants identified a need for HIV education and suggested individuals living with HIV serve as mentors. A peer-to-peer intervention for delivering HIV prevention education may address these needs and reduce HIV stigma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11462-9.

Apolipoprotein E (APOE) ε4 Status Moderates the Relationship Between Close-Range Blast Exposure and Cognitive Functioning

OBJECTIVES

Recent studies suggest that close-range blast exposure (CBE), regardless of acute concussive symptoms, may have negative long-term effects on brain health and cognition; however, these effects are highly variable across individuals. One potential genetic risk factor that may impact recovery and explain the heterogeneity of blast injury's long-term cognitive outcomes is the inheritance of an apolipoprotein (APOE) ε4 allele, a well-known genetic risk factor for Alzheimer's disease. We hypothesized that APOE ε4 carrier status would moderate the impact of CBE on long-term cognitive outcomes.

METHODS

To test this hypothesis, we examined 488 post-9/11 veterans who completed assessments of neuropsychological functioning, psychiatric diagnoses, history of blast exposure, military and non-military mild traumatic brain injuries (mTBIs), and available APOE genotypes. We separately examined the effects of CBE on attention, memory, and executive functioning in individuals with and without the APOE ε4 allele.

RESULTS

As predicted, we observed a differential impact of CBE status on cognition as a function of APOE ε4 status, in which CBE ε4 carriers displayed significantly worse neuropsychological performance, specifically in the domain of memory. These results persisted after adjusting for clinical, demographic, and genetic factors and were not observed when examining other neurotrauma variables (i.e., lifetime or military mTBI, distant blast exposure), though these variables displayed similar trends.

CONCLUSIONS

These results suggest APOE ε4 carriers are more vulnerable to the impact of CBE on cognition and highlight the importance of considering genetic risk when studying cognitive effects of neurotrauma.

Post-traumatic Headache and Mild Traumatic Brain Injury: Brain Networks and Connectivity

PURPOSE OF REVIEW

Post-traumatic headache (PTH) consequent to mild traumatic brain injury (mTBI) is a complex, multidimensional, chronic neurological disorder. The purpose of this review is to evaluate the current neuroimaging studies on mTBI and PTH with a specific focus on brain networks and connectivity patterns.

RECENT FINDINGS

We present findings on PTH incidence and prevalence, as well as the latest neuroimaging research findings on mTBI and PTH. Additionally, we propose a new strategy in studying PTH following mTBI. The diversity and heterogeneity of pathophysiological mechanisms underlying mild traumatic brain injury pose unique challenges on how we interpret neuroimaging findings in PTH. Evaluating alterations in the intrinsic brain network connectivity patterns using novel imaging and analytical techniques may provide additional insights into PTH disease state and therefore inform effective treatment strategies.

Use of Medical Cannabis to Treat Traumatic Brain Injury

There is not a single pharmacological agent with demonstrated therapeutic efficacy for traumatic brain injury (TBI). With recent legalization efforts and the growing popularity of medical cannabis, patients with TBI will inevitably consider medical cannabis as a treatment option. Pre-clinical TBI research suggests that cannabinoids have neuroprotective and psychotherapeutic properties. In contrast, recreational cannabis use has consistently shown to have detrimental effects. Our review identified a paucity of high-quality studies examining the beneficial and adverse effects of medical cannabis on TBI, with only a single phase III randomized control trial. However, observational studies demonstrate that TBI patients are using medical and recreational cannabis to treat their symptoms, highlighting inconsistencies between public policy, perception of potential efficacy, and the dearth of empirical evidence. We conclude that randomized controlled trials and prospective studies with appropriate control groups are necessary to fully understand the efficacy and potential adverse effects of medical cannabis for TBI.

Understanding the Link Between Traumatic Brain Injury Accompanied by Loss of Consciousness and Well-Being: A Sample of UK Military Veterans

OBJECTIVE

To investigate the association between reported traumatic brain injury plus loss of consciousness (TBI + LOC) and a range of demographic, military, and physical and mental health factors among a sample of UK veterans seeking support for mental health difficulties.

DESIGN

The present study was a cross-sectional study.

PARTICIPANTS

Clinical records were used to identify a sample of treatment-seeking UK veterans (N = 3335), of which a total of 403 took part.

MAIN MEASURES

Information on demographic characteristics, military experiences, and a range of physical and mental health difficulties was collected.

RESULTS

Almost half of the sample (48%) reported a TBI + LOC, which was most strongly associated with drug use and childhood adversity. More modest associations also emerged with earlier service termination, likelihood of unemployment, as well as chronic pain and poor mobility.

CONCLUSION

The findings suggested that TBI + LOC may not specifically be associated with symptoms of posttraumatic stress in a sample of treatment-seeking veterans. The demonstrated links between TBI + LOC and adverse childhood, drug use, physical health, and employment may be useful in improving the assessment and rehabilitation of veterans with TBI + LOC.

Comparison of Clinical Outcomes 1 and 5 Years Post-Injury Following Combat Concussion

OBJECTIVE

To compare 1-year and 5-year clinical outcomes in 2 groups of combat-deployed service members without brain injury to those of 2 groups with combat-related concussion to better understand long-term clinical outcome trajectories.

METHODS

This prospective, observational, longitudinal multicohort study examined 4 combat-deployed groups: controls without head injury with or without blast exposure and patients with combat concussion arising from blast or blunt trauma. One-year and 5-year clinical evaluations included identical batteries for neurobehavioral, psychiatric, and cognitive outcomes. A total of 347 participants completed both time points of evaluation. Cross-sectional and longitudinal comparisons were assessed. Overall group effect was modeled as a 4-category variable with rank regression adjusting for demographic factors using a 2-sided significance threshold of 0.05, with post hoc Tukey p values calculated for the pairwise comparisons.

RESULTS

Significant group differences in both combat concussion groups were identified cross-sectionally at 5-year follow-up compared to controls in neurobehavioral (Neurobehavioral Rating Scale-Revised [NRS]; Cohen d, -1.10 to -1.40, confidence intervals [CIs] [-0.82, -1.32] to [-0.97, -1.83] by group) and psychiatric domains (Clinician-Administered PTSD Scale for DSM-IV [CAPS]; Cohen d, -0.91 to -1.19, CIs [-0.63, -1.19] to [-0.76, -1.62] by group) symptoms with minimal differences in cognitive performance. Both combat concussion groups also showed clinically significant decline from 1- to 5-year evaluation (66%-76% neurobehavioral NRS; 41%-54% psychiatric CAPS by group). Both control groups fared better but a subset also had clinically significant decline (37%-50% neurobehavioral NRS; 9%-25% psychiatric CAPS by group).

CONCLUSIONS

There was an evolution, not resolution, of symptoms from 1- to 5-year evaluation, challenging the assumption that chronic stages of concussive injury are relatively stable. Even some of the combat-deployed controls worsened. The evidence supports new considerations for chronic trajectories of concussion outcome in combat-deployed service members.

Concussive head injury exacerbates neuropathology of sleep deprivation: Superior neuroprotection by co-administration of TiO2-nanowired cerebrolysin, alpha-melanocyte-stimulating hormone, and mesenchymal stem cells

Sleep deprivation (SD) is common in military personnel engaged in combat operations leading to brain dysfunction. Military personnel during acute or chronic SD often prone to traumatic brain injury (TBI) indicating the possibility of further exacerbating brain pathology. Several lines of evidence suggest that in both TBI and SD alpha-melanocyte-stimulating hormone (α-MSH) and brain-derived neurotrophic factor (BDNF) levels decreases in plasma and brain. Thus, a possibility exists that exogenous supplement of α-MSH and/or BDNF induces neuroprotection in SD compounded with TBI. In addition, mesenchymal stem cells (MSCs) are very portent in inducing neuroprotection in TBI. We examined the effects of concussive head injury (CHI) in SD on brain pathology. Furthermore, possible neuroprotective effects of α-MSH, MSCs and neurotrophic factors treatment were explored in a rat model of SD and CHI. Rats subjected to 48h SD with CHI exhibited higher leakage of BBB to Evans blue and radioiodine compared to identical SD or CHI alone. Brain pathology was also exacerbated in SD with CHI group as compared to SD or CHI alone together with a significant reduction in α-MSH and BDNF levels in plasma and brain and enhanced level of tumor necrosis factor-alpha (TNF-α). Exogenous administration of α-MSH (250μg/kg) together with MSCs (1×10⁶) and cerebrolysin (a balanced composition of several neurotrophic factors and active peptide fragments) (5mL/kg) significantly induced neuroprotection in SD with CHI. Interestingly, TiO₂ nanowired delivery of α-MSH (100μg), MSCs, and cerebrolysin (2.5mL/kg) induced enhanced neuroprotection with higher levels of α-MSH and BDNF and decreased the TNF-α in SD with CHI. These observations are the first to show that TiO₂ nanowired administration of α-MSH, MSCs and cerebrolysin induces superior neuroprotection following SD in CHI, not reported earlier. The clinical significance of our findings in light of the current literature is discussed.

Characteristics and Impact of U.S. Military Blast-Related Mild Traumatic Brain Injury: A Systematic Review

As a result of armed conflict, head trauma from exposure to blasts is an increasing critical health issue, particularly among military service members. Whilst numerous studies examined the burden of blast-related brain injuries on service members', few systematic reviews have been published. This work provides a comprehensive summary of the evidence on blast-related mild traumatic brain injury (mTBI) burden in active U.S. military service members and inactive Veterans, describing characteristics and outcomes. Records published up to April 2017 were identified through a search of PubMed, Web of Science, Scopus, Ovid MEDLINE, and Cochrane Library. Records-based and original research reporting on U.S. military service members and Veterans with mild blast TBI were included. Data on subject characteristics, exposure, diagnostic criterion, and outcomes were extracted from included studies using a standardized extraction form and were presented narratively. Of the 2,290 references identified by the search, 106 studies with a total of 37,515 participants met inclusion criteria for blast-related mTBI. All but nine studies were based out of military or Veteran medical facilities. Unsurprisingly, men were over-represented (75–100%). The criteria used to define blast-related mTBI were consistent; however, the methodology used to ascertain whether individuals met those criteria for diagnosis were inconsistent. The diagnosis, most prevalent among the Army, heavily relied on self-reported histories. Commonly reported adverse outcomes included hearing disturbances and headaches. The most frequently associated comorbidities were post-traumatic stress disorder, depression, anxiety, sleep disorders, attention disorders, and cognitive disorders. The primary objective of this review was to provide a summary of descriptive data on blast-related mTBI in a U.S. military population. Low standardization of the methods for reaching diagnosis and problems in the study reporting emphasize the importance to collect high-quality data to fill knowledge gaps pertaining to blast-related mTBI.

TBI-CareQOL military health care frustration in caregivers of service members/veterans with traumatic brain injury

PURPOSE

Caregivers of service members/veterans (SMVs) encounter a number of barriers when navigating the military health care system. The purpose of this study was to develop a new measure to assess potential caregiver frustration with the systems of care and benefits in the United States Departments of Defense and Veterans Affairs.

METHOD

The TBI-CareQOL Military Health Care Frustration measure was developed using data from 317 caregivers of SMVs with TBI who completed an item pool comprised of 64 questions pertaining to anger or frustration with accessing military health care services.

RESULTS

Exploratory and confirmatory factor analyses supported the retention of 58 items. Constrained graded response model (GRM) overall fit and item fit analyses and differential item functioning investigations of age and education factors supported the retention of 43 items in the final measure. Expert review and GRM item calibration products were used to inform the selection of two 6-item static short forms (TBI-CareQOL Military Health Care Frustration-Self; TBI-CareQOL Military Health Care Frustration-Person with TBI) and to program the TBI-CareQOL Military Health Care Frustration computer adaptive test (CAT). Preliminary data supported the reliability (i.e., internal consistency and test-retest reliability) as well as the validity (i.e., convergent, discriminant, and known-groups) of the new measure.

CONCLUSIONS

The new TBI-CareQOL Military Health Care Frustration measure can be used to examine caregiver perceptions of and experience with the military health care system, to target improvements. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Psychosocial functioning in veterans with combat-related PTSD: An evolutionary concept analysis

BACKGROUND

Veterans returning from combat have a greater risk for developing posttraumatic stress disorder (PTSD) and greater severity of psychosocial functioning impairment. Previous research has demonstrated the strong association between PTSD and psychosocial functioning impairment. Psychosocial functioning is an ambiguous term often used in literature to discuss PTSD-associated consequences, intervention response, and symptom progression. An evolutionary concept analysis was conducted to clarify understanding of psychological functioning in veterans with combat-related PTSD. Rodgers' method for an evolutionary concept analysis was used to examine the concept of psychosocial functioning. A literature search using the Cumulative Index to Nursing and Allied Health Literature and SCOPUS databases and subsequent screening yielded twenty articles meeting established criteria for analysis. The analysis highlights significant attributes, antecedents, consequences, and implications for future concept development. Psychosocial functioning environment/domain, social support, and engagement in treatment were distinguishing attributes identified. Combat exposure and various PTSD symptoms are related antecedents. Consequences such as decreased intimacy, decreased work function, low parenting satisfaction, and inadequate productivity in educational settings are all components of this concept. The concept of psychosocial functioning is meaningful in the everyday lives of US combat veterans with PTSD and requires special consideration in treatment planning by healthcare providers.

Prevalence of Lifetime History of Traumatic Brain Injury among Older Male Veterans Compared with Civilians: A Nationally Representative Study

Traumatic brain injury (TBI) is common among older adults as well as among veterans in the United States and can increase risk for dementia. We compared prevalence of TBI in older male veterans and civilians using a nationally representative sample. We examined data from 599 male respondents to the 2014 wave of the Health and Retirement Study (HRS), a nationally representative survey of older adults, randomly selected to participate in a comprehensive TBI survey. Respondents self-reported no injury, non-TBI head/neck injury (NTI), or TBI. We used weighted analyses to examine prevalence of injury and relative risk of injury subtypes. Among male veterans, we found a national prevalence of more than 70% for lifetime history of any head/neck injury (TBI plus NTI), 14.3% for multiple NTI, and 36% for lifetime history of at least one TBI. In contrast, prevalence estimates for male civilians were 58% for lifetime history of head/neck injury, 4.8% for multiple NTI, and 45% for lifetime history of at least one TBI (all comparisons, p < 0.001). Male civilians have higher self-reported TBI prevalence, whereas male veterans have higher self-reported NTI and multiple-NTI prevalence. Further research on drivers of the unexpectedly higher prevalence of lifetime history of TBI in male civilians, as well as on mechanisms and sequelae of the highly prevalent non-TBI head/neck injuries among older male veterans, is warranted.

Mild TBI in interdisciplinary neurorehabilitation: Treatment challenges and insights

BACKROUND

Traumatic brain injury (TBI) has an estimated prevalence rate of 1.7 million occurrences a year in the United States with over 75% of traumatic brain injuries classified as 'mild.' The majority of individuals with mild traumatic brain injuries resume their daily functioning fairly quickly, and many fully within the first year. However, a minority of persons with mild TBI (mTBI), with estimates ranging between 1% and 20%, develop persistent cognitive, emotional, behavioral, and physical symptoms. Clinicians vary considerably in their clinical opinions regarding these individuals and there is no consensus on the treatment protocol for this population.

OBJECTIVE

This manuscript presents four case studies of mild TBI with persistent symptoms treated by a transdisciplinary team in an outpatient neurorehabilitation setting based on community reintegration. Clinical challenges and insights involved in conceptualizing and effectively treating these individuals are discussed to facilitate future direction.

METHODS

Four different mild TBI cases, each with persistent symptoms, but different injury mechanisms, dynamics, and factors affecting symptom persistence, expression, course, and outcome were included in the analysis of their treatment course and outcome. The treatment protocol included: brain injury education combined with supportive counseling for cultivation of positive expectancy effects, symptom-based, graded treatment involving most disciplines, frequent treatment team consultations, collaborations, and planning, and consistent team messages about post-injury recovery and expected return to community activities. Treatment outcomes were assessed with self and family reports, as well as the Mayo Portland Adaptability Inventory (MPAI-4) at admission and at discharge.

RESULTS AND CONCLUSIONS

Each of the individuals made functional progress during rehabilitation, as evidenced by self and family reports and the MAPI-4. The cases posed various challenges to the treatment team, though a transdisciplinary team under the guidance of a rehabilitation physician and rehabilitation neuropsychologist was able to help patients navigate the path to their functional recovery. In addition to the specific treatment protocol, transdisciplinary team collaboration guided by rehabilitation neuropsychology contributed to treatment success.

Update on treatment options for blast-induced hearing loss

PURPOSE OF REVIEW

The incidence of blast injuries has increased, and the ear is the highest risk organ. Ear injury induced by blast exposure is important in both military and civilian conditions. The permanent hearing loss caused by blast exposure is associated with a decline in the quality of life. In this review, I describe recent therapeutic strategies for each of the ear pathologies caused by blast exposure.

RECENT FINDINGS

For tympanic membrane perforation after blast exposure, basic fibroblast growth factor (bFGF) has been used as a less invasive treatment to repair the tympanic membrane. The closure rates of tympanic membrane perforations treated with bFGF were reported to be comparable to those following conventional tympanoplasty.For sensorineural hearing loss after blast exposure, treatment with neurotrophic factors, such as nerve growth factor (NGF) or neurotrophin-3, antioxidants, and Atoh1 induction have recently been applied, and some of them were considered for clinical application.

SUMMARY

Recent advances of therapeutics for blast-induced hearing loss, based on their pathologies, have been outlined. There are several promising therapeutic approaches for both middle and inner ear disorders after blast exposure; however, further research is needed to establish new treatments for blast-induced hearing dysfunction.

The Associations Between Physical and Psychological Symptoms and Traumatic Military Deployment Exposures

Current paradigms regarding the effects of traumatic exposures on military personnel do not consider physical symptoms unrelated to injury or illness as independent outcomes of trauma exposure, characteristically dealing with these symptoms as comorbidities of psychological disorders. Our objective was to ascertain the proportions of deployed military personnel who experienced predominantly physical symptoms, predominantly psychological symptoms, and comorbidity of the two and to examine the association between traumatic deployment exposures (TDEs) and these symptomatic profiles. Data were taken from a cross-sectional study of Australian Defence Force personnel who were deployed to the Middle East during 2001-2009 (N = 14,032). Four groups were created based on distributional splits of physical and psychological symptom scales: low-symptom, psychological, physical, and comorbid. Multinomial logistic regression models assessed the probability of symptom group membership, compared with low-symptom, as predicted by self-reported TDEs. Group proportions were: low-symptom, 78.3%; physical, 5.0%; psychological, 9.3%; and comorbid, 7.5%. TDEs were significant predictors of all symptom profiles. For subjective, objective, and human death and degradation exposures, respectively, the largest relative risk ratios (RRRs) were for the comorbid profile, RRRs = 1.47, 1.19, 1.48; followed by the physical profile, RRRs = 1.27, 1.15, 1.40; and the psychological profile, RRRs = 1.22, 1.07, 1.22. Almost half of participants with physical symptoms did not have comorbid psychological symptoms, suggesting that physical symptoms can occur as a discrete outcome trauma exposure. The similar dose-response association between TDEs and the physical and psychological profiles suggests trauma is similarly associated with both outcomes.

Proteomic Profiling of Mouse Brains Exposed to Blast-Induced Mild Traumatic Brain Injury Reveals Changes in Axonal Proteins and Phosphorylated Tau

Alzheimer's disease (AD), the most prevalent form of dementia, is characterized by two pathological hallmarks: Tau-containing neurofibrillary tangles and amyloid-β protein (Aβ)-containing neuritic plaques. The goal of this study is to understand mild traumatic brain injury (mTBI)-related brain proteomic changes and tau-related biochemical adaptations that may contribute to AD-like neurodegeneration. We found that both phosphorylated tau (p-tau) and the ratio of p-tau/tau were significantly increased in brains of mice collected at 3 and 24 h after exposure to 82-kPa low-intensity open-field blast. Neurological deficits were observed in animals at 24 h and 7 days after the blast using Simple Neuroassessment of Asymmetric imPairment (SNAP) test, and axon/dendrite degeneration was revealed at 7 days by silver staining. Liquid chromatography-mass spectrometry (LC-MS/MS) was used to analyze brain tissue labeled with isobaric mass tags for relative protein quantification. The results from the proteomics and bioinformatic analysis illustrated the alterations of axonal and synaptic proteins in related pathways, including but not being limited to substantia nigra development, cortical cytoskeleton organization, and synaptic vesicle exocytosis, suggesting a potential axonal damage caused by blast-induced mTBI. Among altered proteins found in brains suffering blast, microtubule-associated protein 1B, stathmin, neurofilaments, actin binding proteins, myelin basic protein, calcium/calmodulin-dependent protein kinase, and synaptotagmin I were representative ones involved in altered pathways elicited by mTBI. Therefore, TBI induces elevated phospho-tau, a pathological feature found in brains of AD, and altered a number of neurophysiological processes, supporting the notion that blast-induced mTBI as a risk factor contributes to AD pathogenesis. LC/MS-based profiling has presented candidate target/pathways that could be explored for future therapeutic development.

Faith of Our Sister Soldiers: National Guard Women Share Stories of Their Faith During and After Deployment

In this qualitative study, we explored the religious and spiritual beliefs of women in the National Guard, the role of religion in their lives, and the effect of deployment and reintegration on women's belief systems. We conducted semi-structured interviews with 39 women service members who had been deployed. Results of the content analysis revealed five themes: (1) Religious Identity/Belief in God, (2) Religion/Spirituality has a Positive Impact, (3) Religious Activities, (4) Religiosity and Deployment, and (5) Religiosity/Spiritual Experiences Change over Time. Implications for future research and the incorporation of faith-based practices with women service members who may seek mental health treatment are discussed.

Relationships Between Subcortical Shape Measures and Subjective Symptom Reporting in US Service Members With Mild Traumatic Brain Injury

OBJECTIVE

To assess interactions of subcortical structure with subjective symptom reporting associated with mild traumatic brain injury (mTBI), using advanced shape analysis derived from volumetric MRI.

PARTICIPANTS

Seventy-six cognitively symptomatic individuals with mTBI and 59 service members sustaining only orthopedic injury.

DESIGN

Descriptive cross-sectional study.

MAIN MEASURES

Self-report symptom measures included the PTSD Checklist-Military, Neurobehavioral Symptom Inventory, and Symptom Checklist-90-Revised. High-dimensional measures of shape characteristics were generated from volumetric MRI for 7 subcortical structures in addition to standard volume measures.

RESULTS

Several significant interactions between group status and symptom measures were observed across the various shape measures. These interactions were revealed in the right thalamus and globus pallidus for each of the shape measures, indicating differences in structure thickness and expansion/contraction for these regions. No relationships with volume were observed.

CONCLUSION

Results provide evidence for the sensitivity of shape measures in differentiating symptomatic mTBI individuals from controls, while volumetric measures did not exhibit this same sensitivity. Disruptions to thalamic nuclei identified here highlight the role of the thalamus in the spectrum of symptoms associated with mTBI. Additional work is needed to prospectively, and longitudinally, assess these measures along with cognitive performance and advanced multimodal imaging methods to extend the utility of shape analysis in relation to functional outcomes in this population.

The Value of Physical Symptoms in Screening For Posttraumatic Stress Disorder in the Military

Physical symptoms are highly comorbid with posttraumatic stress disorder (PTSD). As PTSD is underdiagnosed, this study explored the value of self-reported physical symptoms in screening for 30-day PTSD in military personnel. Two physical symptom scales were constructed using items from a 67-item health symptom checklist, clinical interviews were used as the diagnostic reference standard, and diagnostic utility of physical symptoms was compared with the current gold standard screen, the PTSD checklist (PCL). Receiver operating characteristic analyses showed that both a 9-item and a 10-item physical symptom scale were of value in predicting PTSD (areas under the curve 0.81 and 0.85). Importantly, two thirds of PTSD positive personnel missed by the PCL were captured with physical symptoms scales, and when physical symptoms were added to the PCL, prediction was improved (areas under the curve 0.90 to 0.92). Our findings highlight the value of including assessing physical symptoms in PTSD screening.

Relationships Between Sleepiness, Mood, and Neurocognitive Performance in Military Personnel

Neurocognitive computerized assessment tools (NCATs) were developed to assist military clinicians with the tracking of recovery from injury and return to full duty decisions with a recent focus on the setting of post-concussion evaluations. However, there is limited data on the impact of deployment on neurocognitive functioning, sleepiness, and mood in healthy, non-concussed Service members. Automated Neuropsychological Assessment Metrics version 4 TBI Military (ANAM) data was obtained for a sample of active duty deployed personnel (n = 72) without recent history of mild traumatic brain injury (mTBI). A linear regression was conducted to examine the effects of sleepiness and mood state on neurocognitive performance. The overall multivariate regression was statistically significant. Negative mood states were the most salient predictors of neurocognitive performance with higher levels of endorsement associated with lower scores. The findings support measures of negative mood state, but not sleepiness, as relevant predictors of neurocognitive performance as measured by the ANAM. These results indicate that mood needs to be considered when reviewing neurocognitive data to ensure that appropriate clinical decisions are made; in particular for return-to-duty decisions in deployed settings after concussion recovery.

Neurotoxic tau oligomers after single versus repetitive mild traumatic brain injury

Mild traumatic brain injury accounts for the majority of head injuries and has been correlated with neurodegeneration and dementia. While repetitive mild traumatic brain injury is highly correlated to neurodegeneration, the correlation of a single mild traumatic brain injury with neurodegeneration is still unclear. Because tau aggregates are the main form of mild traumatic brain injury induced pathology, toxic forms of tau protein most likely play a role in the development of post-mild traumatic brain injury neurodegeneration. Therefore, it becomes crucial to characterize the properties of soluble tau aggregates in single versus repetitive mild traumatic brain injury. Herein, we isolated tau oligomers from wild-type mice exposed to single or repetitive mild traumatic brain injury and characterized the tau aggregates at functional, biochemical and biophysical levels. We demonstrated that single versus repetitive mild traumatic brain injuries frequencies lead to the formation of different tau oligomeric polymorphisms. These polymorphisms express different long-term potentiation impairment potencies, toxicity potentials, morphologies and strain indicating properties. To our knowledge, this is the first evidence that soluble tau oligomers derived from single versus repetitive mild traumatic brain injuries form distinct polymorphisms that possibly correlate with the risk of neurodegeneration after mild traumatic brain injury.

Tinnitus, Traumatic Brain Injury, and Posttraumatic Stress Disorder in the Military

PURPOSE

Acoustic trauma is more prevalent in military settings, especially among individuals with combat-related military occupational specialties. Gunfire, improvised explosive devices, and mortar explosions are a few examples that may cause hearing degradation and tinnitus. It is possible that the same events that are associated with auditory problems can cause traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD).

METHOD

This paper reviews the distinct and overlapping symptoms of tinnitus, TBI, and PTSD, and how these disorders interact to synergistically promote negative outcomes.

RESULTS

Tinnitus may serve as a significant contributor to symptoms of TBI and PTSD. Therefore, tinnitus subtypes could be identified as physiologically or psychologically based, or both.

CONCLUSIONS

Additional research is warranted to determine the common and unique symptoms and associated neurological pathways of tinnitus, TBI, and PTSD. Brief treatment recommendations are provided, including a multidisciplinary approach for the physical and psychological distress associated with tinnitus.

Association Between 5-Year Clinical Outcome in Patients With Nonmedically Evacuated Mild Blast Traumatic Brain Injury and Clinical Measures Collected Within 7 Days Postinjury in Combat

IMPORTANCE

Although previous work has examined clinical outcomes in combat-deployed veterans, questions remain regarding how symptoms evolve or resolve following mild blast traumatic brain injury (TBI) treated in theater and their association with long-term outcomes.

OBJECTIVE

To characterize 5-year outcome in patients with nonmedically evacuated blast concussion compared with combat-deployed controls and understand what clinical measures collected acutely in theater are associated with 5-year outcome.

DESIGN, SETTING, AND PARTICIPANTS

A prospective, longitudinal cohort study including 45 service members with mild blast TBI within 7 days of injury (mean 4 days) and 45 combat deployed nonconcussed controls was carried out. Enrollment occurred in Afghanistan at the point of injury with evaluation of 5-year outcome in the United States. The enrollment occurred from March to September 2012 with 5-year follow up completed from April 2017 to May 2018. Data analysis was completed from June to July 2018.

EXPOSURES

Concussive blast TBI. All patients were treated in theater, and none required medical evacuation.

MAIN OUTCOMES AND MEASURES

Clinical measures collected in theater included measures for concussion symptoms, posttraumatic stress disorder (PTSD) symptoms, depression symptoms, balance performance, combat exposure intensity, cognitive performance, and demographics. Five-year outcome evaluation included measures for global disability, neurobehavioral impairment, PTSD symptoms, depression symptoms, and 10 domains of cognitive function. Forward selection multivariate regression was used to determine predictors of 5-year outcome for global disability, neurobehavior impairment, PTSD, and cognitive function.

RESULTS

Nonmedically evacuated patients with concussive blast injury (n = 45; 44 men, mean [SD] age, 31 [5] years) fared poorly at 5-year follow-up compared with combat-deployed controls (n = 45; 35 men; mean [SD] age, 34 [7] years) on global disability, neurobehavioral impairment, and psychiatric symptoms, whereas cognitive changes were unremarkable. Acute predictors of 5-year outcome consistently identified TBI diagnosis with contribution from acute concussion and mental health symptoms and select measures of cognitive performance depending on the model for 5-year global disability (area under the curve following bootstrap validation [AUCBV] = 0.79), neurobehavioral impairment (correlation following bootstrap validation [RBV] = 0.60), PTSD severity (RBV = 0.36), or cognitive performance (RBV = 0.34).

CONCLUSIONS AND RELEVANCE

Service members with concussive blast injuries fared poorly at 5-year outcome. The results support a more focused acute screening of mental health following TBI diagnosis as strong indicators of poor long-term outcome. This extends prior work examining outcome in patients with concussive blast injury to the larger nonmedically evacuated population.

Neurobehavioral Management of the Polytrauma Veteran

Since the inception of the Afghanistan and Iraq wars, an increasing number of veterans have sought treatment from the Department of Veterans Affairs for combat-related injuries. Many veterans experience postconcussive symptoms, traumatic stress, chronic pain, sensory deficits, and/or headaches. The goal of this article was to highlight some of the challenges treatment providers may face, while providing rehabilitation specialists with important evaluation and treatment considerations in working with this population to maximize outcomes for these veterans.

Why "Moral Enhancement" Isn't Always Moral Enhancement: The Case of Traumatic Brain Injury in American Vets

In this article, I argue that as we learn more about how we might intervene in the brain in ways that impact human behavior, the scope of what counts as "moral behavior" becomes smaller and smaller because things we successfully manipulate using evidence-based science are often things that fall outside the sphere of morality. Consequently, the argument that we are morally obligated to morally enhance our neighbors starts to fall apart, not because humans should be free to make terrible choices, but because morality is not something subject to such manipulation. To illustrate my argument, I shall use the rise of veteran diversion courts in the United States as a putative instance of an intervention designed to change human behavior for the better. Part of my purpose in working my way through this case study is to demonstrate that many philosophers have the psychology of immoral action wrong.

Hemostatic nanoparticles increase survival, mitigate neuropathology and alleviate anxiety in a rodent blast trauma model

Explosions account for 79% of combat related injuries and often lead to polytrauma, a majority of which include blast-induced traumatic brain injuries (bTBI). These injuries lead to internal bleeding in multiple organs and, in the case of bTBI, long term neurological deficits. Currently, there are no treatments for internal bleeding beyond fluid resuscitation and surgery. There is also a dearth of treatments for TBI. We have developed a novel approach using hemostatic nanoparticles that encapsulate an anti-inflammatory, dexamethasone, to stop the bleeding and reduce inflammation after injury. We hypothesize that this will improve not only survival but long term functional outcomes after blast polytrauma. Poly(lactic-co-glycolic acid) hemostatic nanoparticles encapsulating dexamethasone (hDNPs) were fabricated and tested following injury along with appropriate controls. Rats were exposed to a single blast wave using an Advanced Blast Simulator, inducing primary blast lung and bTBI. Survival was elevated in the hDNPs group compared to controls. Elevated anxiety parameters were found in the controls, compared to hDNPs. Histological analysis indicated that apoptosis and blood-brain barrier disruption in the amygdala were significantly increased in the controls compared to the hDNPs and sham groups. Immediate intervention is crucial to mitigate injury mechanisms that contribute to emotional deficits.

Deployment of personnel to military operations: impact on mental health and social functioning

This Campbell systematic review examines the effects of deployment on mental health. The review summarizes evidence from 185 studies. All studies used observational data to quantify the effect of deployment. This review includes studies that evaluate the effects of deployment on mental health. A total of 185 studies were identified. However, only 40 of these were assessed to be of sufficient methodological quality to be included in the final analysis. The studies spanned the period from 1993 to 2017 and were mostly carried out in the USA, UK and Australia. The studies all had some important methodological weaknesses. None of the included studies used experimental designs (random assignment). Deployment to military operations negatively affects the mental health functioning of deployed military personnel. For assessments taken more than 24 months since exposure, we consistently found adverse effects of deployment on all mental health domains (PTSD, depression, substance abuse/dependence, and common mental disorders), particularly on PTSD. For assessments taken less than 24 months (or a variable number of months since exposure) the evidence was less consistent and in many instances inconclusive.

Plain language summary

Deployment to military operations negatively affects the mental health functioning of deployed military personnel: While additional research is needed, the current evidence strongly supports the notion that deployment negatively affects mental health functioning of deployed military personnel.What is this review about?: When military personnel are deployed to military operations abroad they face an increased risk of physical harm, and an increased risk of adverse shocks to their mental health.The primary condition under consideration is deployment to an international military operation. Deployment to a military operation is not a uniform condition; rather, it covers a range of scenarios. Military deployment is defined as performing military service in an operation at a location outside the home country for a limited time period, pursuant to orders.The review included studies that reported outcomes for individuals who had been deployed. This review looked at the effect of deployment on mental health outcomes. The mental health outcomes are: post-traumatic stress disorder (PTSD), major depressive disorder (MDD), common mental disorders (depression, anxiety and somatisation disorders) and substance-related disorders.By identifying the major effects of deployment on mental health and quantifying these effects, the review can inform policy development on deployment and military activity as well as post-deployment support for veterans. In this way the review enables decision-makers to prioritise key areas.What are the main findings of this review?: What studies are included?: This review includes studies that evaluate the effects of deployment on mental health. A total of 185 studies were identified. However, only 40 of these were assessed to be of sufficient methodological quality to be included in the final analysis. The studies spanned the period from 1993 to 2017 and were mostly carried out in the USA, UK and Australia. The studies all had some important methodological weaknesses. None of the included studies used experimental designs (random assignment).Does deployment have an effect on mental health?: Deployment to military operations negatively affects the mental health functioning of deployed military personnel. For assessments taken more than 24 months since exposure, we consistently found adverse effects of deployment on all mental health domains (PTSD, depression, substance abuse/dependence, and common mental disorders), particularly on PTSD. For assessments taken less than 24 months (or a variable number of months since exposure) the evidence was less consistent and in many instances inconclusive.What do the findings of this review mean?: The odds of screening positive for PTSD and depression were consistently high in the longer term. This suggests that efforts should be increased to detect and treat mental disorders, as effects may be long-lasting.Overall the risk of bias in the majority of included studies was high. While it is difficult to imagine a randomised study design to understand how deployment affects mental health, other matters such as changes to personnel policy, or unanticipated shocks to the demand for military personnel, could potentially be a rich source of quasi-experimental variation.How up-to-date is this review?: The review authors searched for studies up to 2017. This Campbell systematic review was published in March 2018.

Executive summary

BACKGROUND: When military personnel are deployed to military operations abroad they face an increased risk of physical harm, and an increased risk of adverse shocks to their mental health. Research suggests that the increased risk to mental health is mainly due to the hazards of war, combat exposure: firing weapons, road side bombs, seeing fellow soldiers, friends, civilians, and enemies being injured, maimed or killed. These experiences may lead to severe mental stress. The adverse impact on mental health is the psychological cost of war, and it is of interest to policymakers to learn the magnitude of these effects. This review sets out to synthesise available evidence about the consequences of deployment for deployed military personnel in the mental health and social functioning domains.OBJECTIVES: The objective of this review isto synthesise the consequences of deployment to military operation on the mental health and social functioning of deployed military personnel.SEARCH METHODS: We searched electronic databases, grey literature, and references from primary studies and related reviews. No language or date restrictions were applied to the searches. We searched the following electronic databases: Academic Search Elite, Cochrane Library, EMBASE, ERIC, MEDLINE, PsycINFO, Science Citation Index, Social Science Citation Index, SocINDEX, as well as the Nordic platforms: bibliotek.dk, BIBSYS, and LIBRIS. The conclusions of this review are based on the most recent searches performed. The last search was performed in April 2017.SELECTION CRITERIA: Primary studies had to meet the following inclusion criteria: Participants: The participants should be military personnel.Intervention: The condition should be deployment to a military operation.Comparison: The relevant comparisons were either comparing a) deployed military personnel to non-deployed military personnel, b) deployed military personnel to military personnel deployed elsewhere, for example personnel deployed to non-combat operations, c) military personnel deployed to the same operation but stratified by combat exposure.Outcomes: The study should report on one or more mental health outcomes, and/or social functioning for the deployed participants. In particular studies should report on one or more of the following mental health outcomes: PTSD, major depression, substance abuse or dependence (including alcohol), and common mental disorders (depression and anxiety disorders). The following social functioning outcomes were relevant: employment, and homelessness.Study Designs: Both experimental and quasi-experimental designs with a comparison group were eligible for inclusion in the review. Studies were excluded if they: Reported on deployments taking place before 1989.Used a within group pre-post study design.Did not report on at least one of the mental health or social functioning outcomes. DATA COLLECTION AND ANALYSIS: The total number of potentially relevant studies constituted31,049records. A total of 185 studies met the inclusion criteria and were critically appraised by the review authors. The final selection of 185 studies was from 13 different countries.Forty eight of the 185 studies did not report effect estimates or provide data that would allow the calculation of an effect size and standard error. Fifty four studies were excluded because of overlapping samples. The majority of those studies were from USA but the main reason for not using studies from USA in the synthesis was lack of information to calculate an effect size. Nearly half the studies from the UK could not be used in the synthesis due to overlap of data samples. Forty three studies were judged to have a very high risk of bias (5 on the scale) and, in accordance with the protocol, we excluded these from the data synthesis on the basis that they would be more likely to mislead than inform., Thus a total of 40 studies, from five different countries, were included in the data synthesis.Random effects models were used to pool data across the studies. We used the odds ratio. Pooled estimates were weighted with inverse variance methods, and 95% confidence intervals were calculated. The meta-analyses were carried out by time since exposure (short, medium, long, and other time since exposure) and by type of comparison (deployed versus non-deployed, all deployed but stratified by either combat operations versus non-combat operations, or stratified by combat exposure). We performed single factor subgroup analysis. The assessment of any difference between subgroups was based on 95% confidence intervals. Funnel plots were used to assess the possibility of publication bias. Sensitivity analysis was used to evaluate whether the pooled effect sizes were robust across components of methodological quality.MAIN RESULTS: The findings were mixed, depending on the outcome, the time since exposure and the approach (deployed versus non-deployed termed absolute or stratified by extent of combat termed relative) used to investigate the effect. It was not possible to analyse the outcomes homelessness and employment. All studies that could be used in the data synthesis reported on the impact of deployment on mental health; PTSD, depression, substance use or common mental disorder.For assessments taken less than 24 months since exposure the evidence was inconclusive either because too few studies reported results in the short and medium term and/or the degree of heterogeneity between studies was large.For assessments taken at other time points (a variable number of months since exposure) the evidence was inconclusive for the relative comparisons due to either too few studies or a substantial degree of heterogeneity between studies. For the absolute comparison the analysis of common mental disorder was inconclusive, whereas the average effects of PTSD and depression were positive and statistically significant (PTSD odds ratio (OR) was 1.91 (95% confidence interval (CI): 1.28 to 2.85) and OR=1.98 (95% CI: 1.05 to 3.70) for depression). The analysis concerning substance use indicated that deployed participants did not have higher odds of screening positive for substance use compared to non-deployed participants (OR=1.15 (95% CI: 0.98 to 1.36)).For assessments taken more than 24 months post exposure, meta-analyses indicated that the odds of screening positive for PTSD, depression, substance use and common mental disorder were higher for participants in the deployed group compared to participants in the group that were not deployed (PTSD OR=3.31 (95% CI: 2.69 to 4.07), OR=2.19 (95% CI: 1.58 to 3.03) for depression, OR=1.27 (95% CI: 1.15 to 1.39) for substance use, and OR=1.64 (95% CI: 1.38 to 1.96) for common mental disorder). Likewise, participants reporting high combat exposure had higher odds of screening positive for PTSD and depression than participants reporting lower exposure for long term assessments (PTSD OR=3.05 (95% CI: 1.94 to 4.80) and OR=1.81 (95% CI: 1.28 to 2.56) for depression). The analyses of substance use and common mental disorder were inconclusive due to too few studies.On the basis of the prevalence of mental health problems in pre-deployed or non-deployed population based comparison sampleswe would therefore expect the long term prevalence of PTSD in post-deployed samples to be in the range 6.1 - 14.9%, the long term prevalence of depression to be in the range from 7.6% to 18%, the long term prevalence of substance use to be in the range from 2.4% to 17.5% and the prevalence of common mental disorder to be in the range from 10% to 23%.Sensitivity analyses resulted in no appreciable change in effect size, suggesting that the results are robust.It was only possible to assess the impact of two types of personnel characteristics (branch of service and duty/enlistment status) on the mental health outcomes. We found no evidence to suggest that the effect of deployment on any outcomes differ between these two types of personnel characteristics.AUTHORS' CONCLUSIONS: Deployment to military operations negatively affects the mental health functioning of deployed military personnel. We focused on the effect of deployment on PTSD (post-traumatic stress disorder), depression, substance abuse/dependence, and common mental disorders (depression and anxiety disorders). For assessments taken less than 24 months (or a variable number of months since exposure) the evidence was less consistent and in many instances inconclusive. For assessments taken more than 24 months since exposure, we consistently found adverse effects of deployment on all domains, particularly on PTSD. There is increased political awareness of the need to address post deployment mental health problems. The odds of screening positive for PTSD and depression were consistently high in the longer term. This suggests that efforts should be increased to detect and treat mental disorders, as effects may be long lasting. Mental illness is of particular concern in the military for operational reasons, but they may be hard to detect in the military setting because a military career is intimately linked with mental and physical strength.It was not possible to examine a number of factors which we had reason to expect would impact on the magnitude of the effect. This would have been particularly relevant from a policy perspective because these are direct parameters that one could use to optimally "organize" deployment in order to minimize impacts on mental health functioning.While additional research is needed, the current evidence strongly supports the notion that deployment negatively affects mental health functioning of deployed military personnel. The next step is to begin to examine preventive measures and policies for organizing deployment, in order to minimize the effects on mental health.

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.

Repeated Mild Traumatic Brain Injury: Potential Mechanisms of Damage

Mild traumatic brain injury (mTBI) represents a significant public healthcare concern, accounting for the majority of all head injuries. While symptoms are generally transient, some patients go on to experience long-term cognitive impairments and additional mild impacts can result in exacerbated and persisting negative outcomes. To date, studies using a range of experimental models have reported chronic behavioral deficits in the presence of axonal injury and inflammation following repeated mTBI; assessments of oxidative stress and myelin pathology have thus far been limited. However, some models employed induced acute focal damage more suggestive of moderate–severe brain injury and are therefore not relevant to repeated mTBI. Given that the nature of mechanical loading in TBI is implicated in downstream pathophysiological changes, the mechanisms of damage and chronic consequences of single and repeated closed-head mTBI remain to be fully elucidated. This review covers literature on potential mechanisms of damage following repeated mTBI, integrating known mechanisms of pathology underlying moderate–severe TBIs, with recent studies on adult rodent models relevant to direct impact injuries rather than blast-induced damage. Pathology associated with excitotoxicity and cerebral blood flow-metabolism uncoupling, oxidative stress, cell death, blood-brain barrier dysfunction, astrocyte reactivity, microglial activation, diffuse axonal injury, and dysmyelination is discussed, followed by a summary of functional deficits and preclinical assessments of therapeutic strategies. Comprehensive characterization of the pathology underlying delayed and persisting deficits following repeated mTBI is likely to facilitate further development of therapeutic strategies to limit long-term sequelae.

Characteristics and Health Outcomes of Post-9/11 Caregivers of US Service Members and Veterans Following Traumatic Brain Injury

OBJECTIVES

To (a) characterize a sample of post-9/11 caregivers providing help to service members and veterans (SMV) following traumatic brain injury (TBI), (b) examine the level of support provided, and (c) determine caregiver health and well-being outcomes.

SETTING

Military treatment facility.

PARTICIPANTS

Caregivers (N = 278) of SMVs who sustained a mild, moderate, severe, or penetrating TBI (96.0% female; 86.0% spouse/partner; age: M = 38.7 years, SD = 10.4). Participants were divided into 3 groups on the basis of the level of support provided (low, medium, high).

DESIGN

Prospective observational.

MAIN MEASURES

Caregiver Appraisal Scale, SF-36v2 Health Survey, Mayo-Portland Adaptability Inventory-4, Caregiver Questionnaire.

RESULTS

The majority of caregivers were helping an SMV with mild TBI and comorbid posttraumatic stress disorder/depression, who was injured in a blast-related incident during combat. Caregivers helped predominantly with activities of daily living and/or instrumental activities of daily living and spent more than 40 hours per week providing care. High-support caregivers were more likely to be caring for an SMV with comorbid posttraumatic stress disorder, report poor physical and mental health outcomes, and have a negative impact on employment and finances.

CONCLUSIONS

A better understanding of protective factors is required to ensure that burden of care does not exceed the caregiver's health and financial capacity, or undermine the care, well-being, and recovery of the SMV.

Ultrastructural brain abnormalities and associated behavioral changes in mice after low-intensity blast exposure

Explosive blast-induced mild traumatic brain injury (mTBI), a "signature wound" of recent military conflicts, commonly affects service members. While past blast injury studies have provided insights into TBI with moderate- to high-intensity explosions, the impact of primary low-intensity blast (LIB)-mediated pathobiology on neurological deficits requires further investigation. Our prior considerations of blast physics predicted ultrastructural injuries at nanoscale levels. Here, we provide quantitative data using a primary LIB injury murine model exposed to open field detonation of 350 g of high-energy explosive C4. We quantified ultrastructural and behavioral changes up to 30 days post blast injury (DPI). The use of an open-field experimental blast generated a primary blast wave with a peak overpressure of 6.76 PSI (46.6 kPa) at a 3-m distance from the center of the explosion, a positive phase duration of approximate 3.0 milliseconds (ms), a maximal impulse of 8.7 PSI × ms and a sharp rising time of 9 × 10^-3 ms, with no apparent impact/acceleration in exposed animals. Neuropathologically, myelinated axonal damage was observed in blast-exposed groups at 7 DPI. Using transmission electron microscopy, we observed and quantified myelin sheath defects and mitochondrial abnormalities at 7 and 30 DPI. Inverse correlations between blast intensities and neurobehavioral outcomes including motor activities, anxiety levels, nesting behavior, spatial learning and memory occurred. These observations uncover unique ultrastructural brain abnormalities and associated behavioral changes due to primary blast injury and provide key insights into its pathogenesis and potential treatment.

Consistency of Recall for Deployment-Related Traumatic Brain Injury

OBJECTIVE

To examine the temporal consistency of self-reported deployment-related traumatic brain injury (TBI) and its association with posttraumatic stress disorder (PTSD) symptom severity.

SETTING

In-person interviews at US Army installations (postdeployment); phone interviews (long-term follow-up).

PARTICIPANTS

A total of 378 US Army soldiers and veterans deployed to Iraq; 14.3% (n = 54) reported TBI with loss of consciousness during an index deployment.

DESIGN

Participants were evaluated after returning from deployment and again 5 to 9 years later.

MAIN MEASURES

Temporal consistency of TBI endorsement based on TBI screening interviews; PTSD Checklist, Civilian Version.

RESULTS

The concordance of deployment-related TBI endorsement from the postdeployment to long-term follow-up assessment was moderate (κ = 0.53). Of the 54 participants reporting (predominantly mild) TBI occurring during an index deployment, 32 endorsed TBI inconsistently over time. More severe PTSD symptoms at postdeployment assessment were independently associated with discordant reporting (P = .0004); each 10-point increase in PCL scores increasing odds of discordance by 69% (odds ratio = 1.69; 95% confidence interval, 1.26-2.26).

CONCLUSIONS

Deployment-related TBI may not be reported reliably over time, particularly among war-zone veterans with greater PTSD symptoms. Results of screening evaluations for TBI history should be viewed with caution in the context of PTSD symptom history.

On the Accurate Determination of Shock Wave Time-Pressure Profile in the Experimental Models of Blast-Induced Neurotrauma

Measurement issues leading to the acquisition of artifact-free shock wave pressure-time profiles are discussed. We address the importance of in-house sensor calibration and data acquisition sampling rate. Sensor calibration takes into account possible differences between calibration methodology in a manufacturing facility, and those used in the specific laboratory. We found in-house calibration factors of brand new sensors differ by less than 10% from their manufacturer supplied data. Larger differences were noticeable for sensors that have been used for hundreds of experiments and were as high as 30% for sensors close to the end of their useful lifetime. These observations were despite the fact that typical overpressures in our experiments do not exceed 50 psi for sensors that are rated at 1,000 psi maximum pressure. We demonstrate that sampling rate of 1,000 kHz is necessary to capture the correct rise time values, but there were no statistically significant differences between peak overpressure and impulse values for low-intensity shock waves (Mach number <2) at lower rates. We discuss two sources of experimental errors originating from mechanical vibration and electromagnetic interference on the quality of a waveform recorded using state-of-the-art high-frequency pressure sensors. The implementation of preventive measures, pressure acquisition artifacts, and data interpretation with examples, are provided in this paper that will help the community at large to avoid these mistakes. In order to facilitate inter-laboratory data comparison, common reporting standards should be developed by the blast TBI research community. We noticed the majority of published literature on the subject limits reporting to peak overpressure; with much less attention directed toward other important parameters, i.e., duration, impulse, and dynamic pressure. These parameters should be included as a mandatory requirement in publications so the results can be properly compared with others.

Longitudinal evaluation of ventricular volume changes associated with mild traumatic brain injury in military service members

PRIMARY OBJECTIVE

To investigate differences in longitudinal trajectories of ventricle-brain ratio (VBR), a general measure of brain atrophy, between Veterans with and without history of mild traumatic brain injury (mTBI).

RESEARCH DESIGN

Structural magnetic resonance imaging (MRI) was used to calculate VBR in 70 Veterans with a history of mTBI and 34 Veterans without such history at two time points approximately 3 and 8 years after a combat deployment.

MAIN OUTCOMES AND RESULTS

Both groups demonstrated a quadratic relationship between VBR and age that is consistent with normal developmental trajectories. Veterans with history of mTBI had larger total brain volume, but no interaction between mTBI and age was observed for brain volume, ventricular volume, or VBR.

CONCLUSIONS

In our longitudinal sample of deployed Veterans, mTBI was not associated with gross brain atrophy as reflected by abnormally high VBR or abnormal increases in VBR over time.

Combat exposure and pain in male and female Afghanistan and Iraq veterans: The role of mediators and moderators

Veterans experience physical health problems associated with disability and poor quality of life following combat exposure (CE). Understanding the CE-physical health relationship, specifically pain intensity and somatic pain, may inform etiological models and interventions. This study examined the CE-pain relationship, associated mediators, and gender as a moderator. 2381 veterans at the VA San Diego Healthcare System completed paper or electronic self-report measures of pain intensity and somatic pain. Analyses examined associations of pain with CE and posttraumatic stress disorder (PTSD), depression, and resilience as mediators of the CE-pain association. Moderated mediation models explored gender as a moderator of significant mediated pathways. Controlling for age, veterans with CE had significantly higher pain intensity and somatic pain, and PTSD and depression scores significantly mediated the CE-pain relationships. Gender significantly moderated the CE-pain intensity association through depression scores such that the indirect effect was stronger for female veterans relative to male veterans. CE is associated with pain intensity and somatic pain, with greater levels of PTSD and depression mediating the CE-pain link and gender moderating the depression mediated CE-pain association. Future studies should examine gender differences and mediators in the CE-pain relationships using longitudinal designs to inform etiological models and targeted pain interventions.

Staying in service with posttraumatic headache

Objective:

To predict the probability of a military outcome (medical discharge/retirement) in patients with mild traumatic brain injury from a clinical analysis of predetermined patient and headache characteristics.

Methods:

This retrospective cohort study sampled all new patients referred for headache evaluation at the Brain Injury Clinic of the Womack Army Medical Center, Ft. Bragg, NC (August 2008–January 2010). Headache characteristics were extracted and analyzed. Multivariable binary logistic regressions were conducted to predict probability of medical discharge/retirement.

Results:

Ninety-five soldiers (age 31.3 ± 7.4 years, male 93.7%) reported 166 headaches. The most common injury cited was a blast (53.7%). Patients with a continuous headache have almost 4 times the odds of a medically related discharge/retirement compared to patients without such a headache (continuous headache regression coefficient estimate: p < 0.042, odds ratio 3.98, 95% Wald confidence interval 1.05–15.07). Results suggest that, compared to service members who did not have a continuous headache, patients with headache histories with severe holocephalic pain who medicate to keep functioning had the highest probability of medical discharge/retirement.

Conclusions:

Certain headache characteristics may be predictive of military outcomes after mild traumatic brain injury, and we propose a profile that may be useful in that prediction. These data could be useful in future attempts to assess and treat patients with posttraumatic headache and to advise longer-term planning for return to duty or discharge.

Functional Magnetic Resonance Imaging of Cognitive Control following Traumatic Brain Injury

Novel and non-routine tasks often require information processing and behavior to adapt from moment to moment depending on task requirements and current performance. This ability to adapt is an executive function that is referred to as cognitive control. Patients with moderate-to-severe traumatic brain injury (TBI) have been reported to exhibit impairments in cognitive control and functional magnetic resonance imaging (fMRI) has provided evidence for TBI-related alterations in brain activation using various fMRI cognitive control paradigms. There is some support for greater and more extensive cognitive control-related brain activation in patients with moderate-to-severe TBI, relative to comparison subjects without TBI. In addition, some studies have reported a correlation between these activation increases and measures of injury severity. Explanations that have been proposed for increased activation within structures that are thought to be directly involved in cognitive control, as well as the extension of this over-activation into other brain structures, have included compensatory mechanisms, increased demand upon normal processes required to maintain adequate performance, less efficient utilization of neural resources, and greater vulnerability to cognitive fatigue. Recent findings are also consistent with the possibility that activation increases within some structures, such as the posterior cingulate gyrus, may reflect a failure to deactivate components of the default mode network (DMN) and that some cognitive control impairment may result from ineffective coordination between the DMN and components of the salience network. Functional neuroimaging studies examining cognitive control-related activation following mild TBI (mTBI) have yielded more variable results, with reports of increases, decreases, and no significant change. These discrepancies may reflect differences among the various mTBI samples under study, recovery of function in some patients, different task characteristics, and the presence of comorbid conditions such as depression and posttraumatic stress disorder that also alter brain activation. There may be mTBI populations with activation changes that overlap with those found following more severe injuries, including symptomatic mTBI patients and those with acute injuries, but future research to address such dysfunction will require well-defined samples with adequate controls for injury characteristics, comorbid disorders, and severity of post-concussive symptoms.