Jason M. Bailie

A Multisite Study of the Relationships between Blast Exposures and Symptom Reporting in a Post-Deployment Active Duty Military Population with Mild Traumatic Brain Injury

Explosive devices have been the most frequent cause of traumatic brain injury (TBI) among deployed contemporary U.S. service members. The purpose of this study was to examine the influence of previous cumulative blast exposures (that did or did not result in TBI) on later post-concussion and post-traumatic symptom reporting after sustaining a mild TBI (MTBI). Participants were 573 service members who sustained MTBI divided into four groups by number of blast exposures (1, 2, 3, and 4-10) and a nonblast control group. Post-concussion symptoms were measured using the Neurobehavioral Symptom Inventory (NSI) and post-traumatic stress disorder (PTSD) symptoms using the Post-traumatic Checklist-Civilian version (PCL-C). Results show groups significantly differed on total NSI scores (p<0.001), where symptom endorsement increased as number of reported blast exposures increased. Total NSI scores were significantly higher for the 3- and 4-10 blast groups compared with the 1- and 2-blast groups with effect sizes ranging from small to moderate (d=0.31 to 0.63). After controlling for PTSD symptoms using the PCL-C total score, NSI total score differences remained between the 4-10-blast group and the 1- and 2-blast groups, but were less pronounced (d=0.35 and d=0.24, respectively). Analyses of NSI subscale scores using PCL-C scores as a covariate revealed significant between-blast group differences on cognitive, sensory, and somatic, but not affective symptoms. Regression analyses revealed that cumulative blast exposures accounted for a small but significant amount of the variance in total NSI scores (4.8%; p=0.009) and total PCL-C scores (2.3%; p<0.001). Among service members exposed to blast, post-concussion symptom reporting increased as a function of cumulative blast exposures. Future research will need to determine the relationship between cumulative blast exposures, symptom reporting, and neuropathological changes.

The experience, expression, and control of anger following traumatic brain injury in a military sample.

Objective:To investigate the impact of traumatic brain injury (TBI) on the experience and expression of anger in a military sample. Participants:A total of 661 military personnel with a history of TBI and 1204 military personnel with no history of TBI. Design:Cross-sectional, between-group design, using multivariate analysis of variance. Main Measure:State-Trait Anger Expression Inventory-2 (STAXI-2). Results:Participants with a history of TBI had higher scores on the STAXI-2 than controls and were 2 to 3 times more likely than the participants in the control group to have at least 1 clinically significant elevation on the STAXI-2. Results suggested that greater time since injury (ie, months between TBI and assessment) was associated with lower scores on the STAXI-2 State Anger scale. Conclusion:Although the results do not take into account confounding psychiatric conditions and cannot address causality, they suggest that a history of TBI increases the risk of problems with the experience, expression, and control of anger. This bolsters the need for proper assessment of anger when evaluating TBI in a military cohort.

Female Service Members and Symptom Reporting after Combat and Non-Combat-Related Mild Traumatic Brain Injury

Females are often excluded from military-related mild traumatic brain injury (mTBI) research because of its relatively low prevalence in this population. The purpose of this study was to focus on outcome from mTBI in female service members, compared with males. Participants were 172 United States military service members selected from a larger sample that had sustained an mTBI, and were evaluated within 24 months of injury (Age: meanu2009=u200928.9, SDu2009=u20098.1) at one of six military medical centers. Eighty-six women were matched to 86 men on nine key variables: TBI severity, mechanism of injury, bodily injury severity, days post-injury, age, number of deployments, theater where wounded, branch of service, and rank. Participants completed the Neurobehavioral Symptom Inventory (NSI) and the Posttraumatic Stress Disorder Checklist (PCL-C). There were no meaningful gender differences across all demographic and injury-related variables (pu2009>u20090.05). There were significant group differences and medium effect sizes for the NSI total score and all four NSI cluster scores. Symptoms most affected related to nausea, sensitivity to light, change in taste/smell, change in appetite, fatigue, and poor sleep. There were significant group differences and small-medium effect sizes for the PCL-C total score and two of the three PCL-C cluster scores. Symptoms most affected related to poor concentration, trouble remembering a stressful event, and disturbing memories/thoughts/images. Females consistently experienced more symptoms than males. As females become more active in combat-related deployments, it is critical that future studies place more emphasis on this important military population.

Utility of the Validity-10 scale across the recovery trajectory following traumatic brain injury.

The Validity-10 scale was recently developed to screen for symptom exaggeration in patients following traumatic brain injury (TBI). However, it has only been validated on patients with TBI largely in the chronic phase of recovery. The influence of time since injury on the Validity-10 scale was investigated in 2,661 male servicemembers with TBI presenting to six U.S. Defense and Veterans Brain Injury Centers. Participants completed the Neurobehavioral Symptom Inventory (NSI). The Validity-10 scale and NSI total score were both weakly statistically significantly (1) positively correlated with time since injury, (2) negatively correlated with bodily injury severity, and (3) higher in participants undergoing medical board evaluations than in participants who returned to duty or were still hospitalized. Participants were statistically more likely to screen positive for possible symptom exaggeration on the Validity-10 scale as time since injury increased. However, the Validity-10 scale was only weakly related to time since injury, TBI severity, bodily injury severity, disposition, age, and return to duty status. That false positives are not increased in the acute phase of recovery and that the Validity-10 scale is not strongly related to clinical factors support the use of the Validity-10 scale in the acute recovery phase and across the TBI recovery trajectory.

Profile Analysis of the Neurobehavioral and Psychiatric Symptoms Following Combat-Related Mild Traumatic Brain Injury: Identification of Subtypes.

Objective:To explore the taxonomy of combat-related mild traumatic brain injury (mTBI) based on symptom patterns. Participants:Up to 1341 military personnel who experienced a combat-related mTBI within 2 years of evaluation. Measures:Neurobehavioral Symptom Inventory and PTSD Checklist-Civilian Version (PCL-C). Results:Cluster analysis revealed the following 4 subtypes: primarily psychiatric (posttraumatic stress disorder) group, a cognitive group, a mixed symptom group, and a good recovery group. The posttraumatic stress disorder cluster (21.9% of the sample) reported symptoms related to hyperarousal and dissociation/depression with few complaints related to cognition or headaches. The cognitive group (21.5% of the sample) had primarily cognitive and headache complaints with few mood symptoms. The mixed profile cluster included 18.6% of the sample and was characterized by a combination of mood complaints (hyperarousal and dissociation/depression), cognitive complaints, and headaches. The largest cluster (37.8% of the sample) had an overall low symptom profile and was labeled the “good recovery” group. Conclusions:The results support a unique taxonomy for combat-related mTBI. The clinical differences among these subtypes indicate a need for unique treatment resources and programs.

Development of a Portable Tool for Screening Neuromotor Sequelae From Repetitive Low-Level Blast Exposure

Blast exposure is a prevalent cause of mild traumatic brain injury (mTBI) in military personnel in combat. However, it is more common for a service member to be exposed to a low-level blast (LLB) that does not result in a clinically diagnosable mTBI. Recent research suggests that repetitive LLB exposure can result in symptomology similar to symptoms observed after mTBI. This manuscript reports on the use of an Android-based smartphone application (AccWalker app) to capture changes in neuromotor functioning after blast exposure. Active duty U.S. Navy personnel (N = 59) performed a stepping-in-place task before repetitive LLB exposure (heavy weapons training), and again immediately after, 24 hours after, and 72 to 96 hours after the completion of the training. The AccWalker app revealed that there are changes in neuromotor functioning after LLB exposure (slower self-selected movement pace and increased stride time variability) in participants who experienced neurocognitive decline. These data suggest that neurocognitive and neuromotor decline can occur after repeated LLB exposure.

Clinical Utility and Psychometric Properties of the Traumatic Brain Injury Quality of Life Scale (TBI-QOL) in US Military Service Members.

Objective:To examine the clinical utility and psychometric properties of the Traumatic Brain Injury Quality of Life (TBI-QOL) scale in a US military population. Participants:One hundred fifty-two US military service members (age: M = 34.3, SD = 9.4; 89.5% men) prospectively enrolled from the Walter Reed National Military Medical Center and other nationwide community outreach initiatives. Participants included 99 service members who had sustained a mild traumatic brain injury (TBI) and 53 injured or noninjured controls without TBI (n = 29 and n = 24, respectively). Procedure:Participants completed the TBI-QOL scale and 5 other behavioral measures, on average, 33.8 months postinjury (SD = 37.9). Main Outcome Measures:Fourteen TBI-QOL subscales; Neurobehavioral Symptom Inventory; Posttraumatic Stress Disorder Checklist–Civilian version; Alcohol Use Disorders Identification Test; Combat Exposure Scale. Results:The internal consistency reliability of the TBI-QOL scales ranged from &agr; = .91 to &agr; = .98. The convergent and discriminant validity of the 14 TBI-QOL subscales was high. The mild TBI group had significantly worse scores on 10 of the 14 TBI-QOL subscales than the control group (range, P < .001 to P = .043). Effect sizes ranged from medium to very large (d = 0.35 to d = 1.13). The largest differences were found on the Cognition-General Concerns (d = 1.13), Executive Function (d = 0.94), Grief-Loss (d = 0.88), Pain Interference (d = 0.83), and Headache Pain (d = 0.83) subscales. Conclusion:These results support the use of the TBI-QOL scale as a measure of health-related quality of life in a mild TBI military sample. Additional research is recommended to further evaluate the clinical utility of the TBI-QOL scale in both military and civilian settings.

Influence of the severity and location of bodily injuries on post-concussive and combat stress symptom reporting after military-related concurrent mild traumatic brain injuries and polytrauma.

Traumatic brain injuries (TBI) sustained in combat frequently co-occur with significant bodily injuries. Intuitively, more extensive bodily injuries might be associated with increased symptom reporting. In 2012, however, French et al. demonstrated an inverse relation between bodily injury severity and symptom reporting. This study expands on that work by examining the influence of location and severity of bodily injuries on symptom reporting after mild TBI. Participants were 579 US military service members who sustained an uncomplicated mild TBI with concurrent bodily injuries and who were evaluated at two military medical centers. Bodily injury severity was quantified using a modified Injury Severity Score (ISSmod). Participants completed the Neurobehavioral Symptom Inventory (NSI) and the Posttraumatic Stress Disorder Checklist (PCL-C), on average, 2.5 months post-injury. There was a significant negative association between ISSmod scores and NSI (r=-0.267, p<0.001) and PCL-C (r=-0.273, p<0.001) total scores. Using linear regression to examine the relation between symptom reporting and injury severity across the six ISS body regions, three body regions were significant predictors of the NSI total score (face; p<0.001; abdomen; p=0.003; extremities; p<0.001) and accounted for 9.3% of the variance (p<0.001). For the PCL-C, two body regions were significant predictors of the PCL-C total score (face; p<0.001; extremities; p<0.001) and accounted for 10.5% of the variance. There was an inverse relation between bodily injury severity and symptom reporting in this sample. Hypothesized explanations include underreporting of symptoms, increased peer support, disruption of fear conditioning because of acute morphine use, or delayed expression of symptoms.

Interpreting change on the neurobehavioral symptom inventory and the PTSD checklist in military personnel

Abstract Objective: The purpose of this study was to examine the prevalence and stability of symptom reporting in a healthy military sample and to develop reliable change indices for two commonly used self-report measures in the military health care system. Participants and method: Participants were 215 U.S. active duty service members recruited from Fort Bragg, NC as normal controls as part of a larger study. Participants completed the Neurobehavioral Symptom Inventory (NSI) and Posttraumatic Checklist (PCL) twice, separated by approximately 30 days. Results: Depending on the endorsement level used (i.e. ratings of ‘mild’ or greater vs. ratings of ‘moderate’ or greater), approximately 2–15% of this sample met DSM-IV symptom criteria for Postconcussional Disorder across time points, while 1–6% met DSM-IV symptom criteria for Posttraumatic Stress Disorder. Effect sizes for change from Time 1 to Time 2 on individual symptoms were small (Cohen’s d = .01 to .13). The test–retest reliability for the NSI total score was r = .78 and the PCL score was r = .70. An eight-point change in symptom reporting represented reliable change on the NSI total score, with a seven-point change needed on the PCL. Conclusions: Postconcussion-like symptoms are not unique to mild TBI and are commonly reported in a healthy soldier sample. It is important for clinicians to use normative data when evaluating a service member or veteran and when evaluating the likelihood that a change in symptom reporting is reliable and clinically meaningful.