Identifying and Predicting Subgroups of Veterans With Mild Traumatic Brain Injury Based on Distinct Configurations of Postconcussive Symptom Endorsement: A Latent Class Analysis

OBJECTIVE

To identify distinct subgroups of veterans with mild traumatic brain injury (mTBI) based on configurations of postconcussive symptom (PCS) endorsement, and to examine predictors of subgroup membership.

SETTING

Outpatient Veterans Health Administration (VHA).

PARTICIPANTS

Veterans with clinician-confirmed mTBI who completed the Neurobehavioral Symptom Inventory (NSI), determined using the Comprehensive Traumatic Brain Injury Evaluation database. Individuals who tended to overreport symptoms were excluded via an embedded symptom validity scale.

DESIGN

Retrospective cohort study leveraging national VHA clinical data from 2012 to 2020. Latent class analysis (LCA) with a split-sample cross-validation procedure was used to identify subgroups of veterans. Multinomial logistic regression was used to examine predictors of subgroup membership.

MAIN MEASURES

Latent classes identified using NSI items.

RESULTS

The study included 72 252 eligible veterans, who were primarily White (73%) and male (94%). The LCA supported 7 distinct subgroups of veterans with mTBI, characterized by diverging patterns of risk for specific PCS across vestibular (eg, dizziness), somatosensory (eg, headache), cognitive (eg, forgetfulness), and mood domains (eg, anxiety). The most prevalent subgroup was Global (20.7%), followed by Cognitive-Mood (16.3%), Headache-Cognitive-Mood (H-C-M; 16.3%), Headache-Mood (14.2%), Anxiety (13.8%), Headache-Sleep (10.3%), and Minimal (8.5%). The Global class was used as the reference class for multinomial logistic regression because it was distinguished from others based on elevated risk for PCS across all domains. Female (vs male), Black (vs White), and Hispanic veterans (vs non-Hispanic) were less likely to be members of most subgroups characterized by lesser PCS endorsement relative to the Global class (excluding Headache-Mood).

CONCLUSION

The 7 distinct groups identified in this study distill heterogenous patterns of PCS endorsement into clinically actionable phenotypes that can be used to tailor clinical management of veterans with mTBI. Findings reveal empirical support for potential racial, ethnic, and sex-based disparities in PCS among veterans, informing efforts aimed at promoting equitable recovery from mTBI in this population.

Cross validation of the Personality Assessment Inventory (PAI) Cognitive Bias Scale of Scales (CB-SOS) over-reporting indicators in a military sample

Following the development of the Cognitive Bias Scale (CBS), three other cognitive over-reporting indicators were created. This study cross-validates these new Cognitive Bias Scale of Scales (CB-SOS) measurements in a military sample and contrasts their performance to the CBS. We analyzed data from 288 active-duty soldiers who underwent neuropsychological evaluation. Groups were established based on performance validity testing (PVT) failure. Medium effects (d = .71 to .74) were observed between those passing and failing PVTs. The CB-SOS scales have high specificity (≥.90) but low sensitivity across the suggested cut scores. While all CB-SOS were able to achieve .90, lower scores were typically needed. CBS demonstrated incremental validity beyond CB-SOS-1 and CB-SOS-3; only CB-SOS-2 was incremental beyond CBS. In a military sample, the CB-SOS scales have more limited sensitivity than in its original validation, indicating an area of limited utility despite easier calculation. The CBS performs comparably, if not better, than CB-SOS scales. CB-SOS-2's differences in performance in this study and its initial validation suggest that its psychometric properties may be sample dependent. Given their ease of calculation and relatively high specificity, our study supports the interpretation of elevated CB-SOS scores indicating those who are likely to fail concurrent PVTs.

Mild traumatic brain injury, PTSD symptom severity, and behavioral dyscontrol: a LIMBIC-CENC study

Background

Behavioral dyscontrol occurs commonly in the general population and in United States service members and Veterans (SM/V). This condition merits special attention in SM/V, particularly in the aftermath of deployments. Military deployments frequently give rise to posttraumatic stress disorder (PTSD) and deployment-related mild TBI traumatic brain injury (TBI), potentially leading to manifestations of behavioral dyscontrol.

Objective

Examine associations among PTSD symptom severity, deployment-related mild traumatic brain injury, and behavioral dyscontrol among SM/V.

Design

Secondary cross-sectional data analysis from the Long-Term Impact of Military-Relevant Brain Injury Consortium - Chronic Effects of Neurotrauma Consortium prospective longitudinal study among SM/V (N = 1,808).

Methods

Univariable and multivariable linear regression models assessed the association and interaction effects between PTSD symptom severity, as assessed by the PTSD Checklist for the Diagnostic and Statistical Manual, 5th edition (PCL-5), and deployment-related mild TBI on behavioral dyscontrol, adjusting for demographics, pain, social support, resilience, and general self-efficacy.

Results

Among the 1,808 individuals in our sample, PTSD symptom severity (B = 0.23, 95% CI: 0.22, 0.25, p < 0.001) and deployment-related mild TBI (B = 3.27, 95% CI: 2.63, 3.90, p < 0.001) were significantly associated with behavioral dyscontrol in univariable analysis. Interaction effects were significant between PTSD symptom severity and deployment mild TBI (B = -0.03, 95% CI: -0.06, -0.01, p = 0.029) in multivariable analysis, indicating that the effect of mild TBI on behavioral dyscontrol is no longer significant among those with a PCL-5 score > 22.96.

Conclusion

Results indicated an association between PTSD symptom severity, deployment-related mild TBI, and behavioral dyscontrol among SM/V. Notably, the effect of deployment-related mild TBI was pronounced for individuals with lower PTSD symptom severity. Higher social support scores were associated with lower dyscontrol, emphasizing the potential for social support to be a protective factor. General self-efficacy was also associated with reduced behavioral dyscontrol.

Symptom validity indices in the Posttraumatic Stress Disorder Checklist for DSM-5

The use of symptom validity tests (SVTs) is standard practice in psychodiagnostic assessments. Embedded measures are indices within self-report measures. To date, no embedded SVTs have been identified in the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5). This research aimed to develop and validate PCL-5 SVTs in two samples of veterans. Participants completed one of two prospective research studies that included cognitive and psychological tests. Participants in Study 1 were veterans (N = 464) who served following the September 11, 2001, terrorist attacks; participants in Study 2 were veterans or service members (N = 338) who had been deployed to Iraq and/or Afghanistan. Both studies included the PCL-5 and the Structured Inventory of Malingered Symptomatology (SIMS), the latter of which served as the criterion for identifying PCL-5 SVTs. For Study 1, two separate SVTs were developed: the PCL-5 Symptom Severity scale (PSS), based on the PCL-5 total score, and the PCL-5 Rare Items scale (PRI), based on PCL-5 items infrequently endorsed at the highest item ratings. At the most conservative SIMS cutoff score, the PSS achieved excellent discrimination for both the Study 1, AUC = .840, and Study 2 samples, AUC = .858, with specific cutoff scores of ≥ 51 and ≥ 56 maximizing sensitivity while maintaining a specificity of .90. The PRI achieved good discrimination, AUCs = .760 and.726, respectively, with a cutoff score of 2 or higher indicated by both studies. The results of these two studies provide provisional support for these two embedded SVTs in the PCL-5.

Headache among combat-exposed veterans and service members and its relation to mild traumatic brain injury history and other factors: a LIMBIC-CENC study

Background

Headache (HA) is a common persistent complaint following mild traumatic brain injury (mTBI), but the association with remote mTBI is not well established, and risk factors are understudied.

Objective

Determine the relationship of mTBI history and other factors with HA prevalence and impact among combat-exposed current and former service members (SMs).

Design

Secondary cross-sectional data analysis from the Long-Term Impact of Military-Relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium prospective longitudinal study.

Methods

We examined the association of lifetime mTBI history, demographic, military, medical and psychosocial factors with (1) HA prevalence ("lately, have you experienced headaches?") using logistic regression and (2) HA burden via the Headache Impact Test-6 (HIT-6) using linear regression. Each lifetime mTBI was categorized by mechanism (blast-related or not) and setting (combat deployed or not). Participants with non-credible symptom reporting were excluded, leaving N = 1,685 of whom 81% had positive mTBI histories.

Results

At a median 10 years since last mTBI, mTBI positive participants had higher HA prevalence (69% overall, 78% if 3 or more mTBIs) and greater HA burden (67% substantial/severe impact) than non-TBI controls (46% prevalence, 54% substantial/severe impact). In covariate-adjusted analysis, HA prevalence was higher with greater number of blast-related mTBIs (OR 1.81; 95% CI 1.48, 2.23), non-blast mTBIs while deployed (OR 1.42; 95% CI 1.14, 1.79), or non-blast mTBIs when not deployed (OR 1.23; 95% CI 1.02, 1.49). HA impact was only higher with blast-related mTBIs. Female identity, younger age, PTSD symptoms, and subjective sleep quality showed effects in both prevalence and impact models, with the largest mean HIT-6 elevation for PTSD symptoms. Additionally, combat deployment duration and depression symptoms were factors for HA prevalence, and Black race and Hispanic/Latino ethnicity were factors for HA impact. In sensitivity analyses, time since last mTBI and early HA onset were both non-significant.

Conclusion

The prevalence of HA symptoms among formerly combat-deployed veterans and SMs is higher with more lifetime mTBIs regardless of how remote. Blast-related mTBI raises the risk the most and is uniquely associated with elevated HA burden. Other demographic and potentially modifiable risk factors were identified that may inform clinical care.

Associations Between Sociodemographic, Mental Health, and Mild Traumatic Brain Injury Characteristics With Lifetime History of Criminal Justice Involvement in Combat Veterans and Service Members

INTRODUCTION

Veterans and service members (V/SM) may have more risk factors for arrest and felony incarceration (e.g., posttraumatic stress disorder and at-risk substance use) but also more protective factors (e.g., access to health care) to mitigate behaviors that may lead to arrest. As such, understanding which factors are associated with criminal justice involvement among V/SM could inform prevention and treatment efforts. The current study examined relationships between lifetime history of arrests and felony incarceration and sociodemographic, psychological, and brain injury characteristics factors among combat V/SM.

MATERIALS AND METHODS

The current study was a secondary data analysis from the Chronic Effects of Neurotrauma Consortium multicenter cohort study, approved by local institutional review boards at each study site. Participants were V/SM (N = 1,540) with combat exposure (19% active duty at time of enrollment) who were recruited from eight Department of Veterans Affairs and DoD medical centers and completed a baseline assessment. Participants were predominantly male (87%) and white (72%), with a mean age of 40 years (SD = 9.7). Most (81%) reported a history of at least one mild traumatic brain injury, with one-third of those experiencing three or more mild traumatic brain injuries (33%). Participants completed a self-report measure of lifetime arrest and felony incarceration history, a structured interview for all potential concussive events, the post-traumatic stress disorder checklist for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), and the Alcohol Use Disorders Identification Test-Consumption. Three groups were compared on self-reported level of lifetime history of criminal justice system involvement: (1) no history of arrest or incarceration (65%); (2) history of arrest but no felony incarceration (32%); and (3) history of felony incarceration (3%).

RESULTS

Ordinal regression analyses revealed that hazardous alcohol consumption (β = .44, P < .001; odds ratio = 1.56) was positively associated with increased criminal justice involvement after adjusting for all other variables. Being married or partnered (β = -.44, P < .001; odds ratio = 0.64) was negatively associated with decreased criminal justice involvement.

CONCLUSIONS

The rate of lifetime arrest (35%) in this V/SM sample was consistent with rates of arrests in the U.S. general population. One modifiable characteristic associated with lifetime arrest and felony incarceration was hazardous alcohol consumption. Alcohol use should be a top treatment target for V/SM at risk for arrest and those with history of criminal justice involvement.

Functional Overlay Model of Persistent Post-Concussion Syndrome

Persistent post-concussion syndrome (PPCS) is a complex and debilitating condition that can develop after head concussions or mild traumatic brain injury (mTBI). PPCS is characterized by a wide range of symptoms, including headaches, dizziness, fatigue, cognitive deficits, and emotional changes, that can persist for months or even years after the initial injury. Despite extensive research, the underlying mechanisms of PPCS are still poorly understood; furthermore, there are limited resources to predict PPCS development in mTBI patients and no established treatment. Similar to PPCS, the etiology and pathogenesis of functional neurological disorders (FNDs) are not clear neither fully described. Nonspecific multifactorial interactions that were also seen in PPCS have been identified as possible predispositions for FND onset and progression. Thus, we aimed to describe a functional overlay model of PPCS that emphasizes the interplay between functional and structural factors in the development and perpetuation of PPCS symptoms. Our model suggests that the initial brain injury triggers a cascade of physiological and psychological processes that disrupt the normal functioning of the brain leading to persistent symptoms. This disruption can be compounded by pre-existing factors, such as genetics, prior injury, and psychological distress, which can increase the vulnerability to PPCS. Moreover, specific interventions, such as cognitive behavioral therapy, neurofeedback, and physical exercise can target the PPCS treatment approach. Thus, the functional overlay model of PPCS provides a new framework for understanding the complex nature of this condition and for developing more effective treatments. By identifying and targeting specific functional factors that contribute to PPCS symptoms, clinicians and researchers can improve the diagnosis, management, and ultimately, outcomes of patients with this condition.

Atypical symptom reporting after mild traumatic brain injury

OBJECTIVE

Early reporting of atypical symptoms following a mild traumatic brain injury (mTBI) may be an early indicator of poor prognosis. This study aimed to determine the percentage of people reporting atypical symptoms 1-month post-mTBI and explore links to recovery 12 months later in a community-dwelling mTBI sample.

METHODS

Adult participants (>16 years) who had experienced a mTBI were identified from a longitudinal incidence study (BIONIC). At 1-month post-injury, 260 participants completed the Rivermead Post-Concussion Symptoms Questionnaire (typical symptoms) plus four atypical symptom items (hemiplegia, difficulty swallowing, digestion problems and difficulties with fine motor tasks). At 12 months post-injury, 73.9% (n = 193) rated their overall recovery on a 100-point scale. An ordinal regression explored the association between atypical symptoms at 1 month and recovery at 12 months post-injury (low = 0-80, moderate = 81-99 and complete recovery = 100), whilst controlling for age, sex, rehabilitation received, ethnicity, mental and physical comorbidities and additional injuries sustained at the time of injury.

RESULTS

At 1-month post-injury <1% of participants reported hemiplegia, 5.4% difficulty swallowing, 10% digestion problems and 15.4% difficulties with fine motor tasks. The ordinal regression model revealed atypical symptoms were not significant predictors of self-rated recovery at 12 months. Older age at injury and higher typical symptoms at 1 month were independently associated with poorer recovery at 12 months, p < 0.01.

CONCLUSION

Atypical symptoms on initial presentation were not linked to global self-reported recovery at 12 months. Age at injury and typical symptoms are stronger early indicators of longer-term prognosis. Further research is needed to determine if atypical symptoms predict other outcomes following mTBI.

Putting the pieces together to understand anger in combat veterans and service members: Psychological and physical contributors

Dysregulated anger can result in devastating health and interpersonal consequences for individuals, families, and communities. Compared to civilians, combat veterans and service members (C-V/SM) report higher levels of anger and often have risk factors for anger including posttraumatic stress disorder (PTSD), traumatic brain injury (TBI), pain, alcohol use, and impaired sleep. The current study examined the relative contributions of established variables associated with anger (e.g., combat exposure, current PTSD symptoms, history of TBI, pain interference, and hazardous alcohol use) in 1263 C-V/SM. Sleep impairments, represented by poor sleep quality and obstructive sleep apnea (OSA) risk, were also evaluated as potential mediators of the relationships between established risk factors and anger, and therefore potential modifiable treatment targets. Multiple regression model results revealed that PTSD symptoms (β = 0.517, p < .001), OSA risk (β = 0.057, p = .016), pain interference (β = 0.214, p < .001), and hazardous alcohol use (β = 0.054, p = .009) were significantly associated with anger. Results of the mediation models revealed that OSA risk accounted for the association between PTSD and anger, in addition to the association between pain interference and anger. The current study extends previous literature by simultaneously examining factors associated with anger using a multivariable model in a large sample of C-V/SM. Additionally, treating OSA may be a novel way to reduce anger in C-V/SM who have PTSD and/or pain interference.

Factor structure of the modified Rivermead Post-concussion Symptoms Questionnaire (mRPQ): an exploratory analysis with healthy adult simulators

OBJECTIVE

Persistent postconcussion symptoms (PPCS) are challenging to diagnose. An improved diagnostic process could consider typical and atypical postconcussion symptoms. This study examined the structure of a modified Rivermead Post-concussion Symptoms Questionnaire (mRPQ) with both symptom types.

METHOD

298 adult volunteers were randomized into groups: honest responders, mild traumatic brain injury (mTBI) simulators (MS), and biased mTBI simulators (BMS). Both mTBI simulating groups were coached about mTBI and primed about the simulation context (compensation evaluation). The BMS group was also encouraged to bias (exaggerate) symptoms. The participants completed an online battery of tests, including the mRPQ.

RESULTS

An exploratory factor analysis of the mRPQ (full sample) revealed a three-factor solution, including a separate dimension for atypical symptoms (all item loadings >0.45, ~4% of explained variance). The overall and group analyses of the standard RPQ items (typical symptoms) found a one- or two-factor solution, as did the analyses of atypical symptoms.

CONCLUSIONS

Consistent with prior RPQ research, a unidimensional or bifactor structure was measurable from standard RPQ symptoms. Whilst this study did not find support for domain-level symptom scores for either typical or atypical symptoms, the findings support the use of an overall atypical symptoms score.

Validating the modified Rivermead Post-concussion Symptoms Questionnaire (mRPQ)

OBJECTIVE

Response distortions in the reporting of postconcussion symptoms can occur for many reasons. The Rivermead Post-concussion Symptoms Questionnaire (RPQ) was recently modified to include an embedded symptom validity indicator to test for atypical symptoms. The present study used a simulation design to investigate the psychometric properties of the modified RPQ (mRPQ).

METHOD

298 adult volunteers were randomised into three groups: honest responding (Controls, C) who reported actual, current symptoms; mild traumatic brain injury (mTBI) simulators (MS) who role played being injured, and; biased mTBI simulators (BMS) who role played being injured and were asked to bias (exaggerate) their response. The MS and BMS participants received instructions to support the simulation. All participants completed the mRPQ and a modified Neurobehavioral Symptom Inventory (mNSI).

RESULTS

A 2 × 3 mixed ANOVA with one within-group variable (Symptom type: Standard or Atypical) and one between-group variable (Instruction type: C, MS, BMS) found a significant two-way interaction (p < .05, ηp2 = .08).

CONCLUSIONS

The BMS group had score elevations for both standard and atypical postconcussion symptoms; therefore, both symptom types should be considered when evaluating for biased responding. The mRPQ has promising psychometric properties and should be further developed.

The role of posttraumatic stress symptoms on memory complaints and performance in active-duty service members

OBJECTIVE

Memory complaints are the most common form of cognitive limitation reported by military service members, but prior research suggests that posttraumatic stress symptoms (PTSS) may account for the link between subjective cognitive complaints and objective cognitive performance. The mechanisms underlying this relationship are largely unknown, including whether the finding applies to memory complaints and performance, which clinical dimensions are involved, and how the association varies when memory complaints are non-credible.

METHOD

Using a sample of 196 US military service members, the present study aims to address these gaps by modeling the relationship between objective memory performance and plausible/implausible subjective memory complaints, then evaluating how the association is influenced by PTSS and clinical traits commonly found within PTSS (e.g. depression, anxiety, and somatic concerns).

RESULTS

Overall memory complaints were associated with immediate and delayed recall, but both associations were fully mediated by PTSS (95% CI -0.14, -0.01; 95% CI -0.14, -0.02, respectively). Implausible memory complaints, however, were inconsistently linked to memory performance, and no PTSS mediation was observed. Of the clinical traits, only depression moderated the impact of PTSS, specifically by influencing the link between PTSS and overall memory complaints (β = -0.02, SE = 0.004, p < .001).

CONCLUSIONS

These results corroborate the importance of assessment for PTSS and depression in service members who report subjective memory complaints and highlight how targeted intervention for these conditions may play a key role in the management of memory complaints.

Concussion coach for postconcussive symptoms: A randomized, controlled trial of a smartphone application with Afghanistan and Iraq war Veterans

Objective: Investigate the effectiveness of Concussion Coach, an interactive smartphone application, as a treatment for residual neurobehavioral symptoms and distress in Veterans with a history of mild traumatic brain injury (mild TBI). Methods: Veterans with mild TBI were randomized to Concussion Coach (n = 238) or Treatment-as-Usual (TAU) (n = 241) in a 3-month randomized controlled trial. Primary outcome measures included postconcussive symptom (PCS) severity as measured by the Neurobehavioral Symptom Inventory (NSI), and psychological distress as measured by the Brief Symptom Inventory-18 (BSI-18). Measures of self-efficacy, social support, and comfort with technology were administered as potential moderators and mediators. An intention-to-treat (ITT) analysis was performed (N = 461: Concussion Coach = 231 and TAU = 230) using Bayesian Network (BN)modeling. Results: The probability of decreased PCS severity was significantly greater for those assigned to Concussion Coach, .35 [.32,.37], than for TAU, .29 (.27, .32), with an odds ratio (OR) of 1.29. Also, Concussion Coach showed a significantly greater probability of increased self-efficacy (.36 [.32, .39]) than did TAU (.28 [.25, .30], OR = 1.42). In turn, self-efficacy (increased vs. decreased) showed a significantly greater probability of decreased PCS severity (.51 [.47, .54] vs. .27 [.24, .30], OR = 2.71) and decreased psychological distress (.53 [.49, .56] vs. .32 [.29, .35], OR = 2.35), suggesting that self-efficacy may have mediated Concussion Coach effects. Conclusions: Concussion Coach is effective at reducing PCS severity and psychological distress. Increased self-efficacy/perception of self-management of symptoms may be key to successful treatment of residual symptoms in those with history of concussion.

Post-concussive symptoms mediate the relationship between sleep problems and participation restrictions among veterans with mild traumatic brain injury

Background

Sleep problems are common among Veterans with mild traumatic brain injury (mTBI) and may contribute to participation restrictions. However, explanatory mechanisms underlying this relationship are poorly understood. Sleep problems are associated with post-concussive symptoms (e.g., headaches). In turn, post-concussive symptoms contribute to participation restrictions. We hypothesized that post-concussive symptom severity mediates the purported relationship between sleep problems and participation restrictions among Veterans with mTBI.

Materials and Methods

This study was a retrospective analysis of clinical data among 8,733 Veterans with mTBI receiving Veterans Health Administration outpatient care. Sleep problems (yes/no) were identified using the sleep-related item from the Neurobehavioral Symptom Inventory (NSI). Post-concussive symptoms were measured using remaining NSI items. Participation restrictions were measured using the Mayo-Portland Adaptability Inventory Participation Index. We specified a latent variable path model to estimate relationships between: (1) sleep problems and three latent indicators of post-concussive symptoms [vestibular-sensory (e.g., headache)]; mood-behavioral [e.g., anxiety]; cognitive [e.g., forgetfulness]); and, (2) the three latent indicators of post-concussive symptoms and two latent indicators of participation restrictions (social and community participation [e.g., leisure activities]; productivity [e.g., financial management]). We examined the indirect effects of sleep problems upon participation restrictions, as mediated by post-concussive symptoms. Estimates were adjusted for sociodemographic factors (e.g., age), injury characteristics (e.g., blast), and co-morbid conditions (e.g., depression).

Results

87% of Veterans reported sleep problems. Sleep problems were associated with greater social and community participation restrictions, as mediated by mood-behavioral (β = 0.41, p < 0.001) and cognitive symptoms (β = 0.13, p < 0.001). There was no evidence that vestibular-sensory symptoms mediated this relationship (β = -0.01, p = 0.48). Sleep problems were associated with greater productivity restrictions, as mediated by vestibular-sensory (β = 0.16, p < 0.001) and cognitive symptoms (β = 0.14, p < 0.001). There was no evidence that mood-behavioral symptoms mediated this relationship (β = 0.02, p = 0.37).

Discussion

Findings suggest that evidence-based sleep treatment should occupy a prominent role in the rehabilitation of Veterans with mTBI. Indirect effects of sleep problems differed when considering impact on social and community participation vs. productivity, informing individualized rehabilitative care for Veterans with mTBI.

Sensory Phenotypes for Balance Dysfunction After Mild Traumatic Brain Injury

BACKGROUND AND OBJECTIVES

Recent team-based models of care use symptom subtypes to guide treatments of individuals with chronic effects of mild traumatic brain injury (mTBI). However, these subtypes, or phenotypes, may be too broad, particularly for balance (e.g., vestibular subtype). To gain insight into mTBI-related imbalance, we (1) explored whether a dominant sensory phenotype (e.g., vestibular impaired) exists in the chronic mTBI population, (2) determined the clinical characteristics, symptomatic clusters, functional measures, and injury mechanisms that associate with sensory phenotypes for balance control in this population, and (3) compared the presentations of sensory phenotypes between individuals with and without previous mTBI.

METHODS

A secondary analysis was conducted on the Long-Term Impact of Military-Relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium. Sensory ratios were calculated from the sensory organization test, and individuals were categorized into 1 of the 8 possible sensory phenotypes. Demographic, clinical, and injury characteristics were compared across phenotypes. Symptoms, cognition, and physical function were compared across phenotypes, groups, and their interaction.

RESULTS

Data from 758 Service Members and Veterans with mTBI and 172 individuals with no lifetime history of mTBI were included. Abnormal visual, vestibular, and proprioception ratios were observed in 29%, 36%, and 38% of people with mTBI, respectively, with 32% exhibiting more than 1 abnormal sensory ratio. Within the mTBI group, global outcomes (p < 0.001), self-reported symptom severity (p < 0.027), and nearly all physical and cognitive functioning tests (p < 0.027) differed across sensory phenotypes. Individuals with mTBI generally reported worse symptoms than their non-mTBI counterparts within the same phenotype (p = 0.026), but participants with mTBI in the vestibular-deficient phenotype reported lower symptom burdens than their non-mTBI counterparts (e.g., mean [SD] Dizziness Handicap Inventory = 4.9 [8.1] for mTBI vs 12.8 [12.4] for non-mTBI, group × phenotype interaction p < 0.001). Physical and cognitive functioning did not differ between the groups after accounting for phenotype.

DISCUSSION

Individuals with mTBI exhibit a variety of chronic balance deficits involving heterogeneous sensory integration problems. While imbalance when relying on vestibular information is common, it is inaccurate to label all mTBI-related balance dysfunction under the vestibular umbrella. Future work should consider specific classification of balance deficits, including specific sensory phenotypes for balance control.

Long-Term Effects of Repeated Blast Exposure in United States Special Operations Forces Personnel: A Pilot Study Protocol

Emerging evidence suggests that repeated blast exposure (RBE) is associated with brain injury in military personnel. United States (U.S.) Special Operations Forces (SOF) personnel experience high rates of blast exposure during training and combat, but the effects of low-level RBE on brain structure and function in SOF have not been comprehensively characterized. Further, the pathophysiological link between RBE-related brain injuries and cognitive, behavioral, and physical symptoms has not been fully elucidated. We present a protocol for an observational pilot study, Long-Term Effects of Repeated Blast Exposure in U.S. SOF Personnel (ReBlast). In this exploratory study, 30 active-duty SOF personnel with RBE will participate in a comprehensive evaluation of: 1) brain network structure and function using Connectome magnetic resonance imaging (MRI) and 7 Tesla MRI; 2) neuroinflammation and tau deposition using positron emission tomography; 3) blood proteomics and metabolomics; 4) behavioral and physical symptoms using self-report measures; and 5) cognition using a battery of conventional and digitized assessments designed to detect subtle deficits in otherwise high-performing individuals. We will identify clinical, neuroimaging, and blood-based phenotypes that are associated with level of RBE, as measured by the Generalized Blast Exposure Value. Candidate biomarkers of RBE-related brain injury will inform the design of a subsequent study that will test a diagnostic assessment battery for detecting RBE-related brain injury. Ultimately, we anticipate that the ReBlast study will facilitate the development of interventions to optimize the brain health, quality of life, and battle readiness of U.S. SOF personnel.

Olfactory Changes After Military Deployment Are Associated With Emotional Distress but Not With Mild Traumatic Brain Injury History

OBJECTIVE

The aim of the study was to identify the impact of mild traumatic brain injury history and current emotional status on olfactory functioning.

DESIGN

This was a cross-sectional study of 49 predominantly male, military veterans, reservists, and active duty service members with Operations Enduring Freedom, Iraqi Freedom, and New Dawn deployments and varying mild traumatic brain injury histories.

RESULTS

Those with a positive history of mild traumatic brain injury (n = 32) endorsed significantly higher rates of self-reported olfactory disturbance. However, there were no differences between the mild traumatic brain injury and no mild traumatic brain injury groups for rates of objective odor identification dysfunction (none vs. microsmia or more severe) or overall accuracy of odor identification. In keeping with this, self-reported olfactory disturbance also failed to associate with odor identification dysfunction. In both groups, those self-reporting olfactory disturbance reported significantly greater emotional distress, severity of posttraumatic stress symptoms, and attentional impulsivity. However, self-reported olfactory disturbance was not associated with other behavioral factors frequently attributed to TBI, such as aggression, motor impulsiveness, poor planning, and cognitive flexibility.

CONCLUSIONS

These findings indicate mild traumatic brain injury is not a risk factor for postacute microsomia among Operations Enduring Freedom, Iraqi Freedom, and New Dawn military veterans. Higher observed rates of self-reported olfactory disturbance in patients with mild traumatic brain injury may be a function of emotional distress rather than organic brain injury.

Mild Traumatic Brain Injury and Postconcussive Symptom Endorsement: A Parallel Comparison Between Two Nonclinical Cohorts

INTRODUCTION

The prevalence of mild traumatic brain injury (mTBI) is commonly estimated based on indirect metrics such as emergency department visits and self-reporting tools. The study of postconcussive symptoms faces similar challenges because of their unspecific character and indistinct causality. In this article, we compare two nonclinical, epidemiological studies that addressed these two elements and were performed within a relatively narrow period in the state of Colorado.

MATERIALS AND METHODS

De-identified datasets were obtained from a random digit-dialed survey study conducted by the Craig Hospital and a study surveying soldiers returning from deployment by Defense and Veteran Traumatic Brain Injury Center. Information pertinent to participants' demographics, a history of mTBI, and symptom endorsement was extracted and homogenized in order to establish a parallel comparison between the populations of the two studies.

RESULTS

From the 1,558 (Warrior Strong, 679; Craig Hospital, 879) records selected for analysis, 43% reported a history of at least one mTBI. The prevalence was significantly higher among individuals from the Defense and Veteran Traumatic Brain Injury Center study independent of gender or race. Repetitive injuries were reported by 15% of the total combined cohort and were more prevalent among males. Symptom endorsement was significantly higher in individuals with a positive history of mTBI, but over 80% of those with a negative history of mTBI endorsed at least one of the symptoms interrogated. Significant differences were observed between the military and the civilian populations in terms of the types and frequencies of the symptoms endorsed.

CONCLUSIONS

The prevalence of mTBI and associated symptoms identified in the two study populations is higher than that of previously reported. This suggests that not all individuals sustaining concussion seek medical care and highlights the limitations of using clinical reports to assess such estimates. The lack of appropriate mechanisms to determine symptom presence and causality remains a challenge. However, the differences observed in symptom reporting between cohorts raise questions about the nature of the symptoms, the impact on the quality of life for different individuals, and the effects on military health and force readiness.

Performance validity and symptom validity tests: Are they measuring different constructs?

OBJECTIVE

To evaluate the relationships among performance validity, symptom validity, symptom self-report, and objective cognitive testing.

METHOD

Combat Veterans (N = 338) completed a neurocognitive assessment battery and several self-report symptom measures assessing depression, posttraumatic stress disorder (PTSD) symptoms, sleep quality, pain interference, and neurobehavioral complaints. All participants also completed two performance validity tests (PVTs) and one stand-alone symptom validity test (SVT) along with two embedded SVTs.

RESULTS

Results of an exploratory factor analysis revealed a three-factor solution: performance validity, cognitive performance, and symptom report (SVTs loaded on the third factor). Results of t tests demonstrated that participants who failed PVTs displayed significantly more severe symptoms and significantly worse performance on most measures of neurocognitive functioning compared to those who passed. Participants who failed a stand-alone SVT also reported significantly more severe symptomatology on all symptom report measures, but the pattern of cognitive performance differed based on the selected SVT cutoff. Multiple linear regressions revealed that both SVT and PVT failure explained unique variance in symptom report, but only PVT failure significantly predicted cognitive performance.

CONCLUSIONS

Performance and symptom validity tests measure distinct but related constructs. SVTs and PVTs are significantly related to both cognitive performance and symptom report; however, the relationship between symptom validity and symptom report is strongest. SVTs are also differentially related to cognitive performance and symptom report based on the utilized cutoff score. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Coordinating Global Multi-Site Studies of Military-Relevant Traumatic Brain Injury: Opportunities, Challenges, and Harmonization Guidelines

Traumatic brain injury (TBI) is common among military personnel and the civilian population and is often followed by a heterogeneous array of clinical, cognitive, behavioral, mood, and neuroimaging changes. Unlike many neurological disorders that have a characteristic abnormal central neurologic area(s) of abnormality pathognomonic to the disorder, a sufficient head impact may cause focal, multifocal, diffuse or combination of injury to the brain. This inconsistent presentation makes it difficult to establish or validate biological and imaging markers that could help improve diagnostic and prognostic accuracy in this patient population. The purpose of this manuscript is to describe both the challenges and opportunities when conducting military-relevant TBI research and introduce the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Military Brain Injury working group. ENIGMA is a worldwide consortium focused on improving replicability and analytical power through data sharing and collaboration. In this paper, we discuss challenges affecting efforts to aggregate data in this patient group. In addition, we highlight how "big data" approaches might be used to understand better the role that each of these variables might play in the imaging and functional phenotypes of TBI in Service member and Veteran populations, and how data may be used to examine important military specific issues such as return to duty, the late effects of combat-related injury, and alteration of the natural aging processes.

Towards an embedded symptom validity indicator for the rivermead postconcussion symptom questionnaire

This simulation study aimed to develop and test an embedded symptom validity indicator for use with the Rivermead Post Concussion Symptoms Questionnaire (RPQ). Seven mild traumatic brain injury (mTBI) experts assisted in generating a shortlist of 15 atypical postconcussion symptoms. A modified RPQ (mRPQ) was constructed by embedding these items with the 16 standard RPQ items. Eighty-four mTBI simulators completed the mRPQ after random allocation to a symptom-exaggeration condition (ES group; n = 46) or simulation-only condition (S group; n = 38). They also completed the Test of Memory Malingering (TOMM) and the Recognition Memory Test (RMT), and the groups were re-formed and compared using modified criteria for Malingered Neurocognitive Dysfunction (mMND). There was no significant group by item-type interaction for either grouping methods (i.e. as allocated or as reclassified). Exploratory analyses of the main effects showed that ES group had higher mRPQ scores than the S group, and standard symptoms were endorsed more than atypical symptoms. If further developed, the mRPQ could eventually aid the screening of PCS over-reporting.

The Minnesota Multiphasic Personality Inventory-2-RF in Treatment-Seeking Veterans with History of Mild Traumatic Brain Injury

OBJECTIVE

This study examined the Minnesota Multiphasic Personality Inventory-Second Edition-Restructured Form (MMPI-2-RF) to better understand symptom presentation in a sample of treatment-seeking Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans with self-reported history of mild traumatic brain injury (mTBI).

METHOD

Participants underwent a comprehensive clinical neuropsychological battery including performance and symptom validity measures and self-report measures of depressive, posttraumatic, and post-concussive symptomatology. Those with possible symptom exaggeration (SE+) on the MMPI-2-RF were compared with those without (SE-) with regard to injury, psychiatric, validity, and cognitive variables.

RESULTS

Between 50% and 87% of participants demonstrated possible symptom exaggeration on one or more MMPI-2-RF validity scales, and a large majority were elevated on content scales related to cognitive, somatic, and emotional complaints. The SE+ group reported higher depressive, posttraumatic, and post-concussive symptomatology, had higher scores on symptom validity measures, and performed more poorly on neuropsychological measures compared with the SE- group. There were no group differences with regard to injury variables or performance validity measures. Participants were more likely to exhibit possible symptom exaggeration on cognitive/somatic compared with traditional psychopathological validity scales.

CONCLUSIONS

A sizable portion of treatment-seeking OEF/OIF Veterans demonstrated possible symptom exaggeration on MMPI-2-RF validity scales, which was associated with elevated scores on self-report measures and poorer cognitive performance, but not higher rates of performance validity failure, suggesting symptom and performance validity are distinct concepts. These findings have implications for the interpretation of clinical data in the context of possible symptom exaggeration and treatment in Veterans with persistent post-concussive symptoms.

Limited Prediction of Performance Validity Using Embedded Validity Scales of the Neurobehavioral Symptom Inventory in an mTBI Veteran Sample

OBJECTIVE

To test embedded symptom validity scales of the Neurobehavioral Symptom Inventory (NSI) as predictors of performance validity.

SETTING

A Veterans Affairs Level II TBI/Polytrauma outpatient care unit in the Midwestern United States.

PARTICIPANTS

Veterans with a history of mild traumatic brain injury undergoing neuropsychological assessment as part of their routine care within the TBI/Polytrauma clinic.

DESIGN

Retrospective analysis of the existing clinical data.

MAIN MEASURES

The NSI, the b Test, Test of Memory Malingering, Reliable Digit Span, California Verbal Learning Test-II Forced Choice.

RESULTS

Embedded NSI validity scales were positively correlated with number of performance validity test failures. Participants identified as invalid responders scored higher on embedded NSI validity scales than participants identified as valid responders. Using receiver operating characteristic analysis, the embedded NSI validity scales showed poor sensitivity and specificity for invalid responding using previously published cutoff scores. Only 1 scale differentiated valid from invalid responders better than chance.

CONCLUSION

The embedded NSI validity scales' usefulness in predicting invalid neuropsychological performance validity was limited in this sample. Continued measurement of both symptom and performance validity in clinical settings involving traumatic brain injury treatment is recommended, as the present results support the existing research suggesting symptom validity tests and performance validity tests tap into related but ultimately distinct constructs.

Longitudinal changes in neuroimaging and neuropsychiatric status of post-deployment veterans: a CENC pilot study

PRIMARY OBJECTIVE

The purpose of this study was to evaluate preliminary data on longitudinal changes in psychiatric, neurobehavioural, and neuroimaging findings in Iraq and Afghanistan combat veterans following blast exposure.

RESEARCH DESIGN

Longitudinal observational analysis.

METHODS AND PROCEDURES

Participants were invited to participate in two research projects approximately 7 years apart. For each project, veterans completed the Structured Clinical Interview for DSM-IV Disorders and/or the Clinician-Administered PTSD Scale, Neurobehavioral Symptom Inventory, and magnetic resonance imaging (MRI).

MAIN OUTCOMES AND RESULTS

Chi-squared tests indicated no significant changes in current psychiatric diagnoses, traumatic brain injury (TBI) history, or blast exposure history between assessment visits. Wilcoxon signed-rank tests indicated significant increases in median neurobehavioural symptoms, total number of white matter hyperintensities (WMH), and total WMH volume between assessment visits. Spearman rank correlations indicated no significant associations between change in psychiatric diagnoses, TBI history, blast exposure history, or neurobehavioural symptoms and change in WMH.

CONCLUSION

MRI WMH changes were not associated with changes in psychiatric diagnoses or symptom burden, but were associated with severity of blast exposure. Future, larger studies might further evaluate presence and aetiology of long-term neuropsychiatric symptoms and MRI findings in blast-exposed populations.

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

OBJECTIVES

Determine if mild traumatic brain injury (mTBI) history is associated with balance disturbances.

SETTING

Chronic Effects of Neurotrauma Consortium (CENC) centres.

PARTICIPANTS

The CENC multi-centre study enrols post-9/11 era Service Members and Veterans with combat exposure. This sample (n = 322) consisted of enrolees completing initial evaluation by September 2016 at the three sites conducting computerized dynamic post-urography (CDP) testing.

DESIGN

Observational study with cross-sectional analyses using structural equation modelling.

MAIN MEASURES

Comprehensive structured interviews were used to diagnose all lifetime mild traumatic brain injuries (mTBIs). The outcome, Sensory Organization Test (SOT), was measured on CDP dual-plate force platform. Other studied variables were measured by structured interviews, record review and questionnaires.

RESULTS

The overall positive/negative mTBI classification did not have a significant effect on the composite equilibrium score. However, the repetitive mTBI classification showed lower scores for participants with ≥ 3 mTBI versus 1-2 lifetime mTBIs. For repetitive mTBI, pain interference acted as a mediator for the indirect effect, and a direct effect was evident on some sensory condition equilibrium scores.

CONCLUSION

These findings show that repeated mTBI, partially mediated by pain, may lead to later balance disturbances among military combatants. Further study of CDP outcomes within this accruing cohort is warranted.

Understanding the impact of mild traumatic brain injury on veteran service-connected disability: results from Chronic Effects of Neurotrauma Consortium

OBJECTIVES

Disability evaluation is complex. The association between mild traumatic brain injury (mTBI) history and VA service-connected disability (SCD) ratings can have implications for disability processes in the civilian population. We examined the association of VA SCD ratings with lifetime mTBI exposure in three models: any mTBI, total mTBI number, and blast-related mTBI.

METHODS

Participants were 492 Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn veterans from four US VA Medical Centers enrolled in the Chronic Effects of Neurotrauma Consortium study between January 2015 and August 2016. Analyses entailed standard covariate-adjusted linear regression models, accounting for demographic, military, and health-related confounders and covariates.

RESULTS

Unadjusted and adjusted results indicated lifetime mTBI was significantly associated with increased SCD, with the largest effect observed for blast-related mTBI. Every unit increase in mTBI was associated with an increase in 3.6 points of percent SCD. However, hazardous alcohol use was associated with lower SCD.

CONCLUSIONS

mTBI, especially blast related, is associated with higher VA SCD ratings, with each additional mTBI increasing percent SCD. The association of hazardous alcohol use with SCD should be investigated as it may impact veteran health services access and health outcomes. These findings have implications for civilian disability processes.

Unique Aspects of Traumatic Brain Injury in Military and Veteran Populations

Traumatic brain injury (TBI), in particular mild TBI (mTBI), is a relatively common injury experienced by service members across both deployed and nondeployed environments. Although many of the principles and practices used by civilian health care providers for identifying and treating this injury apply to military settings, there are unique factors that impact mTBI-related care in service members and Veterans. This article reviews several of these factors, including the epidemiology of TBI in the military/Veteran population, the influence of military culture on this condition, and identification and treatment of mTBI in the war zone.

Psychological Predictors of Postconcussive Symptoms Following Traumatic Injury

OBJECTIVE

To determine the contribution of demographics, injury type, pain, and psychological factors on postconcussive symptoms.

SETTING AND PARTICIPANTS

Recently injured (n = 54) and noninjured (n = 184) adults were recruited from a hospital emergency department or the community. Thirty-eight individuals met the diagnostic criteria for a mild traumatic brain injury and 16 individuals received treatment for a minor traumatic non-brain injury.

MAIN MEASURES

Standardized tests were administered to assess 4 postconcussion symptom types and theorized predictors including a "physiogenic" variable (injury type) and "psychogenic" variables (symptoms of anxiety, depression, and stress) within 1 month of the injury.

RESULTS

In the injured sample, after controlling for injury type, demographics, and pain (chronic and current), a hierarchical regression analysis revealed that the combination of psychological symptoms predicted affective (F10,42 = 2.80, P = .009, Rchange = 0.27) but not other postconcussion symptoms types. Anxiety (β = .48), stress (β = .18), and depression (β = -.07) were not statistically significant individual predictors (P > .05). Cognitive and vestibular postconcussion symptoms were not predicted by the modeled factors, somatic sensory postconcussion symptoms were predicted by demographic factors only, and the pattern of predictors for the symptom types differed for the samples.

CONCLUSIONS

Traditional explanatory models do not account for these findings. The predictors are multifactorial, different for injured versus noninjured samples, and symptom specific.

Assault-related mild traumatic brain injury, expectations of injury outcome, and the effect of different perpetrators: A vignette study

Few studies have examined the effect of varying the assault perpetrator on expectations of outcome from mild TBI. Using a cross sectional between groups design, individuals with no history of mild TBI were randomly allocated to one of two vignette conditions. The vignette depicted a mild TBI with fixed injury parameters and a different assault perpetrator (partner, n = 27; or stranger, n = 27). The participants were instructed to imagine that they had been injured as per the depiction, and then to anticipate the injury consequences 6-months later. An online questionnaire was used including: the Neurobehavioral Symptom Inventory, the Posttraumatic Stress Disorder Checklist-Civilian Version, the Impact of Events Scale-Revised, and the Perceived Ability to Cope with Trauma. The depicted injury was rated for the extent to which it was perceived as life-threatening, the subsequent diagnosis, and the global recovery prospects. The anticipated consequences of the injury (symptoms and trauma variables) did not differ across the conditions, all p's > 0.05. The expected outcomes for an assault-related mild TBI were not affected by perpetrator type. However, the study had several limitations and further consideration of this factor may still be warranted.

Postconcussive symptom overreporting in Iraq/Afghanistan Veterans with mild traumatic brain injury

A comprehensive evaluation, including the assessment of neurobehavioral symptoms, has been instituted at the Department of Veterans Affairs (VA) healthcare system to address the large number of Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) Veterans returning with mild traumatic brain injuries (mTBIs). The Validity-10 is measure of symptom overreporting embedded within the Neurobehavioral Symptom Inventory, a component of the comprehensive evaluation that assesses postconcussive symptom severity. The Validity-10 is composed of 10 unlikely/low-frequency items and a validated cutoff score to identify postconcussive symptom overreporting. We examined the items and cutoff used in the initial development and validation study of the Validity-10 through retrospective chart reviews of 331 treatment-seeking Veterans who sustained an mTBI. The Validity-10 exhibited significant relationships with psychiatric variables, VA service connection, and neuropsychological performance validity (all p < 0.01), but nonsignificant relationships with demographic and injury variables (all p > 0.05). Furthermore, the Validity-10 modestly predicted neuropsychological performance validity test failure over and above psychiatric comorbidities and VA service connection. The present study supports the use of the Validity-10 to assess symptom validity in treatment-seeking OIF/OEF Veterans with a history of mTBI.

Use of a multi-level mixed methods approach to study the effectiveness of a primary care progressive return to activity protocol after acute mild traumatic brain injury/concussion in the military

The large number of U.S. service members diagnosed with concussion/mild traumatic brain injury each year underscores the necessity for clear and effective clinical guidance for managing concussion. Relevant research continues to emerge supporting a gradual return to pre-injury activity levels without aggravating symptoms; however, available guidance does not provide detailed standards for this return to activity process. To fill this gap, the Defense and Veterans Brain Injury Center released a recommendation for primary care providers detailing a step-wise return to unrestricted activity during the acute phase of concussion. This guidance was developed in collaboration with an interdisciplinary group of clinical, military, and academic subject matter experts using an evidence-based approach. Systematic evaluation of the guidance is critical to ensure positive patient outcomes, to discover barriers to implementation by providers, and to identify ways to improve the recommendation. Here we describe a multi-level, mixed-methods approach to evaluate the recommendation incorporating outcomes from both patients and providers. Procedures were developed to implement the study within complex but ecologically-valid settings at multiple military treatment facilities and operational medical units. Special consideration was given to anticipated challenges such as the frequent movement of military personnel, selection of appropriate design and measures, study implementation at multiple sites, and involvement of multiple service branches (Army, Navy, and Marine Corps). We conclude by emphasizing the need to consider contemporary approaches for evaluating the effectiveness of clinical guidance.

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 α = .91 to α = .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.

Does the cause of the mild traumatic brain injury affect the expectation of persistent postconcussion symptoms and psychological trauma?

INTRODUCTION

A controlled experiment of the effect of injury cause on expectations of outcome from mild traumatic brain injury (TBI) was conducted.

METHOD

Ninety-three participants were randomly assigned to one of four conditions. The participants read a vignette that described a mild TBI (with fixed injury parameters) from a different cause (sport, domestic assault, fall, or motor vehicle accident). The effect of the manipulation on expectations of persistent postconcussion symptoms and psychological trauma was assessed with standard measures and a novel "threat-to-life" measure.

RESULTS

The Kruskal-Wallis H test for group differences revealed a significant but selective effect of group on symptom and trauma outcomes (ŋ²s ≥ .10; large effects). Post hoc pairwise tests showed that, in most cases, there was an expectation of a worse outcome following mild TBI from a domestic assault than from the other causes (small-to-medium effects).

CONCLUSION

Expectations were selectively altered by an experimental manipulation of injury cause. Given that expectations of outcome are known to affect mild TBI prognosis, the findings suggest the need for greater attention to injury cause.