The Structure of Postconcussion Symptoms on the Neurobehavioral Symptom Inventory: A Comparison of Alternative Models

Factor analysis of the Neurobehavioral Symptom Inventory among a sample of Spanish-speakers

ABSTRACTA study was conducted to examine the factor structure of the Neurobehavioral Symptom Inventory (NSI) among a large community sample of 729 Spanish-speakers from the Continental United States (n = 174, 23.9%), Latin America (n = 465, 63.8%), and Spain (n = 90, 12.3%) The sample was 62.1% female, had at least 10 years of formal education, and ranged in age from 18 to 65 years (M = 36.7, SD = 12.5). The sample was randomly split into two groups with comparable demographics for a sequential analysis that consisted of an exploratory factor analysis on the first subsample followed by a confirmatory factor analysis within a second validation subsample. Results demonstrated a high internal consistency reliability for the Spanish version of the NSI, and a three-factor solution was supported with somatic, affective, and cognitive factors. Findings were comparable to prior studies with the English version of the NSI providing preliminary support for the construct validity of this measure among a large sample of Spanish-speakers. Further study is needed to determine the criterion-related validity of the individual factors as separate subscales and to examine the appropriateness of this measure for individuals with lower levels of education.

Functional connectivity of the anterior cingulate cortex in Veterans with mild traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is one of the most prevalent injuries in the military with mild traumatic brain injury (mTBI) accounting for approximately 70-80 % of all TBI. TBI has been associated with diffuse and focal brain changes to structures and networks underlying cognitive-emotional processing. Although the anterior cingulate cortex (ACC) plays a critical role in emotion regulation and executive function and is susceptible to mTBI, studies focusing on ACC resting state functional connectivity (rs-fc) in Veterans are limited.

METHODS

Veterans with mTBI (n = 49) and with no history of TBI (n = 25), ages 20-54 completed clinical assessments and an 8-minute resting state functional magnetic resonance imaging (rs-fMRI) on a 3 T Siemens scanner. Imaging results were analyzed with left and right ACC as seed regions using SPM8. Regression analyses were performed with time since injury.

RESULTS

Seed-based analysis showed increased connectivity of the left and right ACC with brain regions including middle and posterior cingulate regions, preceneus, and occipital regions in the mTBI compared to the non-TBI group.

CONCLUSIONS

The rs-fMRI results indicate hyperconnectivity in Veterans with mTBI. These results are consistent with previous studies of recently concussed athletes showing ACC hyperconnectivity. Enhanced top-down control of attention networks necessary to compensate for the microstructural damage following mTBI may explain ACC hyperconnectivity post-mTBI.

Factors associated with employment and work perception in combat-exposed veterans

PURPOSE/OBJECTIVE

The purpose of this study was 2-fold: (a) to evaluate whether perception of work ability is associated with employment status in a sample of combat-exposed veterans, and (b) to determine whether the same sets of variables that are associated with employment status are also associated with perception of work ability. Research Method/Design: In this cross-sectional study, veterans (N = 83) underwent a neuropsychological assessment and completed questionnaires assessing demographic characteristics, combat-related experiences, and psychiatric and neurobehavioral/health-related symptoms. Primary outcomes of interest were employment status (unemployed vs. employed) and veterans' perception of whether their ability to work has declined due to an ongoing condition (yes vs. no).

RESULTS

A chi-square analysis revealed a significant relationship between perception of work ability and employment status. Additionally, psychiatric and neurobehavioral/health-related symptoms were associated with employment status and perception of work ability, whereas demographic characteristics (i.e., service-connected disability rating) and combat-related experiences (i.e., mTBI history) were only associated with perception of work ability. Objective cognitive functioning was not associated with employment status or perception of work ability.

CONCLUSIONS/IMPLICATIONS

Although preliminary, results suggest that perception of work ability is an important factor to consider when evaluating employment-related outcomes in veterans. Moreover, results indicate that while there is some overlap among the variables associated with employment status and perception of work ability, additional variables are linked with perception of work ability. Taken together, these findings suggest that perception of one's ability to work and factors that influence it may be particularly important treatment targets in the veteran population. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Associations Between Multiple Remote Mild TBIs and Objective Neuropsychological Functioning and Subjective Symptoms in Combat-Exposed Veterans

OBJECTIVE

The purpose of this study was to evaluate relationships between multiple mild traumatic brain injuries (mTBIs) and objective and subjective clinical outcomes in a sample of combat-exposed Veterans, adjusting for psychiatric distress and combat exposure.

METHOD

In this cross-sectional study, 73 combat-exposed Iraq/Afghanistan Veterans were divided into three groups based on mTBI history: 0 mTBIs (n = 31), 1-2 mTBIs (n = 21), and 3+ mTBIs (n = 21). Veterans with mTBI were assessed, on average, 7.78 years following their most recent mTBI. Participants underwent neuropsychological testing and completed self-report measures assessing neurobehavioral, sleep, and pain symptoms.

RESULTS

MANCOVAs adjusting for psychiatric distress and combat exposure showed no group differences on objective measures of attention/working memory, executive functioning, memory, and processing speed (all p's > .05; ηp2 = .00-.06). In contrast, there were significant group differences on neurobehavioral symptoms (p's = < .001-.036; ηp2 = .09-.43), sleep difficulties (p = .037; ηp2 = .09), and pain symptoms (p < .001; ηp2 = .21). Pairwise comparisons generally showed that the 3+ mTBI group self-reported the most severe symptoms, followed by comparable symptom reporting between the 0 and 1-2 mTBI groups.

CONCLUSIONS

History of multiple, remote mTBIs is associated with elevated subjective symptoms but not objective neuropsychological functioning in combat-exposed Veterans. These results advance understanding of the long-term consequences of repetitive mTBI in this population and suggest that Veterans with 3+ mTBIs may especially benefit from tailored treatments aimed at ameliorating specific neurobehavioral, sleep, and pain symptoms.

Intimate Partner Violence Among Female OEF/OIF/OND Veterans Who Were Evaluated for Traumatic Brain Injury in the Veterans Health Administration: A Preliminary Investigation

Many female veterans have deployed to Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF), and Operation New Dawn (OND), and some experience traumatic brain injury (TBI). Although TBI is increasingly recognized as an important health issue for female OEF/OIF/OND veterans, there is little attention to stressful experiences that may exacerbate health problems or hinder recovery among veterans who may have experienced TBI. Lifetime intimate partner violence (IPV) is common among general samples of female veterans. Given the negative implications of IPV on women's health, it is important to understand whether there is a relationship between lifetime IPV and health functioning among female veterans who have experienced possible TBI. This study provides an exploration of lifetime IPV and its associations with physical and mental health, as well as community reintegration, among female OEF/OIF/OND veterans who have been evaluated for TBI. The sample comprised 127 female veterans who participated in a larger study that examined reintegration among OEF/OIF/OND veterans who received a TBI evaluation in the Veterans Heath Administration (VHA) and completed an assessment of lifetime IPV. Primary and secondary data sources included survey responses (e.g., health symptoms and reintegration) and VHA administrative data (e.g., health diagnoses). Results indicated that nearly two thirds (63.0%) of women who completed a TBI evaluation reported lifetime IPV, though clinician-confirmed TBI was not associated with IPV. Women who experienced IPV, compared with those who did not, reported higher levels of neurobehavioral symptoms and were significantly more likely to have diagnoses of back pain (48.6% vs. 30.0%, respectively) and substance abuse (12.2% vs. 0%, respectively). Notwithstanding, women with and without lifetime IPV reported similar levels of reintegration. Findings provide evidence that lifetime IPV may be common among female OEF/OIF/OND veterans who are evaluated for TBI, and that IPV is associated with several treatable health problems among this population.

Comparing Composite Scores for the ANAM4 TBI-MIL for Research in Mild Traumatic Brain Injury

OBJECTIVE

The Automated Neuropsychological Assessment Metrics (Version 4) Traumatic Brain Injury Military (ANAM4 TBI-MIL) is commonly administered among U.S. service members both pre-deployment and following TBI. The current study used the ANAM4 TBI-MIL to develop a cognition summary score for TBI research and clinical trials, comparing eight composite scores based on their distributions and sensitivity/specificity when differentiating between service members with and without mild TBI (MTBI).

METHOD

Male service members with MTBI (n = 56; Mdn = 11 days-since-injury) or no self-reported TBI history (n = 733) completed eight ANAM4 TBI-MIL tests. Their throughput scores (correct responses/minute) were used to calculate eight composite scores: the overall test battery mean (OTBM); global deficit score (GDS); neuropsychological deficit score-weighted (NDS-W); low score composite (LSC); number of scores <50th, ≤16th percentile, or ≤5th percentile; and the ANAM Composite Score (ACS).

RESULTS

The OTBM and ACS were normally distributed. Other composites had skewed, zero-inflated distributions (62.9% had GDS = 0). All composites differed significantly between participants with and without MTBI (p < .001), with deficit scores showing the largest effect sizes (d = 1.32-1.47). The Area Under the Curve (AUC) was lowest for number of scores ≤5th percentile (AUC = 0.653) and highest for the LSC, OTBM, ACS, and NDS-W (AUC = 0.709-0.713).

CONCLUSIONS

The ANAM4 TBI-MIL has no well-validated composite score. The current study examined multiple candidate composite scores, finding that deficit scores showed larger group differences than the OTBM, but similar AUC values. The deficit scores were highly correlated. Future studies are needed to determine whether these scores show less redundancy among participants with more severe TBIs.

Beliefs About the Influence of Rest During Concussion Recovery May Predict Activity and Symptom Progression Within an Active Duty Military Population

OBJECTIVES

To evaluate relationships between beliefs about the impact of rest and the level of activities and symptoms over time among active duty Service members sustaining concussion, and whether these relationships vary by provision of concussion education.

DESIGN

Longitudinal study using multilevel modeling to assess the relationship between beliefs about rest within 72 hours of concussion and change in activity and symptom level over time, as well as interaction by concussion education at the initial clinic visit.

SETTING

Three military treatment facilities.

PARTICIPANTS

Study participants included active duty Service members diagnosed with a concussion (N=111; median age, 24 y). Individuals with previous history of concussion within 12 months of study enrollment were excluded.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Activity questionnaire and the Neurobehavioral Symptom Inventory assessed within 72 hours of concussion; at 1 week; and at 1, 3, and 6 month(s) postinjury.

RESULTS

Receipt of concussion education from providers was significantly associated with greater belief that rest influences concussion recovery. Greater belief that rest influences symptom recovery at the acute stage of concussion was associated with a greater increase in activities over time, but only among those who received education from their provider. Additionally, greater belief about the influence of rest was related to a more rapid decrease in symptoms over time.

CONCLUSIONS

Concussed Service members who underestimate the influence of rest during acute recovery may be at risk for poorer recovery. Treatment of Service members with postconcussive symptoms should consider patient knowledge and/or beliefs about rest and recovery, which may influence prognosis. Our results support the provider's use of concussion education to correct potential misconceptions that may negatively impact symptom recovery.

Dissociation of BDNF Val66Met polymorphism on neurocognitive functioning in military veterans with and without a history of remote mild traumatic brain injury

OBJECTIVE

Since neurocognitive functioning following mild traumatic brain injury (mTBI) may be influenced by genetic factors that mediate synaptic survival and repair, we examined the influence of a common brain-derived neurotrophic factor (BDNF) polymorphism (Val66Met) on cognition using a well-defined sample of military Veterans with and without a history of mTBI.

METHOD

Participants included 138 Veterans (mTBI = 75; military controls [MCs] = 63) who underwent neuropsychological testing, including completion of self-report measures assessing psychiatric distress, and BDNF genotyping. The mTBI group was tested roughly 66.7 months following their most recent mTBI. Veterans were divided into two groups-Met+ (Met/Met and Met/Val; n = 49) and Met- (Val/Val; n = 89) and compared on domain-specific cognitive composite scores representing memory, executive functioning, and visuospatial speed.

RESULTS

ANCOVAs adjusting for psychiatric distress, sex, years of education, and ethnicity/race revealed a significant group (mTBI vs. MC) by BDNF genotype (Met + vs. Met-) interaction for the memory (p = .024; η_p ² = .039) and executive functioning (p = .010; η_p ² = .050) composites, such that Met+ mTBI Veterans demonstrated better performance than Met- mTBI Veterans on the cognitive measures, whereas Met+ MCs demonstrated worse performance relative to Met- MCs on the cognitive measures. No significant interaction was observed for the visuospatial speed composite (p = .938; η_p ² < .001).

CONCLUSIONS

These findings offer preliminary evidence to suggest that the Met allele may be protective in the context of remote mTBI. Findings need to be replicated using larger samples, and future studies are necessary to elucidate the precise mechanisms and neural underpinnings of this interaction.

Validating the usefulness of the NSI validity-10 with the MMPI-2-RF

Purpose/Aim of the Study: The Neurobehavioral Symptom Inventory (NSI) is a 22-item self-report measure created to quantify the somatosensory, cognitive, and affective symptoms of Post-concussive Syndrome. Developers of the NSI used a subset of 10 items, the Validty-10, to measure symptom overreporting. We compared the Validity-10 versus the remaining NSI items (i.e., the Remaining-12) for how accurately they detect symptom exaggeration on the Minnesota Multiphasic Personality Inventory Second Edition - Restructured Form (MMPI-2-RF).Materials and Methods: We used a sample of 45 veterans evaluated in a Polytrauma/TBI Clinic of a Midwest VA Healthcare System who completed the NSI and MMPI-2-RF.Results: The Vaidity-10, Remaining-12, and Total Score all strongly correlated with mean of the MMPI-2-RF validity scales (r = .65, .67, and .70, respectively), illustrating equivalency among the various NSI scores. Groups were created based on significant T score elevation on any MMPI-2-RF validity scale (i.e. F-r > 119, or Fp-r, F-s, FBS, or RBS > 99). ROC analyses demonstrated that areas under the curve were equivalent for NSI Total Score (.84), Validity-10 (.81), and Remaining-12 (.81) in detecting overreporting.Conclusions: These findings do not support the notion that the Validity-10 has unique utility as an embedded symptom validity scale and highlights the likelihood that NSI Total Score can also serve this function.

Use of the Progressive Return to Activity Guidelines May Expedite Symptom Resolution After Concussion for Active Duty Military

BACKGROUND

Clinical recommendations for concussion management encourage reduced cognitive and physical activities immediately after injury, with graded increases in activity as symptoms resolve. Empirical support for the effectiveness of such recommendations is needed.

PURPOSE

To examine whether training medical providers on the Defense and Veterans Brain Injury Center's Progressive Return to Activity Clinical Recommendation (PRA-CR) for acute concussion improves patient outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This study was conducted from 2016 to 2018 and compared patient outcomes before and after medical providers received an educational intervention (ie, provider training). Patients, recruited either before or after intervention, were assessed at ≤72 hours, 1 week, 1 month, 3 months, and 6 months after a concussion. The participant population included 38 military medical providers and 106 military servicemembers with a diagnosed concussion and treated by one of the military medical providers: 58 patient participants received care before the intervention (ie, provider training) and 48 received care after intervention. The primary outcome measure was the Neurobehavioral Symptom Inventory.

RESULTS

The patients seen before and after the intervention were predominantly male (89.7% and 93.8%, respectively) of military age (mean ± SD, 26.62 ± 6.29 years and 25.08 ± 6.85 years, respectively) and a mean ± SD of 1.92 ± 0.88 days from injury. Compared with patients receiving care before intervention, patients receiving care after intervention had smaller increases in physical activities (difference in mean change; 95% CI, 0.39 to 6.79) and vestibular/balance activities (95% CI, 0.79 to 7.5) during the first week of recovery. Although groups did not differ in symptoms at ≤72 hours of injury (d = 0.22; 95% CI, -2.21 to 8.07), the postintervention group reported fewer symptoms at 1 week (d = 0.61; 95% CI, 0.52 to 10.92). Postintervention patients who completed the 6-month study had improved recovery both at 1 month (d = 1.55; 95% CI, 5.33 to 15.39) and 3 months after injury (d = 1.10; 95% CI, 2.36 to 11.55), but not at 6 months (d = 0.35; 95% CI, 5.34 to 7.59).

CONCLUSION

Training medical providers on the PRA-CR for management of concussion resulted in expedited recovery of patients.

Sleep problems contribute to post-concussive symptoms in service members with a history of mild traumatic brain injury without posttraumatic stress disorder or major depressive disorder

BACKGROUND:

Many with a history of mild traumatic brain injury (TBI) experience sleep problems, which are also common symptoms of stress-related and mood disorders.

OBJECTIVE:

To determine if sleep problems contributed unique variance to post-concussive symptoms above and beyond symptoms of posttraumatic stress disorder/major depressive disorder (PTSD/MDD) after mild TBI.

METHODS:

313 active duty service members with a history of mild TBI completed sleep, PTSD, and mood symptom questionnaires, which were used to determine contributions to the Neurobehavioral Symptom Inventory.

RESULTS:

59% of the variance in post-concussive symptoms were due to PTSD symptom severity while depressive symptoms and sleep problems contributed an additional 1% each. This pattern differed between those with and without clinical diagnosis of PTSD/MDD. For those with PTSD/MDD, PTSD and depression symptoms but not sleep contributed to post-concussive symptoms. For those without PTSD/MDD, PTSD symptoms and sleep contributed specifically to somatosensory post-concussive symptoms. Daytime dysfunction and sleep disturbances were associated with post-concussive symptoms after PTSD and depression symptoms were controlled.

CONCLUSIONS:

PTSD symptom severity explained the most variance for post-concussive symptoms among service members with a history of mild TBI, while depression symptoms, daytime dysfunction, and sleep disturbances independently contributed small amounts of variance.

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.

Neuropsychological Performance and Subjective Symptom Reporting in Military Service Members With a History of Multiple Concussions: Comparison With a Single Concussion, Posttraumatic Stress Disorder, and Orthopedic Trauma

OBJECTIVE

To examine differences in objective neurocognitive performance and subjective cognitive symptoms in individuals with a history of a single concussion, multiple concussions, orthopedic injuries, and posttraumatic stress disorder (PTSD).

METHOD

Participants included 116 military service members who sustained a mild traumatic brain injury (mTBI) during combat deployment. Subjects were subdivided into groups based on concussion frequency: a single concussion (n = 42), 2 concussions (n = 21), and 3 or more concussions (n = 53). Eighty-one subjects sustained an orthopedic injury (n = 60) during deployment or were diagnosed with PTSD (n = 21), but had no history of mTBI. Subjects completed a battery of neuropsychological tests and self-report measures of postconcussive symptoms, PTSD symptoms, and psychopathology.

RESULTS

No differences were found among the concussion groups on a composite neuropsychological measure. The PTSD group had the highest number of symptom complaints, with the 2-concussion and 3-plus-concussion groups being most similar to the PTSD group. The concussion groups showed a nonsignificant pattern of increasing distress with increasing number of concussions.

CONCLUSIONS

The current findings are consistent with meta-analytic results showing no differential effect on neuropsychological functioning due to multiple concussions. Results also support the burden of adversity hypothesis suggesting increasing symptom levels with increasing psychological or physically traumatic exposures.

PTSD as a Mediator in the Relationship Between Post-Concussive Symptoms and Pain Among OEF/OIF/OND Veterans

Introduction

Traumatic brain injury (TBI), pain, and post-traumatic stress disorder (PTSD) commonly co-occur in Veteran populations, particularly among Veterans returning from the recent conflicts in Iraq and Afghanistan. Extant research indicates that both TBI and PTSD can negatively impact pain broadly; however, less is known about how these variables impact one another. The current study examines the impact of self-reported post-concussive symptoms on both pain severity and pain interference among Veterans with PTSD who screened positive for a possible TBI, and subsequently, evaluates the potential mediating role of PTSD in these relationships.

Materials and Methods

Participants were 126 combat Veterans that served in Operation Enduring Freedom, Operation Iraqi Freedom, or Operation New Dawn who were being evaluated for participation in a multisite treatment outcomes study. As part of an initial evaluation for inclusion in the study, participants completed several self-report measures and interviews, including the Brief Traumatic Brain Injury Screen, Neurobehavioral Symptom Inventory, Brief Pain Inventory, and the Clinician Administered PTSD Scale, which were utilized in these analyses.

Results

For pain severity, greater post-concussive symptoms significantly predicted increased pain severity with a significant indirect effect of post-concussive symptoms on pain severity through PTSD (indirect effect = 0.03; 95% confidence interval = 0.0094-0.0526). Similar results were found for pain interference (indirect effect = 0.03; 95% confidence interval = 0.0075-0.0471).

Conclusions

These findings replicate and extend previous findings regarding the relationship between TBI, pain, and PTSD. Self-reported post-concussive symptoms negatively impact both pain severity and pain interference among Veterans with probable TBI, and PTSD serves as a mediator in these relationships. Clinically, these results highlight the importance of fully assessing for PTSD symptoms in Veterans with a history of TBI presenting with pain. Further, it is possible that providing effective PTSD treatment to reduce PTSD severity may provide some benefit in reducing post-concussive and pain symptoms.

Activity Level During Acute Concussion May Predict Symptom Recovery Within an Active Duty Military Population

OBJECTIVE

To evaluate the impact on symptom resolution of activity acutely following a concussion and the role of acute-phase symptoms on this relationship among active duty service members (SMs).

SETTING

Three military installations.

PARTICIPANTS

Sixty-two SMs aged 18 to 44 years who sustained a concussion within 72 hours of enrollment.

DESIGN

Longitudinal design with data collected within 72 hours of injury (baseline, n = 62) and at 1 week (n = 57), 1 month (n = 50), 3 months (n = 41), and 6 months (n = 40) postinjury.

MAIN MEASURES

Baseline activity level using a 60-item Activity Questionnaire. Symptom level at baseline and during follow-up using Neurobehavioral Symptoms Inventory.

RESULTS

Significant interaction (Pi < .05) was found, with significant main effects (P < .05) limited to SMs with elevated baseline symptomatology. Among these participants, greater baseline total activity was significantly related to greater vestibular symptoms at 1, 3, and 6 months (β = .61, .63, and .59, respectively). Significant associations were also found for particular types of baseline activity (eg, physical; vestibular/balance; military-specific) and symptoms at 1, 3, and/or 6 months postinjury.

CONCLUSION

These results provide support for clinical guidance that symptomatic SMs, particularly those with high levels of acute symptoms, may need to avoid excessive activity acutely following concussion.

Activity Level and Type During Post-acute Stages of Concussion May Play an Important Role in Improving Symptoms Among an Active Duty Military Population

Background: Previous research demonstrates that early rest and gradual increases in activity after concussion can improve symptoms; however, little is known about the intensity and type of activity during post-acute time periods-specifically months post-injury-that may promote optimal recovery in an active duty service member (SM) population. Objective: The objectives of this study were to investigate how activity level and type at the post-acute stages of concussion (at 1 and 3 month[s] post-injury) impact subsequent symptoms among SMs, and how this relationship might differ by the level of symptoms at the time of injury. Methods: Participants included 39 SMs ages 19-44 years from 3 military installations who were enrolled within 72 h after sustaining a concussion. Linear regression was used to evaluate whether the association between activity level at 1 or 3 month(s) post-injury (as measured by a multi-domain Activity Questionnaire) and subsequent symptoms at 3 and/or 6 months (as measured by the Neurobehavioral Symptom Inventory) varied by the level of symptoms at acute stages of concussion. Partial correlation was used to evaluate relationships that did not differ by acute symptom level. Symptoms at the time of activity assessment (1 or 3 month[s]) were accounted for in all models, as well as activity level at acute stages of concussion. Results: Greater physical and vestibular/balance activity at 1 month were significantly correlated with lower symptoms at 3 months, but not at 6 months post-injury. There were no significant associations found between activity (total or by type) at 3 months and symptoms at 6 months. The association between activity level at either 1 or 3 months and subsequent symptoms at 3 and/or 6 months did not differ by the level of acute symptoms. Conclusion: The intensity and type of activities in which SMs engage at post-acute stages of concussion may impact symptom recovery. Although low levels of activity have been previously shown to be beneficial during the acute stage of injury, higher levels of activity may provide benefit at later stages. These findings provide support for the importance of monitoring and managing activity level beyond the acute stage of concussion.

Rasch Analysis of Postconcussive Symptoms: Development of Crosswalks and the Brain Injury Symptom Scale

OBJECTIVE

The first aim of this study was to develop a Rasch-based crosswalk between 2 postconcussive symptom measures, the Neurobehavioral Symptom Inventory (NSI) and the Rivermead Postconcussive Symptom Questionnaire (RPQ). The second goal was to utilize Rasch analysis to formulate a new proposed scale containing the best theoretical and psychometric items.

DESIGN

Prospective cohort observational study.

SETTING

Three acute inpatient rehabilitation hospitals in the United States.

PARTICIPANTS

Community-dwelling persons (N=497) who were previously hospitalized and were diagnosed with mild to severe traumatic brain injury. Participants were (1) 18-64 years old; (2) could give informed consent; (3) able to complete study measures in English; (4) did not have an interfering medical or psychiatric condition.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

NSI, RPQ.

RESULTS

Rasch analysis revealed 4 subdimensions across the 2 scales: cognitive, affective, physical, and visual. Crosswalk tables were generated for the first 3. Visual items were too few to generate a crosswalk. Iterative Rasch analysis produced a new scale with items rated from none to severe including the best items in each of these dimensions.

CONCLUSIONS

The NSI and RPQ have considerable overlap and measure the same overarching constructs. Crosswalk tables may be helpful for clinicians and researchers to convert scores from 1 measure to the other. A more psychometrically sound scale, the Brain Injury Symptom Scale, composed of items from the NSI and RPQ, is proposed and will need further validation.

Differences in Posttraumatic Stress Disorder, Depression, and Attribution of Symptoms in Service Members With Combat Versus Noncombat Mild Traumatic Brain Injury

OBJECTIVE

This study compares combat-related mild traumatic brain injury (mTBI) to non-combat-related mTBI in rates of posttraumatic stress disorder (PTSD) and depression after injury, severity of postconcussive symptoms (PCSs), and attribution of those symptoms to mTBI versus PTSD.

PARTICIPANTS

A total of 371 active duty service members (SMs) with documented history of mTBI, divided into combat and non-combat-related cohorts.

DESIGN

Retrospective cohort study.

MAIN MEASURES

Diagnoses of PTSD and depression based on medical record review and self-report. PCSs measured using Neurobehavioral Symptom Index. Attribution of symptoms based on a rating scale asking how much mTBI, PTSD, depression, deployment, or readjustment stress contributed to current symptoms.

RESULTS

Prevalence of PTSD was significantly higher after a combat-related mTBI, compared with a noncombat mTBI (P = .001). Prevalence of depression did not differ between the 2 groups. PCSs were high in both combat and noncombat mTBIs, with no statistical difference between groups. SMs with PTSD reported higher PCS, regardless of combat status. SMs without PTSD attributed symptoms mainly to mTBI, whereas SMs with PTSD, regardless of combat status, were much more likely to attribute symptoms to PTSD, depression, and deployment/readjustment stress.

CONCLUSIONS

This research contributes to our understanding of the complex interplay between mTBI and PTSD in both combat and noncombat injuries within the military population and the importance of addressing both simultaneously.

Functional Outcome and Mental Health Symptoms in Military Personnel and Veterans Pursuing Postsecondary Education After Traumatic Brain Injury: A VA TBI Model Systems Study

Background

TBI is a leading cause of disability among veterans and active duty military personnel, and presents an obstacle to community reintegration. Prior studies examining adult survivors of TBI pursuing postsecondary education have methodological flaws that limit the understanding the scope and severity of sequelae experienced by persons with TBI who attend college.

Objective

To describe (a) physical and cognitive functioning, and (b) postconcussion and mental health symptoms in veterans and military personnel (V/M) with traumatic brain injury (TBI) enrolled in postsecondary education programs after discharge from rehabilitation.

Method

Cross-sectional study. Participants were recruited from five Veterans Affairs (VA) Polytrauma Rehabilitation Centers, enrolled in the VA TBI Model Systems parent study, and attending school during follow-up (N= 155). Outcome measures included the Functional Independence Measure (FIM), Neurobehavioral Symptom Inventory (NSI), Post-traumatic Stress Disorder (PTSD) Checklist-Civilian version (PCL-C), Patient Health Questionnaire-Depression (PHQ-9), and Generalized Anxiety Disorder Questionnaire (GAD-7).

Findings

Participants were mostly male (92.9%) and White (81.4%), with mild (40.0%), moderate (11.5%), severe (34.5%), or very severe TBI (23.0%). Depression, anxiety, PTSD, and postconcussion symptoms were lowest in participants with very severe TBI and highest in those with mild TBI. There were no significant differences in FIM across TBI severity levels.

Conclusion

This study supports the need for rehabilitation counselors, educators, and administrators to prepare future practitioners to deliver tailored services to student V/M with TBI. These services can facilitate successful community reintegration and transition into civilian school settings. Symptom profiling may inform personalized cognitive interventions to enhance these students’ academic success.

Modeling the Structure of Acute Sport-Related Concussion Symptoms: A Bifactor Approach

OBJECTIVES

Concussions cause diverse symptoms that are often measured through a single symptom severity score. Researchers have postulated distinct dimensions of concussion symptoms, raising the possibility that total scores may not accurately represent their multidimensional nature. This study examined to what degree concussion symptoms, assessed by the Sport Concussion Assessment Tool 3 (SCAT3), reflect a unidimensional versus multidimensional construct to inform how the SCAT3 should be scored and advance efforts to identify distinct phenotypes of concussion.

METHODS

Data were aggregated across two prospective studies of sport-related concussion, yielding 219 high school and college athletes in the acute (<48 hr) post-injury period. Item-level ratings on the SCAT3 checklist were analyzed through exploratory and confirmatory factor analyses. We specified higher-order and bifactor models and compared their fit, interpretability, and external correlates.

RESULTS

The best-fitting model was a five-factor bifactor model that included a general factor on which all items loaded and four specific factors reflecting emotional symptoms, torpor, sensory sensitivities, and headache symptoms. The bifactor model demonstrated better discriminant validity than the counterpart higher-order model, in which the factors were highly correlated (r=.55-.91).

CONCLUSIONS

The SCAT3 contains items that appear unidimensional, suggesting that it is appropriate to quantify concussion symptoms with total scores. However, evidence of multidimensionality was revealed using bifactor modeling. Additional work is needed to clarify the nature of factors identified by this model, explicate their clinical and research utility, and determine to what degree the model applies to other stages of injury recovery and patient subgroups. (JINS, 2018, 24, 793-804).

Comprehensive analysis of the predictors of neurobehavioral symptom reporting in veterans

OBJECTIVE

This study assessed the strength of military-related concussion-, psychological-, and behavioral-related measures to predict neurobehavioral symptom (NBS) reporting in order to help clarify the extent to which persistent NBS reflect lingering effects of concussion vs other psychological/behavioral factors among veterans.

METHODS

Baseline analysis included 351 consecutively enrolled veterans in the Translational Research Center for Traumatic Brain Injury and Stress Disorders longitudinal cohort study. One hundred eighty-six returned for a follow-up evaluation averaging 24 months post baseline. The Neurobehavioral Symptom Inventory (NSI) was used to measure NBS reporting. Predictor variables included diagnosis of military-related mild traumatic brain injury (M-mTBI), psychological measures, including posttraumatic stress disorder, mood, anxiety, and substance abuse disorders, and behavioral measures, including self-reported current pain and sleep impairment. Hierarchical and multivariable regression analyses examined the relationships between the predictor variables and NSI scores. The k-fold cross-validation assessed generalizability and validity of the regressions.

RESULTS

Baseline analysis revealed that psychological and behavioral conditions independently accounted for 42.5% of variance in the NSI total score compared to 1.5% for M-mTBI after controlling for psychological and behavioral conditions. Prospective analysis revealed that M-mTBI at baseline did not significantly predict NSI score at follow-up, while psychological and behavioral measures at baseline independently accounted for 24.5% of NSI variance. Posttraumatic stress disorder was the most consistent predictor. Cross-validation analyses supported generalizability of the results.

CONCLUSIONS

Psychological and behavioral-related measures are strong predictors of persistent NBS reporting in veterans, while M-mTBI is negligible. NBS more likely reflect influential comorbidities as opposed to brain injury, per se.

Do postconcussive symptoms from traumatic brain injury in combat veterans predict risk for receiving opioid therapy for chronic pain?

OBJECTIVES

Opioid therapy is contraindicated in patients with traumatic brain injury (TBI) with neuropsychological impairment, yet guidelines do not consistently predict practice. We evaluated independent risk for initiation of opioid therapy among combat veterans with chronic pain diagnoses and persistent postconcussive symptoms.

METHODS

We assembled a retrospective cohort of 53 124 Iraq and Afghanistan veterans in Veterans Affairs (VA) healthcare between October 2007 and March 2015 who received chronic pain diagnoses, completed a Comprehensive TBI Evaluation (CTBIE) and had not received opioid therapy in the prior year. Primary exposure variables were self-reported severe or very severe Emotional, Vestibular, Cognitive and Somatic/Sensory symptoms measured using the Neurobehavioral Symptom Inventory. Outcome measures were initiation of short-term and long-term opioid therapy within the year following CTBIE.

RESULTS

Self-reported severe and very severe postconcussive symptoms predicted initiation of long-term and short-term opioid use for chronic pain in both unadjusted and adjusted analyses. In adjusted analyses, all four postconcussive symptom domains significantly predicted initiation of long-term opioid therapy, with Emotional symptoms being the strongest predictor [ARR = 1.68 (1.52, 1.86)].

CONCLUSIONS

Increased opioid prescribing in veterans with self-reported severe persistent postconcussive symptoms indicates a need to educate prescribers and make non-opioid pain management options available for veterans with TBI and neuropsychological sequelae.

Utility of the Neurobehavioral Symptom Inventory As an Outcome Measure: A VA TBI Model Systems Study

OBJECTIVE

To examine the utility of the Neurobehavioral Symptom Inventory (NSI)-a measure of postconcussion symptoms used within the Veterans Health Administration-as an index of rehabilitation outcome.

SETTING

Veterans Administration Polytrauma Rehabilitation Centers Traumatic Brain Injury (TBI) Model Systems program.

PARTICIPANTS

A total of 159 Veterans (14% with mild TBI; 86% with moderate-severe TBI).

MAIN MEASURES

Disability Rating Scale; Functional Independence Measure; Glasgow Outcome Scale-Extended; NSI; Participation Assessment with Recombined Tools-Objective; Posttraumatic Stress Disorder Checklist-Civilian Version; Satisfaction With Life Scale; Supervision Rating Scale.

ANALYSES

Correlations and exploratory factor analyses examined the interrelations among outcome measures. Hierarchical regression analyses were utilized to determine if the NSI predicted rehabilitation outcome measures after controlling for demographic variables, TBI severity, and time since injury. NSI reliable changes from pretreatment to 1-year follow-up were examined. Receiver operating characteristics curve analyses were conducted to evaluate the ability of changes in the NSI to predict meaningful change in functioning and employment status.

RESULTS

The NSI correlated with psychological distress measures. The NSI administered prior to brain injury rehabilitation had limited predictive utility beyond satisfaction with life. A minority of patients (32%) demonstrated reliable changes on the NSI from baseline to 1-year follow-up. Changes on the NSI were not predictive of meaningful change in employment or functioning.

CONCLUSION

The NSI was not useful for assessing meaningful change in a sample of mixed severity TBI patients.

Hyperarousal Symptoms Explain the Relationship Between Cognitive Complaints and Working Memory Performance in Veterans Seeking PTSD Treatment

OBJECTIVE

Comorbidity and symptom overlap between traumatic brain injury and posttraumatic stress disorder (PTSD) in veterans returning from deployment present challenges with respect to differential diagnosis and treatment. Both conditions frequently manifest with attention and working memory deficits, though the underlying neuropsychological basis differs. This study evaluated whether hyperarousal symptoms explain the relationship between subjective and objective measures of cognition in a veteran sample.

PARTICIPANTS AND PROCEDURES

One-hundred three veterans completed the military version of the PTSD Checklist (PCL), the Neurobehavioral Symptom Inventory, and the Wechsler Memory Scale, 3rd edition digit span task with adequate effort.

RESULTS

Hierarchical regression suggested that hyperarousal, but not other PTSD symptoms, explained the relationship between neurobehavioral symptoms and cognitive functioning. This relationship was present regardless of whether veterans met full PTSD diagnostic criteria or screened positive on a traumatic brain injury screener and was robust to other moderators.

CONCLUSION

These findings highlight the importance of considering traumatic brain injury and PTSD symptom overlap, particularly the relationship between hyperarousal symptoms and attention and working memory deficits, in conceptualizing cases and treatment planning.

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.

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.

Postconcussion symptoms reported by Operation Enduring Freedom/Operation Iraqi Freedom veterans with and without blast exposure, mild traumatic brain injury, and posttraumatic stress disorder

OBJECTIVE

This study examined symptom reporting related to the 10th Edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) criteria for postconcussional syndrome (PCS) in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) Veterans. Our aims were to: (a) examine relationships among PCS symptoms by identifying potential subscales of the British Columbia Postconcussion Symptom Inventory (BC-PSI); and (b) examine group differences in BC-PSI items and subscales in Veterans with and without blast exposure, mild traumatic brain injury (mTBI), and posttraumatic stress disorder (PTSD).

METHOD

Our sample included Veterans with blast-related mTBI history (n = 47), with blast exposure but no mTBI history (n = 20), and without blast exposure (n = 23). Overall, 37 Veterans had PTSD, and 53 did not. We conducted an exploratory factor analysis (EFA) of the BC-PSI followed by multivariate analysis of variance to examine differences in BC-PSI subscale scores by blast exposure, mTBI history, and PTSD.

RESULTS

BC-PSI factors were interpreted as cognitive, vestibular, affective, anger, and somatic. Items and factor scores were highest for Veterans with blast exposure plus mTBI, and lowest for controls. Vestibular, affective, and somatic factors were significantly higher for Veterans with blast exposure plus mTBI than for controls, but not significantly different for those with blast exposure but no mTBI. These results remained significant when PTSD symptom severity was included as a covariate. Cognitive, anger, and somatic subscales were significantly higher for Veterans with PTSD, though there was no interaction effect of PTSD and mTBI or blast history.

CONCLUSIONS

EFA-derived subscales of the BC-PSI differentiated Veterans based on blast exposure, mTBI history, and PTSD.

Cross-Phenotype Polygenic Risk Score Analysis of Persistent Post-Concussive Symptoms in U.S. Army Soldiers with Deployment-Acquired Traumatic Brain Injury

Traumatic brain injury (TBI) contributes to the increased rates of suicide and post-traumatic stress disorder in military personnel and veterans, and it is also associated with the risk for neurodegenerative and psychiatric disorders. A cross-phenotype high-resolution polygenic risk score (PRS) analysis of persistent post-concussive symptoms (PCS) was conducted in 845 U.S. Army soldiers who sustained TBI during their deployment. We used a prospective longitudinal survey of three brigade combat teams to assess deployment-acquired TBI and persistent physical, cognitive, and emotional PCS. PRS was derived from summary statistics of large genome-wide association studies of Alzheimer's disease, Parkinson's disease, schizophrenia, bipolar disorder, and major depressive disorder (MDD); and for years of schooling, college completion, childhood intelligence, infant head circumference (IHC), and adult intracranial volume. Although our study had more than 95% of statistical power to detect moderate-to-large effect sizes, no association was observed with neurodegenerative and psychiatric disorders, suggesting that persistent PCS does not share genetic components with these traits to a moderate-to-large degree. We observed a significant finding: subjects with high IHC PRS recovered better from cognitive/emotional persistent PCS than the other individuals (R² = 1.11%; p = 3.37 × 10^-3). Enrichment analysis identified two significant Gene Ontology (GO) terms related to this result: GO:0050839∼Cell adhesion molecule binding (p = 8.9 × 10^-6) and GO:0050905∼Neuromuscular process (p = 9.8 × 10^-5). In summary, our study indicated that the genetic predisposition to persistent PCS after TBI does not have substantial overlap with neurodegenerative and psychiatric diseases, but mechanisms related to early brain growth may be involved.

Older Age Results in Differential Gene Expression after Mild Traumatic Brain Injury and Is Linked to Imaging Differences at Acute Follow-up

Older age consistently relates to a lesser ability to fully recover from a traumatic brain injury (TBI); however, there is limited data to explicate the nature of age-related risks. This study was undertaken to determine the relationship of age on gene-activity following a TBI, and how this biomarker relates to changes in neuroimaging findings. A young group (between the ages of 19 and 35 years), and an old group (between the ages of 60 and 89 years) were compared on global gene-activity within 48 h following a TBI, and then at follow-up within 1-week. At each time-point, gene expression profiles, and imaging findings from both magnetic resonance imaging (MRI) and computed tomography were obtained and compared. The young group was found to have greater gene expression of inflammatory regulatory genes at 48 h and 1-week in genes such as basic leucine zipper transcription factor 2 (BACH2), leucine-rich repeat neuronal 3 (LRRN3), and lymphoid enhancer-binding factor 1 (LEF1) compared to the old group. In the old group, there was increased activity in genes within S100 family, including calcium binding protein P (S100P) and S100 calcium binding protein A8 (S100A8), which previous studies have linked to poor recovery from TBI. The old group also had reduced activity of the noggin (NOG) gene, which is a member of the transforming growth factor-β superfamily and is linked to neurorecovery and neuroregeneration compared to the young group. We link these gene expression findings that were validated to neuroimaging, reporting that in the old group with a MRI finding of TBI-related damage, there was a lesser likelihood to then have a negative MRI finding at follow-up compared to the young group. Together, these data indicate that age impacts gene activity following a TBI, and suggest that this differential activity related to immune regulation and neurorecovery contributes to a lesser likelihood of neuronal recovery in older patients as indicated through neuroimaging.

[Formula: see text]Interpreting change on the neurobehavioral symptom inventory and the PTSD checklist in military personnel

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.