This study compared findings from whole-brain diffusion tensor imaging (DTI) and volumetric magnetic resonance imaging (MRI) among 90 Active Duty Service Members with chronic mild traumatic brain ...injury (TBI;
= 52), chronic moderate-to-severe TBI (
= 17), and TBI-negative controls (
= 21). Data were collected on a Philips Ingenia 3T MRI with DTI in 32 directions. Results demonstrated that history of TBI was associated with differences in white matter microstructure, white matter volume, and cortical thickness in both mild TBI and moderate-to-severe TBI groups relative to controls. However, the presence, pattern, and distribution of these findings varied substantially depending on the injury severity. Spatially-defined forms of DTI fractional anisotropy (FA) analyses identified altered white matter organization within the chronic moderate-to-severe TBI group, but they did not provide clear evidence of abnormalities within the chronic mild TBI group. In contrast, DTI FA "pothole" analyses identified widely distributed areas of decreased FA throughout the white matter in both the chronic mild TBI and chronic moderate-to-severe TBI groups. Additionally, decreased white matter volume was found in several brain regions for the chronic moderate-to-severe TBI group compared with the other groups. Greater number of DTI FA potholes and reduced cortical thickness were also related to greater severity of self-reported symptoms. In sum, this study expands upon a growing body of literature using advanced imaging techniques to identify potential effects of brain injury in military Service Members. These findings may differ from work in other TBI populations due to varying mechanisms and frequency of injury, as well as a potentially higher level of functioning in the current sample related to the ability to maintain continued Active Duty status after injury. In conclusion, this study provides DTI and volumetric MRI findings across the spectrum of TBI severity. These results provide support for the use of DTI and volumetric MRI to identify differences in white matter microstructure and volume related to TBI. In particular, DTI FA pothole analysis may provide greater sensitivity for detecting subtle forms of white matter injury than conventional DTI FA analyses.
To evaluate a neurocognitive eye tracking task, the Bethesda Eye & Attention Measure (BEAM), for use in cognitive screening of patients with a history of mild traumatic brain injury (TBI).
US ...military TBI rehabilitation clinic.
Cross-sectional study of 191 military personnel receiving outpatient services related to history of mild TBI. Main measures: BEAM; neuropsychological screening measures of attention, processing speed, executive function, and memory.
Medium effect sizes were found for partial correlations (controlling for age) between key BEAM metrics and neuropsychological screening tests. Linear regression analyses demonstrated that BEAM saccadic eye movements and manual (button press) metrics each provided complementary value in measurement of cognitive performance, above and beyond effects of demographic factors and clinical characteristics.
This study provides initial support for the use of BEAM neurocognitive eye tracking in cognitive screening of adults with a history of mild TBI. BEAM saccadic metrics appear to be particularly well-suited for the assessment of visual attention. Study findings also highlight opportunities for greater cognitive sensitivity or testing efficiency that may be missed by tests measuring only one response modality at a time.
Purpose
This study examined the clinical utility of post-traumatic stress disorder (PTSD), low resilience, poor sleep, and lifetime blast exposure as risk factors for predicting future ...neurobehavioral outcome following traumatic brain injury (TBI).
Methods
Participants were 591 U.S. military service members and veterans who had sustained a TBI (
n
= 419) or orthopedic injury without TBI (
n
= 172). Participants completed the Neurobehavioral Symptom Inventory, PTSD Checklist, and the TBI-Quality of Life (TBI-QOL) scale at baseline and follow-up.
Results
Using the four risk factors at baseline, 15 risk factor combinations were examined by calculating odds ratios to predict poor neurobehavioral outcome at follow-up (i.e., number of abnormal scores across five TBI-QOL scales e.g., Fatigue, Depression). The vast majority of risk factor combinations resulted in odds ratios that were considered to be clinically meaningful (i.e., ≥ 2.5) for predicting poor outcome. The risk factor combinations with the highest odds ratios included PTSD singularly, or in combination with poor sleep and/or low resilience (odds ratios = 4.3–72.4). However, poor sleep and low resilience were also strong predictors in the absence of PTSD (odds ratios = 3.1–29.8).
Conclusion
PTSD, poor sleep, and low resilience, singularly or in combination, may be valuable risk factors that can be used clinically for targeted early interventions.
The purpose of this study was to determine the extent to which patient's perspective of symptom improvement, as indexed by the Patient Global Impression of Change (PGIC) survey, is associated with ...symptom improvement on common measures of neurobehavioral and mental health symptoms following concussion.
Data were from 449 US active duty service members receiving treatment in interdisciplinary programs for their concussion. PGIC rating (range = 1-7) was evaluated for compatibility in assessing improvement in or clinically-elevated neurobehavioral (using Neurobehavioral Symptom Inventory NSI) and mental health (using Post-traumatic Stress Disorder Checklist, DSM-5 PCL-5 and Patient Health Questionnaire PHQ-8) symptoms.
Higher PGIC scores were related to a higher prevalence of clinically-relevant
in NSI, PCL-5 or PHQ-8 scores. Participants with a PGIC rating of 3+ (vs.<3) were about 2.2 (CI = 1.4-3.5), 1.6 (CI = 1.1-1.3), and 2.7 (CI = 1.4-5.1) times more likely to report clinically-relevant
in NSI, PCL-5 and PHQ-8 symptoms, respectively.
PGIC may help providers incorporate patients' perspectives on symptom improvement achieved during rehabilitation. An approach combining PGIC with surveys such as NSI, PCL-5 and PHQ-8 may provide a more comprehensive understanding of symptom improvement and realistic view of expectations for what would be deemed recovery to pre-injury symptom levels.
The Blast Exposure Threshold Survey (BETS) is a recently developed and promising new self-report measure of lifetime blast exposure (LBE). However, there are no studies that have examined the ...psychometric properties of the BETS, which currently limits its clinical utility. The purpose of this study was to examine the convergent and discriminant validity of the BETS by comparing the BETS Generalized Blast Exposure Value (GBEV) to six variables hypothesized to be associated with LBE (i.e., single-item LBE, combat exposure, years in the military, number of combat deployments, and military occupation specialty MOS) and three variables hypothesized not to be associated with LBE (i.e., age at the time of injury, estimated pre-morbid Full-Scale Intelligence Quotient FSIQ, and resilience). Participants were 202 United States service members and veterans prospectively enrolled from three military medical treatment facilities (68.7%) and via community recruitment initiatives (31.3%). Participants completed the BETS, Combat Exposure Scale (CES), Deployment Risk and Resiliency Inventory-2 Combat Experiences (DRRI-2 CE), Traumatic Brain Injury-Quality of Life Resilience scale, and a brief structured interview. For some analyses, participants were classified into two blast risk MOS groups: high (
= 89) and low (
= 94). The BETS GBEV was not significantly correlated with all three non-blast related variables (r
= 0.01 to r
= -0.12). In contrast, GBEV was significantly (
< 0.001) associated with all blast-related variables; single-item LBE (r
= 0.76), CES (r
= 0.58), number of combat deployments (r
= 0.53), DRRI-2 CE (r
= 0.48), and high blast risk MOS (r = 0.36, medium effect size). However, a stronger relationship was found between the blast-related variables and three modified GBEV scores when excluding some small weapons categories; single-item LBE (r
= 0.80-0.82), CES (r
= 0.64-0.67), number of combat deployments (r
= 0.56), DRRI-2 CE (r
= 0.51-0.53), and high blast risk MOS (r = 0.42-0.49, medium-large effect size). This is the first study to examine the psychometric properties of the BETS. Overall, these results offer support for the convergent and discriminant validity of the BETS. In order to ensure that the BETS can be confidently used as a valid and reliable measure of LBE, more research is needed to further examine the psychometric properties of the test, particularly with regard to the establishment of test-retest reliability.
Objective: Previous research suggests that saccadic eye movements can be uniquely sensitive to impairment in chronic traumatic brain injury (TBI). This study was conducted to examine saccadic eye ...movements across varying levels of cognitive load and TBI history/severity. We hypothesized that saccadic impairment in chronic mild and moderate-severe TBI would be most pronounced under conditions of high cognitive load.
Methods: In total, 61 participants (including n = 20 with chronic mild TBI, n = 15 with chronic moderate-severe TBI, and 26 uninjured controls) completed a battery of conventional neuropsychological tests and the Fusion n-Back Test, which measures manual and saccadic response time (RT) across varying cognitive load and cueing conditions.
Results: Consistent with our hypotheses, chronic mild and moderate-severe TBI were associated with substantial saccadic impairment under conditions of high cognitive load. Participants with moderate-severe TBI also demonstrated saccadic impairment at low levels of cognitive load. TBI groups and uninjured controls did not differ significantly on manual metrics or conventional neuropsychological measures.
Conclusions: This study provides additional support for the value of eye tracking for enhanced assessment of TBI. Additionally, findings suggest that TBI is associated with greatest susceptibility to oculomotor interference under high levels of cognitive load.
Comorbid mental illness may negatively impact recovery from concussion. This study evaluated whether the level of symptom clusters at clinic intake contribute to poor mental health recovery in ...concussed patients during treatment, which may in turn serve as a target intervention.
The objective of this study is to examine the association between the level of initial symptoms and mental health symptoms among service members with concussion.
Data were obtained from 483 active duty service members treated in interdisciplinary treatment programs for traumatic brain injury, all of which were concussions. Pre-treatment symptom clusters included self-reported hyperarousal, dissociation/depression, cognitive dysfunction/headache and neurological symptoms. The outcomes, clinically-relevant decreases in depressive symptoms (assessed by the 8-item Patient Health Questionnaire, PHQ-8) and PTSD symptoms (assessed by the PTSD Checklist for DSM-5, PCL-5), were defined as a decrease in PHQ-8 > 5 and PCL-5 > 7, respectively. Poisson regression with robust error variance was used to evaluate the relationship between the level of each symptom cluster and clinically-relevant decrease in outcomes.
Participants with higher (vs. lower) levels of pre-treatment hyperarousal and dissociation/depression symptom cluster were less likely to improve in depressive and PTSD symptoms during treatment. The level of cognitive/headache and neurological symptom clusters were not significantly associated with any symptom changes.
These findings support the need for individualized treatment for symptoms identified and treated after determining concussion history, with particular attention to high levels of hyperarousal and dissociation/depression prior to treatment.
Objective: The Neurobehavioral Symptom Inventory (NSI) is a commonly employed measure of self-reported postconcussive symptoms. As the measure is potentially vulnerable to exaggeration, the ...validity-10 was developed as an embedded symptom validity test (SVT). However, the utility of this SVT over the remaining 12 items and NSI total score has been questioned. Method: The present study sought to replicate previous findings in a sample of 271 service members and veterans (SMV) with a history of mild traumatic brain injury (mTBI). Participants were administered the NSI and the MMPI-2-RF. Results: The validity-10, remaining-12, and NSI total score demonstrated strong and comparable correlations to MMPI-2-RF overreporting scales. ROC analyses also demonstrated that areas under the curve were generally equivalent among these scales (NSI total score = .87; validity-10 = .84; and remaining-12 = .86). Conclusions: These findings support previous research that demonstrated equivalency among these scales.
Public Significance Statement
The utility of the Neurobehavioral Symptom Inventory (NSI) validity-10 over the remaining 12 items and NSI total score has been questioned. The present study found that the validity-10, remaining-12, and NSI total score demonstrated strong and comparable correlations to MMPI-2-RF overreporting scales. These findings support previous research demonstrating equivalency among these scales.
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