This study examined whether intracranial neuroimaging abnormalities in those with mild traumatic brain injury (MTBI) (i.e., "complicated" MTBIs) are associated with worse subacute outcomes as ...measured by cognitive testing, symptom ratings, and/or diffusion tensor imaging (DTI). We hypothesized that (i) as a group, participants with complicated MTBIs would report greater symptoms and have worse neurocognitive outcomes than those with uncomplicated MTBI, and (ii) as a group, participants with complicated MTBIs would show more Diffusion Tensor Imaging (DTI) abnormalities. Participants were 62 adults with MTBIs (31 complicated and 31 uncomplicated) who completed neurocognitive testing, symptom ratings, and DTI on a 3T MRI scanner approximately 6-8 weeks post injury. There were no statistically significant differences between groups on symptom ratings or on a broad range of neuropsychological tests. When comparing the groups using tract-based spatial statistics for DTI, no significant difference was found for axial diffusivity or mean diffusivity. However, several brain regions demonstrated increased radial diffusivity (purported to measure myelin integrity), and decreased fractional anisotropy in the complicated group compared with the uncomplicated group. Finally, when we extended the DTI analysis, using a multivariate atlas based approach, to 32 orthopedic trauma controls (TC), the findings did not reveal significantly more areas of abnormal DTI signal in the complicated vs. uncomplicated groups, although both MTBI groups had a greater number of areas with increased radial diffusivity compared with the trauma controls. This study illustrates that macrostructural neuroimaging changes following MTBI are associated with measurable changes in DTI signal. Of note, however, the division of MTBI into complicated and uncomplicated subtypes did not predict worse clinical outcome at 6-8 weeks post injury.
This study examines the relationship of serum total tau, neurofilament light (NFL), ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1), and glial fibrillary acidic protein (GFAP) with neurocognitive ...performance in service members and veterans with a history of traumatic brain injury (TBI).
Service members (n = 488) with a history of uncomplicated mild (n = 172), complicated mild, moderate, severe, or penetrating TBI (sTBI; n = 126), injured controls (n = 116), and non-injured controls (n = 74) prospectively enrolled from Military Treatment Facilities. Participants completed a blood draw and neuropsychological assessment a year or more post-injury. Six neuropsychological composite scores and presence/absence of mild neurocognitive disorder (MNCD) were evaluated. Within each group, stepwise hierarchical regression models were conducted.
Within the sTBI group, increased serum UCH-L1 was related to worse immediate memory and delayed memory (R2Δ = .065-.084, ps < .05) performance, while increased GFAP was related to worse perceptual reasoning (R2Δ = .030, p = .036). Unexpectedly, within injured controls, UCH-L1 and GFAP were inversely related to working memory (R2Δ = .052-.071, ps < .05), and NFL was related to executive functioning (R2Δ = .039, p = .021) and MNCD (Exp(B) = 1.119, p = .029).
Results suggest GFAP and UCH-L1 could play a role in predicting poor cognitive outcome following complicated mild and more severe TBI. Further investigation of blood biomarkers and cognition is warranted.
This study examined postconcussion symptom reporting within the first 5 years after mild traumatic brain injury (mTBI). Participants were 167 U.S. military service members (mean age, 27.6 years; ...74.3% blast; 96.4% male) who were evaluated subsequent to injuries sustained in theater during Operations Iraqi and Enduring Freedom (92.8%) or from other combat-related operations. Participants completed the Neurobehavioral Symptom Inventory and Post-Traumatic Stress Disorder Checklist within 3 months of injury and at least one follow-up telephone interview at 6 (n = 46), 12 (n = 89), 24 (n = 54), 36 (n = 42), 48 (n = 30), and/or 60 months (n = 25) postinjury. Approximately half of the sample (49.7%) met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) symptom criteria for postconcussion disorder (PCD) at baseline. At all six follow-ups, 46.1-72.0% met DSM-IV criteria for PCD. However, only 20.4-48.0% reported persistent PCD from baseline to follow-up. A substantial minority had also improved (4.0-24.1%) or "developed" new symptoms (16.9-27.8%). Using regression analyses, baseline symptoms were somewhat predictive of PCD symptom reporting at follow-up, though this was not always reliable. Follow-up for all service members who sustain a combat-related mTBI in the context of polytrauma, regardless of the presence or absence of symptom reporting in the acute recovery stage, should be considered the rule, not the exception.
The Masking Level Difference (MLD) has been used for decades to evaluate the binaural listening advantage. Although originally measured using Bekesy audiometry, the most common clinical use of the ...MLD is the CD-based Wilson 500-Hz technique with interleaved N0S0 and N0Sπ components. Here, we propose an alternative technique based on manual audiometry as a faster way of measuring the MLD. The article describes the advantages to this administration technique and evaluates if it is a viable alternative for the Wilson technique.
Data were retrospectively analyzed on 264 service members (SMs). All SMs completed both the Wilson and Manual MLDs. Descriptive and correlational statistics were applied to evaluate the comparisons between the two techniques and highlight the differences. Equivalence measures were also completed to compare the tests using a standardized cutoff score. Analyses were also made to compare both techniques to subjective and objective measures of hearing performance.
Moderate to high positive correlations were determined between Wilson and Manual measures of each threshold (N0Sπ and N0S0). Although the Manual and Wilson MLD techniques produced significantly different thresholds, simple linear transformations can be used to obtain approximately equivalent scores on the two tests, and agreement was high for using these transformed scores to identify individuals with substantial MLD deficits. Both techniques had moderate test-retest reliability. The Manual MLD and components had stronger correlations to the subjective and objective hearing measures than the Wilson.
The Manual technique is a faster method for obtaining MLD scores that is just as reliable as the CD-based Wilson test. With the significant reduction in assessment time and comparable results, the Manual MLD is a viable alternative for direct use in the clinic.
To examine the relationship between service member/veteran (SM/V) traumatic brain injury (TBI) severity with caregiver health-related quality of life (HRQOL).
Military treatment facility.
Caregivers ...( N = 316) of SM/Vs following a TBI divided into 2 groups based on SM/V TBI severity: (1) caregivers of SM/Vs following an uncomplicated mild TBI (UnMTBI Caregiver group, n = 246), and (2) caregivers of SM//Vs following a complicated mild, moderate, severe, or penetrating TBI (STBI Caregiver group, n = 70). The STBI Caregiver group was further divided into 2 subgroups: Parent ( n = 21) versus Intimate Partner ( n = 49). The UnMTBI Caregiver group consisted of intimate partners.
Prospective cohort.
Caregivers completed 15 HRQOL measures.
Using analysis of variance and chi-square analysis, the UnMTBI Caregiver group reported worse scores on 12 HRQOL measures and more clinically elevated scores for 6 of 15 comparisons than the STBI Caregiver group. The UnMTBI Caregiver group also reported worse scores on 10 HRQOL measures than intimate partners in the STBI Caregiver group and 5 measures than parents in the STBI Caregiver group. Parents reported worse scores on 3 measures than intimate partners in the STBI Caregiver group. The UnMTBI Caregiver group reported more clinically elevated scores for 7 of 15 comparisons than intimate partners in the STBI Caregiver group.
Intimate partner caregivers of an SM/V following a remote uncomplicated MTBI reported worse HRQOL than intimate partners and parent caregivers of an SM/V following a more severe TBI, mostly likely due to SM/V physical and mental health comorbidities. Interventions that focus on the SM/V's TBI and other comorbidities, the caregiver's behavioral health problems, and the relationship and family factors that interact with each other will likely have the most success in improving individual and family outcomes for military families.
The purpose of this cross-sectional study was to examine the influence of subthreshold posttraumatic stress disorder (PTSD) and full PTSD on quality of life following mild traumatic brain injury ...(mTBI).
Participants were 734 service members and veterans (SMV) classified into two injury groups: uncomplicated mild TBI (MTBI; n = 596) and injured controls (IC, n = 139). Participants completed a battery of neurobehavioral measures, 12-or-more months post-injury, that included the PTSD Checklist Civilian version, Neurobehavioral Symptom Inventory, and select scales from the TBI-QOL and MPAI. The MTBI group was divided into three PTSD subgroups: No-PTSD (n = 266), Subthreshold PTSD (n = 139), and Full-PTSD (n = 190).
There was a linear relationship between PTSD severity and neurobehavioral functioning/quality of life in the MTBI sample. As PTSD severity increased, significantly worse scores were found on 11 of the 12 measures (i.e., MTBI: Full-PTSD > Sub-PTSD > No-PTSD). When considering the number of clinically elevated scores, a linear relationship between PTSD severity and neurobehavioral functioning/quality of life was again observed in the MTBI sample (e.g., 3-or-more elevated scores: Full-PTSD = 92.1 %, Sub-PTSD = 61.9 %, No-PTSD = 19.9 %).
Limitations included the use of a self-report measure to determine diagnostic status that may under/overcount or mischaracterize individuals.
PTSD symptoms, whether at the level of diagnosable PTSD, or falling short of that because of the intensity or characterization of symptoms, have a significant negative impact on one's quality of life following MTBI. Clinicians' treatment targets should focus on the symptoms that are most troubling for an individual and the individual's perception of quality of life, regardless of the diagnosis itself.
The extant literature investigating the relationship between diffusion tensor imaging (DTI) and cognition following traumatic brain injury (TBI) is limited by small sample sizes and inappropriate ...control groups. The present study examined DTI metric differences between service members and veterans (SMVs) with bodily injury (Trauma Control; TC), uncomplicated mild TBI (mTBI), complicated mild TBI (compTBI), and severe-moderate TBI combined (smTBI), and how DTI metrics related to cognition within each group. Participants were 226 SMVs (56 TC, 112 mTBI, 29 compTBI, 29 smTBI) with valid neuropsychological testing and DTI at least 11 months post-injury. The smTBI group demonstrated decreased fractional anisotropy (FA) and increased axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) of the cerebral white matter (CWM) and several individual white matter tracts compared with the TC, mTBI, and compTBI groups (all
s < 0.05;
s = 0.17 to 0.49). The TC, mTBI, and compTBI groups did not differ in terms of any DTI metrics. Within the smTBI group, FA, AD, MD, and RD of the total CWM and several white matter tracts were related to Processing Speed (|
s|: 0.43 to 0.66;
s < 0.05), and/or Delayed Memory (|
s|: 0.41 to 0.67;
s < 0.05). In the compTBI group, Processing Speed was related to left arcuate fasciculus and superior longitudinal fasciculus (SLF) FA, MD, and RD, as well as left uncinate fasciculus MD and RD. In contrast, there were no significant relationships between DTI metrics and cognition/emotional functioning within the mTBI or TC groups. Overall, findings suggest a dose-response relationship between TBI severity and the strength of the relationship between white matter integrity and cognitive performance, with essentially no relationship in mTBI, some findings in compTBI, and several strongly significant relationships in smTBI. In contrast to previously reported findings, there were no differences in DTI metrics between controls, mTBI, and compTBI, and DTI metrics were unrelated to cognition in our relatively large mTBI group.
To examine the influence of depression on postconcussion symptom reporting in patients following mild traumatic brain injury (MTBI).
Sixty patients referred to a specialty clinic following MTBI, 58 ...outpatients with Structured Clinical Interview for DSM-diagnosed depression, and 72 healthy community control participants.
Participants with MTBI were divided into 2 subgroups on the basis of self-reported symptoms of depression (23 MTBI-depressed, 37 MTBI-not depressed). All participants completed a postconcussion symptom questionnaire.
British Columbia Post-concussion Symptom Inventory.
There were significant differences in total reported postconcussion symptoms among all 4 groups (all P < .002; Cohen's d = 0.68-3.24, large to very large effect sizes; MTBI-depressed > depressed outpatients > MTBI-no depression > healthy controls). There were significant differences in the number of symptoms endorsed (P < .05), with the highest number of symptoms endorsed by the MTBI-depressed group, followed by depressed outpatients, MTBI-no depression, and healthy controls.
Patients who experience MTBIs and who have a postinjury recovery course complicated by significant depression report more postconcussion symptoms, and more severe symptoms, than (a) outpatients with depression, and (b) patients with MTBIs who do not have significant symptoms of depression.
Objective: The purpose of this study was to examine the clinical utility of two validity scales designed for use with the Neurobehavioral Symptom Inventory (NSI) and the PTSD Checklist-Civilian ...Version (PCL-C); the Mild Brain Injury Atypical Symptoms Scale (mBIAS) and Validity-10 scale. Method: Participants were 63 U.S. military service members (age: M = 31.9 years, SD = 12.5; 90.5% male) who sustained a mild traumatic brain injury (MTBI) and were prospectively enrolled from Walter Reed National Military Medical Center. Participants were divided into two groups based on the validity scales of the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF): (a) symptom validity test (SVT)-Fail (n = 24) and (b) SVT-Pass (n = 39). Participants were evaluated on average 19.4 months postinjury (SD = 27.6). Results: Participants in the SVT-Fail group had significantly higher scores (p < .05) on the mBIAS (d = 0.85), Validity-10 (d = 1.89), NSI (d = 2.23), and PCL-C (d = 2.47), and the vast majority of the MMPI-2-RF scales (d = 0.69 to d = 2.47). Sensitivity, specificity, and predictive power values were calculated across the range of mBIAS and Validity-10 scores to determine the optimal cutoff to detect symptom exaggeration. For the mBIAS, a cutoff score of ≥8 was considered optimal, which resulted in low sensitivity (.17), high specificity (1.0), high positive predictive power (1.0), and moderate negative predictive power (.69). For the Validity-10 scale, a cutoff score of ≥13 was considered optimal, which resulted in moderate-high sensitivity (.63), high specificity (.97), and high positive (.93) and negative predictive power (.83). Conclusion: These findings provide strong support for the use of the Validity-10 as a tool to screen for symptom exaggeration when administering the NSI and PCL-C. The mBIAS, however, was not a reliable tool for this purpose and failed to identify the vast majority of people who exaggerated symptoms.
Females are often excluded from military-related mild traumatic brain injury (mTBI) research because of its relatively low prevalence in this population. The purpose of this study was to focus on ...outcome from mTBI in female service members, compared with males. Participants were 172 United States military service members selected from a larger sample that had sustained an mTBI, and were evaluated within 24 months of injury (Age: mean = 28.9, SD = 8.1) at one of six military medical centers. Eighty-six women were matched to 86 men on nine key variables: TBI severity, mechanism of injury, bodily injury severity, days post-injury, age, number of deployments, theater where wounded, branch of service, and rank. Participants completed the Neurobehavioral Symptom Inventory (NSI) and the Posttraumatic Stress Disorder Checklist (PCL-C). There were no meaningful gender differences across all demographic and injury-related variables (p > 0.05). There were significant group differences and medium effect sizes for the NSI total score and all four NSI cluster scores. Symptoms most affected related to nausea, sensitivity to light, change in taste/smell, change in appetite, fatigue, and poor sleep. There were significant group differences and small-medium effect sizes for the PCL-C total score and two of the three PCL-C cluster scores. Symptoms most affected related to poor concentration, trouble remembering a stressful event, and disturbing memories/thoughts/images. Females consistently experienced more symptoms than males. As females become more active in combat-related deployments, it is critical that future studies place more emphasis on this important military population.
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