Extracellular vesicle neurofilament light is elevated within the first 12-months following traumatic brain injury in a U.S military population.

Traumatic brain injury (TBI) can be associated with long-term neurobehavioral symptoms. Here, we examined levels of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) in extracellular vesicles isolated from blood, and their relationship with TBI severity and neurobehavioral symptom reporting. Participants were 218 service members and veterans who sustained uncomplicated mild TBIs (mTBI, n = 107); complicated mild, moderate, or severe TBIs (smcTBI, n = 66); or Injured controls (IC, orthopedic injury without TBI, n = 45). Within one year after injury, but not after, NfL was higher in the smcTBI group than mTBI (p = 0.001, d = 0.66) and IC (p = 0.001, d = 0.35) groups, which remained after controlling for demographics and injury characteristics. NfL also discriminated the smcTBI group from IC (AUC:77.5%, p < 0.001) and mTBI (AUC:76.1%, p < 0.001) groups. No other group differences were observed for NfL or GFAP at either timepoint. NfL correlated with post-concussion symptoms (rs = - 0.38, p = 0.04) in the mTBI group, and with PTSD symptoms in mTBI (rs = - 0.43, p = 0.021) and smcTBI groups (rs = - 0.40, p = 0.024) within one year after injury, which was not confirmed in regression models. Our results suggest the potential of NfL, a protein previously linked to axonal damage, as a diagnostic biomarker that distinguishes TBI severity within the first year after injury.

Post-Traumatic Stress Disorder Symptoms Are Related to Cognition after Complicated Mild and Moderate Traumatic Brain Injury but Not Severe and Penetrating Traumatic Brain Injury.

Although post-traumatic stress disorder (PTSD) has been associated with worse cognitive outcomes after mild traumatic brain injury (TBI), its impact has not been evaluated after more severe TBI. This study aimed to determine whether PTSD symptoms are related to cognition after complicated mild, moderate, severe, and penetrating TBI. Service members (n = 137) with a history of complicated mild/moderate TBI (n = 64) or severe/penetrating TBI (n = 73) were prospectively enrolled from United States Military Treatment Facilities. Participants completed a neuropsychological assessment one year or more post-injury. Six neuropsychological composite scores and an overall test battery mean (OTBM) were considered. Participants were excluded if there was evidence of invalid responding. Hierarchical linear regressions were conducted evaluating neuropsychological performance. The interaction between TBI severity and PTSD Checklist-Civilian version total score was significant for processing speed (ß = 0.208, p = 0.034) and delayed memory (ß = 0.239, p = 0.021) and trended toward significance for immediate memory (ß = 0.190, p = 0.057) and the OTBM (ß = 0.181, p = 0.063). For each of these composite scores, the relationship between PTSD symptoms and cognition was stronger in the complicated mild/moderate TBI group than the severe/penetrating TBI group. Within the severe/penetrating TBI group, PTSD symptoms were unrelated to cognitive performance. In contrast, within the complicated mild/moderate TBI group, PTSD symptoms were significantly related to processing speed (R2Δ = 0.077, ß = -0.280, p = 0.019), immediate memory (R2Δ = 0.197, ß = -0.448, p < 0.001), delayed memory (R2Δ = 0.176, ß = -0.423, p < 0.001), executive functioning (R2Δ = 0.100, ß = -0.317, p = 0.008), and the OTBM (R2Δ = 0.162, ß = -0.405, p < 0.001). The potential impact of PTSD symptoms on cognition, over and above the impact of brain injury alone, should be considered with service members and veterans with a history of complicated mild/moderate TBI. In addition, in research comparing cognitive outcomes between patients with histories of complicated-mild, moderate, severe, and/or penetrating TBI, it will be important to account for PTSD symptoms.

Long-term neurobehavioural symptom reporting following mild, moderate, severe, and penetrating traumatic brain injury in U.S. military service members.

The purpose of this study was to examine long-term neurobehavioural symptom reporting following mild, moderate, severe, or penetrating TBI in U.S. military service members and veterans (SMV). Participants were 445 SMVs divided into four groups: 158 uncomplicated mild TBI ("unMTBI" group), 105 penetrating, severe, moderate, or complicated mild TBI ("smcTBI" group), 101 injured controls (IC), and 81 non-injured controls (NIC). Two independent cohorts were examined that included participants 5-years or 10-year post-injury. Participants completed the TBI-Quality of Life, Neurobehavioural Symptom Inventory, and Post-traumatic Stress Disorder Checklist. At 5-years and 10-years post-injury, there were significant main effects for the majority of measures (all p's < .005). At 10-years post-injury, the NIC group had consistently better scores compared to the IC, unMTBI, and smcTBI groups. At 5-years post-injury, either (a) the IC and NIC group had better scores compared to both TBI groups, or (b) the NIC group had better scores compared to the IC, unMTBI, and smcTBI groups. A high proportion of SMVs reported poor long-term neurobehavioural symptoms following TBI or bodily injury without TBI. Injured SMVs (regardless of injury type) can have long-term symptoms that impact mental health and overall quality of life requiring long-term follow-up and care.

Factors related to perceived burden among caregivers of service members/veterans following TBI.

PURPOSE/OBJECTIVE: To examine factors related to perceived caregiving burden in a sample of caregivers assisting service members and veterans (SMVs) across four areas: SMV injury and health status; caregiver life circumstances; caregiver duty and responsibilities; and caregiver needs. Research Method/Design: Participants were 214 caregivers (95.8% female; 86.0% spouse/partner; Age: M = 38.6 years [SD = 10.4]) of SMVs who sustained a mild, moderate, severe, or penetrating traumatic brain injury (TBI). Caregivers were recruited from Walter Reed National Military Medical Center and via community outreach. Participants completed the Caregiver Appraisal Scale, Mayo-Portland Adaptability Inventory-4, and Caregiver Questionnaire. The sample was divided into 2 Caregiver Burden groups: High (n = 138) and Low Burden (n = 76). RESULTS: Factors significantly related to higher levels of perceived burden were (a) experiencing a greater caregiving time commitment now and over time, (b) caring for activities of daily living/instrumental activities of daily living, (c) experiencing an impact of caregiving on employment, income, and out of pocket expenses, (d) parenting more than 1 child, (e) having less time to devote to one's self now and over time, (f) having caregiver needs, and/or (g) assisting a SMV who had incurred a mild TBI; was experiencing greater functional disability; had a posttraumatic stress disorder (PTSD) diagnosis; received mental health and rehabilitation treatment; and/or used an assistive device (all p < .05; odds ratios [ORs] = 1.13 to 14.57; ds = .02 to 1.30). CONCLUSIONS/IMPLICATIONS: Providing care for a SMV after a TBI can impose a heavy burden, particularly for caregivers who provide support to SMVs with comorbid mental health problems, such as PTSD. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Factor analysis of the Caregiver Appraisal Scale in military TBI.

PURPOSE/OBJECTIVE: To (a) examine the factor structure of the original 47-item Caregiver Appraisal Scale (CAS) in caregivers of service members/veterans (SMVs) following traumatic brain injury (TBI) and (b) assess whether the CAS yields a similar factor structure in this population compared to caregivers of civilian adults following TBI. Research Method/Design: Participants were 287 caregivers (female = 96.2%; spouse = 87.8%; mean age = 38.6 years) of SMVs who sustained a mild, moderate, severe, or penetrating TBI, recruited from Walter Reed National Military Medical Center and via caregiver community outreach. Caregivers completed the CAS, Caregiver Questionnaire, and Mayo-Portland Adaptability Inventory-4 upon enrollment in the study. RESULTS: Principal component analysis (PCA) revealed four factors that explained 43.2% of the variance in CAS scores: Perceived Burden, Caregiving Relationship Satisfaction, Caregiving Ideology, and Caregiving Mastery. Thirty-seven of the 47 CAS items loaded significantly onto only one of the four factors (≥ .40). A secondary PCA was performed on these 37 items, resulting in a four-factor solution very similar to that of the 47-item solution, which explained 46.8% of the variance in the 37-item measure. All but one item loaded significantly on a factor corresponding to a conceptually similar construct. CONCLUSIONS/IMPLICATIONS: Military and civilian caregivers have overlapping and differing concerns. The findings support a 37-item four-factor model of caregiving stress appraisal that has the potential for use as an outcome measure for developing caregiver interventions. It may be as useful to administer a reduced 37-item measure of the CAS to caregivers as the original 47-item measure, but further development is required. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Service needs and health outcomes among caregivers of service members and veterans following TBI.

PURPOSE/OBJECTIVE: The purpose of this study was to examine the (a) prevalence of unmet caregiver needs across eight health care and social service needs and the (b) impact of unmet needs on caregiver health and appraisal outcomes. Research Method/Design: Participants were 264 caregivers (95.8% female; 85.2% spouse/partner) providing help to service members and veterans who sustained a mild to severe or penetrating traumatic brain injury. Caregivers were recruited from Walter Reed National Military Medical Center (Maryland) and via community outreach to participate in the congressionally mandated 15-year Longitudinal Traumatic Brain Injury Study (Sec721 NDAA FY2007) supported by the Defense and Veterans Brain Injury Center. Caregivers completed the Caregiver Appraisal Scale, SF-36v2 Health Survey, and caregiver questionnaire. Participants were divided into 3 health care and social service needs groups: no unmet needs, 1-3 unmet needs, and 4-8 unmet needs. RESULTS: Six of the 8 needs were each endorsed by a majority of caregivers (59.1%-70.1%). Each need was reported as unmet by 29.5% to 52.7% of caregivers. A significant linear relation was found between number of needs and poorer outcomes (i.e., 4-8 needs < 1-3 needs < 0 needs). The cumulative number of unmet needs was significantly related to worse outcomes in most areas, while most individual needs were not significantly related to outcomes. One exception was the caregiver's unmet need for medical health, which was significantly related to increased bodily pain. CONCLUSIONS/IMPLICATIONS: Continued support from programs and expansion in the breadth and scope of health care and social services for caregivers is required, including identifying the issues that hinder caregivers accessing the services they need. (PsycINFO Database Record (c) 2019 APA, all rights reserved).