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Background: Given the aging of the overall U.S. population, the resulting changes in healthcare needs especially among veterans, and the high prevalence of traumatic brain injury (TBI) among older adults, additional research is needed on community participation after TBI in older veterans. The current study examined predictors of community participation trajectories over the 5 years after TBI in veterans who were 55 years of age or older upon injury. Method: This study included data from 185 participants in the U.S. Department of Veterans Affairs TBI Model System national study who had sustained a TBI at age 55 or older and had completed at least one of each Participation Assessment with Recombined Tools-Objective (PART-O) subscale scores at one or more follow-up time points (1, 2, and 5 years post-TBI). Results: PART-O Productivity, Social, and Out and About scores remained constant over time. Lower PART-O Productivity trajectories were seen among participants who were unemployed at the time of injury (p = 0.023). Lower PART-O Social trajectories were seen among participants who had a lower education level (p = 0.021), were unmarried at injury (p < 0.001), and had private insurance coverage (p < 0.033). Conclusion: These findings add to the growing body of literature on TBI and community participation by focusing on an older adult veteran population. There is an urgency to understand the needs of this group, many of whom are aging with service-connected disabilities including TBI. Veterans with characteristics identified herein as being associated with lower community participation trajectories would be prime candidates for interventions that aim to increase community and social engagement after later-life TBI.

Abstract Efforts to characterize the late effects of traumatic brain injury (TBI) have been in progress for some time. In recent years much of this activity has been directed towards reporting of chronic traumatic encephalopathy (CTE) in former contact sports athletes and others exposed to repetitive head impacts. However, the association between TBI and dementia risk has long been acknowledged outside of contact sports. Further, growing experience suggests a complex of neurodegenerative pathologies in those surviving TBI, which extends beyond CTE. Nevertheless, despite extensive research, we have scant knowledge of the mechanisms underlying TBI-related neurodegeneration (TReND) and its link to dementia. In part, this is due to the limited number of human brain samples linked to robust demographic and clinical information available for research. Here we detail a National Institutes for Neurological Disease and Stroke Center Without Walls project, the COllaborative Neuropathology NEtwork Characterizing ouTcomes of TBI (CONNECT-TBI), designed to address current limitations in tissue and research access and to advance understanding of the neuropathologies of TReND. As an international, multidisciplinary collaboration CONNECT-TBI brings together multiple experts across 13 institutions. In so doing, CONNECT-TBI unites the existing, comprehensive clinical and neuropathological datasets of multiple established research brain archives in TBI, with survivals ranging minutes to many decades and spanning diverse injury exposures. These existing tissue specimens will be supplemented by prospective brain banking and contribute to a centralized route of access to human tissue for research for investigators. Importantly, each new case will be subject to consensus neuropathology review by the CONNECT-TBI Expert Pathology Group. Herein we set out the CONNECT-TBI program structure and aims and, by way of an illustrative case, the approach to consensus evaluation of new case donations.

Acceleration parameters have been utilized for the last six decades to investigate pathology in both human and animal models of traumatic brain injury (TBI), design safety equipment, and develop injury thresholds. Previous large animal models have quantified acceleration from impulsive loading forces (i.e., machine/object kinematics) rather than directly measuring head kinematics. No study has evaluated the reproducibility of head kinematics in large animal models. Nine (five males) sexually mature Yucatan swine were exposed to head rotation at a targeted peak angular velocity of 250 rad/s in the coronal plane. The results indicated that the measured peak angular velocity of the skull was 51% of the impulsive load, was experienced over 91% longer duration, and was multi- rather than uni-planar. These findings were replicated in a second experiment with a smaller cohort (N = 4). The reproducibility of skull kinematics data was mostly within acceptable ranges based on published industry standards, although the coefficients of variation (8.9% for peak angular velocity or 12.3% for duration) were higher than the impulsive loading parameters produced by the machine (1.1 vs. 2.5%, respectively). Immunohistochemical markers of diffuse axonal injury and blood–brain barrier breach were not associated with variation in either skull or machine kinematics, suggesting that the observed levels of variance in skull kinematics may not be biologically meaningful with the current sample sizes. The findings highlight the reproducibility of a large animal acceleration model of TBI and the importance of direct measurements of skull kinematics to determine the magnitude of angular velocity, refine injury criteria, and determine critical thresholds.