B-58 Post-traumatic Stress Symptoms Are Associated with Worse Neuropsychological Functioning, but not Diffusion Tensor Imaging Findings, in Military Service Members Following Mild Traumatic Brain Injury.

Objective The purpose of this study was to examine neurobehavioral and neurocognitive functioning, and white matter integrity (using Diffusion Tensor Imaging [DTI]), in service members with versus without PTSD following mild traumatic brain injury (MTBI). Method Participants were 101 U.S. military service members who had sustained an uncomplicated MTBI (n = 80) or an injury without TBI (i.e., Injured Control [IC], n = 21) prospectively enrolled from the Walter Reed National Military Medical Center (Bethesda, Maryland). Participants completed a battery of neuropsychological tests, as well as DTI of the brain, on average 4-years post-injury. Measures of FA, MD, AD, and RD were generated for 18 regions of interest [ROIs]. Participants in the MTBI group were divided into two sub-groups based on DSM-IV-TR diagnostic criteria for PTSD: MTBI/PTSD-Present (n = 22) and MTBI/PTSD-Absent (n = 58). Results The MTBI/PTSD-Present group reported a significantly higher number of postconcussion symptoms, had higher scores on the majority of MMPI-2-RF scales, and had worse scores on the vast majority of cognitive domains (i.e., Attention, Processing Speed, Immediate Memory, Delayed Memory, Executive Functioning, Visuospatial Ability) compared to both the MTBI/PTSD-Absent group (all p’s < .05) and IC/PTSD-Absent group (all p’s < .05). For the DTI variables, there were no significant group differences for all DTI measures in all regions of the brain, with the exception of a handful of measures (i.e., right cingulum–cingulate gyrus, and bilaterally in the corticospinal tract). Conclusion These results provide support for a (a) strong relationship between PTSD and poor neurobehavioral and neurocognitive outcome following MTBI, and (b) weak relationship between PTSD and white matter integrity following MTBI.