Cognitive change associated with self-reported mild traumatic brain injury sustained during the OEF/OIF conflicts.

Traumatic brain injury (TBI) has received much attention due to high rates of this injury in Service Members returning from the Iraq/Afghanistan conflicts. This study examined cognitive performance in Service Members tested with ANAM prior to and following deployment. The sample was divided into a control group (n=400) reporting no TBI injury prior to or during most recent deployment, and a group who self-reported a TBI injury (n=502) during most recent deployment. This latter group was divided further based on self-report of post-concussion symptoms at post-deployment testing. All three groups performed similarly at pre-deployment. The group reporting TBI with active symptoms performed worst at post-deployment and included the highest percentage of individuals showing significant decline in cognitive performance over time (30.5%). A small sample of symptomatic individuals with a non-TBI reported injury did not demonstrate similar declines in performance, suggesting that active symptoms alone cannot account for these findings. Of those reporting a TBI injury during deployment, 70% demonstrated no significant change in cognitive performance compared with baseline. Although the exact etiology of observed declines is uncertain, findings indicate that individuals who self-report TBI during deployment with active symptomatology at post-deployment are at greatest risk for declines in cognitive performance. These individuals can be identified using self-report and brief computer-based testing. Importantly, the majority of active-duty individuals reporting TBI during deployment do not present with lasting significant cognitive impairment, a finding consistent with the civilian literature on mild TBI.