Neuropsychological Effects of Self-Reported Deployment-Related Mild TBI and Current PTSD in OIF/OEF Veterans

Abstract

Current combat veterans are exposed to many incidents that may result in mild traumatic brain injury (mTBI) and/or posttraumatic stress disorder (PTSD). While there is literature on the neuropsychological consequences of PTSD only (PTSD-o) and mTBI alone (mTBI-o), less has been done to explore their combined (mTBI+PTSD) effect. The goal of this study was to determine whether Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) veterans with mTBI+PTSD have poorer cognitive and psychological outcomes than veterans with PTSD-o, mTBI-o, or combat exposure-only. The final sample included 20 OIF/OEF veterans with histories of self-reported deployment mTBI (mTBI-o), 19 with current PTSD (PTSD-o), 21 with PTSD and self-reported mTBI (mTBI+PTSD), and 21 combat controls (CC) (no PTSD and no reported mTBI). Groups were formed using structured interviews for mTBI and PTSD. All participants underwent comprehensive neuropsychological testing, including neurocognitive and psychiatric feigning tests. Results of cognitive tests revealed significant differences in performance in the mTBI+PTSD and PTSD-o groups relative to mTBI-o and CC. Consistent with previous PTSD literature, significant differences were found on executive (switching) tasks, verbal fluency, and verbal memory. Effect sizes tended to be large in both groups with PTSD. Thus, PTSD seems to be an important variable affecting neuropsychological profiles in the post-deployment time period. Consistent with literature on civilian mTBI, the current study did not find evidence that combat-related mTBI in and of itself contributes to objective cognitive impairment in the late stage of injury.

The Effects of Mild Traumatic Brain Injury, Post-Traumatic Stress Disorder, and Combined Mild Traumatic Brain Injury/Post-Traumatic Stress Disorder on Returning Veterans

“…This was in contrast to previous findings with a smaller sample, restricted to the Lexington VAMC, that was not matched for age, education, and estimated pre-injury IQ. 33 Compared with VC, the mTBI-o group performed worse on measures of visual scanning and visual attention (D-KEFS Visual Scanning), as well as measures of processing speed (WAIS-IV Digit Symbol Coding). These differences reflect a small to moderate effect for mTBI-o (d = 0.31 to d = 0.45).…”

“…Shandera-Ochsner and colleagues 33 were among the first to explore both neurocognitive and psychiatric impairments following mTBI + PTSD, PTSD-o, and mTBI-o, compared with a combat control group. Their study of 81 OIF/OEF veterans suggested that PTSD has the greatest effect on neuropsychological functioning post-deployment.…”

“…It should be noted that the present sample potentially included all veteran participants from the three centers involved, whereas the previous report by Shandera-Ocshner and colleagues was based on a subset of participants from the Lexington VAMC alone (n = 81). 33 Approval for the study was obtained from the VA Centralized Institutional Review Board (IRB) and the Lexington, Tucson, and Hines VA Medical Center Research and Development Committees. Informed consent and Health Insurance Portability and Accountability Act authorization were obtained from all study participants.…”

Deep brain stimulation of the basolateral amygdala for treatment-refractory combat post-traumatic stress disorder (PTSD): study protocol for a pilot randomized controlled trial with blinded, staggered onset of stimulation

“…Neuropsychological deficits in OIF veterans worsened in proportion to severity of PTSD when assessed one year after return from deployment[56]; and in another study, PTSD mediated the effect of traumatic brain injury (TBI) on psychosocial function in OEF/OIF veterans[57]. In OEF/OIF veterans with both mild TBI (mTBI) and PTSD, PTSD accounts for more impairment on neuropsychological testing than mTBI[58, 59]. Overall, long-term outcomes with even the most intensive treatments reveal persistent suffering and disability for many veterans, even when there is significant symptomatic improvement[60–62].…”

Brain Volume, Connectivity, and Neuropsychological Performance in Mild Traumatic Brain Injury: The Impact of Post-Traumatic Stress Disorder Symptoms

“…Initial studies of mTBI/PTSD have suggested impairments in aspects of executive functioning, including verbal fluency, response inhibition, and attention. [16][17][18] Recent studies looking more broadly at cognitive functioning differences between mTBI groups with or without PTSD failed to find differences between groups. 19,20 While these studies do not provide a consensus on the cognitive profile of patients with co-morbid mTBI/PTSD, it is clear that subjects with mTBI and co-morbid PTSD do not improve at the same rate as those with mTBI alone.…”