C-58 * Using Multimodal Magnetic Resonance Imaging to Explore Biomarkers of Veterans with Post-Traumatic Stress Disorder after Blast Injury

Objective: This study aims to compare neuroimaging measures of gray matter thickness and volume in the medial prefrontal and parietal areas of combat veterans with and without Post-Traumatic Stress Disorder (PTSD) and blast exposure. Secondary objectives include investigating the relationship between neuropsychological and imaging data. Method: Twenty post-9/11 male combat veterans were recruited from the Philadelphia Veterans Affairs Medical Center. All participants had been deployed, 13 had a history of PTSD and blast exposure, and seven did not endorse PTSD or blast. Veterans completed measures of emotional and neuropsychological functioning and one MRI scan. Results: Volumetric measures of the caudal and rostral anterior cingulate cortex (ACC) and precuneus areas were normalized using total gray matter volume. Group differences in gray matter volume across hemispheres were examined using repeated measures analyses of variance and no significant differences were found. Independent samples t-tests also did not find significant group differences in thickness for these areas. Controls outperformed those with TBI and PTSD on a measure of premorbid intelligence, t(18) = 2.65, p = .02, 95% CI [3.77, 32.47]), but no other significant differences in neuropsychological performance were observed. Conclusion(s): These initial findings are unexpected, as previous research has found significantly smaller anterior cingulate cortex volumes in those with PTSD. However, these areas are relatively unexplored in relation to PTSD and blast injury. This study may provide evidence that the medial prefrontal and parietal areas do not serve as biomarkers for the presence of PTSD and blast trauma, but more data are needed to draw firm conclusions.