Magnetic Resonance Spectroscopic Imaging at 7T (7T MRSI) abnormalities in Veterans with PTSD and mild TBI (mTBI) (P5.207)

Objective: To compare brain metabolite changes as measured by 7T MRSI in veterans with mTBI and PTSD from veterans with PTSD alone. Background: Controversy exists regarding the coexistence of PTSD and mTBI in veterans. Veterans with mTBI(s) and PTSD have overlapping symptomatology. Conventional neuroimaging and clinical testing don’t reliably distinguished individuals with PTSD from PTSD+mTBI. Design/Methods: 7T MRSI measurements of hippocampal NAA/Choline, veteran characteristics and neuropsychological testing were collected from 43 Veterans with PTSD +/− mTBI compared to 15 controls. Groups were compared on NAA/Ch and neuropsychological measures using one-way ANOVA with Bonferroni correction for multiple comparisons. In a subgroup, 10 veterans with PTSD+mTBI, additional analysis of network gray matter NAA/Ch was performed. Results: 7T MRSI found statistically significant group differences in NAA/Ch, with substantially decreased values in the anterior portions of the left hippocampus (L3–L5 regions) in subjects with a history of mTBI and PTSD compared to those with PTSD alone (p Conclusions: 7T MRSI can detect metabolite differences in the left hippocampus in veterans with both mTBI and PTSD compared to those with PTSD alone. However, symptoms of PTSD, depression, anxiety and neuropsychological testing in these two populations were indistinguishable. These findings support the co-existence and association of mTBI and PTSD. These findings suggest that 7T MRSI data may help inform the diagnosis of mTBI and PTSD. The finding of correlated abnormalities involving the hippocampus and cingulate may indicate a limbic network of injury in veterans with PTSD and mTBI. Study Supported by: NIH R01 NS081772, PI: Hetherington Disclosure: Dr. Van Cott has nothing to disclose. Dr. Kelly has nothing to disclose. Dr. Roberts has nothing to disclose. Dr. Miller has nothing to disclose. Dr. Kontos has nothing to disclose. Dr. Hetherington has nothing to disclose.