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Abstract #0811

Amplitude of Low Frequency Fluctuations and Functional Connectivity in Resting State FMRI Among PTSD

Xiaodan YAN1, 2, Mariana Lazar1, Victoria Cressman3, Leslie Prichep2, Clare Henn-Haase2, Irene Lee2, Rachel Yehuda4, Thomas Neylan5, Daniel Sodickson1, Charles Marmar2

1Radiology, New York University, New York, NY, United States; 2Department of Psychiatry, New York University, New York, NY, United States; 3Department of Psychiatry, Manhattan VA Medical Center, New York, NY, United States; 4Department of Psychiatry, Mount Sinai School of Medicine, New York, NY, United States; 5Department of Psychiatry, University of California, San Francisco, San Francisco, CA, United States

Neural mechanisms of posttraumatic stress disorder (PTSD) are increasingly being investigated with neuroimaging techniques; however, previous studies have conflicting findings partly due to the differences in designed tasks and targeted behavioral variables. Using resting state fMRI (rs-fMRI), the present study examined the amplitudes of low frequency fluctuation (ALFF) as well as functional connectivity (FC) patterns associated with PTSD among 38 combat veterans (19 diagnosed as PTSD+ and 19 PTSD-, with the two groups matched on age, gender, education level and ethnicity). Compared to the PTSD- group, the PTSD+ group showed significantly decreased ALFF at the thalamus, precuneus, dorsal frontal cortex (DFC), posterior cingulate cortex (PCC), and increased ALFF at ventral anterior cingulate cortex (ACC), insula, and ventral frontal cortex (VFC). PTSD+ demonstrated primarily decreases of FC-s, particularly seeded at the thalamus, PCC, precuneus. ALFF values at DFC were negatively correlated with PTSD severity, whereas those at vACC and thalamus were negatively correlated with severity of re-experience symptom. ALFF at insula and VFC were negatively correlated with depression and dissociative symptoms respectively, and those at precuneus were positively correlated with emotion regulation capacity. These results suggest that spontaneous brain activity is associated with PTSD pathology.