Differences in Brain Structure and Functional Connectivity During Memory Processing in Posttraumatic Stress Disorder

This study aimed to investigate the association between changes in brain volumes and memory task-based functional connectivity (FC) patterns in patients with posttraumatic stress disorder (PTSD) compared to healthy controls (HCs).

This study employed voxel-based morphometry and task-based functional magnetic resonance imaging using memory task to examine alterations in brain volume density and FC within and between relevant brain regions involved in memory processes such as encoding and retrieval.

PTSD patients exhibited increased brain volumes in the right cerebellum (Cb) in the gray matter (GM) region compared to HCs. Analysis of FC patterns revealed that both groups exhibited similar connectivity patterns, but PTSD patients displayed higher and more extensive interregional connectivity relative to HCs. During the memory encoding process, PTSD patients exhibited higher FC linked to the Cb in the right postcentral gyrus, left precentral gyrus (PrCG), left orbito frontal gyrus (OFG), and superior frontal gyrus, while demonstrating lower connectivity in the right hippocampus. In the memory retrieval period, PTSD patients showed higher FC in the right middle frontal gyrus, left middle occipital gyrus, left OFG, right inferior parietal gyrus, and right PrCG, along with lower FC in the right/left inferior frontal gyrus and right superior parietal gyrus. Additionally, a negative correlation was observed between PTSD symptom severity and local GM volumes in the right Cb. However, no significant correlation was found with FC.

Our findings provide insights into the specific alterations in brain structure and connectivity associated with PTSD, contributing to a better understanding of the underlying neural mechanisms of PTSD.