Structural MRI Analysis of Cortical Thickness and Covariance Patterns in Trauma and PTSD

Abstract

Neuroimaging studies have reported cortical thickness and volumetric alterations in post-traumatic stress disorder (PTSD), though results remain inconsistent. Using ultra high field 7T MRI, we examined surface-based morphometric measures in 27 PTSD patients, 27 trauma-exposed (TE) individuals, and 26 non-trauma exposed (NT) controls. TE participants showed increased cortical thickness in temporal and occipital regions compared with NT controls, while PTSD patients demonstrated greater volume in superior frontal areas relative to NT controls. Structural covariance networks constructed from cortical thickness measures showed no significant between-group differences in global network organization. Nodal permutation analyses revealed region specific alterations within the left orbitofrontal cortex, with PTSD patients showing increased degree and betweenness centrality in the medial orbital sulcus and reduced degree in the lateral orbital sulcus relative to NT controls. These findings suggest that trauma exposure and PTSD patients are associated with distinct regional structural alterations, accompanied by localized differences in orbitofrontal network centrality.