unctional Connectivity of Dissociative Responses in osttraumatic Stress Disorder: A Functional Magnetic esonance Imaging Investigation

ackground: The purpose of this study was to assess interregional brain activity covariations during traumatic script-driven imagery n subjects with posttraumatic stress disorder (PTSD). ethods: Functional magnetic resonance imaging and functional connectivity analyses were used to assess interregional brain ctivity covariations during script-driven imagery in PTSD subjects with a dissociative response, PTSD subjects with a flashback esponse, and healthy control subjects. esults: Significant between-group differences in functional connectivity were found. Comparing dissociated PTSD patients and ontrol subjects’ connectivity maps in the left ventrolateral thalamus (VLT) [ 14, 16, 4] revealed that control subjects had higher ovariations between activations in VLT and in the left superior frontal gyrus (Brodmann’s area [BA] 10), right parahippocampal gyrus BA 30), and right superior occipital gyrus (BA 19, 39), whereas greater covariation with VLT in dissociated PTSD subjects occurred n the right insula (BA 13, 34), left parietal lobe (BA 7), right middle frontal gyrus (BA 8), superior temporal gyrus (BA 38, 34), and ight cuneus (BA 19). Comparing dissociated PTSD and flashback PTSD connectivity maps in the right cingulate gyrus [3, 16, 30] evealed that dissociated PTSD subjects had higher covariations between activations in this region and the left inferior frontal gyrus BA 47). onclusions: Greater activation of neural networks involved in representing bodily states was seen in dissociated PTSD subjects than n non-PTSD control subjects. These findings might illuminate the mechanisms underlying distorted body perceptions often observed linically during dissociative episodes.