Typhoon-Related Post-Traumatic Stress Disorder and Trauma Might Lead to Functional Integration Abnormalities in Intra- and Inter-Resting State Networks: a Resting-State Fmri Independent Component Analysis

Abstract

Background/aims: Functional connectivity studies based on region of interest approach suggest altered functional connectivity of the default mode network (DMN), executive control network (ECN), and salience network (SN). The aim of this study is to determine whether intranetwork and internetwork brain connectivity are altered in both post-traumatic stress disorder (PTSD) patients and traumatized subjects without PTSD using a data-driven approach.

Methods: Resting-state functional MRI data were acquired for 27 patients with typhoon-related PTSD, 33 trauma-exposed controls (TEC), and 30 healthy controls (HC). Functional connectivity within the DMN, ECN, and SN as well as functional and effective connectivity between these resting-state networks were examined with independent component analysis (ICA), and then compared between groups by conducting analysis of variance.

Results: Within the DMN, the TEC group showed decreased and increased functional connectivity in the superior frontal gyrus compared with the PTSD group and the HC group, respectively. The TEC group showed increased angular functional connectivity within the DMN and decreased functional connectivity in the superior temporal gyrus/posterior insula within the SN relative to the HC group. Compared with the TEC group, the PTSD group showed increased functional connectivity in the middle frontal gyrus and supplementary motor area within the ECN as well as in the inferior frontal gyrus/anterior insula within the SN. The PTSD group showed decreased functional connectivity in the supplementary motor area within the SN relative to both control groups. Moreover, the PTSD showed increased excitatory influence from the ECN to DMN compared with both control groups, while the TEC group showed increased inhibitory influence from the DMN to ECN compared with the HC group. Intranetwork functional connectivity within the DMN and SN is altered in traumatized subjects irrespective of PTSD diagnosis. PTSD patients also showed altered intranetwork functional connectivity within the ECN.

Conclusions: Distinct changes of effective connectivity between the DMN and ECN in the PTSD group and TEC group may reflect different compensatory mechanisms for rebalance of resting-state networks in the two groups.

Keywords: Effective connectivity; Functional magnetic resonance imaging; Insula; Post-traumatic stress disorder; Resting-state network.