Abnormal insula network characteristics in panic disorder.

Objective: Panic disorder (PD) is a common disabling condition characterized by recurrent panic attacks. Emotional and behavioral impairments are associated with functional connectivity (FC) and network abnormalities. We used whole-brain FC, modular networks, and graph-theory analysis to investigate extensive network profiles in PD.

Methods: Functional magnetic resonance imaging (fMRI) data from 82 subjects with PD and 97 healthy controls were included. Intrinsic FC between each pair of 160 regions, six intra-network, and 15 inter-network FCs were analyzed. Topological properties were explored.

Results: PD patients showed altered FCs within the right insula, between frontal cortex-posterior cingulate cortex (PCC), frontal cortex-cerebellum, and PCC-occipital cortex (corrected p < 0.001). Lower connections within the sensorimotor network (SMN) and SMN-occipital network (OCN) were detected (p < 0.05). Various decreased global and local network features were found in PD (p < 0.05). In addition, significant correlations were found between PD symptoms and nodal efficiency (Ne) in the insula (r = -0.273, p = 0.016) and intra-insula FC (r = -0.226, p = 0.041).

Conclusion: PD patients present with abnormal functional brain networks, especially decreased FC and Ne within the insula, suggesting that dysfunction of information integration plays an important role in PD.