Selective functional disconnection of the orbitofrontal subregions in schizophrenia

As a disconnection syndrome, schizophrenia has shown impaired resting-state functional connectivity (rsFC) in the orbitofrontal cortex (OFC); however, the OFC is a rather heterogeneous region and the rsFC changes in the OFC subregions remain unknown.

A total of 98 schizophrenia patients and 102 healthy controls underwent resting-state functional MRI using a sensitivity-encoded spiral-in imaging sequence (SENSE-SPIRAL) to reduce susceptibility-induced signal loss and distortion. The OFC subregions were defined according to a previous parcellation study that divided the OFC into the anterior (OFCa), medial (OFCm), posterior (OFCp), intermediate (OFCi), and lateral (OFCl) subregions. The rsFC was compared using two-way repeated-measures ANOVA.

Whether or not global signal regression, compared with healthy controls, schizophrenia patients consistently exhibited decreased rsFC between the left OFCi and the left middle temporal gyrus and the right middle frontal gyrus (MFG), between the right OFCi and the right MFG and the left inferior frontal gyrus, between the right OFCm and the middle cingulate cortex and the left Rolandic operculum. These rsFC changes still remained significant even after cortical atrophy correction.

These findings suggest a selective functional disconnection of the OFC subregions in schizophrenia, and provide more precise information about the functional disconnections of the OFC in this disorder.