Altered default mode network activity and cortical thickness as vulnerability indicators for SCZ: a preliminary resting state MRI study.

Abstract

Alterations in brain function in patients with schizophrenia (SCZ) and other neuropsychiatric disorders are evident not only during specific cognitive challenges, but also from functional MRI data obtained during a resting state. Patients with chronic SCZ have shown deficits in default mood network (DMN) and gray matter volume in resting-state functional magnetic resonance imaging (rs-fMRI). However, cortical thickness and surface area in first-episode schizophrenic patients have rarely been investigated. In the present study, we applied independent component analysis (ICA) to a series of rs-fMRIs of 15 SCZ patients and 15 matched healthy controls. The data were analyzed using MELODIC of FMRIB's Software Library (FSL version 5.9; www.fmrib.ox.ac.uk/fsl) to identify large-scale patterns of temporal signal-intensity coherence. Patients with SCZ showed significantly higher functional connectivity in the DMN, auditory network, and cerebellum network (p=0.049, p=0.05, and p=0.007, respectively) than matched healthy controls. The patients also exhibited significantly less cortical thickness, primarily in the bilateral prefrontal and parietal cortex, and higher thickness in the bilateral anterior temporal lobes, left medial orbitofrontal cortex, and left cuneus than the matched healthy controls. These results indicate that significantly abnormal DMN connectivity and cortical thickness contribute to local functional pathology in patients with SCZ.