Decreased resting-state interhemispheric coordination in first-episode, drug-naive paranoid schizophrenia

Abstract

Background: Dysconnectivity hypothesis posits that schizophrenia relates to abnormalities in neuronal connectivity. However, little is known about the alterations of the interhemispheric resting-state functional connectivity (FC) in patients with paranoid schizophrenia. In the present study, we used a newly developed voxel-mirrored homotopic connectivity (VMHC) method to investigate the interhemispheric FC of the whole brain in patients with paranoid schizophrenia at rest.

Methods: Forty-nine first-episode, drug-naive patients with paranoid schizophrenia and 50 age-, gender-, and education-matched healthy subjects underwent a resting-state functional magnetic resonance imaging (fMRI) scans. An automated VMHC approach was used to analyze the data.

Results: Patients exhibited lower VMHC than healthy subjects in the precuneus (PCu), the precentral gyrus, the superior temporal gyrus (STG), the middle occipital gyrus (MOG), and the fusiform gyrus/cerebellum lobule VI. No region showed greater VMHC in the patient group than in the control group. Significantly negative correlation was observed between VMHC in the precentral gyrus and the PANSS positive/total scores, and between VMHC in the STG and the PANSS positive/negative/total scores.

Conclusions: Our results suggest that interhemispheric resting-state FC of VMHC is reduced in paranoid schizophrenia with clinical implications for psychiatric symptomatology thus further contribute to the dysconnectivity hypothesis of schizophrenia.

Keywords: ACC; BOLD; DMN; DUP; Default mode network; FC; FD; FOV; Functional connectivity; GRF; Gaussian Random Field; MNI; MOG; Montreal Neurological Institute; PANSS; PCu; Paranoid schizophrenia; Positive and Negative Symptom Scale; R-fMRI; ROI; Resting state; SCID; STG; Structured Clinical Interview of the DSM-IV; TR/TE; VMHC; Voxel-mirrored homotopic connectivity; anterior cingulate cortex; blood oxygen level-dependent; default mode network; duration of untreated psychosis; fMRI; field of view; framewise displacement; functional connectivity; functional magnetic resonance imaging; middle occipital gyrus; precuneus; region of interest; repetition time/echo time; resting-state fMRI; superior temporal gyrus; voxel-mirrored homotopic connectivity.