Decreased interhemispheric coordination in schizophrenia: a resting state fMRI study

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Schizophrenia is increasingly viewed as a disorder of brain connectivity.
• Previous research focused on within-hemispheric connectivity, with less attention to interhemispheric interactions.
• Emerging evidence suggests callosal structure and interhemispheric communication may be abnormal in schizophrenia.

Purpose of the Study:

• To investigate interhemispheric functional connectivity in schizophrenia using voxel-mirrored homotopic connectivity (VMHC).
• To identify specific brain regions with altered interhemispheric coordination in patients with schizophrenia or schizoaffective disorder.

Main Methods:

• Utilized resting-state functional magnetic resonance imaging (fMRI) data.
• Performed voxel-mirrored homotopic connectivity (VMHC) analyses on data from 23 healthy controls and 25 patients.
• Examined functional connectivity between homotopic points across the brain.

Main Results:

• Patients with schizophrenia exhibited significantly reduced VMHC in multiple brain regions, notably the occipital lobe, thalamus, and cerebellum.
• No regions showed increased VMHC in the patient group compared to controls.
• Reduced VMHC in the postcentral gyrus, extending to the precentral gyrus, correlated with higher PANSS Total scores.

Conclusions:

• Schizophrenia is characterized by substantial impairments in interhemispheric coordination.
• VMHC is a sensitive measure for detecting disruptions in brain connectivity relevant to schizophrenia.
• These findings highlight the importance of studying interhemispheric communication in the pathophysiology of schizophrenia.