Altered intra- and inter-hemispheric functional dysconnectivity in schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Schizophrenia is increasingly understood as a disorder of brain dysconnectivity.
• The specific contribution of intra-hemispheric versus inter-hemispheric deficits to this dysconnectivity remains unclear.

Purpose of the Study:

• To investigate the source of functional dysconnection in schizophrenia by examining intra- and inter-hemispheric brain networks.
• To determine whether intra-hemispheric topological properties or inter-hemispheric nodal strength are primarily affected.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was conducted on 66 patients with schizophrenia and 73 healthy controls.
• Functional brain networks were constructed and partitioned into intra- and inter-hemispheric connections.
• Analysis focused on intra-hemispheric topological properties and inter-hemispheric nodal strength.

Main Results:

• Intra-hemispheric network topology, including small-world properties and lateralization, was preserved in patients with schizophrenia.
• A significant deficit in inter-hemispheric connectivity was observed, particularly in hub regions, indicating a hypo-connectivity pattern.
• Aberrations in regional efficiency were noted in subcortical and cingulate regions, independent of hemisphere.

Conclusions:

• Schizophrenia is characterized by preserved intra-hemispheric network topology but altered inter-hemispheric functional connectivity.
• The observed inter-hemispheric hypo-connectivity is a key feature of brain dysorganization in schizophrenia.
• These network abnormalities correlate with the clinical features of schizophrenia.