MEASURING INTER-HEMISPHERIC INTEGRATION IN BIPOLAR AFFECTIVE DISORDER USING BRAIN NETWORK ANALYSES AND HARDI.

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Bipolar disorder involves extreme mood swings and is associated with white matter abnormalities.
• Previous studies suggest altered white matter in fronto-limbic and callosal systems, but findings are inconsistent.
• No prior research has applied graph theory to analyze brain networks in bipolar disorder.

Purpose of the Study:

• To investigate white matter integrity and structural brain networks in euthymic bipolar I disorder patients.
• To utilize diffusion-weighted imaging (DWI) and graph theory to assess brain connectivity.

Main Methods:

• Acquired 64-direction DWI data from 25 euthymic bipolar I subjects and 25 healthy controls.
• Computed white matter integrity in 50 regions of interest (ROIs).
• Constructed whole-brain structural connectivity networks using graph theory and analyzed inter-hemispheric integration metrics.

Main Results:

• Impaired white matter integrity was found in the corpus callosum of bipolar subjects.
• Bipolar patients exhibited preserved intra-hemispheric connectivity but significantly impaired inter-hemispheric integration.
• Graph theory analysis revealed specific deficits in brain network communication.

Conclusions:

• Bipolar disorder is associated with compromised inter-hemispheric communication.
• Brain network analysis using graph theory offers novel insights into the neurobiology of bipolar disorder.
• Findings highlight the importance of studying brain connectivity in bipolar illness.