Frequency-Specific Resting Connectome in Bipolar Disorder: An MEG Study

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Bipolar disorder (BD) lacks clinical biomarkers and has a high suicide rate.
• Magnetoencephalography (MEG) offers a novel approach to investigate brain connectivity.
• Previous studies have not explored frequency-specific resting-state connectomes in BD patients.

Purpose of the Study:

• To investigate functional connectivity in bipolar disorder using resting-state MEG.
• To explore oscillatory representations of clinical symptoms in BD via graph analysis.
• To identify potential biomarkers for BD diagnosis and symptom severity.

Main Methods:

• A prospective case-control study involving 17 BD patients and 22 healthy controls (HCs).
• Resting-state MEG data acquisition and source current distribution estimation.
• Orthogonalized envelope correlations analyzed across seven network modules in different frequency bands.

Main Results:

• Significantly altered inter-community edges in the limbic network (LM), default mode network (DMN), and salience network (SAL) in BD patients.
• Increased intra-community edges in the left LM at the high beta band in the BD group.
• Positive correlations between left LM connectivity at high beta band and depressive symptom severity in BD.

Conclusions:

• Graph theory analysis of resting-state MEG provides novel insights into BD functional connectivity.
• Altered connectivity in the LM at the beta band may serve as an objective biomarker for depressive symptoms in BD.
• This MEG-based approach may aid in the diagnosis and understanding of BD, compensating for fMRI limitations.