Enhanced Dynamic Laterality Based on Functional Subnetworks in Patients with Bipolar Disorder

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Abnormal brain laterality is frequently observed in bipolar disorder (BD).
• Understanding altered brain lateralization is crucial for exploring BD pathogenesis.
• Dynamic changes in brain lateralization in BD remain understudied.

Purpose of the Study:

• To investigate dynamic changes in brain laterality in patients with bipolar disorder (BD) compared to normal controls (NC).
• To provide new insights into BD neuropathology through the analysis of dynamic brain lateralization.

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) data from 48 BD patients and 48 NC.
• Extracted dynamic laterality index (DLI) over sliding windows to create dynamic laterality time series.
• Employed k-means clustering and the Arenas-Fernandez-Gomez (AFG) algorithm to identify laterality states.

Main Results:

• BD patients showed higher mean laterality index (MLI) in the right hemisphere's attention network (AN) across all windows and in state 1 compared to NC.
• The left hemisphere's AN exhibited more frequent laterality fluctuations in BD patients.
• Higher MLI in the right hemisphere's AN during state 1 was associated with BD symptom severity.

Conclusions:

• Dynamic brain laterality analysis reveals distinct patterns in BD patients.
• Altered laterality in the attention network is a key feature of BD neuropathology.
• Findings contribute to a deeper understanding of BD's underlying brain mechanisms.