Interhemispheric disconnectivity in the sensorimotor network in bipolar disorder revealed by functional connectivity...

Area of Science:

• Neuroimaging
• Neuroscience
• Psychiatry

Background:

• Interhemispheric functional connectivity (FC) via the corpus callosum is poorly understood in bipolar disorder (BD).
• Altered FC may underlie emotional processing deficits in BD.

Purpose of the Study:

• To investigate corpus callosum integrity and sensorimotor network FC in individuals with BD.
• To explore the relationship between structural and functional brain changes and clinical symptoms in BD.

Main Methods:

• Diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS) were used to assess white matter integrity.
• Resting-state functional magnetic resonance imaging (fMRI) and independent component analysis (ICA) were employed to analyze neural network connectivity.

Main Results:

• BD subjects exhibited reduced fractional anisotropy (FA) in the corpus callosum.
• Reduced functional within-connectivity was observed in sensorimotor network (SMN) clusters in BD subjects.
• Corpus callosum FA correlated with interhemispheric FC and symptom severity (YMRS scores).

Conclusions:

• Interhemispheric FC dysfunction in the SMN is associated with impaired corpus callosum nerve fibers in BD.
• These findings suggest a potential pathophysiological basis for emotion processing dysregulation in BD patients.
• Medication effects represent a potential confounding factor in the study results.