Decreased Resting-State Interhemispheric Functional Connectivity in Parkinson's Disease

Area of Science:

• Neuroimaging
• Neurology
• Systems Neuroscience

Background:

• Parkinson's disease (PD) is associated with white matter abnormalities and altered functional networks.
• Inter-hemispheric interactions in PD remain underexplored.

Purpose of the Study:

• To investigate inter-hemispheric functional connectivity using voxel-mirrored homotopic connectivity (VMHC) in drug-naive Parkinson's disease patients.
• To explore the relationship between VMHC alterations and clinical features in PD.

Main Methods:

• Resting-state functional magnetic resonance imaging (rs-fMRI) was performed on 51 drug-naive PD patients and 51 healthy controls.
• Voxel-mirrored homotopic connectivity (VMHC) analysis was used to compare inter-hemispheric functional connectivity.
• Correlations between VMHC and clinical measures (UPDRS motor scores, illness duration) were examined.

Main Results:

• PD patients exhibited significantly lower VMHC in the putamen and sensorimotor/supramarginal cortical regions compared to controls.
• Lower VMHC in sensorimotor cortex correlated with higher UPDRS motor scores.
• Reduced VMHC in the supramarginal gyrus was associated with longer illness duration.

Conclusions:

• Functional coordination between homotopic brain regions is impaired in Parkinson's disease.
• Findings support a disturbance in inter-hemispheric connections in PD, extending knowledge of corticostriatal circuit disconnection.