Disrupted Brain Network Hubs in Subtype-Specific Parkinson's Disease

Area of Science:

• Neuroscience
• Medical Imaging
• Graph Theory

Background:

• Parkinson's disease (PD) is characterized by impaired topological organization of brain functional networks.
• Understanding altered functional network hubs in different PD subtypes is crucial but not fully elucidated.

Purpose of the Study:

• To systematically investigate intrinsic functional connectivity patterns in whole-brain networks of PD subtypes.
• To identify differences in brain network hubs between tremor-dominant (TD) and postural instability/gait difficulty (PIGD) PD subtypes.

Main Methods:

• Utilized 3T resting-state functional MRI (fMRI) and voxel-based graph-theory analysis.
• Constructed whole-brain voxel-wise functional networks by measuring temporal correlations between voxel pairs.
• Analyzed functional connectivity strength to identify brain network hubs in 31 PD patients (12 TD, 19 PIGD) and 22 controls.

Main Results:

• Both TD and PIGD subtypes exhibited widespread disrupted brain regions, including basal ganglia, cerebellum, and temporal and frontal gyri.
• The PIGD subgroup demonstrated more disrupted cerebellar hubs compared to the TD subgroup.
• Hub connectivity disruptions did not correlate with Hoehn and Yahr (HY) stage or disease duration.

Conclusions:

• Findings highlight subtype-specific degeneration of brain hubs in Parkinson's disease.
• Provides novel insights into the pathophysiological mechanisms of connectivity dysfunction across different PD subgroups.