Basal ganglia connectivity and network asymmetry in Parkinson's disease: A resting-state fMRI study☆

This study investigates the impact of basal ganglia network asymmetry on motor function in Parkinson's Disease (PD). Using resting-state functional magnetic resonance imaging (rs-fMRI), functional connectivity and network asymmetry were analyzed in 15 non-demented PD patients and 15 healthy controls. Sixteen basal ganglia substructures, including the caudate, putamen, and globus pallidus, were selected for a unified analysis of variance framework to evaluate inter-hemispheric connectivity differences. After spatial preprocessing, regions of interest were defined, and time-series data were extracted for functional connectivity and network asymmetry analysis. The results revealed significant alterations in the functional connectivity of the caudate, putamen, and nucleus accumbens (NAc) in PD patients. Notably, the absence of intra-network asymmetry in the left NAc and bilateral amygdala correlated with motor dysfunction, likely due to overactivity of the inhibitory indirect pathway. Furthermore, pronounced asymmetry in the left putamen and right frontal gyrus suggested a compensatory neural mechanism supporting motor performance. These findings highlight the critical role of basal ganglia network asymmetry in the pathophysiology of PD. The identified asymmetry characteristics may serve as potential biomarkers for early diagnosis and disease progression monitoring, offering new directions for targeted therapeutic interventions.