Correlation between brain symmetry index and motor function in Parkinson’s disease: a cross-sectional study

There were hemispheric asymmetry in the PD patients. The pdBSI was a potential electrophysiological biomarker for hemispheric asymmetry in the PD. β2-pdBSI in the central and posterior region was significantly associated with the severity of gait impairment in aPD patients. In addition, the stage-dependent gradient elucidates the dynamic shift from unilateral to bilateral network involvement. Our findings underscore that quantifying interhemispheric asymmetry, beyond examining power in isolated regions, provides unique insights into the pathophysiology and clinical progression of PD.