EEG Microstates Are Associated with Motor Function in Parkinson's Disease: A Cross-Sectional Observational Study

Electroencephalogram (EEG) microstates can precisely capture transient brain activity changes on sub-second time scales and are used to evaluate global dynamic functional alterations in the brains of Parkinson's disease (PD) patients. This study primarily investigates the differences in microstate features between PD patients and healthy subjects, while exploring their correlations with clinical symptoms.

We enrolled 75 PD patients and 44 healthy controls (HCs) who underwent simultaneous EEG microstate recording and Montreal Cognitive Assessment (MoCA) evaluation. All PD patients underwent comprehensive evaluation using the International Movement Disorder Society Unified Parkinson's Disease Rating Scale Parts I and III (MDS-UPDRS I & III).

PD patients demonstrated significantly increased mean coverage and duration of microstate D compared with HCs, together with elevated transition probabilities from microstates A, B, and C to D. Importantly, both the mean coverage of microstate D and the transition probability from microstate B to D showed significant positive correlations with MDS-UPDRS III scores. Furthermore, receiver operating characteristic (ROC) curve analysis revealed that the mean coverage of microstate D (AUC = 0.674) and the transition probability from microstate B to D (AUC = 0.617) could distinguish between PD patients and HCs.

The observed abnormalities in microstate dynamics among PD patients may stem from an imbalance in neural network dynamics. These results indicate that EEG microstates may serve as potential biomarkers for assessing and monitoring motor function in PD.