Advanced Parkinson's Disease: Clinical, Pathologic, and Imaging Markers—A Review

This review addresses the lack of consensus definition for advanced Parkinson's disease by synthesizing clinical features (motor fluctuations, falls, cognitive decline), pathological burden markers, and neuroimaging findings associated with disease progression. The authors propose a longitudinal assessment model incorporating clinical markers and quality-of-life metrics to better characterize and predict disease trajectory in PD patients.