Prodromal Parkinson's Disease: A Snapshot of the Landscape.

Early observations of specific nonmotor and subtle motor symptoms preceding clinical diagnosis of Parkinson's disease (PD) have paved the way for prodromal PD research, significantly propelling our understanding of early, subclinical stages of neurodegeneration. Prodromal PD has emerged as a complex concept with some researchers suggesting that the period before PD onset is divided into the "at-risk," "preclinical," and "prodromal" phases. Advances in genetic, imaging, laboratory, and digital technologies have enabled the identification of pathophysiological patterns and the potential development of diagnostic, progressive, and therapeutic biomarkers, which could lead to early PD detection and intervention.