The New Diagnostic Criteria for Parkinson's Disease

This chapter summarizes the advances in diagnosis of Parkinson's disease (PD) that were encapsulated in new International Parkinson Disease and Movement Disorders Society diagnostic criteria for PD. Numerous changes in our understanding of PD have occurred, including our understanding of the nonmotor profile of disease, the recognition of PD as a synucleinopathy, identification of genetic causes, novel hypotheses about spread of disease, etc. These have been reflected in a new definition of PD, which includes a clinicogenetic subtype of PD, removes dementia with Lewy Bodies as an exclusion criterion against PD, and recognizes multiple stages of early disease. The Clinical Diagnostic Criteria for PD reflect these changes and offer a new standardized diagnostic method for use in clinical research and even clinical practice. The criteria for prodromal PD use a method not seen in previous diagnostic criteria; they rely upon published studies of PD predictors to calculate the probability that any individual will develop PD. The field of PD is constantly advancing, and our methods of diagnosis need to advance with it; one hopes for a future filled with constant revisions and updates in our diagnostic methodology.