Revisiting the 2015 MDS diagnostic criteria for Parkinson disease: insights from autopsy-confirmed cases

The 2015 International Parkinson and Movement Disorder Society (MDS) Diagnostic criteria for Parkinson Disease are based on expert consensus opinion and defines core motor features, 'Absolute Exclusion Criteria' and a balance of 'Supportive Criteria' and 'Red Flags'. To assess validity of each criterion in pathologically-confirmed cases, a scoping literature review between 1988-2024 using search terms for clinicopathological PD and atypical parkinsonian disorders identified 28 articles. Supportive criteria were higher in PD, with excellent levodopa response and rest tremor most useful. Absolute exclusion criteria and red flags were present more often in atypical parkinsonian disorders. However, supranuclear gaze palsy, rapid progression of gait impairment to wheelchair requirement and bilateral symptoms were reported in >5% PD. Data was limited by few appropriate pathological studies with sufficient clinical data; challenges in applying highly-specific definitions to retrospective studies and likely co-pathologies. This review provides empiric data to support some items of the MDS Criteria with future potential refinement.