AbstractObjectives:Update data for diagnostic accuracy of a clinical diagnosis of Parkinson’s disease (PD) using neuropathological diagnosis as the gold standard.Methods:Data from the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND) was used to determine the predictive value of a clinical PD diagnosis. Two clinical diagnostic confidence levels were used, Possible PD (PossPD, never treated or not responsive) and Probable PD (ProbPD, 2/3 cardinal clinical signs + responsive to dopaminergic medications). Neuropathological diagnosis was the gold standard.Results:Based on first visit to AZSAND, 15/54 (27.8%) PossPD cases and 138/163 (84.7%) ProbPD had confirmed PD. PD was confirmed in 24/34 (70.6%) ProbPD with <5 yrs and 114/128 (89.1%) with >5 yrs disease duration. Using the consensus final clinical diagnosis following death, 161/187 (86.1%) ProbPD had neuropathologically confirmed PD. Diagnostic accuracy for ProbPD improved if included motor fluctuations, dyskinesias, and hyposmia, and hyposmia for PossPD.Conclusions:This updated study confirmed lower clinical diagnostic accuracy for elderly, untreated or poorly responsive PossPD participants and for ProbPD with <5 yr disease duration, even when medication responsive. Caution continues to be needed when interpreting clinical studies of PD, especially studies of early disease, that do not have autopsy confirmation.Classification of Evidence:This study provides Class II evidence that a clinical diagnosis of probable PD at first visit identifies patients who will have pathologically confirmed PD with a sensitivity of 82.6% and specificity of 86.0%.
Low clinical diagnostic accuracy of early vs advanced Parkinson disease: Clinicopathologic study
