Accuracy of Clinical Diagnosis in Early Parkinson Disease

I was interested to read in the conclusion of the abstract of the report of Jankovic et al¹ that "only 65 (8.1%) of 800 patients initially diagnosed as having Parkinson disease (PD) were later found to have an alternate diagnosis based on multifactorial clinical criteria." This conclusion ignores the "gold standard" neuropathological data in the text suggesting the possibility of a much higher misdiagnosis rate.