A.01 Parkinson’s disease prognosis by early motor subtypes

Background: Studies of autopsy-confirmed cases suggest that Parkinson’s disease (PD) prognosis can be predicted using motor symptom severity at first visit. We evaluated the association between motor symptom subtype at first visit and severity at eight years disease duration among clinically-diagnosed cases at the Saskatchewan Movement Disorder Program. Methods: Retrospective data review identified 374 patients with first visit within three years of symptom onset, a clinical diagnosis of idiopathic PD, and a follow-up visit eight years after symptom onset. Subtypes were grouped as tremor-dominant (TD) if tremor was greater than rigidity and bradykinesia, akinetic-rigid (AR) if rigidity or bradykinesia was greater than tremor, and mixed (MX) if patient was neither TD nor AR based on assessment of all four limbs. Primary outcome was disease severity as measured by Hoehn & Yahr score at eight years after symptom onset. Results: The most common subtype was AR (n=164) followed by MX (n=156). TD was least common (n=54). There was no significant difference between subtypes in H&Y scores at eight years disease duration. Conclusions: These findings suggest that early PD prognosis cannot be predicted based on motor symptoms in all four limbs at first visit. Earlier studies had longer follow-up and future studies will examine progression at longer periods of disease duration.