FACTORS PREDICTIVE OF THE NEED FOR LEVODOPA THERAPY IN EARLY, UNTREATED PARKINSONS-DISEASE

Objective: To identify characteristics of patients with early, untreat ed Parkinson's disease that are the most important predictors of rapid functional decline. Design: Prospective observational study of a coho rt of 800 patients with early, untreated Parkinson's disease who were involved in a multicenter, randomized, double-blind, controlled clinic al trial of selegiline hydrochloride (L-deprenyl) and vitamin E (alpha -tocopherol). Primary Outcome Variable: Time from randomization to the onset of disability that necessitated levodopa therapy (end point), a s judged by the enrolling investigator. Methods: Stepwise Cox regressi on was used in combination with clinical judgment to identify the most important independent baseline predictors of the primary end point am ong a host of variables, including treatment with selegiline and vitam in E, global and specific clinical measures of disease severity, demog raphic variables, and neuropsychological test results. Results: In add ition to selegiline treatment and global disease severity measures, su ch as the stage according to the criteria of Hoehn and Yahr, impaired domestic capacity, and the activities of daily living score, the compl ex of postural instability/gait difficulty and bradykinesia were found to be the factors that were most highly associated with the risk of r eaching the end point. Conclusions: The findings suggest that patients with Parkinson's disease whose early clinical presentation includes e ither postural instability/gait difficulty or bradykinesia are at high risk for rapid functional decline.