Deprenyl's effect at slowing progression of parkinsonian disability: the DATATOP study. The Parkinson Study Group

Studying a cohort of 800 mildly-affected parkinsonians, the North American DATATOP* project has concluded that progression in disability can be attenuated by the use of deprenyl, 10 mg/day. Interim results of this controlled clinical trial were reported after participants received treatment for an average of 12 months. The study found that deprenyl treatment almost halved the risk of reaching a stage of Parkinsonism at which the start of levodopa treatment becomes imperative for lessening disability. In addition to this study end-point, other ratings supported an improved clinical outcome from the chronic deprenyl (DP) regimen. The 34 investigators conducted clinical evaluations both while subjects received medication and after a 4-week wash-out. Though some subjects experienced mild symptomatic improvements of Parkinsonism from DP, these effects were insufficient to account for the DP-treated group's delay at reaching the study end-point. In addition to DP, this placebo-controlled double-blind study also assessed the possibility of protective effects from another antioxidative strategy, a 2,000 I.U./day regimen of alpha-tocopherol. To date, results of the latter trial have not been reported. Monoamine oxidase type-B (MAO-B) metabolism of dopamine generates hydrogen peroxide and, thereby, an oxidative stress on the nigrostriatal dopaminergic neuron. The inhibition of MAO-B by DP may have been the means by which progression of Parkinsonism was attenuated, although other mechanisms are also tenable. DATATOP has pointed to the potential for arresting the progression of Parkinson's disease, and has provided an unparalleled opportunity to study the clinical course and neurochemical indices of untreated Parkinsonism.(ABSTRACT TRUNCATED AT 250 WORDS)