Selegiline Use to Prevent Progression of Parkinson's Disease

• To test the hypothesis that selegiline (L-deprenyl), a selective inhibitor of B-type monoamine oxidase, can halt the natural progression of Parkinson's disease, its use in 22 naive patients (mean age, 58 years; mean Parkinson's disease duration, 2.3 years) in the early stages (1 to 2) of the disease was studied. Patients were started and maintained on a daily dose of 10 mg of selegiline, and they underwent neurologic examinations at 3-month intervals using our center's disease staging and total rated disability scores. The criterion set for disease progression was defined as either the appearance of a new objective sign and/or a definite, persistent worsening (>25%) of existing signs after the initiation of the selegiline trial. Patients remained on a regimen of selegiline alone for periods ranging from 7 to 84 months. At the time of their latest neurologic examination, 17 (77%) of the 22 patients had conditions that demonstrably worsened with selegiline alone at an average of 10.8 months from the start of the drug therapy. Six of these 17 patients with worsening conditions (or 27% of the original 22) eventually required the addition of levodopa with carbidopa (Sinemet) on average at 13 months from the start of selegiline therapy; they have continued, to date, taking this combination for an additional mean follow-up period of 20.7 months. Four of the original 22 patients had relatively unchanged, stable neurologic status at the time of their latest examination (average follow-up period, 11.6 months). One patient had improvement in his overall disability scores greater than 25% with unchanged disease stage, which was maintained throughout his selegiline trial of 12.5 months, when he was unavailable for follow-up. The use of selegiline in the early phase of Parkinson's disease neither prevents the emergence of new signs nor halts the progression of those previously present. Although our data demonstrate that selegiline cannot halt the progression of the disease, the possibility that selegiline reduces the rate of progression remains open.