Selegiline and cognitive function in Parkinson's disease.

Eighteen patients with Parkinson's disease were treated with placebo for 4 weeks and with the MAO-B inhibitor selegiline for 8 weeks without levodopa in a randomized double-blind clinical study. The maximum dose of selegiline was 30 mg/day and the patients' cognitive functions were evaluated before treatment and at week 12 when they were either on 30 mg selegiline or placebo. A series of neuropsychological tests were used to study general cognitive reasoning, memory, visuospatial abilities, attention, cognitive flexibility, motor functions and depression. Specific cognitive effects were not observed. Slight improvement occurred mainly in learning (easy word associations) which may reflect a limited, nonspecific arousal effect.