Selegiline reduces daytime sleepiness in patients with Parkinson's disease

Excessive daytime sleepiness (EDS) affects a large percentage of Parkinson's disease (PD) patients, and it is enhanced by dopamine agonist drugs. Currently, there is no treatment of choice for EDS in PD. Our aim was to check the clinical impression that some patients who were given selegiline, a selective inhibitor of monoamine oxidase B, experienced an improvement in their daytime somnolence.

In the present study, we retrospectively identified 45 Parkinson's disease patients (21 females and 24 males) among those referred to the PD Center in Varese that (a) showed excessive daytime sleepiness, usually developed after the introduction of a dopamine agonist, (b) were given selegiline 10 mg to improve their treatment schedule independently of excessive sleepiness, and (c) in whom the Epworth Sleepiness Scale (ESS) and the Parkinson's Disease Sleep Scale (PDSS) scores were available both before and 3 months after the introduction of selegiline.

We compared the corresponding scores (ESS, PDSS, and UPDRS III) evaluated before and 3 months after the introduction of selegiline by the nonparametric Mann-Whitney U test: The differences showed a statistically significant improvement of somnolence but no change in the UPDRS III scores.

Despite some limitations, our data suggest that selegiline may be a valuable add-on therapy in PD patients to reduce their daytime somnolence.