Dopamine agonists and sleepiness in PD: review of the literature and personal findings

Background and purpose: This study is aimed at evaluating daytime sleepiness in a series of Parkinson's disease (PD) patients chronically treated with dopamine agonists (DAs) alone or in combination with L-Dopa. Patients and methods: A preliminary series of 22 non-demented, adult PD patients (mean age 68.9, 13 men and 9 women) were evaluated by means of structured sleep interview, Epworth sleepiness scale (ESS) and 24-h ambulatory polysomnography (A-PSG). Results: Sleep attacks (SAs) were reported by 32% of the patients, in three of them (43%) after DA treatment was initiated (alone or in addition to L-Dopa). In two patients, both with chronic use of ropinirole, we documented NREM SAs during a continuous ambulatory polysomnography (A-PSG) performed in the patients' real-life settings. The subjects experiencing SAs showed a higher degree of daytime sleep propensity than those without SA, having higher ESS scores and a higher proportion of microsleeps and intentional naps on A-PSG. Interestingly, we found that nocturnal total sleep time is higher in PD patients with SAs than in the others. Conclusions: All in all, our data indicate that SAs are an extreme manifestation of increased daytime sleepiness. The occurrence of SAs in our series of PD patients is unlikely to depend simply on the demands of homeostatic mechanisms. (C) 2004 Elsevier B.V. All rights reserved.