Daytime REM sleep in Parkinson's disease

• Authors: Donald Bliwise, Emory University; Lynn Marie Trotti, Emory University; Jorge Juncos, Emory University; Stewart Factor, Emory University; Alan Freeman, Emory University; David Rye, Emory University
• Journal Title: Parkinsonism and Related Disorders
• Volume: Volume 19, Number 1
• Publisher: Elsevier | 2013-01, Pages 101-103
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1016/j.parkreldis.2012.08.003
• Subjects: Biology, Neuroscience
• Keywords: Parkinson’s Disease; Narcolepsy; REM Sleep

Abstract

Background: Previous studies have demonstrated both clinical and neurochemical similarities between Parkinson’s disease (PD) and narcolepsy. The intrusion of REM sleep into the daytime remains a cardinal feature of narcolepsy, but the importance of these intrusions in PD remains unclear. In this study we examined REM sleep during daytime Maintenance of Wakefulness Testing (MWT) in PD patients. Methods: Patients spent 2 consecutive nights and days in the sleep laboratory. During the daytime, we employed a modified MWT procedure in which each daytime nap opportunity (4 per day) was extended to 40 minutes, regardless of whether the patient was able to sleep or how much the patient slept. We examined each nap opportunity for the presence of REM sleep and time to fall asleep. Results: Eleven of 63 PD patients studied showed 2 or more REM episodes and 10 showed 1 REM episode on their daytime MWTs. Nocturnal sleep characteristics and sleep disorders were unrelated to the presence of daytime REM sleep, however, patients with daytime REM were significantly sleepier during the daytime than those patients without REM. Demographic and clinical variables, including Unified Parkinson’s Disease Rating Scale motor scores and levodopa dose equivalents, were unrelated to the presence of REM sleep. Conclusions: A sizeable proportion of PD patients demonstrated REM sleep and daytime sleep tendency during daytime nap testing. These data confirm similarities in REM intrusions between narcolepsy and PD, perhaps suggesting parallel neurodegenerative conditions of hypocretin deficiency.