Polysomnographic measures in Parkinson's disease: a comparison between patients with and without REM sleep...

To assess the frequency of rapid eye movement (REM) sleep abnormalities in Parkinson's disease (PD) patients and compare polygraphic sleep measures in those with and without REM sleep disturbances.

Polysomnographic recordings of 2 consecutive nights were performed in 45 patients with PD (mean age 65 years, mean Hoehn and Yahr stage 2.2). Twenty patients were treated with dopaminergic drugs, 10 were drug-free for two weeks and 15 had never been treated with L-dopa or dopamine agonists. According to the polysomnographic findings, the patients were divided into those with and without REM sleep abnormalities. Abnormal REM sleep features were defined as REM sleep without atonia (RWA) and REM sleep behavior disorder (RBD).

Eighteen (40%) of the PD patients showed either RWA (24%; 6 men, 5 women) or RBD (16%; 6 men, 1 woman). Patients with REM sleep disturbances had a significantly longer duration of the disease (8.3 vs. 3.9 years), a more severe stage of the disease (2.6 vs. 2.0 Hoehn and Yahr stage) and were treated with a higher dosage of dopaminergic drugs (L-dopa, pergolide and bromocriptin). 67% of the patients with normal REM sleep were untreated at the time of the sleep study, but only 39% of those with REM sleep abnormalities. Sleep EEG measures (sleep efficiency, sleep onset latency, sleep period time, relative amounts of sleep stages) for the second night showed no significant differences between both groups apart from a significantly lower sleep period time in PD patients with RWA/RBD.

Abnormal REM sleep features are a frequent finding in patients with PD. The prevalence seems to increase with a longer disease duration. Therefore, a careful follow-up is necessary. A sleep architecture not different from PD patients without RWA/RBD suggests that the underlying abnormality is confined to REM sleep.