Dario Arnaldi1, Alice Latimier2, Smaranda Leu-Semenescu3, Marie Vidailhet4, Isabelle Arnulf5. 1. Sleep Disorders Unit, APHP-Pitié-Salpêtrière Hospital, Paris, France; Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genova, Italy. 2. Brain Research Institute-UPMC Paris 6 Univ, Inserm U 1127, CNRS UMR 7225, Paris, France. 3. Sleep Disorders Unit, APHP-Pitié-Salpêtrière Hospital, Paris, France; Brain Research Institute-UPMC Paris 6 Univ, Inserm U 1127, CNRS UMR 7225, Paris, France. 4. Brain Research Institute-UPMC Paris 6 Univ, Inserm U 1127, CNRS UMR 7225, Paris, France; Neurology Department, APHP- Pitié-Salpêtrière Hospital, Paris, France. 5. Sleep Disorders Unit, APHP-Pitié-Salpêtrière Hospital, Paris, France; Brain Research Institute-UPMC Paris 6 Univ, Inserm U 1127, CNRS UMR 7225, Paris, France. Electronic address: isabelle.arnulf@psl.aphp.fr.
Abstract
OBJECTIVES: Melatonin is a chronobiotic treatment which also alleviates rapid eye movement (REM) sleep behavior disorder (RBD). Because the mechanisms of this benefit are unclear, we evaluated the clock-dependent REM sleep characteristics in patients with RBD, whether idiopathic (iRBD) or associated with Parkinson's Disease (PD), and we compared findings with PD patients without RBD and with healthy subjects. METHODS: An overnight videopolysomnography was performed in ten iRBD patients, ten PD patients with RBD (PD + RBD+), ten PD patients without RBD (PD + RBD-), and ten controls. The rapid eye movement frequency per minute (REMs index), the tonic and phasic electromyographic (EMG) activity of the levator menti muscle, and the duration of each REM sleep episode were evaluated. A generalized linear model was applied in each group, with the REM sleep cycle (four ordinal levels) as the dependent variable, as a function of REMs index, REM sleep duration, and tonic and phasic EMG activity. RESULTS: From the first to the fourth sleep cycle, REM sleep duration progressively increased in controls only, REMs index increased in subjects without RBD but not in patients with RBD, whether idiopathic or associated with PD, whereas tonic and phasic EMG activity did not change. CONCLUSIONS: Patients with PD or iRBD lost the physiologic nocturnal increase in REM sleep duration, and patients with RBD (either with or without PD) lost the increase of REMs frequency across the night, suggesting an alteration in the circadian system in RBD. This supports the hypothesis of a direct effect of melatonin on RBD symptoms by its chronobiotic activity.
OBJECTIVES:Melatonin is a chronobiotic treatment which also alleviates rapid eye movement (REM) sleep behavior disorder (RBD). Because the mechanisms of this benefit are unclear, we evaluated the clock-dependent REM sleep characteristics in patients with RBD, whether idiopathic (iRBD) or associated with Parkinson's Disease (PD), and we compared findings with PDpatients without RBD and with healthy subjects. METHODS: An overnight videopolysomnography was performed in ten iRBD patients, ten PDpatients with RBD (PD + RBD+), ten PDpatients without RBD (PD + RBD-), and ten controls. The rapid eye movement frequency per minute (REMs index), the tonic and phasic electromyographic (EMG) activity of the levator menti muscle, and the duration of each REM sleep episode were evaluated. A generalized linear model was applied in each group, with the REM sleep cycle (four ordinal levels) as the dependent variable, as a function of REMs index, REM sleep duration, and tonic and phasic EMG activity. RESULTS: From the first to the fourth sleep cycle, REM sleep duration progressively increased in controls only, REMs index increased in subjects without RBD but not in patients with RBD, whether idiopathic or associated with PD, whereas tonic and phasic EMG activity did not change. CONCLUSIONS:Patients with PD or iRBD lost the physiologic nocturnal increase in REM sleep duration, and patients with RBD (either with or without PD) lost the increase of REMs frequency across the night, suggesting an alteration in the circadian system in RBD. This supports the hypothesis of a direct effect of melatonin on RBD symptoms by its chronobiotic activity.