title: Loss of REM sleep features across nighttime in REM sleep behavior disorder.
abstract: OBJECTIVE
  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.
authors: Sleep Disorders Unit, APHP-Pitié-Salpêtrière Hospital, Paris, France; Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genova, Italy.
authors: Dario
authors: D
authors: Arnaldi
authors: Brain Research Institute-UPMC Paris 6 Univ, Inserm U 1127, CNRS UMR 7225, Paris, France.
authors: Alice
authors: A
authors: Latimier
authors: Sleep Disorders Unit, APHP-Pitié-Salpêtrière Hospital, Paris, France; Brain Research Institute-UPMC Paris 6 Univ, Inserm U 1127, CNRS UMR 7225, Paris, France.
authors: Smaranda
authors: S
authors: Leu-Semenescu
authors: Brain Research Institute-UPMC Paris 6 Univ, Inserm U 1127, CNRS UMR 7225, Paris, France; Neurology Department, APHP- Pitié-Salpêtrière Hospital, Paris, France.
authors: Marie
authors: M
authors: Vidailhet
authors: 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.
authors: Isabelle
authors: I
authors: Arnulf
mesh_terms: D000328:Adult; D000368:Aged; D021081:Chronobiology Disorders / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000494:pharmacology / Q000627:therapeutic use; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology; D017286:Polysomnography / Q000379:methods; D020187:REM Sleep Behavior Disorder / Q000188:drug therapy / Q000503:physiopathology*; D012894:Sleep Stages
chemical_list: D008550:Melatonin
keywords: Circadian; Melatonin; PD; RBD