title: Ventricular orexin-A (hypocretin-1) levels correlate with rapid-eye-movement sleep without atonia in Parkinson's disease.
abstract: OBJECTIVE
  Patients with Parkinson's disease frequently complain of sleep disturbances and loss of muscle atonia during rapid-eye-movement (REM) sleep is not rare. The orexin-A (hypocretin-1) hypothalamic system plays a central role in controlling REM sleep. Loss of orexin neurons results in narcolepsy-cataplexy, a condition characterized by diurnal sleepiness and REM sleep without atonia. Alterations in the orexin-A system have been also documented in Parkinson's disease, but whether these alterations have clinical consequences remains unknown.
  
  
  METHODS
  Here, we measured orexin-A levels in ventricular cerebrospinal fluid from eight patients with Parkinson's disease (four males and four females) who underwent ventriculography during deep brain-stimulation surgery and performed full-night polysomnography before surgery.
  
  
  RESULTS
  Our results showed a positive correlation between orexin-A levels and REM sleep without muscle atonia.
  
  
  CONCLUSIONS
  Our results suggest that high levels of orexin-A in Parkinson's disease may be associated with loss of REM muscle atonia.
authors.affiliation: Service de Physiologie, Groupe Henri Mondor, Créteil, France ; Faculté de Médecine, Université Paris Est Créteil, Créteil, France.
authors.forename: Agathe
authors.initials: A
authors.lastname: Bridoux
authors.forename: Stephane
authors.initials: S
authors.lastname: Moutereau
authors.forename: Ala
authors.initials: A
authors.lastname: Covali-Noroc
authors.forename: Laurent
authors.initials: L
authors.lastname: Margarit
authors.forename: Stephane
authors.initials: S
authors.lastname: Palfi
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Nguyen
authors.forename: Jean-Pascal
authors.initials: JP
authors.lastname: Lefaucheur
authors.forename: Pierre
authors.initials: P
authors.lastname: Césaro
authors.forename: Marie-Pia
authors.initials: MP
authors.lastname: d'Ortho
authors.forename: Xavier
authors.initials: X
authors.lastname: Drouot
keywords: Parkinson; REM atonia; orexin-A; ventricular CSF