title: Relationships between clinical characteristics and nocturnal cardiac autonomic activity in Parkinson's disease.
abstract: BACKGROUND
  The aim of the present study was to explore the association between Parkinson's disease (PD) clinical characteristics and cardiac autonomic control across sleep stages.
  
  
  METHODS
  Frequency-domain heart rate variability (HRV) measures were estimated in 18 PD patients undergoing a night of polysomnography.
  
  
  RESULTS
  Significant relationships were found between PD severity and nocturnal HRV indices. The associations were restricted to rapid eye movement (R) sleep.
  
  
  CONCLUSIONS
  The progressive nocturnal cardiac autonomic impairment occurring with more severe PD can be subclinical emerging only during conditions requiring active modulation of physiological functions such as R-sleep.
authors.affiliation: Department of General Psychology, University of Padova, Italy.
authors.forename: Naima
authors.initials: N
authors.lastname: Covassin
authors.forename: Ariel B
authors.initials: AB
authors.lastname: Neikrug
authors.forename: Lianqi
authors.initials: L
authors.lastname: Liu
authors.forename: Jeanne
authors.initials: J
authors.lastname: Maglione
authors.forename: Loki
authors.initials: L
authors.lastname: Natarajan
authors.forename: Jody
authors.initials: J
authors.lastname: Corey-Bloom
authors.forename: Jose S
authors.initials: JS
authors.lastname: Loredo
authors.forename: Barton W
authors.initials: BW
authors.lastname: Palmer
authors.forename: Laura S
authors.initials: LS
authors.lastname: Redwine
authors.forename: Sonia
authors.initials: S
authors.lastname: Ancoli-Israel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology*; D010808:Physical Examination; D017286:Polysomnography; D012720:Severity of Illness Index; D012894:Sleep Stages / Q000502:physiology*; D018709:Statistics, Nonparametric