title: Sleep architecture and attenuated heart rate response to arousal from sleep in patients with autonomic failure.
abstract: OBJECTIVE
  To determine if patients with autonomic failure have increased sleep disturbances and if multiple system atrophy (MSA) and pure autonomic failure (PAF) patients have frequent arousals from sleep associated with an attenuated heart rate (HR) response compared to healthy volunteers.
  
  
  METHODS
  With informed consent, 10 autonomic failure patients and 10 healthy volunteers were studied. Sleep disturbances were scored using standard criteria. Arousals were identified from stage 2 sleep and differences in the R-R interval between groups were tested using a mixed-model regression analysis.
  
  
  RESULTS
  Three MSA and one PAF patient had obstructive sleep apnoea compared to one volunteer. One MSA and three PAF patients had periodic limb movements. One MSA patient had REM behaviour disorder. The autonomic patients had significantly reduced total sleep time (p=0.007) and sleep efficiency (p=0.003). The HR response to arousal was smaller in autonomic failure patients compared to volunteers during the early phase of the arousal (p=0.047), but not the later phase (p=0.67).
  
  
  CONCLUSIONS
  Autonomic failure patients have increased sleep disturbances compared to healthy volunteers. The smaller HR response in autonomic failure patients suggests that an intact sympathetic nervous system is a key component of the HR response associated with arousal from sleep.
authors: Clinical and Academic Unit of Sleep and Ventilation, Royal Brompton Hospital, Imperial College, London, UK.
authors: Simon
authors: S
authors: Freilich
authors: Elizabeth A
authors: EA
authors: Goff
authors: Anura S N
authors: AS
authors: Malaweera
authors: Gillian L
authors: GL
authors: Twigg
authors: Anita K
authors: AK
authors: Simonds
authors: Christopher J
authors: CJ
authors: Mathias
authors: Mary J
authors: MJ
authors: Morrell
mesh_terms: D000328:Adult; D000368:Aged; D001143:Arousal / Q000502:physiology*; D001341:Autonomic Nervous System / Q000503:physiopathology; D015897:Comorbidity; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis / Q000503:physiopathology*; D020189:Nocturnal Myoclonus Syndrome / Q000175:diagnosis / Q000503:physiopathology; D017286:Polysomnography; D054970:Pure Autonomic Failure / Q000175:diagnosis / Q000503:physiopathology*; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis / Q000503:physiopathology; D012016:Reference Values; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology; D012894:Sleep Stages / Q000502:physiology; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000503:physiopathology*