title: Circadian rhythms in the vegetative state.
abstract: OBJECTIVE
  To evaluate whether vegetative state patients maintain circadian rhythms.
  
  
  METHODS
  An observational study of five single cases.
  
  
  METHODS
  Five chronic vegetative state patients underwent clinical and neurological evaluations and 2-week continuous temperature measurements.
  
  
  RESULTS
  The two patients with traumatic brain injury showed well-formed circadian temperature rhythms and had more reflexive behaviours and relatively low cortical and sub-cortical atrophy, whereas the three patients from anoxic-hypoxic origin demonstrated no cycles or rhythmic behaviour.
  
  
  CONCLUSIONS
  The presence of periods of wakefulness does not imply preserved sleep-wake cycling capacity, nor preserved circadian rhythms and it should not be taken as a distinguishing feature for the definition of the vegetative state.
authors.affiliation: Institute of Cognitive Neurology, Buenos Aires, Argentina. tristan.bekinschtein@mrc-cbu.cam.ac.uk
authors.forename: T A
authors.initials: TA
authors.lastname: Bekinschtein
authors.forename: D A
authors.initials: DA
authors.lastname: Golombek
authors.forename: S H
authors.initials: SH
authors.lastname: Simonetta
authors.forename: M R
authors.initials: MR
authors.lastname: Coleman
authors.forename: F F
authors.initials: FF
authors.lastname: Manes
mesh_terms: D000328:Adult; D000368:Aged; D001833:Body Temperature Regulation / Q000502:physiology*; D001930:Brain Injuries / Q000150:complications / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D002534:Hypoxia, Brain / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018458:Persistent Vegetative State / Q000503:physiopathology*; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult