title: Sleep-stage dynamics in patients with chronic fatigue syndrome with or without fibromyalgia.
abstract: OBJECTIVE
  Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are medically unexplained conditions that often have overlapping symptoms, including sleep-related complaints. However, differences between the 2 conditions have been reported, and we hypothesized that dynamic aspects of sleep would be different in the 2 groups of patients.
  
  
  METHODS
  Subjects were 26 healthy control subjects, 14 patients with CFS but without FM (CFS alone), and 12 patients with CFS and FM (CFS+FM)-all women.
  
  
  RESULTS
  We studied transition probabilities and rates between sleep stages (waking, rapid eye movement [REM] sleep, stage 1 [S1], stage 2 [S2], and slow-wave sleep [SWS]) and duration distributions of each sleep stage. We found that the probability of transition from REM sleep to waking was significantly greater in subjects with CFS alone than in control subjects, which may be the specific sleep problem for people with CFS alone. Probabilities of (a) transitions from waking, REM sleep, and S1 to S2 and (b) those from SWS to waking and S1 were significantly greater in subjects with CFS+FM than in control subjects; in addition, rates of these transitions were also significantly increased in subjects with CFS+FM. Result (a) might indicate increased sleep pressure in subjects with CFS+FM whereas result (b) may be the specific sleep problem of subjects with CFS+FM. We also found that shorter durations of S2 sleep are specific to patients with CFS+FM, not to CFS alone.
  
  
  CONCLUSIONS
  These results suggest that CFS and FM may be different illnesses associated with different problems of sleep regulation.
authors: Educational Physiology Laboratory, Graduate School of Education, University of Tokyo, Tokyo, Japan.
authors: Akifumi
authors: A
authors: Kishi
authors: Benjamin H
authors: BH
authors: Natelson
authors: Fumiharu
authors: F
authors: Togo
authors: Zbigniew R
authors: ZR
authors: Struzik
authors: David M
authors: DM
authors: Rapoport
authors: Yoshiharu
authors: Y
authors: Yamamoto
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015673:Fatigue Syndrome, Chronic / Q000150:complications* / Q000503:physiopathology; D005260:Female; D005356:Fibromyalgia / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D017286:Polysomnography; D012894:Sleep Stages / Q000502:physiology; D018709:Statistics, Nonparametric