Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are medically unexplained conditions that share considerable overlapping symptoms, including sleep-related complaints. However, differences between the two conditions have been reported, and we hypothesized that dynamic aspects of sleep, recently attracting scientific interests, would be different in the two groups of patients.
We thus study transition probabilities between sleep stages of CFS patients with or without FM.
Subjects were 26 healthy controls, 14 CFS patients without FM (CFS alone) and 12 CFS patients with FM (CFS+FM) – all women.
We studied transition probabilities between sleep stages (waking, REM sleep and Stage I, Stage II and slow-wave sleep (Stage III+IV)). [For a simple chart describing each sleep stage, see “Everything you always wanted to know about sleep but were too tired to ask,” by Karen Lee Richards.]
• We found that probabilities of transition from REM sleep to waking were significantly greater in CFS alone than in controls; we have reported previously this sleep disruption as the specific sleep problem for CFS alone (Kishi et al., 2008 “Dynamics of sleep stage transitions in healthy humans and patients with chronic fatigue syndrome”).
• Probabilities of transitions from waking, REM sleep and Stage I to Stage II, and those from slow-wave sleep to Stage I, were significantly greater in CFS+FM than in controls; the former might indicate increased sleep pressure in CFS+FM and the latter may be the specific sleep problem of CFS+FM.
These results suggest that CFS and FM are different illnesses associated with different problems of sleep regulation.
Source: Proceedings of Engineering in Medicine and Biology Society, 2010 Annual International Conference of the IEEE, Nov 11, 2010; pp 5391-5394. PMID: 21096267, by Kishi A, Natelson BH, Togo F, Struzik ZR, Rapoport DM, Yamamoto Y. Educational Physiology Laboratory, Graduate School of Education, The University of Tokyo, Japan.