Fibromyalgia is a condition characterized by widespread pain (above and below the waist, right and left and in axial skeleton), and pain on palpation of 18 discrete anatomic locations (tender points) (Wolfe et al., 1990). People with fibromyalgia usually report sleep disturbances and they awaken from sleep feeling worsened rather than improved pain. Other prominent concurrent symptoms include profound fatigue, stiffness, paresthesias, headache, and GI and bladder symptoms. Since there are no pathology markers, fibromyalgia is diagnosed solely by symptom and sign reporting. The disorder occurs disproportionately in women, with reported prevalences in women ranging from 3.4% to 10.5% and in men an estimated 0.5%. Prevalence increases with age and peaks in the 50-80 year age group.

In our ongoing PSG studies of women with insomnia (screened for other major disease/illness), we discovered that a subset of our sample (n=11) had been diagnosed with fibromyalgia, since we had been naive about this condition and had not screened for it. In order to determine whether these women reported more sleep disturbance and had a disturbed PSG sleep pattern, we randomly selected 11 women from our control group for comparison with the 11 subjects with fibromyalgia. On a specific health symptom questionnaire, the women with fibromyalgia scored significantly more disturbed or negatively on sleep items. They did not display profound PSG sleep changes after looking at the sleep variables over the whole night. When we looked at just the first half of the night, however, the women with fibromyalgia did display lighter (less SWS), and more fragmented (more sleep stage changes) sleep (Shaver et al., 1997).

We then decided to mimic this sleep pattern in a control group of women with good sleep and see if we could provoke fibromyalgia-like symptoms by doing selective slow-wave (deep) sleep deprivation. We did not use a yoked control design but controlled for age and activity levels through subject selection. We studied only women in a narrow age (40-55 years old) range who were sedentary--similar to women with fibromyalgia. Sleep was recorded and scored using standard methods for PSG. After a baseline night of sleep and for the next three consecutive nights, the computer was programmed to trigger a sound generator that delivered a 2000 Hz tone upon detection of delta waves (indicative of SWS) and until they disappeared. The tone could be progressively ramped up to a possible maximum of 85dB through a microphone placed close to the ear. Sleep was thus made lighter (no deep sleep) and more fragmented. Each morning, a standard dolorimeter (algometer) was used to examine 8 paired fibromyalgia tender point sites by exerting progressively increased pressure (maximum 8 Kg/1.54cm²) until the subject reported it as painful. One control site (not designated as one of 18 tenderpoint areas in the ACR criterion for fibromyalgia) was also assessed. Subjects completed the Bodily Feelings Questionnaire (Alpher et al., 1987) for somatic symptoms and the Profile of Mood States. The following are PSG sleep data:

Figure 3.9.1: Percent PSG Sleep Stages in Women at Baseline and Over Three Nights of SWS Deprivation Adapted from: Lentz MJ, Landis CA, Rothermel J, Shaver JL. Effects of selective slow wave sleep disruption on musculoskeletal pain and fatigue in middle age women. The Journal of Rheumatology. 1999; 26:1586-1592.

Question 3.9.1

The validity of the study is not supported because not all sleep stages were disrupted.
	True
	False

Question 3.9.2

Loss of deep sleep was supplanted mainly by transitional sleep (Stage 1) in these women who sleep normally.
	True
	False

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