Alpha-like EEG activity in non-REM sleep and the fibromyalgia (fibrositis) syndrome

The occurrence and characteristics of alpha-like activity during non-REM (NREM) sleep were examined in 11 subjects suffering from non-inflammatory (non-rheumatoid) musculoskeletal pain--fibromyalgia ('fibrositis'), and in 15 symptom-free controls. Both groups claimed to be good sleepers. Mean percentage alpha-like activity in sleep stages 2, 3, 4 and for NREM as a whole were greatest for the fibromyalgia group, but not significantly different from those of the controls. Overlap in the distribution of NREM alpha-like activity in sleep between the two groups indicated that it is not directly related to musculoskeletal symptoms. Spectral analyses showed a frontal area prevalence of this (kappa?) activity in the fibromyalgia group.