Alpha sleep characteristics in fibromyalgia

Objective. To characterize the patterns of alpha electroencephalographic sl eep and their associations with pain and sleep in patients with fibromyalgi a. Methods. Pain and sleep symptoms of 40 female patients with fibromyalgia an d 43 healthy control subjects were studied before and after overnight polys omnography, Blinded analyses of alpha activity in nonrapid eye movement (no n-REM) sleep were performed using time domain, frequency domain, and visual analysis techniques. Results. Three distinct patterns of alpha sleep activity were detected in f ibromyalgia: phasic alpha (simultaneous with delta activity) in 50% of pati ents, tonic alpha (continuous throughout non-REM sleep) in 20% of patients, and low alpha activity in the remaining 30% of patients. Low alpha activit y was exhibited by 83.7% of control subjects (P < 0.01). All fibromyalgia p atients who displayed phasic alpha sleep, activity reported worsening of pa in after sleep, compared with 58.3% of patients with low alpha activity (P < 0.01) and 25.0% of patients with tonic alpha activity (P < 0.01). Postsle ep increase in the number of tender points occurred in 90.0% of patients wi th phasic alpha activity, 41.7% of patients,vith low alpha activity, and 25 .0% of patients with tonic alpha activity (P < 0.01). Self ratings of poor deep were reported by all patients with phasic alpha activity, 58.3% of pat ients with low alpha activity (P < 0.01), and 12.5% of patients with tonic alpha activity (P < 0.01). Patients with phasic alpha activity reported lon ger duration of pain than patients in other subgroups (P < 0.01). Additiona lly, patients with phasic alpha sleep activity exhibited less total sleep t ime than patients in other subgroups (P < 0.05), as well as lower sleep eff iciency (P < 0.05) and less slow wave sleep (P < 0.05) than patients with a tonic alpha sleep pattern. Conclusion. Alpha intrusion during sleep can be of different patterns. Phas ic alpha sleep activity was the pattern that correlated better with clinica l manifestations of fibromyalgia.