Sleep, daytime symptoms, and cognitive performance in patients with fibromyalgia

OBJECTIVE: To assess sleep, daytime symptoms, and cognitive performance in patients with fibromyalgia (FM). METHODS: Ten female patients with FM (mean age 32 yrs) and a matched, noncomplaintive comparison group (n = 9; mean age 30 yrs) spent 2 nights in the sleep laboratory. After the 2nd night, subjects completed a computerized 20 min battery of self-assessment and performance tests at hourly intervals from 07:00 to 20:00 h. RESULTS: Patients with FM spent more time in stage 1 sleep; however, there were no group differences on any other sleep measures. They reported greater sleepiness, more fatigue, more pain, more negative mood, and lower accuracy on performance tasks across a 14 h day. The FM group was slower in speed, but not impaired in accuracy, on performance of complex tasks, i.e., grammatical reasoning, serial addition/subtraction, and a simulated multi-task office procedure. CONCLUSION: Patients with FM have diurnal impairment in speed of performance on complex cognitive tasks, which accompany light stage 1 electroencephalographic (EEG) sleep and their experience of diffuse pain and nonrestorative sleep symptoms of sleepiness, fatigue, and negative mood.