Pain, fatigue, and sleep in eosinophilia-myalgia syndrome: relationship to neuropsychological performance

Cognitive problems are frequently reported in patients with eosinophilia-myalgia syndrome (EMS). This is the first study to explore, in EMS, the relationship between specific neuropsychological deficits and fatigue and pain. Relationships among depression, sleep disturbance, and neuropsychological deficits in EMS were also examined. Neither fatigue nor pain was correlated with memory impairment. Sleep disturbance was significantly correlated with verbal memory impairment, but not with deficits in visuospatial memory. These results suggest that cognitive loss in EMS cannot be attributed to pain or fatigue. Although some aspects of memory impairment may be associated with disturbed sleep, visual memory deficits are clearly independent of sleep deficits and may result from direct effects of the disease on the central nervous system.