SLEEP ANOMALIES IN THE CHRONIC-FATIGUE-SYNDROME - A COMORBIDITY STUDY

Polysomnographic findings were compared between a group of patients wi th the chronic fatigue syndrome (CFS; n = 49) and a matched healthy co ntrol (HC) group (n = 20). Sleep initiation and sleep maintenance dist urbances were observed in the CFS group. The percentage of stage 4 was significantly lower in the CFS group. A discriminant analysis allowed a high level of correct classification of CFS subjects and HC. Sleep- onset latency and the number of stage shifts/hour contributed signific antly to the discriminant function. The presence of these anomalies as well as the decrease in stage 4 sleep were not limited to the patient s also diagnosed with fibromyalgia or with a psychiatric disorder. No association was found between sleep disorders and the degree of functi onal status impairment. The mean REM latency and the percentage of sub jects with a shortened REM latency were similar in CFS and HC.