Abstract
Objective: To describe a subgroup of patients with chronic fatigue in whom there is increased physiological sleep tendency.
Design: Prospective case series.
Setting and Patients: Fifty-six consecutive patients with a working diagnosis of chronic fatigue syndrome underwent a sleep interview, overnight polysomnography and a Multiple Sleep Latency Test in a regional Sleep Disorders Center.
Results: Of the 56 patients, 14 satisfied the current International Classification of Sleep Disorders criteria for the diagnosis of narcolepsy. Four of these patients had both excessive somnolence and clear-cut cataplexy and 10 pathological somnolence and polysomno-graphic criteria for narcolepsy. A further 35 had either increased daytime sleepiness, abnormal REM sleep regulation or both. Despite the objective evidence of daytime increased sleep tendency, the majority of the patients complained of fatigue and not of sleepiness. Twenty-nine patients were treated with either dexamphetamine or methylphenidate with good results in about half.
Conclusion: We conclude that among patients investigated for chronic fatigue syndrome it is possible to identify a subgroup with significant daytime sleepiness and REM sleep abnormalities. Symptomatic treatment of these patients is often rewarding.
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