OBJECTIVE: To determine whether patients with "pure" chronic fatigue
syndrome (neurasthenia) have sleep abnormalities which may
contribute to subjective measures of daytime fatigue.
Sleep characteristics of 20 patients meeting research criteria
for chronic fatigue syndrome (CFS) but not depression,
anxiety, or sleep disorder were compared with sleep
characteristics of 20 healthy subjects matched for age and
sex. Measures of sleep included a) subjective interview
reports and sleep diaries and b) home-based polysomnography.
RESULTS: Patients with CFS complained of poor quality
unrefreshing sleep. They also napped during the day.
Polysomnograph data showed no difference in actual nocturnal
sleep time between the two groups although patients with CFS
spent significantly longer in bed (p < .01), slept less
efficiently (p < .03), and spent longer awake after sleep
onset (p < .05). The polysomnographs of seven patients with
CFS and one healthy subject were regarded as significantly
abnormal. Five patients and one healthy subject had difficulty
maintaining sleep. One patient had a disorder of both
initiating and maintaining sleep and one patient woke early.
CONCLUSIONS: Patients with "pure" CFS complain of unrefreshing
sleep but only a minority have a clearly abnormal
polysomnograph. The most common abnormality is of long periods
spent awake after initial sleep onset. Although sleep
abnormalities may play a role in the etiology of CFS, they
seem to be unlikely to be an important cause of daytime
fatigue in the majority of patients. However, pharmacological
and behavioral methods that improve sleep quality may be an
important component of a pragmatically based treatment package
for patients who do have abnormal sleep.