difficulty in initiating and maintaining sleep

Abstract:

Polysomnographic findings were compared between a group of patients with the chronic fatigue syndrome (CFS; n = 49) and a matched healthy control (HC) group (n = 20).

Sleep initiation and sleep maintenance disturbances 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 significantly to the discriminant function.

The presence of these anomalies as well as the decrease in stage 4 sleep were not limited to the patients also diagnosed with fibromyalgia or with a psychiatric disorder. No association was found between sleep disorders and the degree of functional status impairment. The mean REM latency and the percentage of subjects with a shortened REM latency were similar in CFS and HC.

Source: Fischler B, Le Bon O, Hoffmann G, Cluydts R, Kaufman L, De Meirleir K. Sleep anomalies in the chronic fatigue syndrome. A comorbidity study. Neuropsychobiology. 1997;35(3):115-22. http://www.ncbi.nlm.nih.gov/pubmed/9170115

Abstract:

OBJECTIVE: To determine whether patients with the chronic fatigue syndrome have abnormalities of sleep which may contribute to daytime fatigue.

DESIGN: A case-control study of the sleep of patients with the chronic fatigue syndrome and that of healthy volunteers.

SETTING: An infectious disease outpatient clinic and subjects’ homes.

SUBJECTS: 12 patients who met research criteria for the chronic fatigue syndrome but not for major depressive disorder and 12 healthy controls matched for age, sex, and weight.

MAIN OUTCOME MEASURES: Subjective reports of sleep from patients’ diaries and measurement of sleep patterns by polysomnography. Subjects’ anxiety, depression, and functional impairment were assessed by interview.

RESULTS: Patients with the chronic fatigue syndrome spent more time in bed than controls (544 min v 465 min, p < 0.001) but slept less efficiently (90% v 96%, p < 0.05) and spent more time awake after initially going to sleep (31.9 min v 16.6 min, p < 0.05). Seven patients with the chronic fatigue syndrome had a sleep disorder (four had difficulty maintaining sleep, one had difficulty getting to sleep, one had difficulty in both initiating and maintaining sleep, and one had hypersomnia) compared with none of the controls (p = 0.003). Those with sleep disorders showed greater functional impairment than the remaining five patients (score on general health survey 50.4% v 70.4%, p < 0.05), but their psychiatric scores were not significantly different.

CONCLUSIONS: Most patients with the chronic fatigue syndrome had sleep disorders, which are likely to contribute to daytime fatigue. Sleep disorders may be important in the aetiology of the syndrome.

Source: Morriss R, Sharpe M, Sharpley AL, Cowen PJ, Hawton K, Morris J. Abnormalities of sleep in patients with the chronic fatigue syndrome. BMJ. 1993 May 1;306(6886):1161-4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1677618/ (Full article)