Journal: The American Journal of the Medical Sciences. 2007 Feb;333(2):78-84.
Authors and affiliation: Van Hoof E, De Becker P, Lapp C, Cluydts R, De Meirleir K. Department of Human Physiology (Van Hoof, De Becker, Cluydts) and Department of Psychology (Van Hoof, Cluydts), Vrije Universiteit, Brussels, Belgium; Hunter-Hopkins Center, Charlotte, North Carolina, USA (Lapp).
Background: Patients with Chronic Fatigue Syndrome (CFS) present a disordered sleep pattern and frequently undergo polysomnography to exclude a primary sleep disorder.
Such studies have shown reduced sleep efficiency, a reduction of deep sleep, prolonged sleep initiation, and alpha-wave intrusion during deep sleep.
Deregulation of the 2-5A synthetase/RNase L antiviral pathway and a potential acquired channelopathy are also found in a subset of CFS patients and could lead to sleep disturbances.
[RNase L has been defined as “part of the body's innate immune defense, namely the antiviral state of the cell." Elevated RNase L activation is found in a subset of CFS patients.]
This article compiles a large sleep study database on CFS patients and correlates these data with a limited number of immune parameters as it has been thought that RNase L could be associated with these sleep disturbances.
Methods: Forty-eight patients who fulfilled 1994 Centers for Disease Control and Prevention criteria for CFS underwent extensive medical evaluation, routine laboratory testing, and a structured psychiatric interview. Subjects then completed a complaint checklist and a two-night polysomnographic investigation. RNase L analysis was performed by gel electrophoresis using a radiolabeled 2',5'-oligoadenylate trimer. Basic descriptive statistical parameters were calculated.
Results: Patients experienced a prolonged sleep latency, showed a low sleep efficiency index, and had a low percentage of slow wave sleep. The present alpha-delta intrusion correlated with anxiety; no correlations appeared, however, between alpha-delta sleep and immunologic parameters, including RNase L. Conclusions: The main findings are:
- Validation of sleep latency problems and other sleep disturbances as already suggested by several authors;
- Alpha-delta intrusion seems associated with anxiety; and
- Elevated RNase L did not correlate with alpha-delta sleep.