[Note: alpha-delta sleep is deep, slow-wave sleep.]
Journal: The American Journal of the Medical Sciences. 2007 Feb;333(2):78-84
Authors and affiliations: Elke Van Hoof, PhD; Pascale De Becker, PhD; Charles Lapp, MD; Raymond Cluydts, PhD; Kenny De Meirleir, PhD. Department of Human Physiology (EVH, PDB, KDM); Department of Psychology (EVH, RC), Vrije Universiteit, Brussels, Belgium; Hunter-Hopkins Center, Charlotte, North Carolina (CL). [E-mail: Elke.Van.Hoof@vub.ac.be ]
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.
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.
1. Patients experienced a prolonged sleep latency, showed a low sleep efficiency index, and had a low percentage of slow wave sleep.
2. The present alpha-delta intrusion correlated with anxiety.
3. No correlations appeared, however, between alpha-delta sleep and immunologic parameters, including RNase L.
Conclusions. The main findings are:
1. Validation of sleep latency problems and other sleep disturbances as already suggested by several authors;
2. Alpha-delta intrusion seems associated with anxiety; and
3. Elevated RNase L did not correlate with alpha-delta sleep.
Keywords: alpha-delta sleep, median-split, anxiety, specificity, CFS.