title: Defining the occurrence and influence of alpha-delta sleep in chronic fatigue syndrome.
abstract: 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.
  
  
  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 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.
authors.affiliation: Department of Human Physiology, Vrije Universiteit, Brussels, Belgium. Van.Hoof@vub.ac.be
authors.forename: Elke
authors.initials: E
authors.lastname: Van Hoof
authors.forename: Pascale
authors.initials: P
authors.lastname: De Becker
authors.forename: Charles
authors.initials: C
authors.lastname: Lapp
authors.forename: Raymond
authors.initials: R
authors.lastname: Cluydts
authors.forename: Kenny
authors.initials: K
authors.lastname: De Meirleir
mesh_terms: D000328:Adult; D000368:Aged; D000513:Alpha Rhythm; D015703:Antigens, CD / Q000032:analysis; D001007:Anxiety / Q000150:complications / Q000175:diagnosis*; D003700:Delta Rhythm; D004722:Endoribonucleases / Q000032:analysis; D015673:Fatigue Syndrome, Chronic / Q000150:complications* / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012894:Sleep Stages; D012893:Sleep Wake Disorders / Q000150:complications / Q000175:diagnosis*
chemical_list: D015703:Antigens, CD; D004722:Endoribonucleases; C031956:2-5A-dependent ribonuclease