title: Sleep apnea in patients with cluster headache: a case-control study.
abstract: OBJECTIVE
  Polysomnographic investigations have shown an unspecific association between cluster headache and obstructive sleep apnea syndrome. The aim of this study was to investigate this association in a cluster episode compared with a symptom free interval, and to further characterize this association.
  
  
  METHODS
  We investigated 42 patients with episodic (n = 26) or chronic (n = 16) cluster headache by means of polygraphic screening for sleep apnea and compared the data to 28 healthy control subjects matched according to age, sex, and BMI. The patients with episodic cluster headache were screened twice, once in a cluster episode and once in a symptom free interval.
  
  
  RESULTS
  Patients with active cluster headache showed a significantly higher respiratory distress index (8.6 ± 16.0) compared with healthy control subjects (3.4 ± 2.1; p = 0.002). More patients fulfilled the criteria for an obstructive sleep apnea syndrome (29%) than control subjects (7%; p = 0.018). Patients only, but not the control subjects, had central apneas. These differences were only significant when measured during an active cluster episode but not during a symptom free interval.
  
  
  CONCLUSIONS
  Cluster headache is associated with a sleep apnea syndrome only in the active cluster episode. The increased rate of central apneas might be a result of involvement of the hypothalamus in the pathophysiology of cluster headache. Out of five anecdotal cases treated with nasal continuous positive airway pressure, only one patient showed benefit with respect to cluster headache attack frequency.
authors.affiliation: Department of Neurology, University of Münster, Germany Department of Neurology, Krankenhaus Lindenbrunn, Germany everss@uni-muenster.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Evers
authors.affiliation: Department of Neurology, University of Münster, Germany.
authors.forename: Birke
authors.initials: B
authors.lastname: Barth
authors.affiliation: Department of Neurology, University of Münster, Germany Akademie für Manuelle Medizin, Münster, Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Frese
authors.affiliation: Department of Neurology, University of Münster, Germany.
authors.forename: Ingo-W
authors.initials: IW
authors.lastname: Husstedt
authors.affiliation: Department of Neurology, Klinik Maria Frieden, Telgte, Germany.
authors.forename: Svenja
authors.initials: S
authors.lastname: Happe
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003027:Cluster Headache / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012891:Sleep Apnea Syndromes / Q000150:complications* / Q000503:physiopathology
keywords: Cluster headache; central sleep apnea; continuous positive airway pressure treatment; obstructive sleep apnea syndrome