Sleep apnea in patients with cluster headache: A case-control study

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. Conclusion: 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.