title: Ten years of chronic cluster--attacks still cluster.
abstract: The chronic variant can be found in 10-20% of all cluster headache patients. While circadian and circannual rhythmicity are characteristic of the episodic variant, little is known on chronobiology in chronic cluster headache. We report a patient with chronic cluster evolved from episodic who recorded a total of 5447 attacks over 10 years. After spectral analysis, cosinor models were calculated within the frequency ranges of 23-25 h (circadian) and 11-13 months (circannual), respectively. Significant results (P < 0.01) were found for 24-h periods, but not for circannual intervals (12 months). However, with regard to circannual periodicity, a semi-circannual rhythm (5-7 months) was suitable for curve fit and yielded significant results in the cosinor analysis at 6 months (P < 0.05). This remarkable long observation period of 10 years shows that, at least for secondary chronic cluster headache which evolved from the episodic form, a typical circadian and circannual rhythmicity comparable to that of episodic cluster headache exists.
authors: Department of Systems Neuroscience, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany. t.juergens@uke.de
authors: Tim P
authors: TP
authors: Jürgens
authors: Horst J
authors: HJ
authors: Koch
authors: Arne
authors: A
authors: May
mesh_terms: D000368:Aged; D002909:Chronobiology Phenomena / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D003027:Cluster Headache / Q000188:drug therapy / Q000503:physiopathology* / Q000517:prevention & control; D006801:Humans; D008297:Male; D012621:Seasons; D014662:Vasoconstrictor Agents / Q000627:therapeutic use
chemical_list: D014662:Vasoconstrictor Agents