Cluster headache (CH) comprises the most frequent trigeminal-autonomic headache syndrome and has a mean prevalence of 0,1% . The designation highlights its typical pattern, in which each attack (a single episode of headache) occurs in clusters or bouts of variable duration, with a circadian and circannual rhythmicity [1, 2].
Despite being an excruciating headache, little is known about the burden of cluster headache (CH) regarding its various subtypes. In a multicentre, prospective study, patients with chronic CH (n¼27), with episodic CH in the active (n¼26) and outside the active period (n¼22), migraine patients (n¼24) and healthy controls (n¼31) were included
Data on clinical differences between episodic (eCH) and chronic cluster headache (cCH) and accompanying migraine features are limited. History and clinical features of 209 consecutive cluster headache patients (144 eCH, 65 cCH; male:female ratio 3.4 : 1) were obtained in a tertiary headache centre by face-to-face interviews. Relationship between occurrence of accompanying symptoms, pain intensity, comorbid migraine, and circannual and circadian rhythmicity was analyzed.