CHAPTER 11 CLUSTER HEADACHE
1. What is a cluster headache?
The Second Edition of the International Classification of Headache Disorders (ICHD II) defines five clinical criteria for cluster headache (Box 11-1).
Box 11-1 ICHD DIAGNOSTIC CRITERIA FOR CLUSTER HEADACHE
(A) At least five attacks fulfilling B-D
(B) Severe or very unilateral orbital, supraorbital, and/or temporal pain lasting 15 to 180 minutes if untreated1
(C) Headache is accompanied by at least one of the following signs, which have to be present on the pain side:
(D) Attacks have a frequency from one every other day to 8 per day2
ICHD = International Classification of Headache Disorders.
1 During part (but less than half) of the time-course of cluster headache, attacks may be less severe and/or of shorter or longer duration.
2 During part (but less than half) of the time-course of cluster headache, attacks may be less frequent.
3 History and physical and neurologic examinations do not suggest any of the disorders listed in groups 5 to 12, or history and/or physical and/or neurologic examinations do suggest such disorder, but it is ruled out by appropriate investigations, or such disorder is present, but attacks do not occur for the first time in close temporal relation to the disorder.