A revised classification of headache disorders

Regular updates are still necessary

For many years the classification of headache syndromes, and particularly of those conditions without supporting diagnostic tests such as migraine and cluster headache, was a quagmire of vague descriptions that often proved inconsistent or overlapping. The hierarchical classification published in 1988 under the auspices of the International Headache Society proved to be an enormous advance, transforming studies of the epidemiology of headache and also clarifying the recruitment of patients for experimental and therapeutic studies, and particularly for the large trials of each of the triptan drugs.1 Why has a new classification been considered necessary?2

On the publication of the original classification in 1988 Jes Olesen, who chaired both the 1988 committee and the 2003 revision committee, acknowledged that the classification was likely to …