ROME—In 1988, the International Headache Society drew up the International Classification and Diagnostic Criteria for Headache Disorders, a guideline that has been widely followed around the world. But headache research has since progressed, and there is now more opportunity than ever to ground classifications on evidence-based medicine. The result: the revised edition of the International Classification of Headache Disorders (ICHD-II), published as a 150-page supplement to the December Cephalalgia, and announced at the 11th Congress of the International Headache Society.

A PRODUCT OF EXPERIENCE

The ICHD-II has been under development by an international committee since 1999. It includes some important changes from the original guidelines, said committee chairman Jes Olesen, MD, PhD, Professor and Chairman of the Department of Neurology at Glostrup Hospital, University of Copenhagen, in Glostrup, Denmark. But at the same time, the basic format is unchanged, as are “the most important criteria—those for migraine without aura and for tension-type headache,” he said.

The ICHD-II is divided into three parts: the first concerns primary headaches, the second is devoted to secondary headaches, and the third addresses “cranial neuralgias, central and primary facial pain, and other headaches.” The text also includes references to the studies that helped determine new headache classifications, and there are plans to develop a slide kit to accompany the ICHD-II.

THE NEW FACE OF HEADACHE

Dr. Olesen noted that several new entities have been added to the ICHD-II, such as a separate classification for people who have migraines 15 or more days per month, a new chapter on patients presenting with concomitant headache and psychiatric disorder, and another on homeostatic disorders associated with headaches. There are also more exact definitions of primary versus secondary headaches, he said, and the definition of migraine with aura now includes visual changes that can be reversed, as well as speech symptoms.

Despite these advances and refinements, there are some indications that everything is still not totally clear-cut within the new classifications. For example, there is a designation “probable migraine” for patients whose symptoms do not fall into any exact classification. Such gaps in knowledge, Dr. Olesen pointed out, represent opportunities for future research.

AN INTERNATIONAL SCOPE

In introducing the ICHD-II, Dr. Olesen asserted that it was important to have general definitions of headaches that can be accepted throughout the world. “This is particularly true for headache as a young and developing field, and because there is so much prejudice against headache disorders,” he added, concluding with the hope that the ICHD-II “will be received favorably throughout the world and that it will be translated into even more languages than the first edition.”

NR

—Jean McCann

Suggested Reading
Headache Classification Subcommittee of the International Headache Society. The International Classification of Headache Disorders, 2nd Edition. Cephalalgia. 2004;24 (suppl 1):1-150.

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