A structural representation of migraine diagnostic criteria: The experts' view

Objective.-To generate an empirically derived structural representation of migraine diagnostic criteria in a group of international headache experts using the Pathfinder network scaling algorithm in order to evaluate the validity of the migraine criteria used in the International Headache Society (IHS) classification system. Background.-Because it is a disease entity that lacks objective defining markers, developing valid diagnostic criteria for migraine is a challenge. The IHS committee relied on expert consensus to develop their classification system in 1988. Expert consensus also was used to evaluate the validity of the IHS classification system, but further studies employing alternative methods still are needed. Methods.-Headache experts representing the Executive Committee of the IHS and the Board of Directors of the American Headache Society analyzed 14 criteria (7 IHS and 7 non-IHS) considered relevant in diagnosing migraine. Their ratings were submitted to the Pathfinder algorithm to generate a network structure reflecting the experts' conceptualization of migraine diagnostic criteria. Results.-The expert network had 3 groupings: headache characteristics (eg, phonophobia, unilateral pain, throbbing pain), biological contributing factors (eg, family history, hormonal relationship, relief with sleep), and triggering factors (eg, worse with stress, food triggers). The IHS criteria were clustered together in the center portion of the network. A t test showed that each IHS criterion was closer conceptually to other IHS criteria than to non-IHS criteria. Graph theory indices revealed that the most central criteria were unilateral pain, moderate/severe intensity, and nausea/vomiting. Conclusion.-The structural representation of migraine diagnostic criteria from these international headache experts is consistent with the migraine diagnostic criteria set forth in the IHS classification system and thus provides further support for the validity of migraine criteria in the IHS system.