Defining refractory migraine and refractory chronic migraine: proposed criteria from the Refractory Headache Special Interest Section of the American Headache Society.

Certain migraines are labeled as refractory, but the entity lacks a well-accepted operational definition. This article summarizes the results of a survey sent to American Headache Society members to evaluate interest in a definition for RM and what were considered necessary criteria. Review of the literature, collaborative discussions and results of the survey contributed to the proposed definition for RM.