Refractory migraine - a review.

Refractory migraine has long been a challenge to all headache specialists. This subgroup of migraine patients experience disability and impaired quality of life, despite optimal treatment. This article reviews the proposed definitions and epidemiology of refractory migraine, as well as the pathophysiology that may contribute to the genesis of this disorder. Aspects of treatment, including pharmacological, complementary/adjunct, and invasive approaches, are reviewed. Comorbid factors, medication overuse, potential pitfalls to treatment, and areas for future investigation are highlighted.