Hemicrania continua: clinical and nosographic update

Hemicrania continua (HC) is an uncommon primary headache syndrome. The main features of HC are: (i) strict unilaterality of the pain (moderate, fluctuating, relatively long-lasting); and (ii) absolute response to indomethacin. These two features may reflect the most reliable characteristics of the syndrome. Autonomic symptoms are not as prominent in HC as they are in cluster headache and chronic paroxysmal hemicrania, although they may exist. HC will be addressed in the 2003 revision of the International Headache Society (IHS). In this paper we review the clinical features, classification and treatment of HC.