Focus on therapy: hemicrania continua and new daily persistent headache.

Hemicrania continua (HC) and new daily-persistent headache (NDPH) represent the only two forms of chronic daily headache in Chap. IV "Other Primary Headaches" of the second edition of the International Classification of Headache Disorders. HC and NDPH are rare and poorly defined from a pathophysiological point of view; as a consequence, their management is largely empirical. Indeed, there is a lack of prospective, controlled trials in this field, and treatment effectiveness is basically inferred from the results of sparse open-label trials, retrospective case series, clinical experience and expert opinions. In this narrative review we have summarised the information collected from an extensive analysis of the literature on the treatment of HC and NDPH in order to provide the best available and up-to-date evidence for the management of these two rare forms of primary headache. Indomethacin is the mainstay of HC management. The reported effective dose of indomethacin ranges from 50 to 300 mg/day. Gabapentin 600-3,600 mg tid, topiramate 100 mg bid, and celecoxib 200-400 mg represent the most interesting alternative choices in the patients who do not tolerate indomethacin or who have contraindications to its use. NDPH is very difficult to treat and it responds poorly only to first-line options used for migraine or tension-type headache.