Chronic paroxysmal hemicrania and hemicrania continua responding to topiramate: two case reports.

Chronic paroxysmal hemicrania (CPH) is a rare primary headache syndrome, which is classified along with cluster headache and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing as a trigeminal autonomic cephalalgia (TACs). Hemicrania continua (HC) was previously classified as one of the TACs, but in the recent second classification of the International Headache Society this disorder was moved to the group of other primary headaches. Both CPH and HC are characterised by moderate to excruciating pain requiring pharmacological treatment; furthermore, both conditions are characterised by an absolute response to indomethacin, which represents one of the current diagnostic criteria for these two syndromes. Unfortunately, in about one-fourth of cases treatment with indomethacin may cause adverse events, mostly gastrointestinal. We report one subject with CPH and another with HC intolerant to indomethacin, who responded remarkably well to topiramate.