Sumatriptan can alleviate headaches due to carotid artery dissection

Cluster headaches can be mimicked by a spontaneous carotid artery dissectio n. We report a 45-year-old man with a spontaneous carotid artery dissection whose unilateral headache responded to sumatriptan. An oral dose of 50 mg of sumatriptan relieved 90% of the pain after 2 hours. A second dose the ne xt day achieved similar results within 4 hours. The diagnosis of dissection was made later by magnetic resonance angiogram and conventional angiograph y. This case illustrates that a positive response to a triptan can not he u sed to distinguish tile first attack of cluster headache from a carotid art ery dissection.