Cluster headache is recognized by the International Headache Society as a primary headache disorder, consisting of seasonal and daily attacks of severe unilateral periorbital pain accompanied by autonomic symptoms. As with other primary headache disorders, intracranial lesions can rarely mimic cluster headaches, in particular if it presents in an atypical fashion. We report a patient with chronic cluster-like headache secondary to a clival based epidermoid cyst. This is the first such association reported in the literature.

A 39-year-old man with no significant past medical history and no current medications was referred with a three-year history of strictly right-sided headaches. Two to three times daily, he suffered attacks of excruciating pressure-like pain in the periorbital and frontal area on the right. These lasted between 10 and 90 minutes and occasionally woke him from sleep. Theywere always accompanied by numbness of the upper part of his face, increased lacrimation, rhinorrhea and ptosis on that side. Occasionally, he had nausea and vomiting as well. Since theonset of symptoms, attacks occurred almost daily and never remitted for more than four weeks. He tried methysergide, gabapentin, carbamazepine, lithium carbonate and corticosteroids without success. Later, his attacks have occasionally involved the left side.