Coexisting trigeminal autonomic cephalalgias and hemicrania continua.

The trigeminal autonomic cephalalgias (TACs) and hemicrania continua (HC) share many clinical characteristics including unilateral pain and ipsilateral autonomic features. We report a patient with a history of migraine without aura who developed cluster headache and HC simultaneously. The distinctive clinical features and differential response profiles to various treatments indicates that they are distinct disorders. We then review previous reports of patients with coexisting TACs and HC and discuss the relationship between these families of primary headache disorders.