Cluster headache and trigeminal autonomic cephalalgias

Publisher Summary The term “trigeminal autonomic cephalalgias” (TACs) was introduced to delineate a group of primary headache syndromes characterized by short-lasting pain with unilateral trigeminal distribution, associated with ipsilateral cranial autonomic symptoms. These forms include cluster headache (CH), paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), and probable TAC. The etiology of these syndromes is largely unknown, notwithstanding the quite high number of investigations performed, at least in the case of CH. The lack of specific animal models for TACs and their rarity have probably contributed to hampering the process of understanding their underlying mechanisms. If pathophysiological knowledge of TACs is far from satisfactory, the treatment of these conditions emerges as even more challenging. In the case of CH, only a few options are available for prophylactic treatment, with a rate of success that varies between and within subjects. With regard to symptomatic treatment, subcutaneous sumatriptan is very effective, but it has limitations in the daily frequency of intake and it is contraindicated when hypertension or other cardiovascular disorders are present.