Hemicrania Continua

Excerpt

Hemicrania continua is a primary headache disorder with a pathognomonic treatment response to indomethacin. The condition presents clinically with a baseline continuous unilateral headache for at least 3 months that intermittently exacerbates with associated autonomic features. Hemicrania continua was first described in 1981 by Medina and Diamond as a variant of cluster headache. The term hemicrania continua was first coined in 1984 by Sjaastad and Spierings.

Hemicrania continua falls under the category of trigeminal autonomic cephalalgias in the 3rd edition of the International Classification of Headache Disorders (ICHD-3). The main features of trigeminal autonomic cephalalgias are unilateral headaches, occurring mainly in the area innervated by the trigeminal nerve's ophthalmic division, associated with a variable combination of autonomic symptoms, reflecting increased parasympathetic and decreased sympathetic activities. Other trigeminal autonomic cephalalgias include cluster headache, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA), and short-lasting, unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT).