Diagnosis of Trigeminal Autonomic Cephalalgias

Abstract

The trigeminal autonomic cephalalgias (TACs) are defined by several important characteristics. They are all short-lived headaches (except for hemicrania continua, HC) and tend to be severe in intensity. The TACs share a common site of origin in the hypothalamus, but an initial thorough workup for posterior fossa or pituitary pathology is warranted before making the diagnosis of these primary headache disorders. Many of the entities in two groups, the TACs and the other primary headache disorders—with important exceptions—respond to indomethacin; in fact, some of the headaches should be absolutely responsive to indomethacin. TACs often demonstrate ipsilateral parasympathetic hyperactivity and/or sympathetic hypoactivity.

Among the TACs are the indomethacin-sensitive hemicranias, either paroxysmal or chronic depending on the presence, or not, of a full month of remission, and the less common indomethacin-insensitive TACs. The recently introduced third edition of the International Classification of Headache Disorders (ICHD-3) includes new additions to the TACs. HC, the iconic indomethacin-sensitive headache disorder, is now classified as a TAC. The extremely rare short-lasting unilateral neuralgiform headache with conjunctival tearing and injection (SUNCT) and short-lasting unilateral headaches with cranial autonomic symptoms (SUNA) are now included together under the new term, short-lasting unilateral neuralgiform headache attacks (SUNHA). Included with the indomethacin-insensitive headaches in TACs is cluster headache (CH).