Diagnose and adios: practical tips for the ongoing evaluation and care of TAC patients taking indomethacin

Cluster Headache and Other Trigeminal Autonomic Cephalalgias

PURPOSE OF REVIEW

This article covers the clinical features, differential diagnosis, and management of the trigeminal autonomic cephalalgias (TACs). The TACs are composed of five diseases: cluster headache, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA), and hemicrania continua.

RECENT FINDINGS

New classifications for the TACs have two important updates; chronic cluster headache is now defined as remission periods lasting less than 3 months (formerly less than 1 month), and hemicrania continua is now classified as a TAC (formerly classified as other primary headache). The first-line treatments of TACs have not changed in recent years: cluster headache is managed with oxygen, triptans, and verapamil; paroxysmal hemicrania and hemicrania continua are managed with indomethacin; and SUNCT and SUNA are managed with lamotrigine. However, advancements in neuromodulation have recently provided additional options for patients with cluster headache, which include noninvasive devices for abortive therapy and invasive devices for refractory cluster headache. Patient selection for these devices is key.

SUMMARY

The TACs are a group of diseases that appear similar to each other and to other headache disorders but have important differences. Proper diagnosis is crucial for proper treatment. This article reviews the pathophysiology, epidemiology, differential diagnosis, and treatment of the TACs.

Paroxysmal Hemicrania

Paroxysmal hemicrania (PH) is a primary headache disorder belonging to the group of trigeminal autonomic cephalalgias(TACs). Patients typically experience intense lateralzsed headaches with pain primarily in the ophthalmic trigeminal distribution (V1) associated with superimposed ipsilateral cranial autonomic features. PH is distinguished from other TACs by an exquisite responsiveness to therapeutic doses of indomethacin. Patients may need to be maintained on indomethacin for several months before trials of reduction can be attempted. The disorder does have a tendency toward chronicity. PH is uncommon, but early recognition will prompt initiation of effective treatment to avoid unsuccessful trials of drugs effective in other primary headaches. As with other TACs, hypothalamic and trigeminovascular mechanisms are implicated in the pathophysiologic mechanism of PH. Neuroimaging findings in PH demonstrate a posterior hypothalamic activation similar to that observed in the other TACs. This review will address the epidemiology, clinical presentation, pathophysiology, evaluation, and treatment of PH.