Trigeminal Autonomic Cephalgias and Hemicrania Continua
The trigeminal autonomic cephalgias (TACs) include cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). The TACs are primary headache disorders characterized by short-lasting unilateral head pain that occurs with ipsilateral cranial autonomic findings. They can be difficult to treat and are best managed by neurologists.
Cluster headache is 3–4 times as common in men as in women. Although the typical age of onset is in the second and third decades of life, it can occur at any age and is typically precipitated by alcohol use. Cluster headache is characterized by excruciating bouts of pain lasting 15 minutes to 180 minutes and localized behind one eye in the distribution of the ophthalmic division of CN V (V1). Associated features include ipsilateral tearing, conjunctival injection, rhinorrhea, and transient (although it can become permanent) postganglionic Horner syndrome. The pain may wake the patient from sleep and cause restlessness. Headaches occur in clusters of episodes over days or weeks, typically beginning like clockwork at the same time of day, then remit for months or years, suggesting that the hypothalamus may play a role in the pathogenesis. Cluster headaches can be difficult to treat. Abortive drugs include subcutaneous or intranasal triptans, inhaled oxygen, dihydroergotamine, and intranasal lidocaine. Verapamil, lithium, methysergide, corticosteroids, topiramate, and gabapentin can be useful for prophylaxis.
Paroxysmal hemicrania is characterized by short, severe attacks of pain with cranial autonomic features that occur several times daily. The headache typically lasts between 2 minutes and 30 minutes but may persist for hours. A dramatic resolution of the headache occurs with indomethacin administration.
SUNCT is characterized by unilateral orbital or temporal pain that is severe and throbbing or stabbing. The headache typically occurs more than 20 times per day, lasts 5 seconds to 240 seconds, and is often associated with conjunctival injection and tearing.
Unlike the other TACs, hemicrania continua is characterized by a continuous unilateral headache of variable intensity that waxes and wanes without disappearing completely. The forehead, temple, orbit, and occiput are common sites of pain. Autonomic symptoms are present in most patients. This primary headache disorder is also responsive to treatment with indomethacin.
Excerpted from BCSC 2020-2021 series: Section 5 - Neuro-Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.