Headache: Cluster Headaches

Cluster headaches are an uncommon headache type, occurring in only about 0.4% of the general population. Cluster headaches are five times more common in men than in women. The headaches can occur at any age, including childhood and adolescence (although they are rare in children younger than 10 years), but usually begin in the third or fourth decade of life. As the name denotes, this condition is marked by periods of recurrent headaches (one to eight a day) interspersed with periods of remission. In 90% of patients, the clusters occur episodically. In the remaining 10%, the clusters are chronic, with cluster periods lasting for more than 1 year without remission or with remission lasting less than 14 days.

Clinical Features

Cluster headaches are one sided and severe. The most common types of pain, in order of decreasing frequency, are orbital, retro-orbital, temporal, supraorbital, and infraorbital. The headache may alternate sides between cluster periods or, rarely, within the same period. The pain is described as constant, boring, pressing, burning, or stabbing, and about 30% of patients describe throbbing or pulsating pain. Cluster headaches have a rapid onset, with peak intensity in 5 to 10 minutes, and usually a short duration of 30 to 45 minutes, although a minority of patients may have pain persisting up to 3 hours (rarely longer). During attacks, most patients prefer to walk, sit, kneel, stand, or jog in place. Many find it difficult to lie down, and they feel restless and agitated.

Autonomic symptoms are present in over 97% of cases. Lacrimation and conjunctival injection are each present in about 80% of cases, and ipsilateral nasal congestion or clear drainage is present in 75%.⁴⁴ A partial Horner syndrome with a slight ipsilateral ptosis or miosis or a combination of both is present in about 65% of cases and, in some patients, may persist between attacks in later stages of the disorder. Increased forehead sweating may occur in some patients during attacks. Erythema of the eyelid or a circumscribed area of the face or forehead may be present. Nausea and sensitivity to light and noise accompany the headache in some patients. An aura, usually visual, occasionally precedes the headache. Small quantities of alcohol, nitroglycerin, and histamine can trigger attacks during cluster periods but not during remission.

Diagnostic Testing

Cluster headaches can usually be diagnosed on the basis of the clinical criteria alone. Neuroimaging, preferably MRI, may be considered in cases with the following features: a pattern of clusterlike headache that does not conform to the clinical criteria; onset of cluster headache after age 40; a progressive pattern of headaches; chronic cluster headache; and any focal neurologic deficit other than Horner syndrome.

Symptomatic or secondary cluster headache can result from head trauma or iatrogenic trauma (e.g., orbital enucleation or dental extraction). A variety of pathologic conditions have been associated with clusterlike headaches, including arteriovenous malformations, aneurysms, sphenoid sinusitis, parasellar tumors, upper cervical cord meningioma and infarction, subdural hematoma, cerebral metastases, and temporal arteritis. These headaches are usually atypical in their lack of periodicity or response to medications or their accompaniment with abnormal neurologic signs.