Cluster headache

Cluster headache is a neurological disorder characterized by episodes of severe headaches on one side of the head, typically around the eye and temple, lasting between 15 minutes to three hours. Episodes are often accompanied by eye watering, nasal congestion, drooping eyelids, or swelling around the eye on the affected side. Cluster headaches are unique in their periodicity and regularity: the headaches occur at around the same hour every day during a cluster period, which typically lasts 8–10 weeks a year. Between cluster periods are pain-free intervals without headaches, which last a little less than one year, but some patients can have chronic cluster headaches without remission periods. The disease is considered among the most painful conditions known to medical science.

Triggers of cluster headaches may include alcohol, nitroglycerin, and histamine; a history of exposure to tobacco smoke (whether personal or secondhand smoke) is a significant risk factor. The underlying cause is unknown, but may include a genetic component, as a family history of migraines increases risk. Structurally, the disease is likely related to dysfunction of the posterior hypothalamus.

The diagnosis is based on the unique pattern of headaches and associated symptoms. There are no specific laboratory tests, physical exam maneuvers, or neuroimaging findings associated with the disease. However, neuroimaging may be required in the case of patients with red flag symptoms, such as a sudden change in the characteristics of the headache.

Recommended management includes lifestyle adaptations, including smoking cessation and avoiding potential triggers. Medical treatments for acute attacks include oxygen or a fast-acting triptan. Preventative medications recommended to decrease the frequency of attacks include steroid injections, galcanezumab, civamide, verapamil, or oral glucocorticoids such as prednisone. Nerve stimulation or surgery may occasionally be used if other measures are not effective.

The condition affects about 0.1% of the general population at some point in their life and 0.05% in any given year. The condition usually first occurs between 20 and 40 years of age. Men are affected about four times more often than women. These debilitating headaches significantly impact daily activities, and due to the severity of the pain, they have also been referred to as "suicide headaches".