First recognized in 1867, cluster headaches remain one of the
most painful and frustrating headache syndromes. Their cause is
unclear, and no treatment is fully effective. People with
cluster headaches may go for more than a year without any
attacks, and then suddenly the headaches appear and strike
several times a day. Each headache lasts from 30 minutes to 2
hours and consists of very severe pain on one side of the head,
generally in the region of the eye. These daily headaches
continue for 4 to 8 weeks, and then disappear for another year
or more. A more chronic, continuous form of cluster headaches
can also occur. Cluster headaches are different from migraine
headaches (although they may possess some underlying
similarities) and much more difficult to treat. During cluster
headache episodes, rapid-acting treatments are used, including
aerosolized ergotamine, pure oxygen, lidocaine nasal spray, and
anesthetic inhalation. For prevention, drugs such as ergotamine,
prednisone, methysergide, and lithium may re