There are two basic approaches to treating cluster headache. One is prophylactic or preventive medication to prevent attacks, and the other is abortive medication to stop an attack underway.
Abortive treatment of cluster headache can be difficult because the headache is sudden and relatively brief. Oral medication may take 30 to 45 minutes to take effect, by which time the attack may be nearly over. Ergotamine in sublingual or suppository form can be helpful. Dihydroergotamine (DHE) given by intramuscular or subcutaneous injection is also useful for controlling a cluster headache episode.
Oxygen is perhaps the most successful abortive treatment currently available. When administered with a facial mask at 7-10 liters a minute for 15 minutes, it is effective in up to 80% of cases. It is recommended that patients sit with the head forward during oxygen administration. The local anesthetic lidocaine has also been reported to be successful when administered nasally in a 4% solution. Patients who experience nasal congestion with a cluster attack may benefit from using decongestant nose drops just prior to the lidocaine.
Sumatriptan has been shown to be quite effective in the treatment of cluster headache, although the FDA has not yet approved this use. Given the frequency of headaches during a cluster period, the cost of sumatriptan may be a significant disadvantage for many cluster headache patients.
Preventive therapy is the mainstay in treatment of cluster headache. Patients with episodic cluster headache need preventive drugs only during the cluster period, while patients in the chronic subgroup stay on their medication indefinitely. For most sufferers, a single or combination drug therapy can be found that will keep the headaches from occurring altogether. Ergotamine can be taken twice daily to prevent the headaches. A related drug, methysergide, is also effective, but must be discontinued every six months for a “drug holiday” to avoid long-term side effects. Lithium is also effective in preventing cluster headache, particularly the chronic variety. However, lithium therapy requires careful monitoring because the therapeutic dose range is narrow and higher doses have toxic effects.
Verapamil, a calcium channel blocker, is perhaps one of the more acceptable drugs in terms of side effects. Doses need to be somewhat higher than those usually prescribed for hypertension in order to be effective. Corticosteroids can also be used to prevent cluster headache and have been shown to abort a cluster period when given in high doses for brief periods of time. The chronic use of corticosteroids is not advisable in view of the many side effects of these drugs. Many physicians prefer to prescribe a short 7-10 day course of corticosteroids, followed by verapamil if the headaches persist. More recently, sodium valproate, an anticonvulsant drug, has been used to prevent cluster headache. This drug also requires careful monitoring, but it provides an alternative that is beneficial for some patients. These various medications may also be used in combination if no single agent proves effective.
If all drugs fail, the option of surgery can be considered for chronic cluster headache patients who are very disabled by their condition. In a procedure known as radiofrequency trigeminal neurotomy, radiofrequency waves are used to destroy the pain-carrying fibers of the trigeminal nerve. Most patients who undergo this procedure have good relief from pain. Because these patients lose all sensation of pain (not of touch) in the cornea of the eye, good eye care is essential and there is increased risk of injury to the eye. For this reason, the procedure is reserved for severe cases that do not respond to other treatment.
(Jack A. Klapper, M.D., Colorado Neurology and Headache Center, Denver, Colorado)