Cluster Headaches

What is a cluster headache?

Relative to other types of primary headache, cluster headaches are rare. The pain they produce is severe and tends to recur in the same way each time for individuals who experience cluster headaches.

Cluster headaches occur in groups, or clusters, and individual attacks last about one to three hours on average. The frequency of occurrence may range from every other day to multiple times a day. Cluster periods are followed by remissions that may last months or years. 

What are the symptoms of cluster headaches?

While symptoms may differ, the following are common symptoms of a cluster headache:

• Sudden onset of pain, generally around or behind the eye (retro-orbital)

• Pain builds to a peak in about 10 to 15 minutes

• Restlessness or agitation

• Red or watering eyes

• Nasal congestion

• Sweating on the forehead

• Eyelid drooping or swelling

The symptoms of a cluster headache may resemble other conditions or medical problems. Always see your doctor for a diagnosis.

Facts about cluster headaches:

• Males are affected more than females

• Headaches typically begin around age 30

• Heredity may influence cluster headaches

• The exact cause of cluster headaches is unknown

How are cluster headaches diagnosed?

According to the American Academy of Family Physicians (AAFP), cluster headaches are diagnosed by a reported history of a pattern of recurrent bouts of near-daily headache attacks lasting for days, weeks, or months. While not used routinely for diagnosis, positron emission tomographic (PET) scanning and functional magnetic resonance imaging (fMRI) are being used by researchers to help understand how cluster headaches are caused and how they affect the human body.

How are cluster headaches treated?

A two-pronged approach is necessary for treatment of cluster headaches: acute treatment and prevention. The first step is to stop or at least subdue an attack in progress. The AAFP recommends oxygen therapy through a face mask to help stop an acute attack.

A nasal spray called sumatriptan (Imitrex®) is also used to relieve the severe pain of a cluster headache. Sumatriptan is a selective serotonin receptor agonists - a medication that causes blood vessels in the brain to constrict, thereby relieving pain.

The second part of cluster headache treatment is to prevent recurrent attacks by using daily medication. There are numerous medications that are used to prevent cluster headache attacks, but only a few have been tested through randomized controlled clinical trials.

Medications that may be used to prevent cluster headaches include:

• Verapamil - a medication that relaxes blood vessels

• Prednisone - a steroid medication that reduces inflammation and swelling

• Ergotamine - a medication that works together with caffeine to prevent blood vessels in the head from expanding