Cluster Headaches - The Basics

Patient Expert

Cluster headaches are often said to be the most painful of all headaches. They have been described as "boring," bearing, burning," "like a hot poker in the eye," and as "suicide headaches." The age of onset of cluster headaches is most often between the ages of 20 and 40, and they are more common in men than women at a ratio of 2.1. For many years, that ratio was stated to be 3:1. Researchers theorize that women have long been misdiagnosed because cluster headaches were thought to be so predominantly found in men.

Several terms have previously been used to refer to cluster headaches: ciliary neuralgia, erythro-melalgia of the head, erythroprosopalgia of Bing, hemicrania angioparalytica, hemicrania neuralgiformis chronica, histaminic cephalalgia, Horton's headache, Harris-Horton's disease, migrainous neuralgia (of Harris), petrosal neuralgia (of Gardner).

Cluster headache symptoms:

Cluster headaches are attacks of severe pain lasting 15-180 minutes and occurring from once every other day up to eight times in one day.

The pain is:

  • severe

  • unilateral

  • orbital (near the orbit, the bone framing the eye), supraorbital (above the orbit), temporal (at the tempe), or a combination of those sites.

These attacks also include one or more of these symptoms ipsilaterally (on the same side as the pain):

  • conjunctival injection (forcing of fluid into the conjuctiva, the mucous membrane that lines the eyelids)

  • eyelid edema (swelling)

  • forehead and facial sweating

  • lacrimation (tearing)

  • miosis (abnormal contraction of the pupils)

  • nasal congestion

  • rhinorrhea (runny nose)

  • ptosis (drooping eyelid)

Most cluster headache patients are restless or agitated during attacks and find it hard to be still. Cluster sufferers characteristically pace the floor during an attack.

Cluster headaches are diagnosed as "episodic" when the attacks occur in periods lasting 7 days to 1 year separated by pain-free periods lasting 1 month or longer. In "chronic" cluster headaches, attacks occur for more than 1 year without remission or with remissions lasting less than 1 month.

The term cluster headaches comes from the attacks usually occur in series (cluster periods) lasting for weeks or months separated by remission periods usually lasting months or years. However, about 10-15% of patients have chronic symptoms without remissions.

There are no diagnostic tests to confirm cluster headaches. Diagnosis is accomplished by reviewing the patient's personal and family medical history, studying their symptoms, and conducting an examination. Cluster headache is then diagnosed by ruling out other causes for the symptoms.

Treatment of cluster headaches:

Acute treatment: The most commonly used therapies to shorten or abort a cluster attack are:

• 100% oxygen administered by mask

• sumatriptan (Imitrex, Imigran) nasal spray or subcutaneous injection

• DHE-45

The most commonly used preventive medications are:


• lithium

• divalproex sodium (Depakote, Depakote ER)

• topiramate (Topamax)

• melatonin

In the International Headache Society's International Classification of Headache Disorders, 2nd Edition (ICHD-II), cluster headache is described as,

"Attacks of severe, strictly unilateral pain which is orbital, supraorbital, temporal or in any combination of these sites, lasting 15-180 minutes and occurring from once every other day to 8 times a day. The attacks are associated with one or more of the following, all of which are ipsilateral: conjunctival injection, lacrimation, nasal congestion, rhinorrhoea, forehead and facial sweating, miosis, ptosis, eyelid oedema. Most patients are restless or agitated during an attack."

The diagnostic criteria for cluster headaches under ICHD-II are:

  1. At least 5 attacks fulfilling criteria B-D
  1. Severe or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15-180 minutes if untreated
  1. Headache is accompanied by at least one of the following:
1.  ipsilateral conjunctival injection and/or lacrimation
  1. ipsilateral nasal congestion and/or rhinorrhoea
  1. ipsilateral eyelid oedema
  1. ipsilateral forehead and facial sweating
  1. ipsilateral miosis and/or ptosis
  1. a sense of restlessness or agitation
  1. Attacks have a frequency from one every other day to 8 per day

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"The International Classification of Headache Disorders, 2nd Edition." Cephalalgia 24 (s1). doi: 10.1111/j. 1468-2982.2003.00824.x

Stephen D. Silberstein, MD; Alan Stiles, DMD; William B Young, MD; Todd D. Rozen, MD. "An Atlas of Headache." Parthenon Publishing, 2002.

Randolph W. Evans, Nina T. Mathew. "Handbook of Headache, Second Edition." Philadelphia: Lipincott Williams & Wilkins. 2005.

Young, William B., MD; Silberstein, Stephen D., MD. "Migraine and Other Headaches." Ney York: AAN Press. 2004.

Stephen D. Silberstein, MD, Richard B. Lipton, MD, and Donald J. Dalessio, MD. "Wolff's Headache and Other Head Pain," seventh edition. Oxford University Press, 2001.

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