Cluster headache

Cluster headaches are rare headaches that occur in groups or clusters. Cluster headache sufferers typically experience very severe headaches of a piercing quality near one eye or temple that last for between 15 minutes and three hours. Cluster headaches are frequently associated with drooping eyelids, red, watery eyes, and nasal congestion on the affected side of the face. The headaches are unilateral and occasionally change sides. The neck is often stiff or tender in association with cluster headaches, and jaw and teeth pain is sometimes reported.

In episodic cluster headache, these headaches occur once or more daily, often at the same times each day, for a period of several weeks, followed by a headache-free period lasting weeks, months, or even years. Approximately 10-15% of cluster headache sufferers are chronic; they can experience multiple headaches every day for years. Cluster headaches are occasionally referred to as "alarm clock headaches", as they can occur at night and wake a person from sleep. Other synonyms for cluster headache include Horton's syndrome and "suicide headaches" (a reference to the excruciating pain and resulting desperation).

The location and type of pain has been compared to a 'brain-freeze' headache from rapidly eating ice cream; this analogy is limited, but may offer some insight into the cluster headache experience. Persons who have experienced both cluster headaches and other painful conditions (childbirth, migraines) report that the pain of cluster headaches is far worse. During a cluster headache attack, a person often alternates between pacing and laying still. Sensitivity to light is more typical of a migraine, as is vomiting, but they can be present in some sufferers of cluster headache.

Whereas other headaches, such as migraines occur more often in women, cluster headaches occur in men at a rate 2.5 to 3 times greater than in women. Between 1 and 4 people per thousand experience cluster headaches in the U.S. and Western Europe; statistics for other parts of the world are fragmentary. Latitude plays a role in the occurrence of cluster headaches, which are more common as one moves away from the equator towards the poles. It is believed that greater changes in day length are responsible for the increase.

While the immediate cause of pain is in the trigeminal nerve, the true cause(s) of cluster headache is complex and not fully understood. Among the most widely accepted theories is that cluster headaches are due to an abnormality in the hypothalamus. This can explain why cluster headaches frequently strike around the same time each day, and during a particular season, as one of the functions the hypothalamus performs is regulation of the biological clock. Certain immune dysfunctions and metabolic abnormalities have also been reported in patients. There is a genetic component to cluster headaches, although no single gene has been identified as the cause. As a group, cluster headache patients are more likely to have suffered brain trauma than the general population. Sinus problems, damage to the jaw, and sleep apnea are also more common in cluster headache patients, but these factors do not adequately explain the disease.

Treatment

Many doctors are unfamiliar with this disease, and cluster headaches often go undiagnosed for many years. Paroxysmal Hemicrania (PH) is a condition similar to cluster headache, but PH responds well to treatment with the anti-inflammatory drug indomethacin and the attacks are very much shorter, often lasting seconds only.

Medically, cluster headaches are considered benign, but because of the extreme and often debilitating pain associated with them, a severe attack is nevertheless treated as a medical emergency by doctors who are familiar with the condition. Doctors who are less familiar with the disease may neglect sufferers in emergency rooms and force them to endure inordinate spans of time before receiving treatment, if any treatment at all is granted. Sometimes, sufferers of the disease may even be accused of drug seeking behavior.

Even narcotics are mostly ineffective due to the intensity of the pain involved in cluster attacks. Anecdotal evidence indicates that cluster headaches, on occasion, can be so excruciating that even morphine does little to ease the pain. Usually, however, demerol is sufficient if used at the onset of pain.

Over the counter pain medications (such as aspirin, acetaminophen, and ibuprofen) have no effect on the pain from a cluster headache. Some have reported partial relief from narcotic pain killers, but the frequency of their use in a cluster cycle (1-3 times a day) often disqualifies them from use. However, some newer medications like fentanyl have shown great promise in early studies and use.

Medications to treat cluster headaches are classified as either abortives or prophylactics (preventatives). The most successful abortives include breathing pure oxygen (12-15 liters per minute in a non-rebreathing apparatus) and triptan drugs like sumatriptan and zolmitriptan. A wide variety of prophylactic medicines are in use, and patient response to these is highly variable. Preventitives include muscle relaxants, lithium, calcium channel blockers such as Verapimil, ergot compounds, anti-seizure medicines, and atypical anti-psychotics.

Magnesium supplements have been shown to be of some benefit in about 40% of patients. Melatonin has also been reported to help some. Hot showers have helped about 15% of people who try it. Feverfew, a herb used to treat migraine, is not clearly beneficial according to anecdotes from web forums.

There is substantial anecdotal evidence that psilocybin (mushrooms) and LSD may be able to abort cluster cycles. A clinical study under the auspices of MAPS is being developed at Harvard University.

Nitroglycerin (glyceryl trinitrate) can sometimes induce cluster headache similar to spontaneous attacks. Alcohol is recognized as a common trigger of cluster headaches when a person is in cycle or susceptible. Hydrocarbons (petroleum solvents, perfume) are also recognized as a trigger for cluster headaches. Many patients have a decreased tolerance to heat, and this may act as a trigger in some. The role of diet and specific foods in triggering cluster headaches is controversial and not well understood.

Some people with extreme headaches of this nature (especially if they are not unilateral) may actually have something else: an ictal headache. Anti-convulsant medications can significantly improve this condition, so make sure you talk with your doctor about this possibility if you think you might be affected.

See also

• Trigeminal neuralgia
• Headache
• Tension headaches
• Migraine
• Rebound headaches
• Chronic Paroxysmal Hemicrania

External links

• Clusterheadaches.com (http://www.clusterheadaches.com) The largest online support group for people with cluster headaches.
• O.U.C.H. (http://www.ouch.org) Organization for Understanding Cluster Headaches, a non-profit education and advocacy group
• WebMD (http://my.webmd.com/content/article/46/1826_50688.htm)
• Clusterbusters  (http://www.clusterbusters.com)
• Researching psylocibin to abort cluster cycles (http://www.maps.org/research/index.html#PSILOCYBIN)
• Diagnosis criteria (http://www.w-h-a.org/wha2/Newsite/resultsnav.asp?color=C2D9F2&idContentNews=751) from World Headache Aliancenl:Clusterhoofdpijn