Cluster headache (CH) is the most intense and extreme type of headache that exists. This headache is expressed in severe pain in one side of the head. It is a very intens pounding, sharp pain around the eye socket. The condition is fortunately very rare and not life-threatening. Cluster headache falls under the heading of ‘headache’.
The exact cause of cluster headache is unknown. Periods of frequent attacks, known as cluster periods, can last for weeks to months. These are followed by rest periods, during which the attacks of headache (even for months or years) completely disappear.
Attacks usually occur regularly during a day and the cycle of cluster periods is often seasonal. This indicates indirectly that the biological clock of humans is involved. The human biological clock is located in the hypothalamus, deep in the center of the brain. Defects of the hypothalamus may account for the timing and the cyclical nature of cluster headache. Studies have demonstrated an increased activity in the hypothalamus during an attack of cluster headache.
In contrast to migraine and tension headache, cluster headache is generally not associated with triggers, such as foods, hormonal changes or stress. However, once a cluster period begins, the consumption of alcohol can quickly lead to a splitting headache. Other possible triggers are the use of medicines, such as nitroglycerin.
The signs and symptoms of cluster headache are:
- A sharp headache in one side of the head, usually around the temple.
- Radiation of pain to the eye, above the ear, upper jaw and neck.
- Stuffy nose at the side of the pain.
- Red teary eye at the side of the pain.
- Reduction of the pupil at the side of the pain.
- Drooping eyelid at the side of the pain.
- Increased body temperature.
- Increased urge to move.
Cluster headache is divided into episodic cluster headache and chronic cluster headache. In episodic cluster headache, the cluster attacks occur during fixed cluster periods. Chronic cluster headache continues year round.
Cluster headache has a characteristic kind of pain and pattern of attacks. The diagnosis is dependent on the description of the attacks, the pain, the location, the frequency, the duration, the severity of the headache and the associated symptoms.
In addition, the following tests may be carried out:
- Neurological examination. This can help the doctor to determine the physical signs of the cluster headache. The pupil of the eye may sometimes appear smaller or the eyelid may sag, even between attacks.
- Brain imaging techniques. In order to exclude other serious causes of the headache (such as a tumor or aneurysm), a CT or MRI scan may be performed.
A treatment with oxygen will usually help well in an attack of cluster headache. In hospital, extra oxygen is administered for fifteen minutes. This is done through a tube in the nose or through a cap over the nose and mouth. The patient may also be enabled to administer oxygen by himself at home.
Another treatment is medication. These constrict the blood vessels in the brain and reduce the pain stimulus. This may help to prevent headache attacks during a cluster period. The medication is usually prescribed by the neurologist.
The effects of cluster headache are often very severe: memory and concentration problems, lack of understanding of the environment, social isolation and even disability. Cluster headache is a lifelong condition, but in the course of the years, the pain gets less and the duration of the attacks shorter. The severe chronic attacks of cluster headache may also change to the episodic type.
- Sometimes, particular circumstances can trigger an attack of cluster headache, such as drinking alcohol, using certain heart medications (nitrates), a long plane trip or a stay at high altitude, for example in the mountains. It’s better to avoid these circumstances during a period of headaches.
- In many patients, a high dose of caffeine (for example very strong coffee or energy drink), quickly taken immediately at the start of an attack, has a relieving effect or may even terminate an attack. In combination with drugs, the attack will significantly reduce in many cases. Here, it's important to be in time. When taken too late (and the attack has already begun) it has no effect, or may even worsen an attack.
- Cluster headache was discovered in 1939 by the American doctor Bayard Taylor Horton, hence the name Horton’s cephalalgia.
- The disease owes its name to the fact that it occurs in cyclical patterns or clusters.
- The prevalence of cluster headache is approximately 0.01%.
- Men are twice more likely to have this condition than women.