Clinical Description
Cluster headaches. Cluster headaches, named for their repeated occurrence over weeks or months at roughly the same time of day or night in clusters, begin as a minor pain around one eye, eventually spreading to that side of the face. The pain quickly intensifies, compelling the victim to pace the floor or rock in a chair. "You can't lie down, you're fidgety," explains a cluster patient. "The pain is unbearable." Other symptoms include a stuffed and runny nose and a droopy eyelid over a red and tearing eye.
This graphic illustrates the Trigeminal Nerve. This nerve has three branches, one which goes to the forehead and eye, one which goes to the cheek and one which goes to the lower face and jaw. During a cluster headache, the trigeminal nerve is activated, causing pain along one or more of it's three branches, usually along the one leading to the eye and forehead. This accounts for the centering of the pain of CH around the eye.
Cluster headaches last between 30 and 45 minutes. But the relief people feel at the end of an attack is usually mixed with dread as they await a recurrence. Clusters may mysteriously disappear for months or years. Many people have cluster bouts during the spring and fall. At their worst, chronic cluster headaches can last continuously for years.
Cluster attacks can strike at any age but usually start between the ages of 20 and 40. Unlike migraine, cluster headaches are more common in men.
Studies of cluster patients show that they are likely to have hazel eyes and that they tend to be heavy smokers and drinkers. Paradoxically, both nicotine, which constricts arteries, and alcohol, which dilates them, trigger cluster headaches. The exact connection between these substances and cluster attacks is not known.
Despite a cluster headache's distinguishing characteristics, its relative infrequency and similarity to such disorders as sinusitis can lead to misdiagnosis. Some cluster patients have had tooth extractions, sinus surgery, or psychiatric treatment in futile efforts to cure their pain.
Other research studies have turned up several clues as to the cause of cluster headache, but no answers. One clue is found in the thermograms of untreated cluster patients, which show a "cold spot" of reduced blood flow above the eye. The cause of cluster headaches is unknown. They may be genetic, since people whose parents or siblings have cluster headaches are at more risk for developing them.
Cluster headaches may be caused by a problem in an area of the brain called the hypothalamus. This area of the brain seems to be more active in people who have cluster headaches. The hypothalamus is a region of the brain that regulates sleep cycles, body temperature, pituitary gland activity, and other autonomic nervous system functions. When the hypothalamus malfunctions, thyroid problems, cluster headaches, and sleeping, eating, or reproductive problems may result.
The sudden start and brief duration of cluster headaches can make them difficult to treat; however, research scientists have identified several effective drugs for these headaches:
- The antimigraine drug sumatriptan can subdue a cluster, if taken at the first sign of an attack.
- Injections of dihydroergotamine, a form of ergotamine tartrate, are sometimes used to treat clusters.
- Corticosteroids also can be used, either orally or by intramuscular injection.
Some cluster patients can prevent attacks by taking: - propranolol,
- methysergide,
- valproic acid,
- verapamil, or
- lithium carbonate.
Another option that works for some cluster patients is rapid inhalation of pure oxygen through a mask for 5 to 15 minutes. The oxygen seems to ease the pain of cluster headache by reducing blood flow to the brain.
In chronic cases of cluster headache, certain facial nerves may be surgically cut or destroyed to provide relief. These procedures have had limited success. Some cluster patients have had facial nerves cut only to have them regenerate years later.