Cluster headache is perhaps the most painful and severe type of headache. The term “cluster” is used because these headaches come in clusters, occurring for weeks to months at a time, then disappearing suddenly and completely for months or years. Many people also report that the clusters occur with striking regularity in a cyclical daily or seasonal pattern. Cluster headaches are often mistaken for sinus or migraine headaches. Cluster headache is present in less than one percent of the population. It is more commonly seen in men. These headaches can begin at any age, but usually occur between the ages of 20 and 40 years. Cluster headaches are not life-threatening and do not cause any permanent damage to the brain. However they can be quite debilitating and interfere with work and enjoyment of life. In a small number of cluster headache sufferers headaches continue for more than a few months, sometimes for years. These are called chronic cluster headaches.
Cluster headache attacks often occur at night, waking the person from sleep. The pain is usually described as sharp, stabbing, or burning, like a “hot poker in the eye.”
Characteristic features include the following:
Severe, one-sided pain in or around the eye, temple, forehead or cheek areas
Individual attacks lasting 15 minutes to 3 hours.
Begins suddenly and peaks quickly (within minutes)
Can occur from every other day to 8 times a day
Sense of agitation or restlessness during the headache
Often triggered by alcohol
Accompanied by at least one of these “autonomic features” on the same side as the head pain:
Redness of the eye
Forehead or facial sweating
The cause of cluster headaches is not fully understood. Since the headaches are characterized by pain, autonomic features, and a regular cyclical pattern, several parts of the brain are probably involved. The pain itself is likely to be related to the activation of the trigeminal nerve deep in the brain, which has connections to the layers of tissue covering the brain as well as the blood vessels. Stimulation of this nerve results in inflammation, which results in pain. However, the underlying cause of cluster headache is much more complex. The hypothalamus, which regulates the body’s biological clock, has been proposed as the activation center for cluster headache given the striking clockwork-like pattern of attacks seen in most patients. Genetics may also play a role since many patients with cluster headaches have family members who have cluster or migraine headaches. Further studies are needed to fully clarify the cause of cluster headaches.
Both acute and preventative medications are used in the treatment of cluster headache. Acute treatment includes oxygen inhalation, triptans (such as Imitrex injections and Zomig nasal spray) or ergotamines. Preventative medications are taken on a daily basis as prophylaxis against cluster attacks. These include blood pressure medications (high doses of verapamil), anti-epilepsy drugs (Depakote, Topamax), Lithium, and other. In a small number of cases, an herbal product Boswellia has been reported to help cluster headaches. Several of my patients with chronic cluster headaches responded very well to Botox injections. Botox is approved for chronic migraines but not cluster headaches, which may complicate efforts to get insurance companies to pay for it. Magnesium infusions, which can be given in the office, are also helpful in treating cluster headaches. In many cases, a short course of a steroid medication, such as prednisone can quickly stop the headache cycle.