A type of headache that predominantly affects middle-aged men. It includes episodes of severe, one-sided pain around the eye that occurs daily for several weeks and accompanied by other symptoms. It is also known as migrainous neuralgia.
The headache is always unilateral, excruciating, and most uniquely, in timed attacks called "clusters."
Cluster headaches are characterized by intense burning and boring pain, frequently located in or around one eye and temple and occasionally in one cheek or jaw. The affected eye is bloodshot and teary. The nostril on that side often becomes blocked and may run profusely.
Other features can include reduced pupil size, a drooping eyelid and a flushed face. The pain swiftly intensifies within 5 to 10 minutes to a peak that typically persists for 30 minutes to 2 hours. Affected persons usually do not lie down during the attack because it usually worsens the pain.
Cluster headaches have an abrupt onset and can happen at any time, but they most commonly occur two to three hours after falling asleep, usually during the phase of deep sleep known as rapid eye movement (REM). They usually last for less than two hours. The headaches can occur daily for days, weeks, or months before a remission period that can last weeks or years (episodic attacks), or can occur for a year or more without remission (chronic attacks). A chronic phase may begin after a period of episodic attacks.
The cause of cluster headaches is unclear, but may relate to a vascular headache disorder or a disturbance of serotonin (a neurotransmitter or chemical in the brain). Unlike migraine headaches, which more often affect women, cluster headaches predominantly affect men.
While the basic cause of cluster headache is not known, current research links the expanding of blood vessels in the head with chemically active proteins found in nerve endings around blood vessels of the trigeminal nerve (the fifth cranial nerve).
The first attack most frequently arises during adolescence or the early 20s. Many patients report that alcohol triggers an attack. Others report that stress, glare, or ingestion of specific foods may trigger an attack. There is usually no family history of similar headaches.
A typical cluster headache starts suddenly and without warning. In half of the cases, the attack awakens the patient within two hours of falling asleep. The attack may begin with a sensation of pressure in the eye or temple. The pain is unilateral, constant and severe. The excruciating pain reaches a peak within 15 minutes.
Individual attacks usually last less than two hours. Towards the end of the attack, the patient may experience additional paroxysms of stabbing pain superimposed on the constant severe pain.
In contrast to patients with migraine headaches, patients with cluster headaches are restless, active, and even violent during attacks. Most apply pressure or cold to the painful area, and many attempt to keep the head low but avoid lying down, since this position can initiate and increase cluster headache pain.
The physician should have little difficulty in diagnosing the condition. Nevertheless, some tests may be performed to exclude other ailments that cause similar pain; an aneurysm of the carotid artery in the head, a tumor made up of newly formed blood vessels, sinusitis, or glaucoma.
The majority of patients with cluster headache can be controlled on medication. However, a small number of patients have a chronic form of cluster headache which is resistant to medical therapy and therefore very difficult to treat.
Cluster headaches are resistant to analgesic painkillers because these drugs take effect slowly.
Inhalation of 100 percent oxygen often provides relief. This may be the most effective treatment for frequent cluster headaches that occur primarily at night.
Ergotamine tartrate in a suppository, tablet, injection, or aerosol form is an effective pain reliever for some people, but the dosage must be limited to avoid side effects, especially nausea. It may also be prescribed to prevent attacks.
Sumatriptan (Imitrex) has been demonstrated to be effective in migraine headaches and in acute cluster headache attacks. It is given as a subcutaneous injection at the start of an attack.
Corticosteroid medications, such as prednisone, may be prescribed if the cluster headaches are of recent onset or if there is a pattern of short attack episodes and long remissions. Side effects prohibit long-term use.
About 60 percent of all persons with cluster headaches respond to methysergide maleate, which acts to relieve and prevent the attacks. It is used during periods of pain and is tapered off slowly during remission.
Lithium carbonate can be effective during a chronic phase of cluster headaches; then the dosage is tapered to avoid side effects.
Calcium channel blocking agents, such as verapamil, are effective for the prevention of cluster headaches in many people.
Different types of surgery have been used over the years to treat chronic cluster headaches, but those which deaden the pain-sensitive cells of the fifth cranial nerve have worked best.
Use of radiofrequency heating by means of a needle that deadens the trigeminal root nerve fibers may be effective, with fewer side effects than other invasive procedures. However, this therapy is usually used only after all other treatment has failed.