What are cluster headaches?
Cluster headaches are the most severe headaches. A cluster headache can be many times more intense than a migraine attack. It has been called the "suicide headache" because many people have taken their lives either during an attack or in anticipation of an attack.
The term "cluster headache" refers to headaches that have a characteristic grouping of attacks. Cluster headaches occur one to three times per day during a cluster period, which may last 2 weeks to 3 months. The headaches may disappear completely (go into "remission") for months or years, only to recur. A cluster headache typically awakens a person from sleep 1 to 2 hours after going to bed. These nocturnal attacks can be more severe than the daytime attacks.
Who is affected by cluster headaches?
Cluster headaches are the least common type of primary headaches, affecting less than 1 in 1,000 people. Cluster headaches are a young person’s disease: the headaches typically start before age 30. Cluster headaches are more common in men, but more women are starting to be diagnosed with this disorder. The male to female gender headaches appear to be six times more common in men than women, especially men in their 20s or 30s.
What causes cluster headaches?
The true biochemical cause of cluster headaches is unknown. However, the headaches occur when a trigeminal-autonomic reflex pathway in the brainstem is activated. The trigeminal nerve is the chief sensory nerve of the face. When activated, the trigeminal nerve leads to the eye pain associated with cluster headaches. The trigeminal nerve also stimulates the parasympathetic autonomic system, which causes the eye tearing and redness, nasal congestion and discharge with cluster attacks. Cluster headaches appear to be generated by the hypothalamus (the part of the brain that is home to the suprachiasmatic nucleus or circadian clock). Recent imaging studies have shown activation or stimulation of the hypothalamus during a cluster attack.
Cluster headaches usually are not caused by an underlying condition such as a tumor or aneurysm.
What triggers cluster headaches?
The season is the most common trigger for cluster headaches, which often occur in the spring or autumn. Due to their seasonal nature, cluster headaches are often mistakenly associated with allergies or business stress. The seasonal nature of cluster headaches most likely results from stimulation or activation of the hypothalamus.
Cluster headaches are also common in people who smoke and drink alcohol frequently.
During a cluster period, the sufferer is more sensitive to the action of alcohol and nicotine, and minimal amounts of alcohol can trigger the headaches. During headache-free periods the patient can consume alcohol without provoking a headache.
Smoking can also increase the severity of cluster headaches during a cluster period.
What are the symptoms of a cluster headache?
Cluster headaches generally reach their full force within five or ten minutes after onset. The attacks are usually very similar, varying only slightly from one attack to another.
Type of pain
The pain of cluster headache is almost always one-sided, and during a headache period, the pain remains on the same side. When a new headache period starts, it rarely occurs on the opposite side.
Severity/intensity of pain
The pain of cluster headache is generally very intense and severe and is often described as having a burning or piercing quality. It may be throbbing or constant. The pain is so intense that most cluster headache sufferers cannot sit still and will often pace during an attack.
Location of pain
The pain is located behind one eye or in the eye region, without changing sides. It may radiate to the forehead, temple, nose, cheek, or upper gum on the affected side.
The scalp may be tender, and the pulsing in the arteries often can be felt.
Duration of pain
The pain of a cluster headache can last anywhere from a few minutes to three hours. In general, the headaches last for 30 to 90 minutes. The headache will disappear only to recur later that day. Typically in between attacks, people with cluster headaches are headache free.
Frequency of headaches
Most sufferers get one to three headaches per day during a cluster period (the time when the headache sufferer is experiencing daily attacks). They occur very regularly, generally at the same time each day, and have been called "alarm clock headaches" because they often awaken the person at the same time during the night.
The cluster periods can last from two weeks to three months and then disappear completely for months or years. The cluster headache sufferer has variable pain-free intervals between headache attacks.
Attacks appear to be linked to the circadian (or "biological") clock. Most people with cluster headaches will develop cluster periods at the same time each year -- either in the spring or fall or the winter or summer.
Most cluster sufferers (80 to 90%) have episodic cluster headaches that occur in periods lasting seven days to one year, separated by pain-free episodes lasting 14 days or more.
In about 20 percent of people with cluster headaches, the attacks may be chronic. Some patients will note that the series of headaches are not separated by periods of remission. These cases are chronic, meaning there are less than 14 headache-free days per year. Chronic cluster headaches vary from episodic cluster headaches, as they are continuous.
Warning signs
Although the pain of a cluster headache starts suddenly, a minimal type of warning of the oncoming headache may occur, including a feeling of discomfort or a mild one-sided burning sensation.
The affected eye may become swollen or droop. The pupil of the eye may get smaller and the conjunctiva (the tissue that lines the inside of the eyelid) will redden. There may be nasal discharge or congestion and tearing of the eye during an attack, which occur on the same side as the pain.
Excessive sweating may occur, and the face may become flushed on the affected side. Cluster headaches are not typically associated with the nausea or vomiting. People with cluster headaches appear to develop as much sensitivity to light that are found in other types of headaches, such as migraine and sound as people who have migraines.
It is possible for someone with cluster headaches to also suffer from migraines.
People who suffer from cluster headaches--especially people who have tooth or cheek pain with the cluster attacks--have an increased risk of developing a stomach ulcer.
Researchers believe that histamines, which dilate or expand blood vessels, influence the onset of a cluster headache because during a cluster headache, the level of histamine increases in a person’s blood and urine.
How are cluster headaches treated?
Abortive medications: The most successful treatments are sumatriptan (Imitrex) injections and oxygen inhalation therapy (100% oxygen delivered by a face mask at eight to 10 liters per minute for twenty minutes). Other choices include: zolmitriptan tablets, ergotamine preparations and intranasal lidocaine.
Preventive medications: Medications should be prescribed as early as possible in order to shorten the length of the headache period as well as decrease the severity of the headaches. All cluster headache sufferers must take preventive medication unless their cluster periods last less than two weeks. Some medications used in the prevention of cluster headaches include: calcium channel blockers, verapamil, lithium carbonate, divalproex sodium, corticosteroids or methysergide (only short courses), methysergide, melatonin, and topiramate.
Surgical intervention may be considered for people with chronic cluster headaches who have not been helped with standard therapy.
Because of the brief duration of an attack, the abortive treatment of these headaches is difficult. Often, the acute headache has disappeared before the patient arrives at the emergency department or physician's office to receive treatment. Oxygen inhalation by facial mask can be used at the first signs of a cluster attack and has been used successfully in aborting an acute cluster headache. Sumatriptan (Imitrex) injections are often prescribed for the acute treatment of cluster headaches.
Some patients have gained some relief with the use of intranasal applications of a local anesthetic agent, such as lidocaine.
All of these treatments should be used under the direction of a physician familiar with cluster headache therapy. As with any medication, it is important to carefully follow the label instructions and your physician’s advice. This is especially important to prevent rebound headaches.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 4/10/2009...#5003
