What are cluster headaches?
Cluster headaches are among the most severe forms of pain known to man. Without treatment, they are almost unbearable for those affected. The term “cluster” (English for “cluster”) indicates that the symptoms do not occur sporadically but in clusters: periods without symptoms are followed by active phases, which are called clusters.
Unlike migraine, which is very common and affects more than 10 percent of people, cluster headaches are among the rarer conditions. Only about one in every thousand people is affected by this type of headache. For Switzerland, this means that an estimated 9,000 residents suffer from cluster headaches occasionally or frequently. They occur about twice as often in men as in women. Cluster headaches often first appear between the ages of 20 and 40, but they can also occur at any later stage of life. Children and adolescents, on the other hand, are affected only very rarely.
Types of Cluster Headaches
Depending on the frequency with which cluster headaches occur, they are classified into one of these two groups:
Episodic Cluster Headaches
More than 80 percent of patients with cluster headaches experience pain only during certain periods; in between, there are symptom-free intervals that last at least three months, and sometimes even years. This large majority of patients suffers from this type of cluster headache.
Typical cluster episodes (also known as active cluster periods) last an average of about four to twelve weeks and often occur in the spring or fall. If you are experiencing such an active episode, the cluster headaches may occur with varying frequency. Maybe you’ll be lucky and only have one episode every other day. On bad days, I can experience up to eight episodes of pain. On average, those affected experience about one attack per day. They often begin at night or in the early morning hours and wake those affected from their sleep. Between painful cluster episodes, there are often long periods without symptoms; these can last for months or even years.
Chronic Cluster Headaches
There are also cluster headache patients who experience no breaks at all or only brief ones—they have recurring pain attacks without any periods between them. If a cluster episode lasts longer than one year, or if the periods of remission between attacks are shorter than three months, the condition is referred to as chronic cluster headache.
The episodic form of cluster headaches can eventually progress to a chronic form; this is the case for about 10 percent of all those affected. The reverse progression—where chronic cluster headaches become an episodic condition—is, by contrast, rare.
Symptoms: What are the signs of cluster headaches?
Cluster headaches are typically characterized by a throbbing or stabbing pain in the eye, forehead, and temple areas. Cluster headaches can be so severe that they are almost unbearable—some patients describe them as feeling like “a stab in the eye with a red-hot knife.” Cluster headaches always occur on one side of the head. A seizure usually lasts between 15 minutes and three hours; on average, about an hour.
The pain is often accompanied by other symptoms that appear on the same side of the face:
- Red Eye
- Watery eyes
- Drooping Eyelid
- Swollen Eyelid
- Stuffy Nose
- Runny Nose
- A feeling of fullness in the ear
- Sweat on the forehead
In addition, physical restlessness is very common and can be agonizing for those affected. Some of those affected pace back and forth, rocking their upper bodies restlessly or hitting the intensely painful area on their face—in the hope that the pain will subside. In most cases, the pain reaches its peak after about 8 minutes—unless the attack is treated quickly.
Causes: What Causes Cluster Headaches?
The cause of cluster headaches is unknown. The hypothalamus is likely to play an important role—a control center in the diencephalon that regulates, among other things, our biological clock and sleep-wake cycle. Genetic factors also appear to play a role. Cluster headaches therefore appear to be at least partially hereditary, even though there is no single “cluster headache gene.” In addition, smoking is also thought to be a possible cause—at least two-thirds of all people with cluster headaches smoke or have smoked.
Trigger Factors as Causes of Cluster Headaches
Sometimes cluster headache attacks are triggered by external stimuli. That is why it makes sense to consistently avoid known trigger factors. Since they are not the cause but only the trigger for the pain attacks, cluster headaches will still occur even without triggers, but the frequency of the pain attacks may decrease. Alcohol consumption is most often cited as the trigger.
During symptom-free episodes, these triggers—which vary from person to person—often have no effect, making it difficult for those affected to identify them.
Cluster headaches resulting from other medical conditions
Cluster headaches do not always occur as a primary (stand-alone) condition; in extremely rare cases, they can also be a consequence of other medical conditions. In this case, the condition is referred to as secondary or symptomatic cluster headaches. If you’ve been experiencing cluster headaches for some time, however, it’s very unlikely that you have the secondary form. We would be happy to advise you on these matters.
Diagnosis: How Do You Recognize Cluster Headaches?
Many diseases can be definitively diagnosed through laboratory blood tests or imaging procedures. Unfortunately, that’s not possible with cluster headaches. However, a computed tomography (CT) scan or a magnetic resonance imaging (MRI) scan may still be useful for ruling out other conditions using these imaging techniques.
If you suspect that you may be suffering from cluster headaches, your doctor will need you to describe your headache symptoms—including their duration and frequency—as accurately as possible. A headache diary can be a useful tool in this regard and can aid in the diagnosis. Only once it has been determined whether you are suffering from cluster headaches or one of the many other types of headaches can your doctor treat your pain effectively.
Here you can find general information about headaches and their various forms:
Treatment: How are cluster headaches treated?
Cluster headaches cannot be cured, but it is possible to reduce the frequency and intensity of the headache attacks. There are two complementary approaches to treating cluster headaches: acute headache treatment during a pain attack and preventive cluster headache treatment to delay or alleviate future pain attacks.
Acute Treatment for Cluster Headaches
For many people with cluster headaches, oxygen inhalation has proven to be an effective acute treatment. This is done using a face mask. If oxygen is inhaled at the onset of a pain attack, it can bring the cluster headache to an end within about 15 to 20 minutes for many people affected. The costs of this acute cluster headache treatment are covered by health insurance if the treatment was prescribed by a doctor following a confirmed diagnosis.
Certain medications from the triptan class are also suitable for the acute treatment of cluster headaches. They cause the blood vessels in the brain to constrict and affect the release of certain neurotransmitters. The active ingredient sumatriptan is often injected under the skin; sometimes the substance zolmitriptan is also administered as a nasal spray, although it takes significantly longer to relieve the attack.
Prevention of Cluster Headaches
To prevent cluster headaches, the active ingredient verapamil is usually used first. Although it was developed as a blood pressure-lowering medication, it has also proven effective in preventing cluster headaches. The effects of the medication, which is taken in tablet form, do not occur immediately but rather after seven to 14 days at the earliest; the dose often needs to be adjusted over time.
Under no circumstances should you try to treat cluster headaches on your own without consulting a doctor. Common headache remedies are ineffective against severe cluster headache attacks or take too long to take effect. We recommend that you seek treatment from specialists, for example, at our headache clinic. At the USZ, you will receive expert advice based on the latest medical findings. Here, experts from various disciplines work hand in hand to find the best solution for your cluster headaches.
Details About the Treatments
