Cluster headache is one of the most painful conditions known to medical science, affecting about 1 in 1,000 people.
About cluster headache.
1. What are the symptoms?
The symptoms of cluster headache are distinctive. As the name suggests, these headaches occur in clusters, also known as ’bouts’. Bouts consist of recurring attacks of excruciating pain always on one side of the head. The pain is usually located around one eye or temple and sometimes spreads further across the same side of the face such as the forehead and jaw. Cluster headaches are sometimes misdiagnosed as migraines, however, one of the most notable differences is the severity of pain and reaction to it.
If you have a migraine, you are inclined to lie down in a dark, quiet room, and be still. However, if you have a cluster headache, you are unable to lie down or stay still – it is so excruciating that you may pace around, rock back-and-forth, and hold your head in pain.
During an attack at least one of the following symptoms usually occurs on the side of the face where the pain is:
- redness and tearing of the eye
- a runny or blocked nostril
- drooping of the eyelid
- constriction of the pupil
- sweating of the face
During bouts of cluster headache, attacks often happen at a similar time each day. Attacks commonly start at night, often waking people between one and two hours after falling asleep. Attacks come on rapidly, and the pain reaches its full intensity usually within 5-10 minutes and lasts at this excruciating level of pain for 45 minutes to 90 minutes – though it is known for attacks to last between 15 minutes to 3 hours. After which time the headache stops rather abruptly, usually as rapidly as it began. Some people may experience attacks once every other day, and others up to 10 times per day. The frequency of attacks can vary throughout a cluster period. Painkillers are almost always ineffective to help relieve the pain of attacks.
About 85% of people with cluster headache will experience these attacks during a bout that usually lasts between 4-12 weeks. These bouts often occur once or twice a year – usually around spring and autumn – however the next bout of headaches may not return for several months or even years. This is known as episodic cluster headache. The remaining 15% of people with cluster headache do not have these periods of pain free intervals and are known as chronic cluster headache.
2. Who gets it?
Anyone of any age can develop cluster headache but it most commonly develops in adults who are in their 20s or older.
Unlike migraine, it affects around 5 times as many men than women. It is more common in people who smoke and drink alcohol. Around 1 in 20 cluster headache sufferers also have a family member with the condition.
3. The causes?
The cause of cluster headache is not yet fully understood. Research shows that the hypothalamus becomes overactive during each attack. However, it is not known what causes this overactivity. The hypothalamus is the part of the brain that regulates and controls the body’s daily rhythms and has an effect on mood, appetite and sleep. This most probably explains why cluster headache attacks occur at specific times of day with uncanny regularity.
During a bout, there are a number of recognised triggers that bring on cluster headache attacks. Alcohol is a very common trigger for attacks and should be avoided completely for the duration of a bout. Strong smelling substances such as petrol, paint fumes, cigarette smoke, perfume and other solvents can be triggers for attacks too. A raise in body temperature, such as exercise or becoming overheated, can also bring on an attack.
Currently there is no cure for cluster headache. However, there are a number of treatments that aim to reduce the severity of cluster headache attacks as well as treatments to help prevent attacks from starting.
Abortive treatment is for stopping and reliving pain once it has started.
Because of the rapid onset of attacks, the treatments need to be fast acting. Ordinary painkillers are almost always ineffective because of the time they take to work as well as the severity of the pain.
- Oxygen at 100% concentration is the safest and usually an effective way to relieve an attack. Breathing pure oxygen at a rate of between 7-15 litres per minute usually begins to work within 15 minutes. Home oxygen can be provided by having your GP completing and sending off a Home Oxygen Order Form (HOOF) to the relevant oxygen supplier for your area.
- Triptans are the most successful abortive treatment for attacks. They are a relatively expensive and powerful drug, but due to the severity of the condition, it is regarded as unethical to refrain from prescribing them. It should be noted that triptans have a very strict maximum dosage for a 24 hour period, and so sufferers with multiple attacks a day will be unlikely to use triptans for each attack. Sumatriptan injections are self-administered, just beneath the skin, and have been found to reduce pain and abort attacks within 10 minutes. Sumatriptan and Zolmitriptan nasal sprays are an alternative way to administer triptans, but onset of action is usually slower at around 15 minutes.
Preventative treatment is used to help prevent attacks from starting in the first place.
There are a wide variety of preventative treatments available. The most common treatments are:
- Verapamil is the most commonly used preventative treatment. It is a drug that is normally used to treat high blood pressure among other heart problems. The doses used for preventing Cluster Headache are usually high and so ECGs are required when building up the dose, as well as ECG checkups thereafter.
- Lithium can be effective, more so in chronic cluster headache sufferers, but requires careful monitoring.
- Corticosteroids are fast acting but can be only used for a short period of 2 to 3 weeks in an attempt to break the cluster headache cycle and to allow longer term preventative medication to be implemented. After this short period the dosage of corticosteroids is tapered off gradually.
- Methysergide is usually very effective and is more likely to be used for episodic cluster headache sufferers and can be taken for a maximum of 6 months.
- Topiramate is primarily an antiepileptic drug and is also used to prevent migraine. There have been recent studies to show that Topiramate is effective in preventing cluster headache.
- Ergotamine is found to be useful, but is infrequently prescribed and is not usually suitable for chronic cluster headache sufferers.