Cluster headache

What is cluster headache?

Cluster headache is a primary headache, i.e. a headache due to the headache condition itself and not due to another cause. Cluster headache is one of the most painful conditions someone can have. It’s a rare type of headache, approximately 1 in 1000 people have it. It is more common in men than women. It most commonly starts when people are in their 30s and 40s (but can affect people at any age).

The main symptom is an excruciating headache on one-side of the head, often around the eye. It most often occurs in cycles or clusters.

Symptoms

Cluster headache features a severe headache often described as ‘boring’, burning or piercing. It comes on very quickly, often without warning and only affects one side of the head (although it can change sides). It usually occurs behind or around the eye. The pain usual makes people agitated and restless.  People often pace, rock back and forth or hold their head. This is in contrast to most people with migraine who prefer their head to be still during an attack. People may also experience one or more of these during the cluster attack:

• red or watering eye
• drooping or swelling of the eyelid
• a smaller pupil
• sweaty face
• blocked or runny nose

Attacks usually last between 15 minutes and three hours. Some people may have multiple attacks a day, up to eight for some people.

Many people find attacks come on at night, and they may wake up with it in the middle of the night, very often at the same time every night

Some people do experience nausea and sensitivity to light during cluster headache. Some people have aura, but this is considered rare.

The pain usually ends suddenly. Most people are pain free but exhausted after an attack

Pattern of attacks

People are likely to experience bouts of frequent attacks (cluster periods) which last from weeks to months. These are then followed by a period of remission where the person  has no headache for months, or even years.

During a cluster period the headaches can occur every day, every other day and sometimes many times a day. It can also occur at the same time of day.

People may find the start of the cluster, and the duration is consistent from one bout to another. Some people experience cluster headache seasonally – during the spring or autumn, and at the same time each year.

Cluster headache can be episodic or chronic:

• episodic cluster headache – bouts last from 7 days to one year separated by pain free periods lasting at least 3 months. Most cluster periods usually last between 2 weeks and 3 months.
• chronic cluster headache – persistent attacks for more than a year without remission, or remission lasts less than three months. Up to 2 in 10 people with cluster headache have chronic cluster headache.

Cluster headache tends to get better with age, with people having less frequent bouts and prolonged periods of remission.

What causes cluster headache?

It’s not clear what causes cluster headache. However, it’s thought to be linked to the hypothalamus. The hypothalamus is the part of the brain that is responsible for a range of bodily functions including body temperature, thirst, sleep cycles, blood pressure and heart rate.

For some people there may be a family link. Often people who develop cluster headache are smokers.

Diagnosing cluster headache

There is no test for cluster headache. Usually a doctor will make a diagnosis by:

• asking about symptoms and history of headache. It can be helpful to keep a headache diary detailing symptoms.
• performing a neurological examination.
• sending people for further tests including a brain scan to rule out a secondary cause

People with cluster headache are often referred to a consultant neurologist or headache specialist for review and treatment.

Treatment for cluster headache

There is no cure for cluster headache. Treatment for cluster headache falls into two categories:

• Acute treatment to stop an attack when it’s happening.
• Preventive treatment to decrease the severity and prevent attacks.

Acute treatment

The main acute treatments for cluster headache are:

• Sumatriptan, 6 mg injection provides relief within 15 minutes
• High flow Oxygen, 100% at 7-15 litres/minute for 15-20 minutes is effective at stopping attacks.
• Some people who can’t tolerate these or find them ineffective may benefit from a triptan nasal spray – either sumatriptan or zolmitriptan.

gammaCore, an electrical device, can be used as an acute or preventive  treatment. It is not suitable for everyone.

Preventive treatment

Verapamil is the preventive treatment of choice for cluster headache. It can cause abnormal heart rhythms in some people so regular monitoring, by taking a heart tracing (ECG) is required.

Besides verapamil, other options include:

• Greater Occipital Nerve (GON) block (an injection around a nerve at the back of the head)– has been found to be on average 50% effective in cluster headache and often provides relief while finding other long-term treatments.
• Corticosteroids – these can provide short-term relief. They shouldn’t be used long-term and are often used while finding other treatments that work.

Other things that may be effective include lithium, melatonin, and Sphenopalatine Ganglion Stimulation.

During a cluster bout many people find alcohol and strong smells can trigger an attack, it’s helpful to avoid these if possible.

Useful organisations

OUCH UK (Organisation for the Understanding of Cluster Headache)

Raise awareness of cluster headache and provide information and support to people affected by Cluster Headache.

Helpline: 0800 6696 824

Website: www.ouchuk.org