Cluster headache, also known as histamine headache, is a rare but painful type of headache that affects approximately 1 to 2 people per 1000 population. It involves several attacks of intense unilateral pain that last for a short period of time.
As the pain reaches a peak very quickly, simple analgesics are not usually able to provide effective relief and fast-acting alternatives are preferred. Preventative treatment to reduce the frequency of attacks also plays an important role to improve patient quality of life.
The precise cause of cluster headache is not well understood, although there may be a link to the hypothalamus in the brain. There may be a genetic link to cause cluster headache, as 1 in 20 people with the condition reports a family member that suffer from cluster headache.
Cluster headaches may present in individuals of any age, but are most likely to begin in early adulthood. Affected individuals usually suffer from cluster headaches throughout their lifetime, although the remittance periods typically extend in length with age.
Triggers for cluster headache include:
- Alcohol consumption
- Excessive smoking
- Inhalation of fumes (e.g. petrol, paint, perfume, bleach, solvents)
- Extreme heat
The pain associated with a cluster headache is always unilateral and usually centered over one eye, temple or the forehead, although the affected side can alternate for some patients.
The headache pain usually presents suddenly and at a particular time each day and reaches a peak in intensity 5-10 minutes later, which may continue for up to a few hours before it stops spontaneously.
Many patients experience a bout of cluster headaches that occur regularly for a few weeks, which then resolves for a period of time, known as episodic cluster headache. A small proportion of patients (approximately 20%) experiences chronic cluster headache with no symptom-free period between attacks.
Other symptoms of cluster headache may include:
- Blocked or runny nose
- Drooping eyelid on affected side of face
- Redness of eye on affected side of face
Diagnosis of cluster headache involves a thorough medical history with particular attention to the symptoms of the headache. There is no specific test used to diagnose the condition, but imaging techniques such as magnetic resonance imaging (MRI) scans can help in the differential diagnosis of other conditions.
During an acute attack, the pain usually reaches a peak very quickly and is thus timely treatment is critical to reduce pain. Simple analgesic medications do not usually provide sufficient relief from the intense pain associated with cluster headaches. Instead, administration of oxygen is a safe and effective treatment option often used in practice, which begins to show effects 15 minutes after administration.
Additionally, sumatriptan injections or nasal sprays may also help to provide effective pain relief during an attack. Administration via injection usually has a faster onset of action, which is critical in the relief of cluster headache pain.
There is no cure for cluster headache and patients that suffer from the condition may experience an attack at any time. However, there are a number of management techniques that can help to prevent attacks from occurring.
Firstly, avoidance of known triggers for cluster headaches, such as smoking, alcohol and strong smells, is important.
There are also some pharmacological options that can be used to aid in the prevention of cluster headaches. These include:
Verapamil is the most commonly used option in practice and is often able to help in the prevention of cluster headaches, although side effects of the medication should be considered. In particularly, verapamil can change the rhythm of the heart and this should be monitored throughout preventative treatment.