Cluster (say: KLUHS-ter) headache is less common than migraine or tension-type headache. It occurrs in about 1 in 1,000 people. Men are much more likely than women to have cluster headaches. The term cluster refers to the fact that the headaches, while brief, occur in clusters of several headaches per day, often at around the same time. They will often occur daily for a period of days, weeks or months, and then resolve for a period of weeks or months (called the interim).
Signs and symptoms
Signs and symptoms may include:
- sharp pain on one side of the head – often around the eye, temple, forehead, or cheek
- pain at the base of the skull or the neck on the same side as the headache
- pain usually lasts 30 to 90 minutes, resolves, and then recurs later in the day. Some patients have very brief episodes that happen hundreds of times in one day.
- runny nose
- watery eye, redness, or swelling around the eye on the same side as the headache
- changes in pupil size
- eyelid drooping
- agitation or restlessness during an attack
- alcohol is often a trigger for attacks
- attacks will often happen at night and wake the patient from sleep
We do not know exactly what causes cluster headaches. Like migraine, it seems that the dilation and constriction (opening and closing) of blood vessels is involved. We think that an area of the brain called the hypothalamus is where the cycle starts. Many people with cluster headaches are heavy smokers or drink alcohol daily, so we think this may be part of the cause of the disorder.
There is a set of criteria used to diagnose migraine, established by the International Headache Society. They include a number of the signs and symptoms listed above.
Your physical exam should be normal when you are in between headaches. If you meet these criteria, and if your physical exam is normal, there is no need for blood tests, computerized tomography (CT) scans, or magnetic resonance imaging (MRIs) to make the diagnosis. If the physical exam is not normal, you may need other tests to make sure the headache is not caused by something else.
Alcohol is a reliable trigger for this condition, so should be avoided.
There are some medicines, which can be useful to treat a headache at the time it occurs (symptomatic medicines). Because the headaches are unpredictable and because they are often very brief, this is not usually the best approach. These include:
- lidocaine nasal spray
- capsaicin nasal spray
Usually, it is more helpful to take a medicine every day to reduce how often the migraines occur and how intense they are (prophylactic or preventive medicines). These include:
- verapamil: usually at higher doses than used for migraine or TTH
- steroids: these are effective, but may have serious side effects
- valproic acid
Studies have shown that non-drug therapies can help to reduce pain levels and enhance pain coping. These include:
- activity pacing
- cognitive behavioural therapy
These self-management strategies can help you to improve your function so you can do more and enjoy life more.
Nerve blocks and surgery
There are other, more invasive therapies which are being studied for extremely severe, disabling daily cluster headaches. They include nerve blocks and surgery. However, there are many possible side effects of these procedures. There is not enough research evidence yet to recommend them.
For more information
American Headache Society
Headache Cooperative of New England
National Headache Foundation
World Headache Alliance
Headache Network Canada
Michigan Head-pain and Neurological Institute
Saper JR, Dodick D, Gladstone JP. Management of chronic daily headache: Challenges in clinical practice. Headache. 2005;45(s1) S74-S85.
Saper JR, et al. Intranasal civamide for the treatment of episodic cluster headaches. Headache. 2003;43(3):306-307.
Dodick DW, Saper JR. Cluster and chronic daily headache. Neurology. 2003;60(7):S31-S37.