Migraine is a disorder usually involving headaches, which can be debilitating, and affects around six million people in the UK. Attacks can be triggered by stress, caffeine, exercise, or changes in eating or sleeping patterns. Recognising personal triggers and avoiding them wherever possible is a good start to dealing with migraine.
People who still have one or two migraines a month will generally turn to medication, including painkillers, anti-inflammatory medicines, and some specifically designed to treat migraine. For those who have more frequent or particularly severe migraine attacks, there are also preventive treatments, including beta blockers (used to treat high blood pressure), antidepressants and anti-epilepsy drugs.
Many of the key advances in our understanding of migraine have come from studies in dogs and cats. The most widely used ways of mimicking migraine involve electrical, mechanical or chemical stimulation of parts of the trigeminovascular system (involving the trigeminal nerve), which researchers believe is central to how migraine develops. The test animals are anaesthetised so that they feel no pain and do not become stressed.
In the 19th century scientists found that ergot, extracted from a fungus, contains a mixture of chemicals. Some of these cause blood vessels to constrict, which reduces head pain. Later chemists managed to isolate the chemical ergotamine from ergot. Several ergotamine variants became available for the acute treatment of migraine and are still prescribed today.
In the early 1970s, UK researchers discovered and developed new medicines called triptans using cats and dogs. But not all migraine sufferers respond to them and they cannot be used safely in people who have heart disease or high blood pressure. Further research, including research in animals, is required to find more effective treatments and prevention of migraine in all sufferers.
Thanks to imaging techniques which allow people to be monitored while they are having a migraine, researchers have identified new brain areas that are active during attacks. If they can mimic this brain activity in animals, it will provide new ways to test migraine treatments in animals, by seeing if treatments reduce this activity,.
For migraine prevention, there are also some hopeful leads, in particular the anti-epileptic drugs. Human trials have shown that topiramate reduces migraine frequency and it is now licensed for prevention of migraines. Researchers are now trying to find out how topiramate achieves its effects by studying animals. The results of these experiments might make it possible to design completely new medicines that will be even better at preventing migraine.
Feverfew, an alternative remedy for migraine, is also being tested in clinical trials as a preventive. Herbal potions can be problematic because they often contain several active compounds - some harmful and some beneficial - and the ratio of these vary. However, experiments in animals are beginning to provide clues about how parthenolide, the active constituent of feverfew, works and are revealing more potential targets in the brain.