CHICAGO: Researchers have identified brain lesions in migraine victims, a finding that could indicate the severe headaches are a progressive brain-damaging disease in some cases, a study said on Tuesday.

The research, which has possible implications for treatment, involved 295 Dutch adults aged 30 to 60, some of whom had migraines with visual disturbances and some migraines without eye problems. They were compared to 140 similar people who were migraine-free.

Using magnetic resonance images, the researchers found that for patients with both migraines and visual problems the risk of cerebral infarction - tissue which has died due to lack of oxygen when a blood clot blocks an artery - was 13 times higher than the group which had no migraines at all.

The problem increased with the frequency of migraine attacks. Patients with migraine but no eye trouble had more than seven times the risk that would normally be expected. The problem occurred in the cerebellar region of the brain, which controls motor motions.

Migraines, which can last from two hours to two days, occur in about 10 per cent of the population and are three times more common in women than men. The study done by Mark Kruit, a physician at Leiden University Medical Center, Leiden, The Netherlands, and colleagues was published in this week's Journal of the American Medical Association.

Lenore Lauer of the US National Institutes of Health, one of the co-authors of the paper, said: "It means we may need to shift the way people think about migraines. They're thought of now as episodic - people get a headache and that's it."

In reality, she said in an interview, the problem may be a chronic one and "one of the future questions to ask is about the path and type of treatment that may be most useful."

She said the study did not determine whether the lesions are the result or the cause of the migraines. There have been previously documented cases of migraine-related stroke in the same region of the brain, she said, and the report said previous research has suggested the presence of brain infarcts in migraine sufferers.-Reuters