Some migraine patients can cut down on medication or stop using it completely by using a newly developed inhaler which changes the composition of the air we breathe, results of a clinical trial say.

Migraines occur as part of a chain reaction during which the veins in the brain contract and the blood cannot therefore supply the brain with sufficient oxygen, the researchers said. In the study, the team from the Aarhus University in Denmark examined a small group of patients who suffer from migraine with aura, which is where they experience either sensory or visual disturbances before the painful headaches begin.

The novel inhaler slightly changes the body's own molecules. It utilises carbon dioxide and oxygen, which are the body's natural molecules for mobilising its own defence against migraine attacks. "The inhaler expands the blood vessels that supply the brain with oxygen by up to seventy per cent and thereby stops the destructive chain reaction," said Troels Johansen, from the varsity.

Johansen added that the effect of the treatment starts after a few seconds. The results, published in the journal Cephalalgia, showed that the effect of the pain relief increased significantly with each use of the inhaler. While 45 per cent people experienced an effect the first time, and that number rose to 78 per cent the second time. "The study shows some very significant physiological effects in the body," Johansen said, adding that the team is now planning to conduct a large clinical trial that will also include migraine without aura and chronic migraine.