Migraines are marked by throbbing pain, usually on only one side of the head. For decades, medical theory postulated that the pain came from enlarged blood vessels outside the skull.
Danish researchers used MRI equipment to examine the brains of 19 healthy women while they suffered a severe, uni-lateral migraine headache without aura. This allowed researchers to compare blood vessels on the side experiencing pain with the side without pain.
“Contrary to what has previously been believed, we found that the arteries on the outside of the skull did not expand during migraine attacks,” according to Faisal Mohammad Amin, a doctor and a PhD student at The Danish Headache Center (DHC), Glostrup Hospital, Denmark.
Thus the pain results from the nerve fibers around blood vessels becoming more sensitive. The throbbing pain reflects the normal beat of the heart
The more interesting aspect of the study is that sumatriptan — the most widely prescribed migraine medicine — had no effect on blood vessel size. This begs the question: how does sumatriptan work if it is not causing arteries to narrow?
Read more at ScienceNordic.