Two Midland hospitals are to play a key role in new research to see if there is a link between migraines and a common heart defect.
A quarter of the UK population are born with a valve-like hole which occasionally allows blood to pass between the two upper chambers of the heart.
But as many as half of those who suffer migraine with aura, or "classic" migraine, have the condition, suggesting a connection.
Birmingham's Queen Elizabeth Hospital and the Royal Shrewsbury Hospital in Shropshire will be at the forefront of the trials to investigate whether correcting the heart problem can prevent migraines.
The defect, called a patent foramen ovale (PFO), often produces no symptoms.
In the womb, the opening is necessary to allow efficient circulation of blood and oxygen before the lungs start functioning.
After birth, it should fuse to produce a wall, or septum, separating the two atrial chambers. But in about 15 million people in the UK the hole remains. It operates like a valve, staying closed most of the time but opening when there is pressure on the chest.
Sneezing or coughing can cause the PFO to open. When this happens, unfiltered venous blood can pass from the right to the left atrium and then circulate to the brain.
If the unfiltered blood contains clots or particles they can cause a stroke or heart attack.
A PFO can be permanently closed with an implant using a key-hole procedure.
Dr Peter Wilmshurst, from the Royal Shrewsbury Hospital, who will lead the study and was one of the first doctors to highlight the PFO-migraine connection, said: "We are very excited to be running a dedicated trial, which we hope will give us answers to increase our understanding of certain types of migraine headache.
"Mist should help us to define the appropriate course of action for patients who experience migraine attacks and also have a PFO." Consultant cardiologist Dr Joe De Giovanni said: "I am excited by the potential in this trial. It is important to find out whether there is a true link between the two or not.
"We will be looking for people who suffer from very bad migraines to come forward so we can see if the anecdotes we have can become evidence."
Six million people in the UK suffer migraines, which account for 18 million lost working days each year and cost the economy £750 million.
A migraine with aura is accompanied by disturbances such as bright, flashing lights or partial loss of vision.
Volunteers recruited into the trial will be randomly assigned to either a genuine or simulated placebo treatment.
All those undergoing the placebo treatment will be offered the real procedure after the trial if it proves effective.
Anyone who suffers migraine with aura and is interested in joining the study should call 0870 050 5898.