Migraine pain, from the heart
DEBORAH KERR has spent more than 30 years battling migraines so severe that at many times in her life she’s been bedridden three or four days a week, horribly nauseated and her head throbbing in pain. Newer migraine drugs eased her symptoms some, but she felt tethered to her medications. “I wouldn’t leave the house even to just go grocery shopping without medicine in my purse,” says the 54-year-old Bristol, Va., resident.
In April, Kerr took an unusual step to find some relief, and became the first person in the U.S. to participate in a test of an experimental migraine treatment. In a 45-minute outpatient procedure, doctors threaded a catheter through an incision in her groin, then snaked it up along a vein to her heart. There they implanted a device, smaller than a dime, to seal a small hole between two chambers.
She can already feel a difference. She now gets about one headache a month, instead of three a week, and the intensity of her pain is greatly diminished. “It’s nothing like it was before,” she says. “On a scale of 1 to 10, the pain used to be a 10. Now it’s about a 3, and it doesn’t last more than a day.”
Growing anecdotal and scientific evidence suggests that a common heart defect might be the culprit behind some severe migraines. Physicians in Europe and the U.S. first became aware of this connection in the late 1990s, when they patched tiny holes in the hearts of stroke victims -- and those patients who also suffered from migraines experienced an unexpected dividend: Their headaches magically vanished.
Now, four of the companies that make devices to plug these holes have launched clinical trials in the U.S. and Europe to test this serendipitous discovery. Kerr is one of more than 1,000 patients who are expected to participate over the next three years.
“Potentially, this could be a breakthrough for some migraine sufferers who don’t respond to conventional treatment,” says Dr. Richard B. Lipton, a neurologist and director of the Montefiore Headache Center in New York City. He adds that there is a long history, in migraines, of chance observations leading to new therapies.
More than 28 million Americans are stricken with these chronic and crippling headaches. About 15% of people who get migraines experience auras, a more severe form of headache with symptoms such as blind spots, flashing lights, or pins and needles in limbs.
Recent research reveals there is a link between these type of migraines and a common heart defect called a patent foramen ovale, or PFO, which is an abnormal opening between the heart’s two upper chambers.
We’re all born with a PFO: During fetal development, it allows the blood to bypass the lungs and go straight to the brain and other parts of the body. Normally, the hole closes shortly after birth but in about a quarter of the population, it may remain open, though it usually doesn’t cause any health problems.
However, physicians have discovered that 40% to 70% of migraine sufferers with auras have a moderate or large PFO, which is several times the incidence in the general population. And in patients who are stricken with types of strokes known as cryptogenic strokes -- which are often associated with PFOs -- about half also have migraines.
“These bad headaches are gone 50% to 75% of the time when we close up their PFO,” says Dr. Jonathan Tobis, an interventional cardiologist at UCLA’s Geffen School of Medicine who is testing one of the devices.
Scientists don’t know why the PFO hole plays a role in triggering migraines, but they speculate that when the blood bypasses the lungs, and instead is shunted directly from the right to the left chamber of the heart, impurities that would have been filtered out by the lungs remain in the blood.
“Something -- either tiny blood clots or chemicals -- is being delivered to the brain that increases the likelihood someone will have migraines,” says Lipton.
In the past, PFO closure required cracking the rib cage and operating directly on the heart. Now, because of the development of tiny implants that can be inserted into the heart through a catheter, sealing these holes has gotten much easier, making the use of this technique for treating migraines far more feasible.
Some European physicians are already sealing PFOs to treat migraine sufferers. “Hardly anyone gets completely cured, but about half show some improvement,” says Dr. Bernhard Meier, head of cardiology at University Hospital in Bern, Switzerland, and the lead investigator on the European clinical trials.
And in a British study involving 147 migraine sufferers, which was presented in March at a medical meeting, patients who received the implant experienced a 37% reduction in migraine burden, meaning the number of headaches and the length of time each one endured. That was compared to a 17% symptom reduction in those who underwent a sham procedure. “These results are as good as any drug,” says Tobis.
Experts don’t think migraine sufferers should get this defect repaired just yet: Large clinical trials are needed first.
“Any time you do an invasive surgical procedure, there is a potential for problems,” says Dr. Stephen Silberstein, a neurologist at Thomas Jefferson University in Philadelphia and a past president of the American Headache Society. “We don’t want to treat people without proof. We should know within the next three years if this works.”
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Alternate routes to relief
Two devices to treat migraines are also being studied in clinical trials. One uses a transcranial magnetic stimulator, an external device that creates a magnetic field, to stave off symptoms of acute migraines. In a 2006 study with 42 volunteers, patients in the TMS group reported that about 70% of their headaches were mild or no longer painful within two hours, compared with 42% in the placebo group.
The other device is an occipital nerve stimulator, which delivers electrical impulses via wires implanted under the skin near the base of the head. In preliminary tests, about 60% of chronic migraine sufferers had significant improvement, and an additional 20% got some relief.
“These were all patients who didn’t get any relief from medication and were severely disabled by their headaches,” says Dr. Todd Schwedt, neurologist at Washington University in St. Louis and an investigator on the ONS study.
-- Linda Marsa
