Some scientific studies have suggested a link between migraine with aura and a patent foramen ovale (PFO), a relatively common congenital heart defect. With this postulated link, controversy arose within the medical community about whether PFOs should be closed to prevent stroke and migraines. The overall consensus leans greatly towards "no."
The foramen ovale is a potential opening between the right and left atrium—the two upper chambers of the heart. During fetal development there is a hole in the atrial septum, which is closed by a flap of tissue immediately after birth. In about 25 percent of us, this flap of tissue can open on occasion, creating a momentary communication between the two atria. This condition is called a patent foramen ovale.
In people with PFO, anything that causes a transient increase in right-sided cardiac pressure (such as straining during a bowel movement) can open the flap for a few moments and allow blood to flow from the right atrium to the left atrium, a so-called right-to-left shunt. This shunting can allow for tiny clots to travel from the heart to the brain, causing transient ischemic attacks (TIAs) or strokes.
A Controversial Link Between Migraines and Patent Foramen Ovale
Studies have suggested that people with migraines with aura are more likely to have a PFO and that, likewise, those with a PFO are more likely to suffer from migraine with aura.
In terms of the reason for this relationship, some experts have suggested that it's due (at least in part) to the mixing of oxygenated and non-oxygenated blood in the heart. Others have hypothesized that tiny clots pass from the right side of the heart to the left through the foramen ovale and that these tiny clots travel to the brain where they trigger migraine attacks. It's important to note that neither of these propositions has been proven—they are vague theories at most.
Many experts argue that studies showing a link between PFO and migraine were not adequately designed and that there is no good quality scientific proof that this link even exists. For one thing, the large majority of people who have a PFO don't have migraines.
Others argue that the evidence is mixed, but that there's more evidence to support an association between PFO and migraine with aura than there is to disprove it.
Common Symptoms of a Migraine Aura
Research studies do not support PFO closure surgery for migraine, as it has been shown to cause little or no improvement. Not only that, PFO closure is not a minor procedure. There are serious potential side effects including, but not limited to, chest pain, abnormal rhythms of the heart, bleeding, and a serious heart condition called cardiac tamponade, which can result in death.
Because of its risks and the fact that evidence doesn't show that it significantly improves the frequency or severity of migraines, PFO closure is not recommended as a conventional or preventive migraine therapy at this time.
This also means that testing for a PFO with an echocardiogram (ultrasound of the heart chambers) is not a routine practice in those with migraines.
Some experts believe there may be subgroups of people with migraine for whom PFO closure surgery would be beneficial, but they acknowledge that more research needs to be done to verify this.
The Controversy Behind Closed PFOs
While the procedure of closing PFOs for treating migraines may have worked for a few select migraineurs, either in the studies or anecdotally, the scientific evidence is simply not there to back it up. Plus, closure of PFO is not a benign procedure—it's risky, and even if you have a PFO, there are much safer, more reasonable options to pursue for your migraine therapy.