Migraine headaches are a particular kind of headache characterized by a "throbbing" or "pounding"-like pain.  They are clasically located on only one side of the head, but many people have migraines with pain on both sides of the head or "all-over".  The pain of a migraine headache is often severe, and during an attack, it is common to have sensitivity to bright lights and noise as well as nausea.  The pain of a migraine headache may last for hours or even days.

Some patients with migraine headaches experience an "aura" 10-30 minutes before the onset of the headache.  Typical auras may be visual - seeing flashing lights, motor -speech difficulty, weakness of an arm or leg, or  sensory - tingling of the face or hands. 

Recent studies have tied the phenomenon of migraine - and especially those with aura - to the presence of a patent formane ovale (PFO).

The pain of migraine headache is thought to be caused by abnormal dilation (opening) of the blood vessels in the head.  The aura that preceedes the headache in many people is thought be represent abnormal constriction (squeezing down) of the blood vessels before they dilate.  This constriction leads to low blood flow in that area of the brain, and transient ischemia (lack of oxygen) which causes the symptoms of aura.

There are several factors that may trigger this hyperreactivity of the blood vessels.  Certain foods - especially those containing substances that are "vasoactive" like red wine, chocolate and aged cheese are often culprits.  In women, hormonal changes at the times of menstruation may be a trigger.  In some patients, the triggers are very clear.  In other patients, the triggers are less well-defined. 

The link between migraine headaches and PFO was found only recently and by chance. There are some patients with strokes and a PFO who also have migraine headaches.  After these patients had their PFO closed to prevent recurrent strokes, many of these people reported a dramatic reduction in migraine frequency.

How could a PFO trigger migraine? It is thought that certain vasoactive substances in the body (those that are active on blood vessels) that are normally taken up by the lungs, could pass unfiltered via a PFO to the blood destined for the brain,  triggering a migraine in susceptible individuals.   By closing the PFO, it is though that these vasoactive substances are prevented from reaching the blood vessels in the head, removing a major migraine trigger.  

Most studies so far have been fairly small and observational.  To establish a true benefit to PFO closure, large randomized-controlled trials (where half the patients get the treatment and the other half do not) are required. 

A recent small randomized trial (MIST) examined the effect of PFO closure using the STARFlex PFO occluder in 147 patients with migraine headache and aura.  42% of patients treated with PFO closure had a greater than 50% reduction in headaches compared with 23% of controls.  While significant, there needs to be further work done to establish the true magnitude of the effect before PFO closure can be recommended as a therapy for migraine headache.

Mount Sinai has been invited to participate in a large, randomized multicenter trial examining the effect of PFO closure on migraine headache.  Details we will available soon for patients who would like to be considered for inclusion in this trial.

If you have migraine headaches and would like to be screened non-invasively for a PFO, please contact us.  If you are found to have a PFO, you may be eligible to participate in an upcoming trial.  Even if you do not wish to participate, knowing that you have a PFO may allow your headache doctor to better tailor your treatment.  Certain medicines may be better at preventing migraine headaches in patients with PFO.  To learn more about PFO screening click here.

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