Migraines and Patent Foramen Ovale - Not Related?

Only 2% of subjects had both patent foramen ovale (PFO) and migraine, as reported by Dr. Tatjana Rundek and colleagues, University of Miami, FL.

Their finding is based on analyzing data from the Northern Manhattan Study (NOMAS). Here's a brief summary of the study:

1101 stroke-free subjects, mean age 69, were asked about their history of migraine, then screened for PFO using transthoracic echocardiography. 16% of the population reported a history of migraine, 15% were found to have PFO. Adjusting for possible confounders, including diabetes, hypertension, smoking, or dyslipidemia, the researches found only 2% reliable overlap of PFO and migraines.

If anyone would bother to ask yours truly opinion, there's at least a couple of problems with this study:

• Mean age 69 means older people. That would exclude many who used to have migraines when they were yonger. Such as women before menopause. That alone would account for a very large group. Men might lose their migraines as they get older as well, be it at much smaller proportion.
• Excluding comorbidities, "diabetes, hypertension, smoking, or dyslipidemia", might not be exactly wise move either. Migraines rarely come alone.
• The study keeps mentioning a "self-reported migraine". Is there any other kind? Is there a way to reliably diagnose migraine otherwise? If there is, yours truly would really like to know.

The doctors behind the study do make a strong case, however:

"Migraine either with or without aura is a very complicated disorder in terms of the pathophysiology, and the mechanisms are still not clearly known to the full extent. It's hard to believe that having a PFO would be completely linked to such a complex mechanism of migraine and that by closing PFO we would completely eradicate migraine," Dr. Rundek said. Earlier studies reporting a link between PFO and migraine "speak more to maybe some underlying genetic mechanism or some specific polymorphism that actually predisposes people to have both conditions than actually having the conditions linked through a certain mechanism."

Dr. Randy Evans, Baylor College of Medicine, Houston, TX - "the link between migraine, stroke, and PFO is becoming more and more tenuous. Despite several positive observational studies, the controversial MIST trial showed no improvement in migraine frequency with PFO closure. And now, despite case-control studies showing an association between migraine with aura and PFO, the population-based NOMAS study shows no association."

Dr. Tobias Kurth, Brigham and Women's Hospital, Boston, MA - "Detection of PFO or PFO closure should not be recommended to patients who have only migraine. It is, however, plausible that PFO may affect specific subgroups of patients with migraine, and future studies identifying and targeting such subgroups are warranted."

Yours truly tends to agree with Dr. Kurth in that more studies are warranted. Population-based study with participants being way above the age where statistically most migraines tend to occur is hardly conclusive.

sources:

NOMAS: Just a 2% overlap for PFO and migraine; St Jude shuts down ESCAPE trial

Patent foramen ovale and migraine: a cross-sectional study from the Northern Manhattan Study (NOMAS)

Migraine. A Matter of the Heart?