The patent foramen ovale-migraine question.

A strong association between migraine with aura and patent foramen ovale (PFO) with shunting has been suggested. Similarly, an association of migraine with aura and Osler-Weber-Rendu disease, probably also due to shunting though pulmonary arteriovenous malformations has been proposed. PFOs are also comorbid with cryptogenic strokes, refractory hypoxaemia in right ventricular infarction or severe lung disease, orthostatic oxygen desaturation and decompression illness in scuba divers.Multiple open-label, retrospective and case-controlled studies of PFO closure report improvement of migraine with aura. MIST, the only prospective sham-controlled study of PFO closure for migraine with aura, did not reach its primary endpoint for migraine resolution, although it clearly demonstrated an association between migraine with aura and the severity of the PFO shunt. One reported secondary endpoint showed a significant 42% reduction of migraine days, suggesting the need for further randomised, sham-controlled PFO closure studies.