Neurological aspects of patent foramen ovale: in search of the optimal treatment.

Although paradoxical embolism through a patent foramen ovale (PFO) has become an established cause of cerebral ischemia in younger patients without other obvious causes of stroke, the therapeutic options have not been investigated satisfactorily. There are still uncertainties about the natural history of PFO patients after suffering a stroke, and diagnostic criteria proving a causal and not incidental relation to the embolic event are not established. The stroke recurrence has been evaluated in several studies in a heterogeneous population and seems as low as 1.9% per year. Secondary prophylactic treatment has become a matter of discussion since efforts were made to close the PFO either surgically or by percutaneous transcatheter methods. Foramen closure seems to be effective in eliminating the mechanism of paradoxical embolism but its benefit-risk ratio has yet to be established. Following the goals of evidence-based medicine, none of the therapeutic options can be recommended. Fortunately, the issue has gone to trial and there are two studies underway to compare foramen closure to medical therapy.