Context

Stroke can rarely be caused by paradoxical emboli passing from the right side of the circulatory system to the left side. Case reports have shown that the most common site of right to left shunt is the patent foramen ovale (PFO), and case control studies have shown a higher prevalence of PFO in patients with cryptogenic stroke as compared to stroke victims with a known cause or non-stroke controls. Therefore, the question arises as to whether closure of the PFO is useful in preventing recurrent stroke in patients with cryptogenic stroke and PFO.