Patent Foramen Ovale in Cryptogenic Stroke: Diagnosis and Treatment

Patent foramen ovale (PFO) is the most common congenital cardiac deformity which is found in about 25% of general population and with a higher incidence of 50% in those with cryptogenic stroke patients.Right-to-left shunting through the PFO (paradoxical embolism) was regarded as the pathomechanism causing ischemic stroke (PFO-stroke).PFO-stoke more appeared as a small cortical lesion in the posterior circulation with less conventional risk factors.Large PFO with more shunting or a coexisting atrial septal aneurysm was regarded as high-risk PFO for ischemic stroke.While earlier clinical trials did not prove superiority of percutaneous PFO-closure over medical therapy, several meta-analyses showed positive results regarding closure.Recently three large randomized clinical trials and one long-term follow-up study have shown that PFO-closure is beneficial over standard medical therapy to cryptogenic stroke patients.However, still finding the true culprit PFO for ischemic stroke is crucial to determine the treatment strategy.This review article describes the relationship between PFO and cryptogenic stroke, reviews the current diagnostic method of the PFO assessment, discusses the clinical characteristics of PFO related stroke, and reviews result of recent randomized clinical trials. J Neurosonol Neuroimag 2018;10(1):5-12