The cause of cerebral infarction is unknown in 35-40% of cases, and the incidence of foramen ovale nonocclusion is higher in younger patients (<55 years of age) about 47-56% of unexplained cerebral infarctions, whereas the incidence of foramen ovale nonocclusion in patients older than 55 years of age is only 4-18%. Younger patients (<60 years) may be caused by paradoxical embolization of small venous emboli through the foramen ovale, a hypothesis that can be demonstrated by transcranial ultrasonography (tcd). Most studies have shown that unexplained stroke is associated with an unclosed foramen ovale. Large-scale controlled studies abroad have found a higher overall relative risk of combined foramen ovale insufficiency in patients with unexplained stroke.The WARSS study showed that neither oral warfarin nor aspirin reduced the risk of recurrent stroke, and the annual recurrence rate of stroke remained as high as 8% in both groups of patients treated with the drug. Since patent foramen ovale is associated with unexplained stroke, closing the PFO has the potential to prevent stroke recurrence. After interventional closure of patent foramen ovale nonocclusion in 3819 patients, the annual recurrence rate of stroke and the rate of transient ischemic attack were significantly reduced to 0.47% and 0.85%, respectively. For unexplained cerebral infarction in young people, transcranial ultrasonography and cardiac ultrasonography are recommended, and positive patients should undergo foramen ovale unclosed interventional occlusion.