People generally think that strokes are mostly a disease of the elderly. It is true that the most common cause of stroke is atherosclerosis, and the incidence of atherosclerosis increases with age, so it is true that stroke patients are more common in the elderly, but young people can also suffer from this “disease of the elderly”. A few days ago, a patient came to the clinic, only in his early 30s, the child was only 3 years old, but he had a stroke, the medical term for a stroke. Although her condition improved after active treatment, she was left with sequelae such as hemiplegia and slurred speech. After examination, it was found that the culprit of her stroke was an unclosed foramen ovale. Another typical example, on October 30, 2011, the famous Italian Milan soccer star Cassano was returning from a match with Roma by plane, when he suddenly felt unwell at the airport and experienced blurred vision, confusion, general weakness and difficulty in speaking, he was immediately sent to Milan General Hospital for examination. The results confirmed that the heart oval foramen was not closed, and the transient lack of blood supply to the brain was caused. At 8:35 a.m. Italian local time on November 4, Cassano had successfully undergone heart surgery. After several months of rest and rehabilitation, Cassano participated in the 2012 World Cup in South Africa. Another celebrity who suffered a stroke due to an unclosed foramen ovale was not as lucky as Cassano: former Israeli Prime Minister Sharon. He had normal blood vessels like young people, but suffered a stroke due to PFO. In order to prevent blood clots, he took oral anticoagulants, which unfortunately led to a brain hemorrhage. Although several craniotomies were performed to stop the bleeding, they failed to prevent his brain from dying. Now Sharon is alive, but his brain is long dead. Sharon’s stroke paralyzed his own body, his family, his career, and his unfulfilled dream of peace in the Middle East. What is the foramen ovale? The foramen ovale is a structure that forms inside the heart during embryonic development and is located between the left and right atria. The foramen ovale is a vital channel necessary for fetal development, and it is through this channel that blood from the mother’s umbilical vein enters the left side of the fetal heart chambers and is then, distributed throughout the body to provide the oxygen and nutrients needed for fetal development. However, after birth, with the first cry, the pressure in the left atrium rises, causing the primary septum on the left to partially adhere to the secondary septum on the right, and functional closure of the foramen ovale occurs, reaching anatomical closure within 1 year. In some people, for various reasons, the foramen ovale does not close after birth, and if the foramen ovale remains unclosed beyond the age of 3 years, it is called unclosed foramen ovale. Ovular foramen insufficiency is by far the most common congenital heart anomaly in adults, and it can be detected in about 1 in 4 people in the normal population. It has long been thought to be “irrelevant” because it does not generally cause a bifurcation of the two chambers and has no effect on the hemodynamics of the heart. In recent years, many studies have shown a close association between patent foramen ovale and patients with unexplained stroke because the following emboli can enter the left heart system through the patent foramen ovale and cause the corresponding clinical symptoms: 1) thrombus in the deep veins of the lower extremities or pelvic veins; 2) air emboli due to diving or decompression sickness; 3) fat emboli after surgery or trauma. Moreover, the risk of recurrence remains high in patients with unclosed foramen ovale who have had a thrombotic event. The association of patent foramen ovale with cryptogenic stroke in young people in China has been shown in a national multicenter study, which was published in the European Journal of Neurology. In recent years, the incidence of stroke in young people has been increasing year by year in China. A proportion of patients without high risk factors for stroke, such as hypertension, hyperlipidemia, smoking, and other common causes such as intracranial and extracranial large vessel stenosis and atrial fibrillation, have had strokes. This cryptogenic stroke is a rare disease and one of the difficult conditions in neurology. In the 1980s, countries such as Europe and the United States proposed that foramen ovale opacities (congenital orifices of the right and left heart that are usually closed after birth) are associated with cryptogenic stroke, and that paradoxical thrombus from a venous source reaching the body circulation via the PFO is an important cause of cerebral infarction. The Chinese population has a very low incidence of venous thrombosis compared to the European and American populations, so confirmation of the association of PFO with cryptogenic stroke in the Chinese population is important for this hypothesis. Unfortunately, there is a long-standing gap in this research area. The results of this study at the Union Hospital suggest that Chinese people, like Westerners, are at risk for stroke occurrence due to unclosed foramen ovale. Therefore, treatment of the cause and closure of the unclosed foramen ovale in high-risk groups is expected to reduce the incidence of stroke. In addition, it has also been found that unclosed foramen ovale is associated with the development of decompression sickness and migraine, and closing the foramen ovale may be beneficial for these patients. Previously, closure of patent foramen ovale relied on surgical procedures. Surgical treatment has a high success rate and a low mortality rate, but it is rarely used in recent years because of the high trauma, the need for chest opening and the use of extracorporeal circulation. With the advances in technology, especially in cardiac catheterization, foramen ovale can be cured by interventional treatment. This technique requires only a very thin catheter inserted at the root of the thigh, through which a blocker is delivered into the heart to completely block the foramen ovale, and the procedure takes about 20 minutes, with the patient being able to move around the same day and be discharged the next day. Interventional occlusion has become the treatment of choice for patent foramen ovale.