[Cryptogenic stroke and patent foramen ovale]

A stroke of unknown etiology is commonly referred to as cryptogenic and is diagnosed in a considerable patient population of especially young age. Numerous case-control studies revealed a strong and consistent association between cryptogenic stroke and the presence of a patent foramen ovale. This relationship corroborates paradoxical embolism as likely stroke mechanism in this patient population. In approximately twenty-five percent of patients with cryptogenic stroke, the patent foramen ovale is accompanied by an atrial septal aneurysm, which considerably heightens the risk for recurrent neurological events. Therapeutic measures for secondary prevention in this patient population encompass medical treatment with antiplatelet agents or anticoagulants and surgical or percutaneous closure of patent foramen ovale. Currently, randomised clinical studies compare medical treatment with closure of patent foramen ovale to determine the most effective treatment strategy in this patient population.