[ESUS (embolic stroke of undetermined sources)].

Cryptogenic stroke is one-fourth among cerebral infarction, but most of them could be ascribed to embolic stroke. ESUS was proposed for unifying embolic stroke of undetermined sources by Hart et al. in 2014. The etiologies underlying ESUS included minor-risk potential cardioembolic sources, covert paroxysmal atrial fibrillation, cancer-associated coagulopathy and embolism, arteriogenic emboli, and paroxysmal embolism. Extensive evaluation including transesophageal echocardiography and cardiac monitoring for long time could identify the etiology of these patients. Although anti-platelet drug is recommended in ESUS in the current guideline, clinical trials are ongoing to determine the efficacy of non-vitamin K antagonist oral anticoagulant in ESUS patients.