Brain arteriovenous malformations in adults.

Arteriovenous malformations of the brain (AMB) can cause stroke when they rupture. Epidemiological and imaging research has found that about 50% of patients with AMB present with haemorrhage, and the other 50% either present with non-focal symptoms, such as headache, seizure, or focal neurological deficit, or have no symptoms and the lesion is found during unrelated investigations. Treatment for arteriovenous malformations aims to prevent and resolve haemorrhage and is a growing interdisciplinary challenge. Although treatment uses enormous resources, there have been few studies on the risk-benefit ratios for treatment of unruptured AMB and the best approaches.