arteriovenous malformations of the brain
Cerebral arteriovenous malformation (AVM) is a congenital malformative communication between the veins and the arteries in the brain in the form of a nidus, an anatomical structure composed of dilated and tangled supplying arterioles and drainage veins with no intervening capillary bed, that can be asymptomatic or cause, depending on the location and the size of the AVM, headaches of varying severity, generalized or focal seizures, focalneurological defects (weakness, numbness, speech difficulties, vision loss) or potentially fatal intracranial hemorrhage in case the AVM ruptures.