Abstract
The cerebrum is served both by the carotid arteries and the vertebral artery (which unite to form the basilar artery). These three blood vessels are connected by the circle of Willis, so that if one fails the others can take over to a degree. Failure of the basilar artery is inevitably catastrophic, however, since the brainstem is deprived of oxygenated blood. Regulation of the cerebral vascular system is autonomous of the rest of the body, so that a fall in blood pressure does not immediately affect the cerebrum. If cerebral perfusion is impaired, infarction can occur. That gives rise to various syndromes, depending on which region is affected. Blood vessel abnormalities in the form of aneurysms, arteriovenous malformations, dissection and a number of less common problems lead to neurological conditions and potentially to serious disability. Diagnosis is based on contrast medium tracking, MRI and/or sonography.