Arteriovenous Malformations Arteriovenous malformations (AVMs) occur when a group of blood vessels in your body forms incorrectly. Carotid Artery Disease Carotid artery disease occurs when the carotid arteries, the main blood vessels that carry oxygenated blood to the brain, become narrowed. Cavernous Malformations Cavernous malformations, also called cavernous venous malformations or, when they are in the brain, cerebral cavernous malformations, occur when the blood vessels don’t form correctly. Developmental Venous Anomalies A developmental venous anomaly (DVA) is an arrangement of small blood vessels that may look like the spokes of a wheel and drain into a larger central vein. DVAs also may be referred to as venous angiomas. Cerebral Aneurysm A cerebral aneurysm is a bulging, weakened area in the wall of an artery in the brain. This weak spot raises the risk that the artery wall will burst open. Spinal Arteriovenous Malformations When veins and arteries don't form correctly and become entangled during development, the result is a condition known as an arteriovenous malformation (AVMs). Cerebral Venous Sinus Thrombosis CVST is a rare form of stroke. Infants, children, and adults all can have this kind of stroke.