Cerebral Arteriovenous Malformations
Submitted by Anthony Chang, MD

General Considerations

• True AVMs contain at least one enlarged feeding artery and at least one enlarged early draining vein.

• These vessels arise congenitally during fetal life and can be supplied from any cerebral vessel.
• Superficial AVMs may be supplied from the external carotid artery with a dural component.
• The AVM complex begins with the dilated feeding artery to the core/nidus (vascular cluster of entangled vessels) to enlarged draining veins

CT findings

• Vascular tangles are serpiginous and hyperdense without contrast from the blood pool effect.
• AVMs may contain punctate or curvilinear calcification.
• AVMs will enhance

MRI findings

• Curvilinear flow voids
• MRA for mapping

Angiogram

• Should demonstrate the three components of the enlarged feeding artery, core/nidus, and enlarged draining vein.
• Smaller AVMs may simple demonstrate early venous filling during the arterial phase of enhancement

Associated syndromes

• Sturge Weber
• Wyburn Mason
• Klippel-Trenaunay-Weber
• Osler Weber Rendu

Complications

• Hemorrhage
• Steal phenomenon where blood supply is preferentially delivered to AVM at the cost of normal brain parenchyma and can lead to focal neurological symptoms, seizure and focal atrophy.
• Aneurysms can form and become a source of hemorrhage

Treatment

• Endovascular embolization
• Surgery
• Radiation therapy

 
Cerebral Arteriovenous Malformation. Unenhanced (top) and enhanced (bottom) axial CTs of brain shows a large, serpiginous AVM in the left parietal lobe adjacent to the tentorium.

The Requisites: Neuroradiology 2^nd edition, Grossman and Youssem