Cerebral Arteriovenous Malformations

Anthony Chang, MD

 

•  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

  
  
  
  

  Unenhanced and enhanced axial CTs of brain shows a large, serpiginous AVM adjacent to the tentorium

  
  

• 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

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