AVM stands for arterio-venous malformation. These lesions are an abnormal communication of the arteries that feed directly into veins, thereby bypassing the normal capillary bed. As a consequence, the veins, which are designed to carry venous blood at a pressure of 5-7 mmHg must carry much higher pressure blood (70-90 mmHg) and therefore are prone to leaking or frankly rupturing. Although people are born with these AVM’s, they tend to leak later in life and cause symptoms either by damaging the surrounding brain or by causing headaches or seizures.
In general, AVM’s are best treated by arterial embolization (blockage), followed by a surgery to remove and cure them. Deep-seated AVM’s may be treated best with focused radiation, such as CyberKnife.
In addition to brain AVM’s, Dr. Watson has special expertise in AVM’s of the spinal cord, having written on the subject while at the NIH. These spinal lesions typically do not need to be embolized but can be cured surgically in 90% of cases.