A brain AVM is an abnormal connection between arteries and veins in your brain. Doctors believe that a brain AVM develops during fetal development. Why this occurs for some babies and not others is unknown.
Normally, your heart sends oxygen-rich blood to your brain through arteries, which branch into smaller arterioles and subsequently to capillaries, the smallest blood vessels. Oxygen is removed from blood in the capillaries and used by your brain. The oxygen-depleted blood then passes into small venules and then into larger veins that drain the blood from your brain, returning it to your heart and lungs to get more oxygen.
If you have a brain AVM, blood passes directly from your arteries to your veins via abnormal vessels. This disrupts the normal process of how blood circulates through your brain.
Feb. 12, 2011
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