A brain arteriovenous malformation may not cause any signs or symptoms until the AVM ruptures, resulting in hemorrhage. In about half of all brain AVMs, hemorrhage is the first sign. AVM AVM But some people with brain AVM may experience signs and symptoms other than bleeding, such as: AVM 
Seizures
Headache or pain in one area of the head
Muscle weakness or numbness in one part of the body
 Some people may experience more-serious neurological signs and symptoms, depending on the location of the AVM, including: AVM 
Severe headache
Weakness, numbness or paralysis
Vision loss
Difficulty speaking
Confusion or inability to understand others
Severe unsteadiness
 Signs and symptoms of a brain AVM may begin at any age but usually emerge between ages 10 and 40. Brain AVMs can damage brain tissue over time. The effects slowly build and often cause symptoms in early adulthood. AVM AVM By middle age, however, brain AVMs tend to remain stable and are less likely to cause symptoms. AVM Research hasn't found that pregnancy increases the risk of hemorrhage for people with a brain AVM. However, more research needs to be done. AVM One severe type of brain AVM involves the vein of Galen. It causes signs and symptoms that emerge soon or immediately after birth. The major blood vessel involved in this type of brain AVM can cause fluid to build up in the brain and the head to swell. It can also cause swollen veins that are visible on the scalp, seizures, failure to thrive and congestive heart failure.