Symptoms of arteriovenous malformation, or brain AVM, include bleeding in the brain, seizures, headache or localized head pain, muscle weakness or numbness and vision loss, according to Mayo Clinic. Other symptoms include difficulty speaking, confusion and unsteadiness.
Brain arteriovenous malformations often do not cause any overt symptoms until they rupture, notes Mayo Clinic. However, hemorrhage is the first symptom in approximately half of all cases. Symptoms usually occur between the ages of 10 to 40, but can become apparent at any age. Over time, episodes can damage brain tissue and cause symptoms in early adulthood. The cause of arteriovenous malformations is unknown as of 2015.