Symptoms

Symptoms of AVM vary based on where it's located. Often the first signs and symptoms appear after bleeding occurs. Besides bleeding, signs and symptoms can include:

• Progressive loss of neurological function
• Headaches
• Nausea and vomiting
• Seizures
• Loss of consciousness

Other possible signs and symptoms include:

• Weak muscles
• Paralysis in one part of the body
• Loss of coordination that can cause problems with gait
• Problems performing tasks that require planning
• Weakness in the lower extremities
• Back pain
• Dizziness
• Vision problems, including losing part of your field of vision, loss of control of eye movements, or swelling of part of the optic nerve
• Problems with speech or understanding language
• Unusual sensations including numbness, tingling or sudden pain
• Memory loss or dementia
• Hallucinations
• Confusion

Children and teens may have trouble with learning or behavior.

One type of AVM called a vein of Galen defect causes symptoms that appear at or shortly after birth. A vein of Galen defect is located deep inside the brain. Signs can include:

• A buildup of fluid in the brain (hydrocephalus) that causes enlargement of the head
• Swollen veins on the scalp
• Seizures
• Failure to thrive
• Congestive heart failure

When to see a doctor

Seek medical attention if you have any of the signs and symptoms of an AVM, such as headaches, dizziness, vision problems, seizures and changes in thinking or neurological function. Many AVMs are currently discovered incidentally, often after a CT scan or an MRI is obtained for reasons not directly related to the AVM.