Usually a congenital condition, arteriovenous malformation (AVM) is an abnormal connection between blood vessels in the brain.

It occurs when the arteries link directly with veins, bypassing capillaries. The resulting malformation can rupture and bleed into the cerebral area.

Why an AVM forms remains a mystery. Cerebral AVMS are extremely rare, but once developed tend to vary both in size and location in the brain. Most people with an AVM have no symptoms; consequently, it is often discovered during treatment for an unrelated disorder. Imaging tests to help with diagnosis include EEG, CT scan and MRI.

Symptoms

• Headache
• Seizures
• Buzzing or other noise in the ears
• Blurred, double or decreased vision
• Speech problems
• Dizziness
• Muscle weakness and even paralysis
• Problems walking
• Numbness and tingling
• Spontaneous pain
• Memory and cognitive problems
• Confusion and disorientation