Brain AVM Frequently Asked Questions
How common are arteriovenous malformations?
An AVM is very rare and affects less than one percent of the population, or about 10 per 100,000 people.
An estimated 300,000 Americans are affected by arteriovenous malformations of the brain and spinal cord (neurological AVMs), but only about 12 percent of the affected population will have symptoms.
Who gets arteriovenous malformations?
Arteriovenous malformations are equally common among men and women of all races and ethnicities. They are believed to be congenital (existing at birth), but they can enlarge over time and cause symptoms at any age.
Pregnancy can sometimes cause a sudden onset or worsening of symptoms because of cardiovascular changes, such as increases in blood volume and blood pressure.
Can you live with a brain AVM?
Many people do live with a brain AVM: Some are too big, too dangerous, and too risky to take out or treat with radiosurgery or other methods. These individuals live with their AVM, and can do well. However, if a non-bleeding AVM converts to a bleeding AVM, the resulting complications and neurological deficits that might require treatment.
How are arteriovenous malformations diagnosed?
Most arteriovenous malformations are detected through diagnostic imaging, such as a CT or MRI scan. Angiography, an imaging technique that involves the injection of a special dye, may be used to get a better look at the AVM.
Because most people with AVMs experience few symptoms, they are often discovered during treatment for an unrelated disorder.
Can a cerebral arteriovenous malformation cause personality changes?
An AVM does not necessarily cause personality changes, unless it has bled and damaged the brain.
Is an AVM serious?
Yes, being diagnosed with a brain AVM is serious. If you’ve been given the diagnosis of having an AVM, you should make an appointment with a neurosurgeon who is an expert in treating these lesions. Your neurosurgeon will then recommend a care plan that could include observation, treatment, and multimodality intervention.
What causes an arteriovenous malformation to bleed?
In AVMs, blood flows directly from arteries to veins without the buffer of capillaries. Arterial pressure is too high for veins to accommodate due to their thinner walls, which can weaken the blood vessels and cause rupture. Researchers are studying other possible factors in AVM rupture.
An AVM is not a stroke, but an AVM can cause a hemorrhagic stroke if it ruptures and bleeds into the brain. This is called an intracerebral hemorrhage, or occasionally a subarachnoid hemorrhage.
Can an arteriovenous malformation cause dementia?
No, the presence of an AVM does not cause dementia. However, a hemorrhagic stroke caused by an AVM can cause problems with memory.
Can an arteriovenous malformation go away on its own?
No, an AVM cannot go away on its own. However, it can be removed with surgery, sealed off with endovascular embolization, or reduced in size with radiosurgery.
What is the difference between an AVM and a brain aneurysm?
An AVM is an abnormal connection between arteries and veins without intervening capillaries with blood flowing through vessels at a high speed and high pressure. An aneurysm is an outpouching of the arterial wall that forms a balloon, or bulge, which can burst. There’s no arteriovenous shunting with an aneurysm, meaning there is no “short circuit” of blood flow. This arteriovenous shunting is the hallmark of AVMs.
Is an AVM a birth defect?
Whether or not an AVM is a birth defect is controversial, with members of the medical and scientific community taking both sides. It once was assumed to be a birth defect but, more recently, AVMs have been produced in mice through genetic manipulation. In light of this, the tide is shifting toward viewing an AVM as a disease that progresses through a genetic mutation that occurs early in life, in combination with some angiogenic stimulus or event.
Can an AVM get worse?
Yes, an AVM can get worse over time if it enlarges, bleeds, or develops other features, like feeding artery aneurysms or venous varices that indicate that the tissues are getting weaker and more prone to bleeding.
Additional Resources
The Aneurysm and AVM Foundation
