No matter who you are or what you’re fighting, a cancer diagnosis can be one of life’s most frightening experiences – but with OC CyberKnife, it’s never something you have to face alone. As a leading radiation oncology clinic serving the Orange County, CA area, we provide world-class cancer treatment from our state-of-the-art cancer center in Orange County. We strive to take an integrated approach to fighting cancer, combining cutting-edge treatments like CyberKnife with a knowledgeable, experienced team of cancer treatment experts. We work hard to keep our patients as educated as possible about their situation and options, which is why we’ve compiled some of the most common question & answers about arteriovenous malformations (AVMs).
Generally speaking, brain AVMs are relatively uncommon and occur in less than 1 percent of the general population – about 1 in 200-500 people may develop an AVM. AVMs are slightly more common in males than in females, although scientists aren’t entirely sure why.
Researchers still don’t know for certain why brain AVMs occur. Brain AVMs are usually congenital, which means patients are born with them, but they don’t appear to be hereditary. For this reason, you aren’t necessarily more likely to have an AVM if your parents had one, and you won’t probably pass on an AVM to your children if you have one.
Brain AVMs may form anywhere within the brain or in the covering of the brain. This means they can form in the four major lobes of the brain – the frontal, parietal, temporal, or occipital lobes – the back of the brain (cerebellum), the brainstem, or the ventricles (the deep spaces in the brain that produce and circulate cerebrospinal fluid).
Generally, AVMs don’t grow or change very much. The vessels involved in the malformation can wide (dilate) and some AVMs can shrink due to clots, while others may grow larger. It depends on the specific case and patient.
By definition, a brain AVM is a malformation of the blood vessels and therefore contains abnormal, weakened blood vessels that direct blood away from healthy brain tissue. Over time, these weakened blood vessels can widen, eventually bursting due to high blood pressure in the AVM. An AVM that bursts causes bleeding in the brain, which can lead to any number of serious side effects, including death.
Any single brain AVM has about a 1-3 percent chance of bleeding every year. Over the course of 15 years, a brain AVM has about a 25% chance of bleeding, usually leading to brain damage and stroke.
The risk of a second (recurrent) bleed from an AVM is slightly higher for a brief period after an initial bleed. Risks vary based on specific conditions, but generally range between a 6 to 18% increase in the first year after a bleed. In the first year after the second bleed, risk may be increased by up to 25%. Risk is also slightly higher for patients between 11 and 35 years old.
Generally speaking, bleeding from a brain AVM is a very serious and dangerous event. The risk of death for each bleed is about 10-15%, and the chance of permanent brain damage ranges from 20 to 30%. This is because anytime blood leaks into healthy brain tissue, the tissue is damaged, resulting in a loss of normal function that may be temporary but can also be permanent. Symptoms of a bleeding AVM can vary widely, but include arm or leg weakness, paralysis, difficulty with speech, or vision and memory loss. The severity of the brain damage depends on the location and severity of the brain bleed.