To diagnose a brain AVM, your neurologist will review your symptoms and conduct a physical examination.
Your doctor may order one or more tests to diagnose your condition. Radiologists trained in brain and nervous system imaging (neuroradiologists) usually conduct imaging tests.
Neurology consultation at Mayo Clinic
Brain AVM Angiogram
Cerebral angiogram showing brain AVM
CT scans allow doctors to see cross-sectional CT scan images (slices) of your body.
Brain MRI scan
Tests used to diagnose brain AVMs include:
Cerebral arteriography. Cerebral arteriography, also known as cerebral angiography, is the most detailed test to diagnose an AVM. The test reveals the location and characteristics of the feeding arteries and draining veins, which is critical to planning treatment.
In this test, your doctor inserts a long, thin tube (catheter) into an artery in the groin and threads it to your brain using X-ray imaging. Your doctor injects dye into the blood vessels of your brain to make them visible under X-ray imaging.
Computerized tomography (CT) scan. A CT scan uses a series of X-rays to create a detailed cross-sectional image of your brain.
Sometimes a doctor injects dye through an intravenous tube into a vein so that the arteries feeding the AVM and the veins draining the AVM can be viewed in greater detail (computerized tomography angiogram).
Magnetic resonance imaging (MRI). MRI uses powerful magnets and radio waves to create detailed images of your brain.
MRI is more sensitive than CT and can show more subtle changes in brain tissue associated with a brain AVM.
MRI also provides information about the exact location of the malformation and any related bleeding in the brain, which is important for determining treatment options.
Your doctor may also inject dye to see the blood circulation in your brain (magnetic resonance angiogram).
There are several potential treatment options for brain AVM. The main goal of treatment is to prevent hemorrhage, but treatment to control seizures or other neurological complications also may be considered.
Your doctor will determine the most appropriate treatment for your condition, depending on your age, health, and the size and location of the abnormal blood vessels.
Medications also may be used to treat symptoms caused by the AVM, such as headaches or seizures.
Surgery is the most common treatment for brain AVMs. There are three different surgical options for treating AVMs:
In endovascular embolization, your doctor inserts a long, thin tube (catheter) into a leg artery and threads it through blood vessels to your brain using X-ray imaging. Your surgeon positions the catheter in one of the feeding arteries to the AVM, and injects an embolizing agent, such as small particles or a glue-like substance, to block the artery and reduce blood flow into the AVM.
Close-up of endovascular embolization
In endovascular embolization for AVM, a catheter deposits particles of a glue-like substance in the affected artery to block blood flow
Gamma Knife targeting
Individual radiation beams are too weak to hurt the brain tissue they travel through on the way to the target. The radiation is most powerful where all the beams intersect.
Surgical removal (resection). If the brain AVM has bled or is in an area that can easily be reached, surgical removal of the AVM via conventional brain surgery may be recommended. In this procedure, your neurosurgeon removes part of your skull temporarily to gain access to the AVM.
With the help of a high-powered microscope, the surgeon seals off the AVM with special clips and carefully removes it from surrounding brain tissue. The surgeon then reattaches the skull bone and closes the incision in your scalp.
Resection is usually done when the AVM can be removed with little risk of hemorrhage or seizures. AVMs that are in deep brain regions carry a higher risk of complications. In these cases, your doctor may recommend other treatments.
Endovascular embolization. In this procedure, your doctor inserts a long, thin tube (catheter) into a leg artery and threads it through blood vessels to your brain using X-ray imaging.
The catheter is positioned in one of the feeding arteries to the AVM, and injects an embolizing agent, such as small particles, a glue-like substance, microcoils or other materials, to block the artery and reduce blood flow into the AVM.
Endovascular embolization is less invasive than traditional surgery. It may be performed alone, but is frequently used prior to other surgical treatments to make the procedure safer by reducing the size of the AVM or the likelihood of bleeding.
In some large brain AVMs, endovascular embolization may be used to reduce stroke-like symptoms by redirecting blood back to normal brain tissue.
Stereotactic radiosurgery (SRS). This treatment uses precisely focused radiation to destroy the AVM. It is not surgery in the literal sense because there is no incision.
Instead, SRS directs many highly targeted radiation beams at the AVM to damage the blood vessels and cause scarring. The scarred AVM blood vessels then slowly clot off in one to three years following treatment.
This treatment is most appropriate for small AVMs that are difficult to remove with conventional surgery and for those that haven't caused a life-threatening hemorrhage.
If you have few or no symptoms or if your AVM is in an area of your brain that's hard to treat, your doctor may prefer to monitor your condition with regular checkups.
Potential future treatments
Researchers are currently studying ways to better predict the risk of hemorrhage in people with brain AVM to better guide treatment decisions. For example, high blood pressure within the AVM and hereditary syndromes associated with neurological issues may play a role.
Innovations in imaging technology, such as 3-D imaging, functional imaging and brain tract mapping also are being evaluated and have the potential to improve surgical precision and safety in removing brain AVMs and preserving surrounding vessels.
In addition, ongoing advances in embolization, radiosurgery and microsurgery techniques are making previously inoperable brain AVMs more accessible and safer for surgical removal.
Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.
Coping and support
Learning that you have a brain AVM can be frightening. It can make you feel like you have little control over your health. But you can take steps to cope with the emotions that accompany your diagnosis and recovery. Consider trying to:
- Learn enough about brain AVM to make informed decisions about your care. Ask your doctor about the size and location of your brain AVM and how that affects your treatment options. As you learn more about brain AVMs, you may become more confident in making treatment decisions.
- Accept your emotions. Complications of brain AVM, such as hemorrhage and stroke, can cause emotional problems as well as physical ones. Recognize that emotions may be hard to control, and some emotional and mood changes may be caused by the injury itself as well as coming to terms with the diagnosis.
- Keep friends and family close. Keeping your close relationships strong will help you during your recovery. Friends and family can provide the practical support you'll need, like accompanying you to doctors' appointments, and serve as emotional support.
- Find someone to talk with. Find a good listener who is willing to listen to you talk about your hopes and fears. This may be a friend or family member. The concern and understanding of a counselor, medical social worker, clergy member or support group also may be helpful.
Ask your doctor about support groups in your area. Or check your phone book, library or a national organization, such as the American Stroke Association or the Aneurysm and AVM Foundation.
Preparing for your appointment
A brain AVM may be diagnosed in an emergency situation, immediately after bleeding (hemorrhage) has occurred. It may also be detected after other symptoms prompt a brain scan.
But in some cases, a brain AVM is found during diagnosis or treatment of an unrelated medical condition. You may then be referred to a doctor trained in brain and nervous system conditions (neurologist or neurosurgeon).
Because there's often a lot to discuss, it's a good idea to arrive well-prepared for your appointment. Here are some tips to help you get ready for your appointment, and what to expect from your doctor.
What you can do
- Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance.
- Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
- Make a list of all medications, vitamins and supplements that you're taking.
- Ask a family member or friend to come with you, if possible. Sometimes it can be difficult to absorb all the information provided to you during an appointment. Someone who accompanies you may remember something that you forgot or missed.
- Write down questions to ask your doctor. Don't be afraid to ask questions that may come up during your appointment.
Your time with your doctor is limited, so preparing a list of questions ahead of time will help you make the most of your time together. For brain AVM, some basic questions to ask your doctor include:
- What are other possible causes for my symptoms?
- What tests are needed to confirm the diagnosis?
- What are my treatment options and the pros and cons for each?
- What results can I expect?
- What kind of follow-up should I expect?
What to expect from your doctor
Your neurologist is likely to ask about your symptoms, if any, conduct a physical examination and schedule tests to confirm the diagnosis.
The tests gather information about the size and location of the AVM to help direct your treatment options. He or she may ask:
- When did you first begin experiencing symptoms?
- Have your symptoms been continuous or occasional?
- How severe are your symptoms?
- What, if anything, seems to improve your symptoms?
- What, if anything, appears to worsen your symptoms?
What you can do in the meantime
Avoid any activity that may raise your blood pressure and put strain on a brain AVM, such as heavy lifting or straining. Also avoid taking any blood-thinning medications, such as warfarin.