My mom was diagnosed with a AVM brain tumor... what exactly is it?

Does it require radiation/surgery if she's over 50?

Arteriovenous malformations (AVMs) are the leading cause of stroke in young people. Formed during embryonic development, an AVM is a tangle of dilated blood vessels that disrupts normal blood flow in the brain by pooling blood within its dense center or nidus. These vessels may enlarge over time.

Often "silent" for many years, AVMs typically begin to cause problems for patients between 10 and 30 years of age when they may experience severe headaches or seizures or suffer a stroke from a hemorrhage (bleeding) in the brain. While the first rupture may be fatal, more than 90 percent of patients survive with appropriate treatment.

The goal of treatment is to reduce this risk of fatal or debilitating hemorrhagic stroke. Twenty years ago, many patients were told their AVM was inoperable because the risks of treatment were considered too high. Today, advanced open skull surgical techniques, radiosurgery and endovascular embolization make the treatment of AVMs safer and highly effective.

Treatment begins with thorough, specialized imaging studies - usually computed tomography (CT), magnetic resonance imaging (MRI) and angiography - to determine precisely the size, location and blood-flow patterns of the AVM.

A multidisciplinary team of neurosurgeons, neuroradiologists, neurologists and neuropsychologists then discusses the case to develop an appropriate treatment plan. Current acceptable treatment usually involves some combination of embolization, open skull surgery and radiosurgery. It is important for the treating team to have all of these options in a state-of-the-art facility housing dedicated angiography suites, microsurgical-equipped operating rooms and radiosurgery.

http://www.ninds.nih.gov/disorders/avms/...

A-V malformation: A haemangioma or arteriovenous malformation is a tangle of abnormal vessels that forms an abnormal communication between the arterial and venous systems. Most are developmental (congenital). If large enough, they may produce a shunt of sufficient magnitude to raise the cardiac output. AVM's may occur in the brain, brainstem and spinal cord, where they may cause headaches, seizures or bleeding (subarachnoid haemorrhage).

An AVM is a collection of blood vessels that have no capillaries and are connected abnormally. They can cause severe to fatal strokes. Surgery can be done to close the artery feeding blood into the AVM. More from a Wikipedia article:

"The treatment in the case of sudden bleeding is focused on restoration of vital function. Anticonvulsant medications such as phenytoin are often used to control seizure; medications or procedures may be employed to relieve intracranial pressure. Eventually, curative treatment may be required to prevent recurrent hemorrhage.

Surgical removal of the blood vessels involved (craniotomy) is the preferred curative treatment for most types of AVM. While this surgery results in an immediate, complete removal of the AVM, risks exist.

Radiation treatment (radiosurgery) has been widely used on smaller AVMs with considerable success. The Gamma Knife, developed by Swedish physician Lars Leksell, is one apparatus used in radiosurgery to precisely apply a controlled radiation dosage to the volume of the brain occupied by the AVM. While this treatment is non-invasive, two to three years may pass before the complete effects are known. Complete occlusion of the AVM may or may not occur.

Embolization, that is, occlusion of blood vessels via coils or screens introduced by a radiographically guided catheter, is frequently used as an adjunct to either surgery or radiation treatment. However, embolization alone is rarely successful in completely blocking blood flow through the AVM."