Arteriovenous malformation (AVM) is an abnormal cluster of blood vessels in the brain that can cause devastating neurological deterioration or even death. It is most commonly diagnosed between ages fifteen to forty, and left untreated, can cause a progression of symptoms that can lead to permanent disabilities or death. The most common presenting symptom for patients with AVMs is brain hemorrhage. In addition, patients can have seizures, headaches and progressive neurological symptoms such as weakness or difficulty with speaking or swallowing. Intellectual functions, such as short or long term memory, may be impaired. All of these symptoms can affect a patient's ability to perform in school, work or simple daily activities.
It is believed that most people who have AVMs are born with them. They can occur in many locations throughout the brain and spine. Many are asymptomatic and will never even be diagnosed. Usually, the presenting symptoms help identify the part of the brain where the AVM is located. For example, if the AVM is in one of the brain's visual areas, there may be changes in vision. If an AVM is located in a part of the brain that controls motor skills, weakness on one side of the body may become apparent. If a hemorrhage occurs from the AVM, there may be severe neurologic impairments related to the location of the resulting clot. Patients often improve dramatically over a period of a few days to months after a hemorrhage, depending on the location and size of the bleed. Some patients have seizures related to these AVMs and require medication to prevent the seizures from reoccurring. Sometimes these seizures can be difficult to control with medications, but may improve dramatically when the AVM is treated.
Diagnosis of AVMs is confirmed with an MRI and angiogram. These studies allow the team to look at the exact size, location and architecture of an AVM in order to offer the best treatment options, taking into consideration the patient's symptoms, age, and treatment preferences.
The treatment for AVMs has improved in recent years. The goal of treating AVM-related lesions is to close off completely the vessels, thereby curing the patient. This is achieved in a variety of ways and requires a large number of specialists to provide the optimal methods available to safely treat the patient and prevent further problems. The methods available for treating AVMs at the Stanford Cerebrovascular Surgery program include stereotactic computer assisted microsurgery, embolization, stereotactic radiosurgery using CyberKnife. Over the past 30 years, we have treated more than 1,000 patients with AVMs.