 | | | | Medical Health Encyclopedia | |
Arteriovenous malformation - cerebral
| | | |
| |
| |
| Arteriovenous malformation - cerebral |
|
Definition:
A cerebral arteriovenous malformation is a congenital disorder (present at birth) of the brain's blood vessels. It is characterized by an abnormal connection between the arteries and the veins in the brain. Alternative Names:
AVM - cerebral
Text Continues Below
Causes, incidence, and risk factors:
The cause of cerebral arteriovenous malformation (AVM) is unknown. The condition occurs when, in the brain, one or more blood vessels develop in which the arteries connect directly to the veins, without having the normal capillaries between them.
Arteriovenous malformations vary in their size and location within the brain.
There are often no symptoms until complications occur, which involve rupture of the AVM and a resulting sudden bleed in the brain. Sudden bleeding in the brain is known as a hemorrhagic stroke, which is essentially what occurs when an AVM breaks. In more than half of patients with AVM, hemorrhage from the malformation is the first symptom. Depending on the location and the severity of the bleed, the hemorrhage can be profoundly disabling or fatal. The risk of bleeding from an AVM is approximately 2-4% per year. The first symptoms often include headache, seizure, or other sudden problems, such as vision problems, weakness, inability to move a limb or a side of the body, lack of sensation in part of the body, or abnormal sensations. Symptoms are the same as for stroke. After a hemorrhage, there is a risk of developing epilepsy. If an AVM bleeds once, the risk might be greater that it will bleed again. Intracerebral (in the brain) or subarachnoid (around the brain) hemorrhages are common with cerebral arteriovenous malformation.
| 
.gif)
