Brain or cerebral arteriovenous malformations are abnormal connections between the arteries and veins in the brain. They usually consist of one or more “feeding” arteries, a tangle of abnormal arteries and veins, usually 1-5cm in size (the “nidus”) and one or more “draining” veins. AVMs are thought to arise in people with a genetic predisposition for them. They occur rarely in children, and most often, develop around puberty. They usually become symptomatic in patients in their 30s-50s.
The most common symptoms of brain arteriovenous malformations include headaches and seizures; while in some of the patients, they can remain asymptomatic. Brain AVMs may also be associated with progressive weakness and numbness, visual disturbances and severe pain. These malformations may rupture, leading to intracranial bleeding.
Treatment for brain AVMs is variable and depends on the size, symptoms, location and architecture of the lesion. In order to establish the location and architecture of an AVM, it is almost always necessary to have both an MRI of the brain and a cerebral angiogram (digital subtraction angiogram). Both should, wherever possible, be carried out by radiologists with subspecialist experience in the diagnosis and management of AVM, and in the case of cerebral angiography, it is strongly advised to have the study performed by an experienced interventional neuroradiologist.
Common treatment strategies for AVMs include open neurosurgery, stereotactic radiosurgery, embolisation (targeted blocking of abnormal vessels under X-ray guidance), or combinations of these. The choice of strategy is usually decided by multidisciplinary discussion between specialists in neurosurgery, radiosurgery and interventional neuroradiology.