Neurological Disorders: AVM (Arteriovenous Malformation)

AVM (arteriovenous malformation) as the name implies is a type of vascular malformation (abnormal formation of blood vessels).

These are mostly congenital in nature and people are born with them, however they usually manifest later during the adulthood. Normally an artery is connected to venous system through a net work of fine capillaries (tiny blood vessels), and in this case there is a direct connection between an artery and a vein and this abnormal connection results in the formation of abnormally dilated & engorged veins and this may result in several complications as discussed later below.

The following manifestations are generally seen;

• Chronic headache either continuous or intermittent that at times is confused with a migraine headache disorder
• Excruciatingly severe headache and/or stroke manifestations if there is bleeding
• Stroke manifestations may also occur due to shunting of blood from the artery to vein
• Seizures, partial onset seizure with or without secondary generalization etc

The following investigations are generally necessary to establish the diagnosis;

• Head CT and/or MRI of the brain
• EEG
• Angiogram etc

The most reliable test for the detection of arterivenous malformation is conventional angiogram. During this test a radioopaque dye is injected into an artery and xray films are obtained of the blood vessels in question. Similar angiogram can be obtained through CAT scan system called as CTA (CT Angiogram) or MRI system called as MRA (Magnetic resonance angiogram). The arteriovenous malformation can also be seen on a CAT scan or MRI and the bleeding associated with the malformation is easily identified on the CAT scan.

The following are the usual treatment options;

• Surgical excision
• Gamma knife therapy
• Embolization etc

Anti seizure medications are required if patient presents with seizures.

A neurologist, neurosurgeon, and interventional neuroradiologist are commonly involved in the management of patients with AVM (arteriovenous malformations).