Central nervous system vascular malformations

Central nervous system vascular malformations are rare issues in blood vessels. They usually form in the brain or spinal cord and their coverings, called membranes.

There are several types of central nervous system vascular malformations:

• Arteriovenous malformations. Also called AVMs, these are unusual tangles of blood vessels that connect arteries and veins. AVMs can be anywhere in the body, but most happen in or near the brain or the spine. This type poses the highest risk of brain bleeds and other complications.
• Capillary telangiectasias. These are small blood vessels, called capillaries, that are wider than usual.
• Cavernous malformations. These blood vessels in the brain or spinal cord don't form correctly. They look like mulberries or popcorn.
• Dural arteriovenous fistulas. These are unusual connections between arteries and veins. They happen in the tough covering over the brain or spinal cord called dura. These connections between arteries and veins can lead to bleeding in the brain or other symptoms.
• Venous malformations. These are enlarged veins in the brain or spinal cord. They're also called developmental venous anomalies.

Symptoms depend on the type of central nervous system vascular malformation and where it's found. Some vascular malformations have no symptoms. They may be found on imaging done to look for another condition.

Symptoms for some central nervous system vascular malformations may include:

• Bleeding.
• Seizures.
• Headache.
• Brain and nervous system problems, called neurological deficits, that get worse over time. Neurological deficits may affect speech, vision, balance, memory and other abilities.

The cause of central nervous system vascular malformations is unclear. Some are present at birth, called congenital. Others may happen later. Some may be caused by a change to a gene, called genetic.

Injury to the central nervous system also may cause these malformations.

A family history of vascular malformations or genetic conditions, such as hereditary hemorrhagic telangiectasia, may increase the risk of vascular malformations. Rare congenital factors, such as blood vessels not developing as they should before birth, increase risk for the condition. Nervous system injuries also may increase risk.

Central nervous system vascular malformations can damage the brain or spinal cord. Damage may come from bleeding, called hemorrhage, into nearby tissues. Once bleeding happens, there's a greater risk of having another bleed.

Vascular malformations also may block oxygen flow to tissues and put pressure on parts of the brain or spinal cord. Being pregnant also may increase the risk of bleeding for someone who has a vascular malformation.

Other complications can include:

• Stroke.
• Brain damage from a burst blood vessel.
• Death.
• Learning and behavior problems in children.

You can't prevent vascular malformations. But if you have any known risk factors, there are a few ways to help with early detection and management.

• Monitoring helps find early signs of malformations using imaging. This is especially important if there is a family history of malformations or related genetic or congenital conditions. Your care team can discuss the best imaging tests for you and how often you need them.
• Managing other conditions such as inflammation and high blood pressure. While this does not prevent malformations, it may lessen the chances of complications such as hemorrhage.