Intracranial venous malformations are veins in the brain that are unusually large. These larger veins aren't likely to cause symptoms or affect how the veins work.

Some people may have an intracranial venous malformation that is never diagnosed and never causes symptoms. Sometimes, they're found by accident during a brain imaging test for another condition.

Intracranial venous malformations usually don't require treatment.

Experts don't understand what causes intracranial venous malformations. Certain genetic changes might play a role, and the malformations may happen during fetal development. However, some types may not be inherited and are acquired later in life, possibly after an injury to the central nervous system.

Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you.

If your healthcare professional thinks that you might have an intracranial venous malformation, you may be referred to a doctor who specializes in diseases that affect the brain and nervous system. This type of doctor is called a neurologist or neurosurgeon.

Because appointments can be brief, it's a good idea to be prepared. Here's some information to help you get ready.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet.
• Write down symptoms you're experiencing, including any that may not seem related to the reason for which you scheduled the appointment.
• Write down important personal information, including major stresses or recent life changes.
• Make a list of all medicines, vitamins or supplements you're taking and the doses.
• Take a family member or friend along. Sometimes it can be very hard to remember all the information provided during an appointment. Someone who goes with you may remember something that you missed or forgot.
• Write down questions to ask your healthcare team.

Your time with your healthcare team is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For intracranial venous malformations, some basic questions to ask include:

• What are other possible causes for my symptoms?
• What tests are needed to confirm the diagnosis?
• What are my treatment options and the pros and cons for each?
• What results can I expect?
• What kind of follow-up should I expect?

Don't hesitate to ask other questions.

What to expect from your doctor

Be prepared to answer questions, such as:

• When did your symptoms begin?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?

Having a family history of intracranial venous malformations can increase your risk. But most types aren't inherited.

Certain hereditary conditions can increase your risk of intracranial venous malformations. These include hereditary hemorrhagic telangiectasia, Sturge-Weber syndrome and Klippel-Trenaunay syndrome.

Because you may not have symptoms with intracranial venous malformations, your healthcare team might find that you have the condition during testing for other neurological problems.

You might have these imaging tests to diagnose other neurological conditions:

• CT scan. A CT scan creates a series of X-rays to create detailed, cross-sectional images of the blood vessels and the brain. Sometimes dye is injected into a vein to assess the brain tissue or the blood vessels in greater detail. This is known as CT angiogram or CT venogram.
• MRI. Magnetic and radio waves create detailed 3D images of your blood vessels and brain. Sometimes a contrast dye is injected into a vein to look at the brain tissue in a different way, and to evaluate your blood vessels.
• MRA. Magnetic resonance angiography is another type of MRI test that focuses on the arteries. An MRA shows how the blood flows through the blood vessels in the brain.
• MRV. Magnetic resonance venogram is a type of MRI that focuses on the veins.

Intracranial venous malformations aren't usually treated because they rarely cause symptoms. If you experience symptoms, such as headaches, your healthcare professional might prescribe medicines.

Rarely, people who have intracranial venous malformations have seizures or bleeding in the brain, called a brain hemorrhage. These are usually caused by other vascular malformations that can be found with a venous malformation. Seizures are typically treated with medicines.

Some hemorrhages require surgery, but many hemorrhages can be treated with medical management and observation in a hospital.

Intracranial venous malformations may never cause symptoms. They are sometimes found by accident during brain imaging tests for another condition. If an intracranial venous malformation does cause symptoms, they may include:

• Headaches.
• Seizures.
• Dizziness.
• Nausea and vomiting.
• Muscle weakness or paralysis.
• Loss of coordination.
• Vision troubles.
• Difficulty speaking.
• Memory problems.

When to see a doctor

Seek medical attention if you have any of the symptoms of an intracranial venous malformation.