Cavernous Malformations

A cerebral cavernous malformation (CCM) is a cluster of abnormal tiny blood vessels (capillaries) and larger stretched out thin-walled blood vessels filled with blood in the central nervous system. In CCM, the walls of the capillaries are thinner than normal. They are also less elastic and likely to leak. Cavernous malformations can happen anywhere in the body. They most commonly cause symptoms when they are found in the brain and spinal cord.

These clusters of blood vessels (lesions) can be less than 1/4 inch to 3 to 4 inches (0.6 cm to 10 cm) in size.   

Common symptoms include headaches or seizures. Having symptoms depends on where the lesions grow and how many are present.

Most of the time, these lesions cause no problems. Many people never know that they have one. But in some people, the lesions can burst and bleed into the brain. This can cause problems, such as stroke, and rarely, death.

Facts about cavernous malformations

Cavernous malformations probably form before or shortly after birth. Some may seem to appear and disappear over time on follow-up MRI scans.

In approximately 20% of cases, the condition is caused by an inherited gene mutation. In other cases, they appear without a family history.


Symptoms of cavernous malformations depend on the location and size of the malformation. Most people who have symptoms are between 20 and 50 years old. Sometimes children have symptoms.

These are physical symptoms:

  • Headaches

  • Seizures

  • Changes in hearing or vision

  • Weakness

  • Balance problems

  • Paralysis

  • Trouble thinking clearly or with remembering things

Complications include:

  • Stroke (hemorrhage or bleeding type)

  • Seizure

  • Death

When to call the healthcare provider

Many people only find out they have a cavernous malformation when it bleeds. This causes stroke in some people. If you notice symptoms, such as seizure, severe headache, numbness, vomiting associated with headache, or physical weakness, go immediately to the emergency room or call 911 to get help.


Healthcare providers will ask about your health history and do a physical exam. The final diagnosis is usually made based on imaging tests that show areas of blood flow. These tests could include:

  • MRI scan

  • Electroencephalogram

  • CT scan

  • Blood tests

  • Gene testing in some clinics


A treatment plan could include:

  • Medicine for symptoms, such as antiepileptic medicines for seizures

  • Surgery to remove the blood vessels

  • MRI scans every year for 2 years then every 5 years if no symptoms are present


Currently, cavernous malformations can’t be prevented. Researchers hope that by learning more about the genes linked to these growths, prevention could become possible. Prenatal genetic testing and counseling are choices for the first person in a family with multiple cavernous malformations or for relatives of those with a family history.

Online Medical Reviewer: Deepak Sudheendra MD
Online Medical Reviewer: Raymond Kent Turley BSN MSN RN
Online Medical Reviewer: Rita Sather RN
Date Last Reviewed: 8/1/2023
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