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Cavernous Malformations

A cerebral cavernous malformation (CCM) is a collection of small blood vessels (capillaries) in the central nervous system that is enlarged and irregular in structure. In CCM, the walls of the capillaries are thinner than normal, less elastic, and are 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 4 inches 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. In some people, however, the lesions can burst and bleed into the brain, causing problems, including stroke and, rarely death.

Facts about cavernous malformations

About 1 in 100 to 200 people have cavernous malformations. They probably form before or shortly after birth. Some may seem to appear and disappear over time on follow-up MRI scans.

About 1 in 4 people with cavernous malformations in the brain never have symptoms.  

In some cases, the condition is caused by a gene mutation. These are inherited from a parent. In other cases, they appear without a family history.


Symptoms of cavernous malformations depend on the location and size of the malformation. Although children sometimes have symptoms, most people who have symptoms are between 20 and 50 years old.

These are physical symptoms:

  • Headaches

  • Seizures

  • Changes in hearing or vision

  • Weakness

  • Paralysis

  • Trouble thinking clearly or with remembering things

Complications include:

  • Stroke (hemorrhage or bleeding type)

  • Headache

  • Seizure

  • Death

When to call the healthcare provider

Many people only find out about 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 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 is available in some clinics


A treatment plan could include:

  • Medicine for symptoms, such as antiepileptic medicines for seizures

  • Surgery to remove the blood vessels

  • Doing an MRI at regular intervals to keep an eye on a lesion 


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 the familial type. .

Online Medical Reviewer: Amy Finke RN BSN
Online Medical Reviewer: Deepak Sudheendra MD
Online Medical Reviewer: Raymond Kent Turley BSN MSN RN
Date Last Reviewed: 8/1/2018
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