Cerebral Cavernous Malformation
Cerebral cavernous malformation (CCM) is a group of abnormal blood vessels that forms within the brain or spinal cord. Some patients have no symptoms at all and will not need treatment beyond monitoring the lesion to ensure that it does not progress.
Others experience symptoms like seizures, headaches, and bleeding into the brain, which may be severe or even life-threatening. Treatment may involve using medications to control symptoms or removal of the lesion through surgery or radiotherapy.
What is a cerebral cavernous malformation?
A cavernous malformation is an abnormal growth of capillaries, which are the smallest type of blood vessels. These capillaries grow in tightly packed formations and don’t provide a useful blood supply to tissues. Cavernous malformations are often described as shaped like a mulberry.
Although a cavernous malformation is made up of capillaries, they don’t have the normal capillary structure. The capillaries of a cavernous malformation have thinner, leakier walls than those of normal capillaries. This makes them fragile and more likely to bleed.
Cavernous malformations can also be known by other names, including:
- Cavernous angioma
- Cavernous hemangioma
All of these terms refer to the same type of lesion. Cavernous malformation is considered the preferred term, but the other terms are still sometimes used.
Cavernous malformations can occur in any part of the body. In most locations, they generally don’t lead to symptoms. However, when they occur in the central nervous system (the brain and spinal cord), cavernous malformations can potentially lead to serious complications. That is because these organs are very sensitive to pressure, which can be created by the cavernous malformation itself or by blood that leaks from it.
Blood is also very irritating to nervous system cells, and blood that leaks from a CCM can interfere with brain function in ways that lead to significant symptoms. Some people have just one cerebral cavernous malformation, while others have multiple lesions.
Is cerebral cavernous malformation a type of cancer?
A CCM is an abnormal tissue growth, but it is not malignant, meaning it’s not a type of cancer. It will not spread through the body as cancer can.
Although they are not cancerous, cerebral cavernous malformations can grow over time. This may occur because more blood vessels grow in the lesion, and it may also be the result of repeated episodes of bleeding. Blood that leaks from the lesion can harden and accumulate around the CCM. As this reoccurs, the lesion may grow.
Not all CCMs will increase in size over time. Some will stay the same size for many years without bleeding or causing symptoms. In some cases, a CCM can disappear on its own over time; this is uncommon but possible.
What causes cerebral cavernous malformations?
Around 20 percent of patients with a CCM have an inherited form, with other relatives also experiencing the disorder. The genetic forms of the condition can be caused by mutations in one of three genes. A person with the inherited form of CCM generally has a 50 percent chance of passing it on to their offspring.
In the other 80 percent of cases, cerebral cavernous malformations arise sporadically in people without a family history of the condition. It’s not known what causes this in certain people.
CCM is usually a congenital condition, meaning someone is born with it. However, CCMs can also develop over time. Radiation therapy to the brain and spinal cord can sometimes cause these lesions; they may form many years after the radiation treatment is completed.
What are the symptoms of a cerebral cavernous malformation?
Some people who have CCMs experience no symptoms, and may not even be aware they have this condition. It is estimated that around 25 percent of people with a CCM never experience symptoms throughout their lives. In fact, some cases of CCM are discovered incidentally, when an MRI is performed for other reasons.
However, others do experience symptoms, which may range from mild to severe. The most common symptoms of CCM include:
- Hemorrhage (bleeding into the brain or spinal cord)
- Neurological deficits: problems related to damage to a specific area of the brain or spinal cord, such as an area of numbness or
weakness, speech or language difficulties, or vision changes
Bleeding from a CCM can cause serious neurological complications. In severe cases, it can even result in death.
How are cerebral cavernous malformations treated?
For those who don’t experience symptoms from their CCM, treatment generally isn’t necessary. Your doctor will monitor you, performing regular MRIs to see whether the lesion is growing. As long as the CCM doesn’t cause any problems, the risks of treatment will generally outweigh the benefits.
For those who experience symptoms, a few different treatment options may be useful. Options may include:
Anti-seizure medications: For patients who experience frequent seizures, medications may help to reduce the regularity of these events. These medications do carry a risk of side effects, such as drowsiness; adjusting the dose of the medication is often helpful in minimizing these side effects.
Surgical removal: When repeated episodes of bleeding from a CCM are causing significant neurological symptoms, then surgical removal may be warranted. Not all CCMs can be removed by surgery; it depends on the specific part of the brain where the CCM is located. Undergoing neurosurgery poses significant risks, and it’s important to weigh the risks of the procedure against the risks of further neurological damage caused by the CCM.
Radiosurgery: Besides a surgical procedure, another option is to target the CCM lesion using radiation. This is known as stereotactic radiosurgery, or Gamma Knife radiosurgery. In this method, multiple beams of radiation are aimed at the CCM lesion from different angles. The beams have minimal effect on nearby healthy tissue but deliver a significant dose of radiation to the cells of the CCM. Over time, the abnormal blood vessels will gradually close off, though this process can take months or even years following the radiosurgery procedure. Some studies have shown that radiosurgery has a relatively high success rate in addressing the symptoms of CCM. Other studies have not confirmed its effectiveness, so further research is needed.
Besides having a procedure to remove it, there is no known way to prevent future bleeding from a CCM. There is also no way to predict which patients will experience bleeding or when it will occur.
Current clinical trials are looking for new ways to treat CCM. These include some studies testing new pharmaceutical agents that may decrease the risk of bleeding in patients with CCM. Some patients may choose to enroll in a clinical trial to get early access to cutting-edge treatment, although it is important to consider the trade-offs of being part of a trial. If you are interested in this option, you should discuss it with your treatment team.