Cerebral Cavernous Malformations: What You Should Know
Cerebral cavernous malformations, or CCMs, are irregular bundles of tiny blood vessels (capillaries) in the brain. The vessels are stretched more than usual. Their abnormal shape and thinner walls can cause them to leak or alter blood flow, which can cause health problems.
CCMs range in size from less than a quarter inch to 4 inches.
What are the symptoms of CCMs?
In about 25% of cases, CCMs do not cause any medical problems or symptoms. When symptoms do appear, they usually first appear between the teens and 50 years of age (although infants and children sometimes show signs of CCMs as well).
Symptoms may vary depending on the location of the CCMs. They can come on quickly and then go away as bleeding from blood vessels is absorbed by the body. Possible signs or symptoms include:
Less commonly, you or your doctor will notice:
- Unusual muscle growth
- Unusual skin texture or growth
- accumulation of calcium in the brain
- Extra growth of blood vessels in your eye (especially in the retina)
What causes CCMs?
The walls of the tiny blood vessels, or capillaries, that make up CCMs are thinner than usual, making them more likely to leak. The walls also lack certain fibers that normally cause blood vessels to expand and then expand again. When their shape changes due to high blood flow, these vessels tend to stay in strange open spaces that doctors call “cavities” — hence their name cavernous malformations.
In most cases, doctors don’t know what causes CCMs. About 20% of the time, people with CCM inherit it from their parents. Scientists have identified a few genes that appear to play a role in the formation of CCMs, but more research is needed.
How do doctors diagnose CCMs?
If your doctor suspects CCM, they will take a full medical history, examine you personally, and ask about any symptoms. They take pictures of your brain with an MRI, electroencephalogram (EEG), or CT scan to look for specific blood flow patterns indicative of CCM. They can also use blood tests and genetic analysis to make a definitive diagnosis.
How do doctors treat CCMs?
Your doctor can simply treat the symptoms of your CCMs. For example, they may prescribe antiseizure drugs to treat seizures caused by CCM, pain relievers for headaches, and rehabilitation exercises for physical symptoms such as weakness or partial paralysis.
If doctors discover your CCMs with no symptoms, they will likely want to monitor them regularly with MRI. In some cases, they may suggest antiseizure medications to protect against possible future symptoms, such as seizures.
In some serious cases, your doctor may wish to contact the CCM directly. They can talk to you about a possible surgery. In general, this is the case when the following conditions are met:
- You are unable to control seizures with medication.
- The CCM is clearly the cause of the seizures.
- The CCM is located in a low-risk location for brain surgery.
Your doctor may also consider surgery if you’ve had at least one brain bleed that caused symptoms or if you have slowly worsening symptoms due to CCM. In these cases, as always, you and your medical team must weigh the surgical risk against the potential benefit.
What is the outlook for someone with CCMs?
The prospects are very different depending on the individual case.
Many people with CCM will never know they have the disease because they will not have any symptoms. (About a quarter of people never have symptoms.) Others may have only minor or occasional symptoms, which they can easily manage with rest and medication.
However, more severe cases can cause life-changing or even permanent symptoms. If possible, these cases may require surgery.
Unfortunately, doctors know of no way to prevent CCMs. Scientists hope that research into genes will eventually lead to preventive treatments.