Understanding Cerebral Cavernous Malformation

What is a cerebral cavernous malformation?

Our bodies contain an enormous network of blood vessels called arteries and veins that transport blood throughout the body.

Arteries carry oxygen-rich blood from the heart to the rest of our organs, and our veins bring oxygen-depleted blood back to the heart. Essential to this circuit are smaller blood vessels called capillaries, which allow blood to pass from our arteries to our veins.

A small number of people have abnormal capillaries that interfere with natural blood flow. These capillaries, which have unusually thin, weak walls that are prone to leaking, tend to clump together like a cluster of grapes. Blood moves through them sluggishly and often stagnates, creating numerous blood-filled pockets or "caverns."

This specific abnormality is called a cavernous malformation (also known as a cavernoma, cavernous angioma or cavernous hemangioma).

Although cavernous malformations can occur anywhere in your body, when they occur in the brain they are called cerebral cavernous malformations, or CCMs.

CCMs range in size from several millimeters to several centimeters. Although they tend to cause fewer and less severe symptoms than other types of blood vessel malformations, including brain AVMs, CCMs can still cause dangerous bleeding in the brain.

What causes CCMs?

There are two types of cerebral cavernous malformation, one with no known cause and one with a genetic component.

Some people have what is called a "sporadic" case, meaning there is only one CCM in their brain and they have no family history of the disease. Among people with sporadic CCM, there are no clear reasons why they developed it.

People who have more than one CCM in their brain are often found to have the "familial" variety of the disease, meaning it is caused by a genetic mutation that runs in families. To date, researchers have discovered three different genes associated with cerebral cavernous malformation.

People of all ages, including children, can develop CCMs. They occur equally among both genders and do not have a higher prevalence among any particular ethnic population.

What are the symptoms of a CCM?

Although people with familial CCM are more likely to develop symptoms than someone with sporadic CCM, many people who have this condition experience few, if any, symptoms. To that end, many people who have a CCM are not aware of it.

If a CCM is pressing up against delicate nerves or brain tissue, it can cause gradual but worsening symptoms. These symptoms vary by individual, depending on the size of the CCM and where in the brain it is located. They include:

• seizures
• headaches
• weakness in an arm or leg
• clumsiness or balance problems
• vision changes
• trouble speaking

Because the capillary walls that make up a CCM are so weak and thin, they can hemorrhage (leak blood). A CCM hemorrhage can range in severity from a very small leak that causes limited damage, to a massive leak that can lead to stroke or death if left untreated.

If blood has begun leaking into your brain, it may cause the following sudden symptoms:

• severe headache
• difficulty speaking
• weakness in an arm or leg
• unsteadiness and difficulty walking
• partial or complete vision loss
• nausea or vomiting
• seizures

Generally speaking, any bleeding in the brain can be a potentially life-threatening condition that requires immediate medical evaluation and treatment.

How are CCMs diagnosed?

If your doctor suspects you have a CCM due to your gradual or sudden symptoms, you will mostly likely have an imaging procedure called magnetic resonance imaging (MRI).

An MRI scan is used to capture 3-D images of the brain and the blood vessels inside the brain. It is considered the "standard of care" for diagnosing CCMs, because the condition cannot easily be detected with other imaging exams.

If your MRI results indicate a CCM, your doctor also may order genetic testing to assess whether you have the known mutations in the genes associated with familial CCM.

How are CCMs treated?

If your doctor confirms you have a CCM, he or she will determine whether to treat you right away or to monitor your condition over time. Your doctor will weigh several important factors, including the size and location of the CCM (together with its potential for hemorrhage), whether there is evidence of past or current bleeding, the severity of your symptoms and your overall health.

Should you require treatment, your neurosurgeon will decide which of the following procedures is most suitable for you:

• Conventional or "open" surgery may be used if the CCM is located in a part of the brain that is easily accessible. During the procedure, a neurosurgeon first performs a craniotomy to temporarily remove a piece of the skull and gain access to the brain, then uses surgical tools to remove the CCM.
• Radiosurgery uses radiation beams to damage, and eventually close, the blood vessels that make up the CCM (despite what the name implies, it is not surgery in the traditional sense because the procedure does not require cutting or an incision). During the procedure, multiple beams of radiation are simultaneously aimed at the brain. The beams meet at the CCM to deliver a single, massive dose of radiation. Radiosurgery may be an option if the CCM is located in a part of the brain that is too difficult or risky to reach using traditional open surgery.

CCM care at Lyerly Neurosurgery

Since Lyerly Neurosurgery was founded in 1934, our physicians have cared for thousands of people who need treatment for a brain or spine condition.

Today our practice continues to build upon a legacy that blends compassion, safety and innovation. Our neurosurgeons provide the full spectrum of evidence-based care, including the latest minimally invasive procedures that can only be offered by neurosurgeons with advanced training and experience.

Together with Baptist Medical Center Jacksonville, our team performs emergency and preventive surgery for patients with cerebral cavernous malformation.