Cavernoma (Cavernous Malformation)

Cavernomas can develop anywhere in the body, including the skin, liver, and eyes, but they present risks for seizures or strokes if they form in the brain or central nervous system. These clusters of blood vessels typically look a bit like raspberries, and they range in size from a few millimeters to several centimeters. Cavernous malformations are made up of small capillaries that contain slow-moving or stagnant blood, in contrast to arteriovenous malformations (AVM), which involve high-pressure blood flow. 

Cavernomas in the brain are relatively common: 1 out of every 500 people have at least one cerebral cavernous malformation. But despite the fragility of the tangled capillaries, very few people ever experience bleeding and the associated symptoms.  

In most cases, the cause of cavernomas is unknown, and the majority develop sporadically, without any relationship to a family history of the condition. However, researchers have determined that about 20% of cases are genetic, and they develop due to variants of the genes CCM1 (KRIT1), CCM2, and CCM3 (PDCV10). These genes produce proteins to connect blood vessel cells to each other, but variants of those genes weaken these connections, causing cavernomas to form. If your parents have genetic cavernomas, you have a 50% chance of having cavernomas yourself. Having more than one cavernoma is more common among those who have a genetic history.

Additionally, you may be at greater risk of developing cavernomas in your brain or central nervous system if you have another type of blood vessel malformation called a developmental venous anomaly (DVA). Radiation therapy of the brain or spine can increase your risk as well, for up to 20 years. 

The following symptoms could be an indication of a cavernoma in the brain or spinal cord:

• Seizures
• Brain hemorrhage
• Blurred vision, double vision or vision loss
• Severe headaches
• Fatigue
• Dizziness
• Memory loss
• Balance issues
• Hearing loss
• Slurred speech
• Tremors
• Numbness
• Weakness or numbness (arm or leg)
• Difficulty with bowel and bladder control

According to the Alliance to Cure Cavernous Malformation, the most common first symptom is seizure (50%). This is followed by hemorrhage (25%) and neurologic deficits (25%) such as weakness in the limbs or blurred vision. 

The symptoms range in severity based on the size and location of the cavernoma, and they usually appear between the ages of 20 and 40, or sometimes up to age 60. If a cavernoma occurs on the outer surface of the brain, it can cause seizures. If a cavernoma bleeds in the spinal cord, it may cause bowel and bladder symptoms or trouble with movement or sensation in the legs and arms.  

Symptoms are more likely to be evident if a cavernoma has ruptured and is bleeding, but even under those circumstances, patients can be asymptomatic. The symptoms usually get worse over time if cavernomas bleed repeatedly. A bleed can happen again soon after the first incident or at some unpredictable time in the future, or it might never happen again. Repeated bleeding can be serious, potentially causing a hemorrhagic stroke and damage to the central nervous system.

If you experience the symptoms mentioned above, you should see a doctor right away, because bleeding cavernomas could lead to a stroke or paralysis. 

Typically, a cavernoma is not diagnosed unless a patient has symptoms that develop after the malformation ruptures and bleeds. To diagnose a cerebral cavernoma, a healthcare provider will review symptoms during a physical exam. The next step would be to perform an MRI. If a malformation is present, it will show up in the MRI, and doctors will look for signs of bleeding or swelling. A very sensitive type of MRI scan called susceptibility-weighted imaging can detect the tiniest cavernomas as well as evidence of prior bleeds. This is helpful information for assessing the risk of future complications. Doctors may also recommend genetic testing to see if you have one of the genetic variants that can cause cavernomas to form.

Sometimes cavernomas are discovered during investigations of other unrelated symptoms or in brain scans ordered for other reasons. These are referred to as “incidental” cavernomas. 

Every case of cavernoma is unique to the individual, and treatment needs to be decided carefully based on the symptoms. The options for treatment vary based on the location of the cavernoma, as shown in an MRI scan, and whether it is bleeding or causing symptoms. After an MRI, care providers typically opt for observation, medications, or surgery. 

If the malformation is not bleeding, doctors frequently recommend a conservative management approach. This means undergoing regularly scheduled imaging scans to monitor the malformation over time. If this approach is recommended, you should follow your doctor’s instructions and arrange medical care if symptoms occur between appointments. 

For a cavernoma that is bleeding, providers may recommend medications to manage seizures and headaches, or surgery to remove the malformation. Surgery might be recommended if it is deemed to be a safe option for you and if you have had one or more symptomatic bleeding episodes, if the bleeding caused vision issues or other neurologic problems that are getting worse, or if you have seizures that do not improve with medication. Additionally, if the MRI scan revealed that there is a future likelihood of serious bleeding in the brain (referred to as an intercranial hemorrhage) leading to worsening symptoms, surgery might be considered as a preventative measure. 

It should be noted that removing a cavernoma is a major operation, and there are some risks of complications. These can include lasting neurological deficits, re-bleeding, swelling, and an increased risk of seizures. Generally, these risks are higher if the cavernoma is deep within the brain, or if it is in the brainstem or spinal cord. 

In some cases, a treatment called stereotactic radiosurgery has been used to “zap” cavernomas with radiation, but the effectiveness of this approach has yet to be determined. 

There is no known way to prevent cavernomas, but as with stroke, aneurysms, and cardiovascular diseases, you can reduce your potential risk of hemorrhage by taking good care of your circulatory health. This includes the following: 

• Managing your blood pressure, cholesterol, and blood glucose levels to be in a healthy range for your body. 
• Getting at least at least 30 minutes of physical activity most of the days of the week
• Refraining from using tobacco products
• Getting regular checkups

It is also important to talk to your provider to determine if any medications you may be taking can increase the risk of bleeding. Blood thinners can have this effect, for example. 

The U.S.-based Alliance to Cure Cavernous Malformation is tracking several medications and other therapies that have potential to treat cavernoma in various ways. Many of these studies are now in phase I or phase II trials. 

The Alliance’s sister organization, Cavernoma Alliance UK, is currently working with the three universities on other projects. Scientists at the University of Edinburgh have a proposal to explore whether aspirin is an effective drug for treating cavernoma (they are awaiting a funding decision at the time of this writing). At the University College London Institute for Women’s Health, a team is working on an early-stage gene therapy project to address the genetic cause of cavernoma. Finally, researchers at the University of Liverpool are investigating whether the protein TLNRD1 plays a role in how some cavernomas form. 

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