Cavernomas are a type of blood vessel malformation. They contain small clusters of blood-filled globules that often look similar to a raspberry. They usually occur in the brain, they are less common in the spinal cord and they are rare elsewhere in the body.

Unlike arteriovenous malformations (AVMs), cavernomas can develop later in life and so become more common with age. Cavernomas are also called various different names: a cerebral cavernous malformation, a cavernous angioma and a cavernous haemangioma are all cavernomas.

How common are cavernomas?

Around one in every 100-200 people in the population will develop a cavernoma. This makes it a slightly more common condition than an AVM. More than three in ten people who have a cavernoma will eventually experience symptoms and need treatment.

Two main forms of cavernoma are recognised, depending on whether they are inherited or not:

  • Familial cavernoma is passed from one generation to another. Several members of the same family can be affected, and there is a higher risk that one or more of them will develop several cavernomas. A mutation in any one of three known genes can be responsible. Only one in five cases of cavernoma is inherited, the other four are sporadic.
  • Sporadic cavernoma is not due to a genetic mutation. Usually only one person in a family is affected and they usually have just one cavernoma, which develops later in life. This form of cavernoma cannot be passed on to the next generation.

What is inside a cavernoma?

A cavernoma is quite an organised structure and it is not likely to break down completely and cause a large bleed in the brain. Each of the caverns of blood that make up the cavernoma is lined with the same type of endothelial cells that usually line blood vessels.

What makes them different to healthy blood vessels is that they lack the outer walls of veins and arteries. This makes them very unstable and prone to leakage but the amount of blood released is usually quite small. Bleeds tend to happen in cycles and multiple bleeds in the same part of the brain can lead to problems over time.

Symptoms of cavernoma

Cavernoma rarely causes strokes but the small bleeds can disrupt the way the brain works causing seizures and various neurological problems. Cavernomas can be misdiagnosed as epilepsy because it often leads to fits that can be the severe tonic-clonic type. Fits in people with cavernoma usually get more frequent over time.

Other symptoms such as loss of vision, problems with hearing, numbness, weakness, balance or memory problems can occur but which symptoms appear depends very much on the position of the cavernoma in the brain.

Getting a cavernoma diagnosed

Today getting a diagnosis if you have a cavernoma is much easier than it was prior to the 1980s. Cavernomas are not areas of high blood flow, so they do not show up on an angiogram and even when CT scans were developed, these were only able to visualise cavernomas in some cases. The only way to reliably diagnose a cavernoma is to do an MRI scan. Even this needs to be done in a specific way with the right contrast method and using a gradient echo sequence and the results must be interpreted by an experienced neuroradiologist.

Before this was possible, people with cavernomas were usually diagnosed with either multiple sclerosis or a type of epilepsy and treated accordingly.