A cerebral cavernous malformation (CCM) is a collection of small blood vessels (capillaries) in the central nervous system (CNS) that is enlarged and irregular in structure and takes the shape of a characteristic honeycomb-like pattern. In CCM, the walls of the capillaries are thinner than normal, less elastic, and prone to leaking. Cavernous malformations can occur anywhere in the body, but usually only produce symptoms when they are found in the brain and spinal cord. Some people with CCM – experts estimate 25 percent -- will never experience any related medical problems. Others will have serious symptoms such as seizures (most commonly), headaches, paralysis, hearing or vision changes, and bleeding in the brain (cerebral hemorrhage). There are familial (inherited) and sporadic (occurring for no clear reason) cases of CCM. Researchers have discovered three different genes associated with CCM. Studies are currently underway to understand the relationship between the mutations of each of these genes and their corresponding symptoms.

Seizures are usually treated with antiepileptic drugs. If seizures don’t respond to medication, or there is recurring bleeding in the brain, surgical removal of the lesion(s) using microsurgical techniques is sometimes necessary.

Some people with CCM will never know they have the disorder because they will never experience symptoms. The prognosis for CCM is variable for each individual, since the location and number of lesions determine the severity of the disorder. CCM can be fatal if it causes severe brain hemorrhages.

Prepared by the National Institutes of Health