Also known as: Cavernous Angiomas; Cavernous Hemangiomas; Cerebral Cavernous Malformations
Cavernomas have been known about since the middle of the nineteenth century, when they were seen by pathologists examining brains under the microscope. Cavernomas look like raspberries. They are made up of abnormal blood vessels through which blood flows slowly – these are the ‘caverns’ that give the condition its name. The cells that line these caverns occasionally ooze small amounts of blood into surrounding brain tissue, which sometimes causes symptoms.
Medical text written September 2010 by Ian Stuart, Cavernoma Alliance UK. Approved September 2010 by Dr Rustam Al-Shahi Salman, Honorary Consultant Neurologist, Western General Hospital, Edinburgh, UK.
Many people diagnosed with a brain cavernoma have symptoms that are not due to the brain cavernoma. These brain cavernomas are ‘incidental’ discoveries. However, a small proportion of the people who have a brain cavernoma do have symptoms related to it. The type, severity, combination and duration of symptoms vary, depending on the location and size of the brain cavernoma and whether it has bled into surrounding tissue.
Single or multiple cavernomas near the surface of the ‘hemispheres’ or ‘lobes’ in the brain can cause epileptic seizures (see entry Epilepsy). Cavernomas can cause neurological deficits in any area of the brain. The most common symptoms of cavernomas are dizziness, numbness, weakness, disturbed vision, speech difficulty, problems swallowing, and unsteadiness.
In most cases, it is impossible to know what caused a brain cavernoma, but there are two recognised causes:
Radiation treatment – Radiation is used to treat a variety of medical conditions. During radiation treatment, a patient’s brain may be exposed to radiation. Some of these people are later found to have a brain cavernoma.
Genes – In fewer than half of the people affected by brain cavernomas, there is likely to be a genetic cause. In people that have more than one cavernoma, or develop more than one cavernoma, there is likely to be a genetic cause. Three genes – CCM1 (or KRIT1), CCM2 (or MGC4607) and CCM3 (or PDCD10) – have been found in families where relatives are affected by more than one brain cavernoma. Therefore, individuals with more than cavernoma may be offered a genetic test to determine if there is a genetic cause. All that is needed for a genetic test is a blood sample.
Magnetic resonance imaging (MRI) is the most accurate test and provides pictures of brain cavernomas.
Medication is available to treat seizures caused by cavernomas. Other symptoms, such as headaches, can also be treated with medication. The main ways used to try to prevent cavernomas bleeding are neurosurgery and stereotactic radiotherapy.
Neurosurgery involves an operation under general anaesthetic. In this operation, the skull is penetrated (called a ‘craniotomy’) and the cavernoma is removed.
Stereotactic radiotherapy involves beams of radiation targeted at a brain cavernoma from many different points around the head.
In most people who have a single brain cavernoma, there is no genetic cause. People affected by multiple cavernomas may have a mutation of one of three genes – CCM1 (or KRIT1), CCM2 (or MGC4607) and CCM3 (or PDCD10). The inheritance of these gene mutations is autosomal dominant.
Genetic tests for the genes implicated in multiple brain cavernoma can be conducted prenatally if there is a family history of the condition, however it is unusual for this to be requested. Genetic counselling should be sought.
Cavernoma Alliance UK
The Alliance is a Registered Charity in England and Wales No. 1114145. It provides information and support to people affected by cavernoma, and runs a group called CaverFamilies which supports families with children with cavernoma and offers events, including an annual residential weekend.
Group details last updated December 2020.