Cavernomas can either be sporadic (occur by chance) or they can be familial (inherited in a genetic pattern). Patients with familial cavernomas more often than not have multiple cavernomas. The genes involved in cavernoma inheritance is well understood, and genetic testing is available to confirm the diagnosis of familial cavernomas.
Most of the time there is no specific reason why some people develop cavernomas and others do not. In a small portion of people with cavernomas, the reason is that they have previously been exposed to radiation in the region of the brain that the cavernoma develops.
The main concern regarding cavernomas relates to the chance of causing a bleed in the brain or in the spinal cord. As best is understood, the risk of haemorrhage from a cavernoma is around 15% per five-year period. Not all cavernomas will bleed, and asymptomatic cavernomas seem much less likely to bleed.
The factors that are thought to increase risk of haemorrhage, are having had a previous haemorrhage, and cavernomas that are deep in the brain, in a region called the brainstem. There is some concern that bleeding risk may be higher in women, if the cavernoma is larger and if there are multiple cavernomas. However, these factors are considered relative risk factors and are not as established risks.
Previously there was a concern that pregnancy increased the risk of haemorrhage. This has been established in large studies of patients with cavernomas to not be the case. Previous recommendations that patients with cavernomas should not deliver babies normally has also been proven to not be necessary. Women with cavernomas should be reassured that there is no reason for them not to get pregnant or deliver their babies normally. Depending on their individual circumstances, they may need genetic counselling regarding the risk of transmitting a predisposition to cavernomas to their unborn child.
The other concern that is often raised in patients with cavernomas is the risk of taking blood thinners increasing the risk of the cavernoma bleeding. There is little evidence to suggest that the risk of bleeding in increased by a patient with a cavernoma taking a blood thinner. It is best to seek specialist advice in your specific case. Most of the time the benefit of the blood thinner outweighs the small potential increased risk of bleeding from the cavernoma.
Most of the time cavernomas are managed conservatively. This means that serial observation of the cavernomas is undertaken for surveillance purposes. If you develop symptoms, you should have imaging done at that time.
Surgery for cavernomas is considered for those that are thought to be at increased risk of bleeding, especially if they are in an area of the brain that is thought to be reached reasonably safely. In areas of the brain, such as the deep brain structures that are very sensitive the risk of surgery often will outweigh any benefit that surgery may offer. Your specialist will assess your specific risk factors and advise you on this.
An alternative to surgery is radiosurgery, this is a specialised type of focussed radiation therapy. This is less commonly used for cavernomas, but may be beneficial for deeper cavernomas that cannot be safely managed with surgery.
Surgery is sometimes also considered to treat epilepsy secondary to cavernomas. This is usually only considered when medical management with anticonvulsant drugs is not working. The evidence would suggest that if the cavernoma is in a relatively safe area, surgery in this situation can be highly successful in controlling seizures.
At the moment there is no medication to treat cavernomas, but there are studies underway looking at options that may be able to offer treatment options in the future.
Written by Dr Marguerite Harding
Reference article used for the blog can be found here
Image c/o Pocket Radiologist: Top 100 Brain diagnoses Osborn, Blaser & Salzman