Cavernomas are also commonly known as blood sponges. It is a vascular malformation, also known as an arteriovenous malformation (AVM). Here, very small veins and arteries combine to form a vascular tangle. As a result, smaller or even larger bleedings occur regularly.
Cavernomas can occur in all tissues. However, only those that occur in the central nervous system (brain and spinal cord) are of clinical significance. For this reason, the English-language scientific literature generally only uses the term cavernoma for cerebral cavernomas.
The blood pressure around the cavernoma is low, so blood loss and tissue damage are limited. For this reason, they are usually asymptomatic in most tissue structures (e.g. legs, arms) .
The situation is different with cerebral cavernomas. These are surrounded by brain or spinal cord tissue. Here, even small bleedings can lead to pronounced symptoms such as severe headaches and seizures.
Cerebral cavernomas are benign malformations of dilated blood vessels in the brain @ Naeblys /AdobeStock
From asymptomatic to life-threatening: the symptoms of cavernomas are highly case-dependent. Around half of all cavernomas in the brain are asymptomatic. In the other half of cases, however, cerebral cavernomas cause a whole range of symptoms due to bleeding and displacement.
The most common consequences are
Major hemorrhages are particularly problematic.
Their symptoms are very similar to those of a stroke:
- signs of paralysis
- dizziness
- visual and sensory disturbances or
- headaches
The frequency of such an event is low: experts estimate the annual risk of bleeding at 1-5 percent. Exactly how high it is depends on where it is located in the brain.
However, 30 percent of those who have suffered from such a hemorrhage suffer from it again within two years. These heavy bleeds not only severely affect the patient, they can also become life-threatening.
In the case of minor hemorrhages, it is not the hemorrhages themselves, but the blood deposits in neighboring areas of the cerebral cortex that cause the symptoms. Cavernomas in the area of the temporal lobe in particular can cause epilepsy.
Cerebral cavernous malformations occur in around 0.5 percent of the German population, often without causing symptoms. How exactly they develop is still unclear.
What is certain is that there is a hereditary variant. It is estimated that one third of cavernomas are caused by a genetic factor.
Six percent have a special form. In this familial form, also known as "multiple cerebral cavernomas", cavernomas occur more frequently.
It is therefore likely that those affected will develop symptoms, especially as the cavernomas often grow more quickly. This form mainly affects children.
Inheritance is autosomal dominant. There is therefore a 50% probability that the children will be affected by the same disease. Multiple cerebral cavernomas are rarer in Europe than in other regions.
However, the mechanisms by which cavernomas develop and why are still unclear. Depending on the genetic predisposition, there are no other known risk factors that prevent the development of cavernomas.
Cavernomas are often incidental findings because less than half of them cause symptoms. If a patient comes to the practice or hospital with symptoms, an imaging procedure is usually carried out for further clarification.
These are used:
CT is used in emergency situations such as strokes or acute bleeding. It only takes a few seconds to perform and evaluate.
MRI is suitable for situations without time constraints, such as planned interventions or after stabilization of the emergency situation.
Performing an MRI is more time-consuming than a CT scan and usually takes 30 to 40 minutes. One advantage of MRI is that the morphology and localization are significantly better.
A so-called popcorn pattern and the typical appearance of a blackberry or mulberry can often be seen. Also typical are calcifications and signals that indicate microbleeds that have occurred for varying periods of time.
As a rule, doctors look for other vascular malformations that often occur together with cavernomas. Examples of this are congenital vascular malformations or tumor diseases.
A cavernoma is diagnosed using imaging examinations such as magnetic resonance imaging (MRI) or computed tomography (CT) @ Yakobchuk Olena /AdobeStock
How exactly and when treatment is necessary for a cavernoma depends on many factors.
The main factors are
- Location in the brain
- Accessibility during surgery
- Risk of bleeding
- Severity of the symptoms
If the cavernoma is purely incidental and asymptomatic, it is usually monitored annually by MRI.
Exceptions are cavernomas whose location requires intervention, for example because they are very close to the brain stem.
Very large cavernomas also often require treatment.
A genetic cause of the cavernoma with a family history of the disease also often leads to a generous indication.
The avoidance of medication that affects blood clotting is controversial. It seems logical, as reduced blood clotting could increase bleeding. However, there are studies on other cerebrovascular diseases that even rate the use of anticoagulants positively. For this reason, no clear recommendation has yet been made.
In the case of epilepsy or a single seizure without symptoms, the International League Against Epilepsy recommends treatment with anticonvulsant medication.
However, there are factors that favor direct removal.
These include
- Young patient age
- Increased risk of bleeding, e.g. with
- Taking blood-clotting medication due to other illnesses
- Epilepsy that is difficult to treat with medication
- Tendency to fall
- High-risk sports (boxing, ski jumping)
- Rapid growth of the cavernoma
- Severe symptoms
Microsurgical removal under MR-guided neuronavigation is the method of choice for cavernoma surgery.
Doctors use special instruments and light sources to remove the diseased tissue through small incisions (microsurgery).
It may also be necessary to sparingly remove the surrounding gliosis zone, i.e. scarred changes in the brain tissue and nerve sheaths.
Neurosurgeons who specialize in diseases of the central nervous system usually perform the operation.
Minimally invasive catheter procedures fall within the remit of neuroradiologists. German experts do not usually recommend radiation (radiotherapy) or chemotherapy.
Cavernomas often remain asymptomatic for a lifetime. When symptoms do appear, the majority of those affected do so between the ages of 10 and 40.
How the disease progresses depends primarily on the location and type of cavernoma. For many patients, living with the risk of cerebral hemorrhage is often a heavy burden.
Symptoms such as headaches, seizures and other neurological deficits can significantly impair quality of life. For young sufferers, a career is often jeopardized. It can even lead to incapacity to work.
One problem here is the dynamic behavior of cavernomas. This means that their growth behavior is difficult to assess.
Sometimes they remain stable for years and hardly change at all. Sometimes formal growth spurts occur , which cause severe symptoms and can be associated with a high risk of bleeding.
Once the cavernoma has been surgically removed, the chances of recovery are often very good. Surgery has comparatively few risks, especially if surgeons can easily reach the cavernoma.
Bleeding or the consequences of epilepsy would often be more serious and more complicated to treat without surgery. As a result, the majority of patients who undergo surgery have fewer complaints. They are therefore more satisfied. In the case of a single small cavernoma, surgery can often cure the disease.
In the familial variant, further spontaneously occurring cavernomas are likely. This form is not curable .
Those affected require long-term monitoring of the cavernomas and possibly drug therapy.
The level of suffering for those affected can be quite high due to a variety of symptoms and growing cavernomas. This is why additional psychological support is helpful.