Cerebral Cavernoma

 

A cavernoma, also called cavernous angioma, is a vascular malformation in the brain. The blood vessels are abnormally dilated and look like "little caverns" (hence the name), and are clustered together in the shape of a small sphere. Three symptoms are characteristic of a cavernoma: a sudden neurological deficit, a seizure, or a slow neurological deterioration. These are usually related to bleeding from the cavernoma, its growth, or changes in the microcirculation. Its discovery is, more often than not, lucky, and it generally requires a regular follow-up. You can treat this disease with the help of telehealth psychiatry services.

Definition and Symptoms

What is Brain Cavernoma?

A cerebral cavernoma is a malformation of the brain's blood system: the vessels are abnormally dilated. In the majority of cases, this anomaly does not involve any symptoms. Sometimes neurological disorders (headaches, blurred vision, etc.) are present.

The number of individuals with this malformation is difficult to assess. In particular, because a cavernoma is often asymptomatic, many patients are unaware that they have one. According to various studies on the subject, the number of carriers of a cerebral cavernoma is estimated between 1 in 200 and 1 in 1000.

A cavernoma affects men and women equally, regardless of their origin. It generally demonstrates between the ages of 20 and 40 but can also lead to symptoms in childhood or adolescence.

The exact origin of this vascular malformation is still unclear. We only know that it is a local anomaly in the development of the vessels. Indeed, a cavernoma consists of small vessels (capillaries) very dilated, twisted, and grouped. A cavernoma looks like a ball of small, intertwined vessels. Its size varies from some millimeters to several centimeters.

20% of cerebral cavernomas are familial forms. In other words, the malformation is associated with a genetic anomaly that is passed on from generation to generation. The genes involved in cerebral cavernoma are CCM1, CCM2, and CCM3. These familial forms often result in the presence of several cavernomas. They carry a greater risk of complications.

To know! We can roughly think of genes as codes for producing proteins. These are essential elements because they contribute to each cell's proper functioning and, therefore, more generally of the body.

What Symptoms?

In the vast majority of cases, namely nearly 90%, the cerebral cavernoma is asymptomatic and remains silent. It is then often discovered by chance during an MRI (Magnetic Resonance Imaging) for another health problem.

In the remaining 10% of cases, the cavernoma is the cause of various symptoms. The first occurs between 20 and 40 years old. They can result in epileptic seizures (up to 70% of cases), headaches, or other neurological disorders (vision disturbance, sensitivity disorder in the limbs, etc.). Symptoms vary a lot from patient to patient and depending on the number of cavernomas, size, and location.

More rarely, some individuals may occasionally exhibit non-neurological symptoms, including red spots on the skin and asymptomatic malformations of the blood vessels in the retina. This type of symptom is more likely to affect patients with the familial form of the disease.

When they exist, symptoms may be due either to the cavernoma itself or to the bleeding caused. The walls of cavernomas are thin and fragile, so they break easily, causing an effusion of blood, which can damage the impacted brain structures. However, even in the incident of a rupture, the bleeding is small. Thus, loss of consciousness or coma is very exceptional. Also, an increasing size cavernoma can sometimes compress the brain areas surrounding it and cause neurological disorders. Finally, epilepsy is linked to the irritation of certain parts of the brain in contact with the cavernoma.

Diagnostic

Brain Imaging

(MRI)Magnetic resonance imaging of the brain is the gold standard for the diagnosis of cerebral cavernomas. The gradient echo sequence (T2 *) is the most sensitive for identifying cavernomas due to its high sensitivity for detecting traces of bleeding in brain tissue. MRI also makes it possible not only to make the diagnosis but also to date the hemorrhage, monitor the evolution of the cavernoma (s) and highlight an associated venous developmental anomaly.

A classification into four categories has been proposed. It is based on MRI of the cavernoma (hyperintense, hypointense) on different sequences (T1, T2, gradient echo). To each type corresponds information concerning the characteristics of the cavernoma (type I: recent bleeding, type II: heterogeneous lesions with bleeding and thrombosis of varying ages, type III: old bleeding, type IV: aspect evoking a cavernoma in the process of the constitution)

The follow-up studies of familial cavernomas have confirmed the dynamic nature of these malformations in brain imaging. The evolution of cavernomas can result in new lesions or changes in their characteristics (particularly their size). The demonstration of endothelial proliferation at the periphery of vascular cavities suggests that angiogenesis phenomena could increase the volume of certain cavernomas.

Vessel Imaging

Cavernomas are not visualized with angiography techniques (CT angiography, magnetic resonance angiography, or cerebral arteriography) because the circulation within the "caverns" (cavities making up the cavernoma) is done at low flow, and the vessels feeding the malformation. They are very small sizes. Sometimes imaging of the brain vessels is necessary to rule out another type of vascular malformation. This examination sometimes reveals a developmental venous abnormality associated with the cavernoma.

Genetic Diagnosis

The identification of CCM genes today makes it technically possible to screen these three genes in hospital practice. In the infinite majority of cases, the mutations identified lead to a premature stop codon's appearance or partial or complete deletion of one of the 3 CCM genes.

The screening sensitivity in a subject with familial adenomatosis is approximately 94% (see above), while it is only 57% for a sporadic case with multiple lesions.

Once the mutation has been identified in a patient, the test's sensitivity reaches 100% for his relatives.

The decision to carry out a genetic test must be preceded by a preliminary analysis of this test's real benefit, particularly in the case of an asymptomatic subject. These tests' indication appears to be very variable and varies in different situations (see next chapter).

What Evolution?

Among patients with asymptomatic single cerebral cavernoma, a minority will take one day to present with neurological symptoms.

People who have symptoms may either stabilize, or even regress, or worsen over time.

The evolution of a cavernoma depends mainly on its risk of bleeding and its location in the brain. A cavernoma is not a precancerous lesion, so there is no risk of cancerization or spread to the rest of the body to worry about.