Cavernous malformations

Overview

Cerebral cavernous malformations (CCM) are collections of closely packed, abnormally thin-walled capillaries that are commonly found in the brain or in the spinal cord. They are also known as cavernous hemangiomas. The blood within the capillaries is frequently slow or non-moving.

A cerebral cavernous malformation has the appearance of a raspberry. It has blood-filled pockets that are divided by connective tissue. Cavernous malformations can be as small as a fraction of an inch or as large as a coin. Most CCMs develop on their own but it can also be genetically acquired.

CCMs are one type of brain vascular malformation that includes aberrant blood vessels. Additional types of vascular abnormalities are arteriovenous malformations (AVMs), dural arteriovenous fistulas, developmental venous anomaly (DVA), and capillary telangiectasias. A person with a DVA will most likely have a CCM, too.

Some cases of cerebral cavernous malformations can cause problems in the brain or spinal cord due to blood leakage. It can generate stroke-like symptoms depending on where the cavernous malformation is located in a person’s nervous system.

Bleeding in the brain can result in convulsions or a stroke. Bleeding in the spinal cord can cause problems with movement and sensation in the legs and arms, as well as bowel and bladder issues. The treatment for this condition may range from watchful waiting, medication, or surgery depending on the severity of symptoms.

Symptoms

A cavernous malformation may or may not have any symptoms. The symptoms differ for every person. The severity and frequency of symptoms are determined by the size, location, and number of hemangiomas.

Seizures typically happen as an initial symptom when there is a CCM on the brain’s outer surface. When CCMs are detected in the brainstem, basal ganglia, or spinal cord, a wide range of signs and symptoms may also occur. For instance, bleeding in the spinal cord may result in bowel and bladder problems, and difficulty moving or sensation in the legs or arms.

Neurological disorders may either develop or increase over time with recurrent bleeding. While some individuals may never experience these complications, others may encounter them either shortly after the initial bleed or at a much later time.

Common signs and symptoms of CCMs include:

• Seizures
• Intense headaches
• Weakness in the arms or legs
• Numbness
• Difficulty with speech or communication
• Memory and concentration issues
• Balance and walking difficulties
• Blurred vision, double vision, and vision loss
• Facial drooping
• Tinnitus, dizziness, and hearing loss
• Irritability or personality changes

If experiencing any of these signs and symptoms, seeking immediate medical consultation is crucial. It is necessary to visit a doctor promptly to obtain a correct diagnosis and receive appropriate medical intervention.

Causes

Around 20% of cavernous malformations are hereditary. A mutation in any of three genes causes these. Those with a familial history are more likely to have multiple cerebral cavernous malformations. Those who have a genetic relationship are also more prone to develop new cavernous malformations over time. Genetic testing is frequently advised for persons who have MRI evidence of several CCMs in the absence of a DVA and a history of CCMs in the family.

However, majority of the CCMs have no known cause. This is referred to as sporadic form of cavernous malformations. Typically, only one cavernous malformation develops. The sporadic variant is frequently accompanied with a developmental venous abnormality (DVA), which is an aberrant vein that resembles a witch’s broom.

Another known cause of cavernous malformations is radiation therapy to the brain or spine. Radiation to the brain or spinal cord can cause CCMs 2 to 20 years later.

Risk factors

Children will have a 50% chance of inheriting a cavernous malformation if either parent has one. Studies have identified three genetic variations accountable for hereditary cavernous malformations, which have been associated with nearly all familial cases of cavernous malformations. These genes include KRIT1, which is also known as CCM1, CCM2, and PDCD10 which is also known as CCM3.

These genes are hypothesized to cooperate in order to communicate between cells and minimize blood vessel leakage. However, it is unclear why these mutations result in CCM. The genetic form of the condition can cause multiple cavernous malformations to occur initially and also increase in number over time.