The types of vascular lesions that are characterized by abnormal connections between arteries and veins in the absence of capillaries are known as arteriovenous malformations or AVMs. These are mostly seen in the brain and spine and they affect around 1 percent of the general population. However, males are more likely to get them and they are usually present at birth, which means these disorders are congenital. There are no hereditary causes though; in fact the cause of AVMs is still not very clear to scientists and doctors all around the world.
Arteriovenous malformations or AVMs are just one type of vascular lesions of the central nervous system.There are many other lesions or malformations that may occur in this region affecting a person’s overall health and causing some mild to severe symptoms and conditions.These signs and symptoms are usually the first thing used by physicians to distinguish among various vascular lesions. After that, a scanning test is performed to confirm the location and nature of the lesion.
Here are some other vascular lesions that may affect the central nervous system;
These are characterized by abnormal collection of blood vessels in the brain, which tend to be large and stretched out. The walls of these vessels are usually very thin, making them vulnerable to rupture and bleeding. They are sometimes known as cerebral cavernous malformations (CCM) but in addition to the brain they can also occur in the spinal cord. Like other vascular lesions, this abnormal assembly of vessels disrupts the normal blood circulation resulting in a number of other complications. These are not congenital but may develop anytime during the life of a person due to some contributing factors. A very rare case of cavernous malformation could be seen in the retina of the eye.
As it is clear from the name, venous malformations are irregular assembly consisting of only veins and not any other blood vessel. This cluster tends to grow over time becoming large mainly due to some internal change including infection, hormonal change, or trauma. This is a type of asymptomatic vascular lesion. What causes venous malformation is not fully understood but it is generally believed by doctors and scientists that it might be due to deficiency of smooth muscle cells that make up the walls of veins. A person may also have multiple venous malformations in his body. The larger ones are associated with risks of rupture, bleeding and clotting.
These are characterized by unusually dilated capillaries within the healthy brain tissue. They can also occur in the spinal cord but mostly they are found in different regions of the brain. Capillary telangiectases are asymptomatic in nature and have a close resemblance with cavernous angiomas. It is very difficult to make a distinction between these two on imaging results. Some people have multiple types of malformations in their brain putting them at higher risk of complications including hemorrhage and stroke. CTSs are not considered as dangerous as other types of malformations in the brain. Mostly MRI or magnetic resonance imaging is performed to detect these types of lesions using a contrast material. Usually no signs and symptoms appear in the patient with these types of malformations.
All these types of vascular lesions are known to affect the central nervous system or CNS. Different imaging or scanning tests can help to make a distinction between various types and devise a treatment accordingly. Sometimes the malformations go unnoticed and undetected throughout the lifetime of a person and are discovered only when a person dies at autopsy or postmortem.