A brain arteriovenous malformation (AVM) is an abnormal tangle of blood vessels in the brain. This defect, which can occur anywhere in the central nervous system, causes blood to flow directly from arteries to veins through an abnormal passageway called a fistula instead of through capillaries. Generally speaking, there are three ways an AVM can damage the brain:
The cerebrovascular system is the network of blood vessels that supply your brain with oxygen and nutrients. The system includes the internal carotid arteries, vertebral arteries, and their branches, which bring blood into the brain, and the veins that carry blood out of the brain.
The carotid arteries are located in the neck and provide blood to the front part of the brain (known as the anterior circulation). The vertebral arteries are located at the back of the neck and provide blood to the back part of the brain (the posterior circulation). These arteries branch off into smaller blood vessels, which then supply different areas of the brain.
Within the brain, the smallest blood vessels are called capillaries, which have thin walls that allow for the exchange of oxygen and nutrients with brain cells. The capillaries then join together to form larger blood vessels called veins, which carry the blood back to the heart to be reoxygenated via the internal jugular veins. As mentioned above, arteriovenous malformations in the brain bypass this capillary network, causing oxygenated and deoxygenated blood to mix via fistulas that directly connect arteries and veins in an area of the AVM known as the nidus.
The cerebrovascular system is essential for the proper functioning of the brain. Any disruption of blood flow to the brain can cause serious health problems, such as stroke or cognitive impairment. Therefore, maintaining a healthy lifestyle and managing risk factors such as high blood pressure or diabetes is important for maintaining the health of the cerebrovascular system.
