The brain arteriovenous malformation (AVM brain) is a tangle of abnormal blood vessels that connect the arteries and veins in the brain. Arteries are responsible for getting oxygen-rich blood from the heart to the brain. The veins carry oxygen-free blood back to the lungs and heart. The AVM brain disturbs this important process.
Arteriovenous malformation may develop anywhere in the body, but most often occurs in the brain or spine. However, AVM brain devices are rare and affect less than 1 percent of the population. The cause of AVM brain is not clear. Most people are born with them, but sometimes they can be created later in life. They are rarely transmitted genetically between families.
Some people with AVM brain experience signs and symptoms, such as headaches or convulsions. AVM brain is commonly found after scanning the brain for a different health problem or after rupture of the blood vessels and bleeding in the brain (hemorrhage). After the diagnosis of AVM, the brain can often be effectively treated to prevent complications such as brain damage or stroke.
Symptoms of AVM brain
Arterial-venous damage to the brain can not cause any signs or symptoms until the AVM ruptures, causing bleeding in the brain (hemorrhage). In about half of all cerebral AVM, hemorrhage is the first symptom. But some people with AVM brain may feel signs and symptoms other than the bleeding associated with AVM.
In people without hemorrhage, AVM symptoms may include:
A headache or pain in one area of the head
Weakness or numbness in one part of the body
Some people may experience more serious neurological symptoms and symptoms, depending on the location of AVM, including:
A severe headache
Weakness, numbness or paralysis
Loss of sight
Difficulties in speaking
Confusion or inability to understand others
Symptoms can occur at any age, but usually, occur between the ages of 10 and 40. Cerebral AVM may eventually damage the brain tissue. The effects slowly grow and often cause symptoms in early adulthood. However, after reaching middle age, the AVMs have a tendency to remain stable and less likely to cause symptoms. Some pregnant women may worsen symptoms due to changes in blood volume and blood pressure.
One major type of AVM brain, called the vein of Galen, results in symptoms that appear soon or immediately after birth. The main blood vessel involved in this type of AVM brain can cause fluid accumulation in the brain and swelling of the head. Symptoms include swelling of blood vessels visible on the scalp, convulsions, inability to develop, and congestive heart failure.
When to go to the doctor
If you notice any symptoms of AVM, such as seizures, headaches or other symptoms, seek medical attention immediately. Brain bleeding AVM is life-threatening and requires immediate medical attention.
Bleeding in the brain (hemorrhage). AVM exerts extreme pressure on the walls of affected arteries and veins, causing them to lose weight or weaken. This may cause AVM to rupture and bleed into the brain (hemorrhage).
The risk of bleeding from the AVM brain is around 2 percent per year. The risk of bleeding may be higher for some types of AVM or if previous AVMs have been broken.
Some AVM-associated hemorrhages remain undetected because they do not cause severe brain damage or symptoms, but potentially life-threatening bleeding episodes can occur.
Brain AVMs account for about 2 percent of all hemorrhagic strokes each year and are often the cause of hemorrhage in children and young adults with cerebral hemorrhage.
Reduced oxygen in brain tissue. Thanks to AVM, blood bypasses the capillary network and flows directly from the arteries to the veins. The blood flows quickly through the changed path because it is not slowed down by the channels of the smaller blood vessels.
The surrounding brain tissue cannot easily absorb oxygen from the fast-flowing blood. Without enough oxygen, the brain tissues weaken or can completely go out. This causes stroke-like symptoms such as difficulty in speaking, weakness, numbness, loss of vision or severe instability.
Thin or weak blood vessels. AVM exerts extreme pressure on the thin and weak walls of the blood vessels. A bulge in the wall of the blood vessel (an aneurysm) may develop and become susceptible to rupture.
Brain damage. As you grow up, your body can recruit more arteries to supply blood to the fast-flowing AVM.
As a result, some AVMs can grow and move or compress parts of the brain. This may prevent the free flow of protective fluids around the cerebral hemispheres. If the fluid rises, it can direct the brain tissue up towards the skull (hydrocephalus).