Moyamoya disease

Overview

Moyamoya disease is a rare blood vessel condition in which the carotid artery in the skull becomes blocked or narrowed. The carotid artery is a major artery that brings blood to the brain. When it's blocked, blood flow to the brain is reduced. Tiny blood vessels then form at the base of the brain to supply the brain with blood.

The condition may cause a ministroke, known as a transient ischemic attack (TIA), or a stroke. It also can cause bleeding in the brain. Moyamoya disease can affect how well the brain functions and can cause cognitive and developmental delays or disability.

Moyamoya disease most commonly affects children. However, adults may have the condition as well. Moyamoya disease is found all over the world. But it's more common in East Asian countries, especially Korea, Japan and China. This may be due to certain genetic factors in those populations.

Risk factors

Though the cause of moyamoya disease is not known, certain factors may increase your risk of having the condition. They include:

• Asian heritage. Although moyamoya disease is found all over the world, it's more common in East Asian countries, especially Korea, Japan and China. This may be due to certain genetic factors in those populations. People with Asian heritage living in Western countries also have a higher risk of moyamoya disease.
• Family history of moyamoya disease. If you have a family member with moyamoya disease, your risk of having the condition is 30 to 40 times higher than that of the general population. This strongly suggests a genetic link.
• Medical conditions. Moyamoya syndrome sometimes happens with other disorders, including neurofibromatosis type 1, sickle cell disease and Down syndrome, among many others.
• Being female. Moyamoya disease is slightly more common in females.
• Being young. Though adults can have moyamoya disease, children younger than 15 years old are most commonly affected.

Complications

Most complications from moyamoya disease are linked to the effects of strokes. They include seizures, paralysis and vision problems. Other complications include speech problems, movement disorders and developmental delays. Moyamoya disease can cause serious and permanent damage to the brain.

Prevention

There is no way to prevent moyamoya disease. However, moyamoya treatments can prevent strokes and other complications.

Living with moyamoya disease?

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