Moyamoya is a very rare cerebrovascular condition that affects the arteries that carry blood to the brain. The condition causes the blood vessels to become narrow, which slows down blood flow. When this happens, the body makes new blood vessels at the base of the brain (moyamoya collateral vessels) in an attempt to increase blood flow. These new arteries pass through the basal ganglia and the thalamus and are more fragile than normal arteries.
Moyamoya gets its name from the Japanese word for “puff of smoke.” When viewed on a cerebral angiogram, the new blood vessels look like black wispy clouds or a puff of smoke drifting into the air.
In most cases, there is no known cause for moyamoya, but it can be found in association with other conditions such as:
Some children may develop moyamoya after radiation therapy or after a viral illness. About 1 in 10 children with moyamoya also have a relative with the condition. In those cases, the condition may be inherited.
Moyamoya can occur in both children and adults.
The symptoms of moyamoya are caused by reduced blood flow to the brain and weakened blood vessels. The first sign of moyamoya is often a transient ischemic attack or a stroke. Symptoms of moyamoya include:
Moyamoya can affect one (unilateral) or both sides (bilateral) of the brain. Without treatment, children with moyamoya can experience multiple strokes that can lead to progressive intellectual and cognitive disability.
If your child shows signs of moyamoya, neurologists and neurosurgeons will perform specific tests to make an accurate diagnosis. Surgery is the only cure for moyamoya. Most children make a complete recovery and can return to normal activities within a month.
The following exams and tests are performed to diagnose moyamoya:
If diagnostic tests determine that moyamoya disease is present, a neurosurgeon will discuss the condition with you and your child and will work with you to create a surgery plan for definitive treatment.
The goal of treatment for moyamoya is to restore blood flow to the brain and remove the risk of stroke. Treatment for moyamoya includes:
Despite moyamoya being a rare condition, pediatric neurosurgeons at Riley at IU Health perform more than 20 pial synangiosis surgeries a year. We are one of only a few hospitals in the U.S. trained in the pial synangiosis surgery technique. As a result, we provide a robust moyamoya treatment program.
Visit the links below to discover support groups and more resources for moyamoya disease.
Riley at IU Health offers a broad range of supportive services to make life better for families who choose us for their children's care.
This government website provides an overview of moyamoya, plus information about treatment, prognosis, research and clinical trials.
This article is about understanding and treating moyamoya disease in children.
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