Moyamoya in Children

What is moyamoya?

Moyamoya is a rare condition in which the blood vessels (internal carotid arteries) that supply blood to the brain become narrowed. This limits the flow of blood to the brain, and puts them at risk for stroke.

The brain tries to make up for reduced blood flow by growing new blood vessels, called collaterals. While these blood vessels can temporarily help increase blood supply, they eventually stop working. The name “moyamoya,” which means “puff of smoke” in Japanese, refers to the wispy, smoke-like appearance of these new blood vessels on an x-ray.

Moyamoya is a progressive condition, meaning that it gets worse over time, so children need treatment to reduce their risk of stroke.

Some children with moyamoya also have another medical condition, such as:

Watch: Learn more about moyamoya

What is moyamoya?

How serious is moyamoya?

How we diagnose moyamoya

What is moyamoya?

 

How serious is moyamoya?

How we diagnose moyamoya

What happens after a diagnosis? Part 1

What happens after a diagnosis? Part 2

What happens during surgery for moyamoya?

What happens after a diagnosis? Part 1

What happens after a diagnosis? Part 2

What happens during surgery for moyamoya?

What happens after surgery for moyamoya?

What happens after surgery for moyamoya?

What are the symptoms of moyamoya?

Children with moyamoya may have symptoms that are similar to a stroke, such as:

  • weakness on one side of the body
  • blurry or otherwise affected vision
  • slurred speech
  • headaches
  • seizures

These symptoms can either begin gradually and get better over time, or develop suddenly and persist.

Rarely, a child with moyamoya may have a brain hemorrhage (bleeding in the brain), though this occurs much more often in adults with moyamoya. Warning signs of a brain hemorrhage can include:

  • nausea
  • vomiting
  • fatigue and lethargy
  • changes in vision
  • severe headache
  • numbness in part of the body

You should seek medical treatment right away if your child has any of the warning signs above.

What causes moyamoya in children?

Because moyamoya is so rare, its causes are not fully understood. Experts believe that a variety of factors — ranging from genetic defects to traumatic injury — may trigger the condition. There may also be a genetic component. About seven percent of children with moyamoya are believed to have an inherited gene defect. However, in at least half of all known cases of moyamoya, the disease has no identifiable cause.

Moyamoya disease is slightly more common in girls than in boys, and somewhat more common in children of Asian descent than in other ethnic backgrounds.

Our areas of innovation for moyamoya

The experts in our Moyamoya Program are international leaders in understanding and treating this life-threatening condition. More than 25 years ago, our physicians developed an effective surgery for moyamoya, called pial synangiosis. This surgery works by allowing new blood vessels to grow from the new scalp artery, which brings more blood to the brain.

Over the past 25 years, our surgeons have performed more than 50 of these procedures each year. Boston Children’s neurosurgeon Edward Smith, MD, is the most experienced surgeon performing this surgery in the country today, with the best results worldwide.

Our Moyamoya Program treats adults as well as children. Contact us to request an appointment, second opinion or consultation.

Getting back in the game after brain surgery

Conner and his family came to Boston Children's Hospital to find answers after he was diagnosed moyamoya.

Conner gives a thumbs up at a Boston Celtics game