Pediatric Neurology and Neurosurgery

Moyamoya Syndrome

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Expert treatment for a rare disorder

Moyamoya syndrome is a rare condition in which the carotid arteries (blood vessels at the base of the skull) progressively narrow, limiting the flow of vital oxygen-rich blood to the brain. The pediatric neurovascular teams at NewYork-Presbyterian Morgan Stanley Children’s Hospital and NewYork-Presbyterian Komansky Children’s Hospital have exceptional expertise in diagnosing and treating children with Moyamoya, relieving your child's symptoms, preventing complications, and restoring your child's quality of life.

Why is it called Moyamoya?

Moyamoya means "puff of smoke" in Japanese, and the condition is so named because the body grows a secondary network of small vessels to compensate for the restricted blood flow. On an angiogram (a scan showing blood vessels), the network of new vessels resembles a cloud or puff of smoke. This new blood vessel network may lead to complications. As blood flow becomes increasingly restricted, the supplementary network may not supply enough blood to the brain, causing a stroke. Also, the new vessels are fragile and may rupture (cerebral hemorrhage). Children with Moyamoya may also experience seizures or headaches.

Signs & symptoms

Because their brains are not receiving enough oxygen, children with Moyamoya may:

  • Have delayed development
  • Appear clumsy as toddlers
  • Have speech problems
  • Seem slow to learn
  • Display impaired school performance

Risk factors for Moyamoya

There are certain groups of children who have a greater risk of Moyamoya syndrome.

  • Children with sickle cell disease have an increased risk of Moyamoya and undergo monitoring for this disorder.
  • Children who have had radiation therapy for benign brain tumors and those with Down syndrome are also at risk.
  • The diagnosis is not made in other children until symptoms arise and other conditions have been ruled out.

Diagnosing Moyamoya

MRI scanning or angiography (an interventional exam where doctors look at your child's arteries' anatomy using x-rays and a special dye) are the methods we use to diagnose Moyamoya. While ultrasound examination of the carotid arteries is often used in adults to assess stroke risk, it is not useful in children with Moyamoya, whose narrowed blood vessels are very close to the brain's base and cannot be imaged in this way.

Our approach to care

Surgery for Moyamoya requires a specialized center, such as NewYork-Presbyterian, with pediatric and vascular neurosurgeons who have the latest technologies to offer a complete evaluation and treatment plan for this rare disorder. Surgery to treat Moyamoya and restore blood flow to the brain is very effective, with 90-95 percent of children remaining free of the disorder 10 years later. It requires pediatric neurosurgeons' exceptional expertise with advanced training handling the tiny, delicate blood vessels in a child's brain.

Advanced surgical treatment

The safest and most effective surgical approach for Moyamoya in children is a microsurgical bypass procedure called "pial synangiosis." The neurosurgeon reroutes a section of the artery normally connected to the scalp (outside the skull) and attaches it to the brain's surface (inside the skull). Over the following months, new blood vessels grow from this section of the artery into the brain itself, providing a new source of blood for the under-supplied area affected by Moyamoya and restoring blood flow to the brain.

Why choose us

Your child is in excellent and highly experienced hands during Moyamoya surgery at NewYork-Presbyterian. Your child's team includes pediatric neurosurgeons and neurologists, pediatric anesthesiologists with experience treating young neurosurgery patients, interventional radiologists, pediatric critical care experts, and others committed to your child's safety and well-being. During the operation, a neurophysiologist uses EEG to monitor your child's brain's oxygen needs and make appropriate changes to ensure those needs are met, reducing stroke risk. Call us today to make an appointment for a consultation.