Moyamoya disease

If your child has been living with moyamoya disease, it can affect the whole family. At Advocate Children’s Hospital, our neuroscience experts can help treat this rare blood vessel disorder. Our pediatric neurosurgery team specializes in preventing complications, using intricate surgeries to restore blood flow.

What is moyamoya disease?

Moyamoya disease was first identified in Japan. It’s a rare disorder that tightens one or both carotid arteries, the major vessels carrying blood to the brain. The narrowing occurs where affected arteries enter the base of the skull, reducing blood flow.

Over time, clusters of tiny blood vessels form around the narrowed area to try to make up for the reduced blood flow. In Japanese, moyamoya means “puff of smoke,” which is how these tangled vessels look on scans. The tiny vessels are prone to blockage from blood clots or rupture.

Is moyamoya disease curable?

There is no cure for moyamoya disease. It is progressive, which means it gets worse over time. Without treatment, it becomes serious and may lead to blood clots, bleeding in the brain or a stroke.

What causes moyamoya disease?

Doctors don’t fully understand the causes of moyamoya disease. Because it can run in families, inherited gene changes could play a role. Researchers have found certain factors that might increase moyamoya disease risk, including:

• Age (diagnosis typically occurs between ages 5 and 10 and no later than 15)
• Asian ancestry
• Family member with the condition
• Health conditions such as Down syndrome, neurofibromatosis type 1 and sickle cell disease

Signs and symptoms of moyamoya disease in children

Moyamoya disease gets worse gradually, and it can take months or years for signs and symptoms to appear. You may notice differences in your child, or your child might experience symptoms and tell you.

In early moyamoya disease, reduced blood flow to the brain can cause:

• Developmental delays
• Headaches
• Impaired thinking
• Seizures
• Vision problems such as blurriness or double vision

Moyamoya disease and pediatric stroke

Sometimes, the first sign of moyamoya disease is a stroke or transient ischemic attack (TIA), also called a mini-stroke. Strokes and TIAs happen when a blood clot blocks the brain’s blood supply. Both conditions cause similar symptoms. The difference is that blockages last only a few minutes with TIAs and symptoms last only a few hours.

If your child experiences stroke-like symptoms, it’s impossible to know how long they will last. Seek emergency medical attention right away – every minute counts.

Read more about stroke and how we treat it.

Moyamoya disease diagnosis

If your child experiences symptoms of a stroke, our pediatric emergency team provides immediate treatment to safeguard their health. The next step is a thorough evaluation with a specialist from our neurology program.

We ask about your child’s symptoms, medical history and overall health. The doctor then does a physical exam and a detailed neurological exam. This series of tests assesses your child’s nerve and muscle functions, including thinking, memory, balance, reflexes, motor function and sensation. Read more about what to expect, including how neurological exams work.

Our specialists may use other tests to confirm a diagnosis of moyamoya disease. Tests may include:

• Magnetic resonance imaging (MRI): We create detailed images of the brain with powerful magnets and radio waves to look for signs of bleeding or tissue damage. We offer fast MRIs with technology that corrects for movement so your child doesn’t need anesthesia.
• Cerebral angiogram: With this scan, we inject dye into blood vessels leading to the brain, making them more visible. We most often do angiograms during an MRI (magnetic resonance angiogram, or MRA) and occasionally CT (computed tomography angiogram, or CTA). Angiograms help us examine blood flow.
• Electroencephalogram (EEG): We place electrodes (small, sticky pads) on your child’s head for this painless test. An EEG measures electrical activity in the brain, which can show a distinctive pattern in children with moyamoya disease.
• Transcranial Doppler ultrasound: We use ultrasound, a painless procedure, to produce images of your child’s brain. Doppler ultrasound shows the speed and direction of blood flow in the brain.
• Computed tomography (CT): A CT scan takes X-rays from multiple angles to create 3D images of the brain. CT can show signs of bleeding or tissue damage.