Brain, Nervous System and Mental Conditions

Moyamoya Symptoms and Diagnosis

Moyamoya Symptoms

Usually, children with moyamoya have no symptoms until they have a transient ischemic attack (TIA) or stroke.

Symptoms of a TIA or a stroke from blocked blood flow (ischemic stroke) include:

  • Trouble speaking, such as slurring words
  • Weakness or numbness on one side of the body
  • Sudden vision problems, such as blurred vision
  • Trouble walking or balancing
  • Seizures

Rarely, children with moyamoya have a stroke from a burst blood vessel (hemorrhagic stroke). This type of stroke may cause:

  • Sudden, severe headache
  • Trouble walking or balancing
  • Trouble staying awake or alert
  • Nausea or vomiting

Sometimes, breathing too fast or too deeply (hyperventilating), which might happen while crying or running, triggers a TIA or stroke in a child with moyamoya.

Even without a stroke, moyamoya may cause headaches.

Moyamoya Diagnosis

Your child’s doctor will use brain imaging to look at the arteries that supply blood to the brain. Your child may need these tests:

  • MRI (magnetic resonance imaging) scan
  • MRA (magnetic resonance scans of the arteries, also called magnetic resonance angiography)
  • CT (computed tomography) scan
  • Cerebral angiogram

Sometimes, other types of imaging are needed to find out how well and how much blood flows to different parts of the brain. Your child’s team will explain in detail which tests your child needs, why and what to expect.