Stanford Moyamoya Center


Typical symptoms of Moyamoya include:

  • Weakness or numbness in an arm or leg
  • Difficulty speaking or understanding language
  • Visual abnormalities
  • Problems with balance
  • Transient ischemic attacks, or TIA's (temporary stroke-like symptoms that don't last long)
  • Seizures

Children can experience temporary weakness in one or more of their extremities during strenuous physical activity or when crying. Adults can also present with brain hemorrhage (from the fragile moyamoya vessels or from aneurysms) causing neurologic symptoms in addition to nonhemorrhagic strokes, TIA's and headaches.

Moyamoya sometimes occurs along with other disorders such as Down Syndrome, brain AVM's (arteriovenous malformations), neurofibromatosis, sickle cell disease and prior radiation for brain tumors.


Although initially thought to be limited to the Asian population, Moyamoya is now known to affect people from all races and ethnicities. The pie chart below shows data of patients treated at the Stanford Moyamoya Center.

Ethnicity and Gender of Moyamoya treated at Stanford

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