Moyamoya disease is a rare, but progressive cerebrovascular disorder. It is caused when certain arteries in the brain are constricted. The constriction, as well as blood clots, blocks the blood flow to the brain. Then, tangle of tiny collateral vessels around the blocked vessels are formed to compensate for the blockage. The formed vessels are small and weak and appear as a “puff of smoke” on X-ray imaging.

The disease most commonly affects children, but it can also occur in adults. The first symptom of Moyamoya in children is usually a stroke or recurrent transient ischemic attacks often known as “mini-strokes”. Other accompanying symptoms are seizures and weakness in the muscles, and also one side of the body can become paralyzed. Adults usually have a hemorrhagic stroke because of blood clots that reoccur in the affected brain vessels. Some people may experience lack of consciousness, speech deficits, impaired sensory and cognitive abilities, vision problems and unintentional movements.

Researchers believe that Moyamoya disease occurs as a result of inherited genetic abnormalities.



Some of the following symptoms can appear in children and adults:

  • Stroke
  • Mini-stoke
  • Seizures
  • Muscle weakness
  • Paralyzed one side of the body
  • Hemorrhagic stroke
  • Disrupted consciousness
  • Speech deficits (aphasia)
  • Sensory impairment
  • Cognitive impairment
  • Vision problems
  • Involuntarily movement



The treatment for Moyamoya disease is usually a surgery. The procedure is called revascularization surgery during which blood flow to the brain is restored by opening narrowed blood vessels or by bypassing blocked arteries. Children usually have better outcome of the surgery that adults, but most of the patients that undergo this kind of surgery don’t experience strokes or any other related problems after the procedure.