What Is Moyamoya Disease?

Moya Moya disease is characterized by the appearance of tiny blood vessels that form to compensate for the result of blocked arteries at the base of the brain. These compensatory vessels (which can appear as a “puff of smoke,” or moya moya in Japanese) are smaller and weaker than typical blood vessels, and more prone to bleeding, thrombosis and aneurysm formation. As the normal blood vessels narrow and become blocked, a person may suffer a stroke.


  • A transient ischemic attack (TIA) also referred to as a minor stroke or mini stroke, can represent an important warning sign of a potential future more serious stroke. A TIA occurs when a blood clot blocks an artery for a short period of time. The symptoms of a TIA are like a stroke but are temporary, usually lasting only a few minutes to hours .
  • An ischemic stroke is a much more serious version of a TIA, occurring when blood flow to the brain is blocked by a blood clot or plaque. Ischemic strokes are by far the most common type of stroke, occurring in approximately 87% of cases. Unlike a TIA, the blockage causing an ischemic stroke won’t go away on its own without urgent treatment.


Although the cause is currently unknown, researchers think moyamoya may be an inherited genetic condition because it tends to run in families.


Northwestern Medicine specialists offer diagnostic tests, including a physical and neurological exam, and provide a review your family medical history. We may also provide diagnostic procedures that include:

If you are diagnosed with moyamoya disease, we will work with you and your primary care physician to tailor treatment to your individual condition.


In the spirit of keeping you well-informed, some of the physician(s) and/or individual(s) identified are neither agents nor employees of Northwestern Memorial HealthCare or any of its affiliate organizations. They have selected our facilities as places where they want to treat and care for their private patients.