Moyamoya disease is the narrowing and ultimately closure of the internal carotid arteries, the two largest arteries feeding the brain. Moyamoya disease is progressive, meaning the vessel walls will continue to narrow over time.
The cause of moyamoya disease is unknown, although genetics are a likely factor. It affects mostly children and adolescents.
In response to the narrowing of the blood vessels, the body will begin to grow many small blood vessels to bypass the blockage.
The word moyamoya means “puff of smoke” in Japanese, and refers to the appearance of these networks of new blood vessels. The condition first was identified in Japan, where its incidence is higher than elsewhere.
The findings of narrow blood vessels at the base of the brain can also be associated with other diseases, and is referred to as moyamoya syndrome. This syndrome can be found in people with:
UPMC offers a variety of surgical techniques to treat Moyamoya disease, depending upon the exact location of the disease.
Because Moyamoya disease may be an inherited genetic abnormality, a doctor will also review the family history.
Signs and symptoms of Moyamoya disease may include:
Adults with Moyamoya disease also often experience hemorrhagic stroke (a burst blood vessel inside the brain).
CT and MRI scans may provide initial indications of the disease. If the disease is suspected, cerebral angiography, a test that creates images of the blood flow through the brain, is conducted to establish the diagnosis.
UPMC is one of the few centers in the nation to have all major methods of measuring brain blood flow.
There is no evidence that medications slow the progression of Moyamoya disease. At UPMC, highly trained and experienced neurosurgeons use revascularization procedures to bypass narrowed or blocked arteries and restore blood supply to the brain.
Revascularization procedures performed at UPMC include:
In rare circumstances, our endovascular team will evaluate the person for minimally invasive alternatives such as:
Without surgery, the majority of people with Moyamoya disease will experience mental decline and multiple strokes because of the progressive narrowing of the arteries. If untreated, Moyamoya disease can be fatal.