The Moyamoya Center was established in 2006 when the National Institute of Neurological Disorders and Stroke granted Washington University a five-year grant to perform a long-term study of moyamoya disease outcomes.

Understanding Moyamoya Disease

In moyamoya disease, the large arteries inside the skull (vessels that carry blood to the brain) narrow and often completely close off. The cause of the narrowing is unknown. To compensate, smaller branches of these arteries grow larger. "Moyamoya" is a Japanese term used to describe the hazy appearance of these small vessels on an angiogram.

The increased blood flow through these smaller arteries causes stress. Hemorrhage (bleeding), aneurysm and thrombosis often result.

This disorder is common in Asia, where it most frequently affects children. In North America, it is much less common and generally affects women in their 30s, 40s and 50s, frequently causing stroke.

Treatment of Moyamoya Disease

Moyamoya is difficult to treat because so little is known about the disease. Some people never have a stroke while others may have several. There are surgical procedures that may improve blood flow to the brain. These procedures may cause complications, however, and may not always achieve the desired result of improving brain blood flow. Sometimes blood flow to the brain is normal despite the blockages because of connections from normal arteries that bypass the blockages. People with normal blood flow may not have anything to gain from surgery.

Research at the Moyamoya Center is ongoing in an effort to better understand and treat this complex neurological condition.