Moyamoya Syndrome Risk Factors & Causes

Moyamoya syndrome is a rare progressive vascular disorder that involves the blocking or narrowing of the skull's carotid artery, which reduces blood flow to the brain. At the base of your brain, tiny blood vessels erupt to try to supply blood to the brain. The blood vessels aren't capable of providing necessary oxygen and blood to the brain, so the patient will suffer a brain injury, the severity of which will vary widely. There is no known root cause of Moyamoya syndrome, but certain characteristics increase the likelihood of developing the disease.

Associated Conditions

Some studies have linked Moyamoya disease with other conditions, including hyperthyroidism, neurofibromatosis type 1, sickle cell anemia, and Down syndrome. Individuals with these conditions may have a higher chance of developing comorbid Moyamoya syndrome.

Unfortunately, there has not been a great deal of research establishing why the comorbidity rates exist, and scientists have different theories. It's possible these disorders are all affected by the same gene or group of genes. It's also possible certain aspects of the associated disorders can increase the chances of narrowing blood vessels in the brain. Until more conclusive research is done regarding comorbidity rates, we don't have an explanation for why these diseases often occur concurrently. We just know they do.