Moyamoya Disease

What is Moyamoya Disease?

Moyamoya Disease is a very rare brain condition that mostly affects children even though some adults can be diagnosed with the condition as well.

This condition begins when the major vessels carrying nourishing blood to some areas of the brain become hardened and narrow. When the normal function of those arteries is compromised, the flow of blood slows to a dangerous level. Blood clots can form and this could significantly increase the chances of having a stroke.

The brain attempts to compensate for the compromised blood flow by generating small blood vessels throughout the affected areas in order to get the blood to go through to where it needs to go. Those vessels show the appearance similar to smoke on an angiogram which give the disease its distinct name. In fact, the Japanese word Moyamoya can literally be translated as  “puff of smoke”.

What are the Symptoms of Moyamoya Disease?

The symptoms of Moyamoya disease are very similar to the signs of a stroke. Anyone, especially children, that may experience these symptoms should be brought for medical attention right away.

Symptoms include

  • Blurry vision
  • Vertigo-like symptoms
  • Numbness and weakness on a particular side of the body
  • Slurred speech
  • Headaches, which can often be debilitating and impair a person completely
  • Seizures, particularly if the child or individual has no other underlying condition which could be connected to seizures

Moyamoya Disease Causes

The direct causes of Moyamoya disease are still unknown, though research is ongoing. The condition is primarily seen in the east, particularly in Japan, Korea and China, but there have been cases of Moyamoya disease in other parts of the world as well. Studies suggest that the concentration of cases in Asia may indicate that the illness is inherited through genetic abnormalities. In cases where a family member has had Moyamoya disease, an individual’s chances of contracting the condition is 30 to 40 times higher than those of the general population.

Additionally, Moyamoya disease has been linked with the presentation of other diseases and defects. Primarily, the development of the condition coincides with cases of Down syndrome, sickle cell anemia, neurofibromatosis type 1, and hyperthyroidism. Known cases of Moyamoya disease suggests that women and younger individuals also run a higher risk of contracting the condition, as women and children under 15 years of age more commonly develop this condition. There also seems to be an increase in the risk of contracting Moyamoya disease after the age of 30. Overall, the instances of Moyamoya disease affects less than 10% of the population.

How is Moyamoya Disease Treated?

Moyamoya disease becomes progressively worse over time.

Treatments include

Children with the condition will eventually need surgery to restore normal and healthy blood flow to their brains and reduce the possibility of a stroke or other neurological conditions. Medications that could be described can manage symptoms, but will not be a path to a cure. Several children’s hospitals across the world are devoted to research and study of this condition, with the goals of coming up with further therapy to alleviate symptoms and eventually find a cure for this rare and difficult condition.

Moyamoya Disease Prevention

While Moyamoya disease is thought to be a hereditary illness, there are ways to reduce the risk of contracting the disease. Following a stroke, doctors suggest diligently treating hypertension as a way of protecting oneself from the onset of the condition. Preventing instances of rebleeding from skin lesions can also prevent Moyamoya disease from occurring. Smoking cessation and alcohol abstinence is also recommended to ensure blood flow remains at an optimum.

Also, in cases where Moyamoya disease is present in a family or where there may be an increased risk of contracting the illness, doctors may prescribe coagulants or blood thinners. This is primarily done to prevent embolization in atrial fibrillation, but will also increase overall blood flow.

Last Reviewed:
September 21, 2016
Last Updated:
March 09, 2018