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MOYAMOYA OVERVIEW 

Brain Scans

Moyamoya disease is a rare disorder where the main blood vessels serving the brain become narrow and blocked over time. Tiny vessels develop around the blockage to try to make up for decreased blood flow and may show up in imaging as a cloud-like group of smaller vessels. Difficult to diagnose, moyamoya affects children and adults and can cause various symptoms including transient ischemic attacks (TIAs), strokes, headaches, seizures and more, which are often mistaken for other conditions. While there is no drug treatment currently effective for moyamoya, surgery is often indicated to bypass the blockage using another artery to restore normal blood flow.

What is moyamoya?

Moyamoya disease is a rare, progressive cerebrovascular disorder caused by blocked arteries

at the base of the brain. The name "moyamoya" means "puff of smoke" in Japanese and describes

the look of the tangle of tiny vessels formed to compensate for the blockage. 

National Institutes of Health

Symptoms of moyamoya

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Symptoms of moyamoya disease vary depending on age and include

  • Headaches.

  • Seizures.

  • Weakness, numbness or paralysis in your face, arm or leg, usually on one side of your body.

  • Recurring transient ischemic attacks (TIAs or temporary stroke-like symptoms that don't last long).

  • Difficulty speaking or understanding others.

  • Fainting or blacking out.

  • Vision problems.

  • Inability to recognize objects,

  • Cognitive or developmental delays.

  • Problems with balance.

  • Progressive difficulty remembering or thinking.

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Children can feel temporary weakness in one or more of their limbs during strenuous physical activity or when crying. Adults can experience brain hemorrhage causing neurologic symptoms as well as non-hemorrhagic strokes, TIAs and headaches.

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Prevalence

A rare condition, moyamoya disease was once thought to affect approximately one in two million people. Initially thought to be limited to those of Asian ancestry, moyamoya is now known to affect people from all races and ethnicities. As the medical community has gained more awareness of the condition, diagnosis of patients is increasing and the prevalence of moyamoya across all populations is believed to be substantially higher; however, it is still thought to be substantially underdiagnosed. 

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The disease is about two times more common in females than males and can occur at any age; however, it occurs more often in children around 5 to 10 years old and adults between 30 and 50.

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Diagnosis

Because moyamoya disease can cause severe brain damage or even death, it is important to diagnose and treat the condition as quickly as possible. Diagnosis usually begins with a physical exam and review of the patient's medical history. Based on that, your physician may order one or all of these tests before making a decision about treatment.

  • Magnetic resonance imaging (MRI)

  • Magnetic resonance angiogram (MRA)

  • Advanced CT scans

  • Neuropsychological assessment — an evaluation of mental abilities that serves as a baseline and provides information about how the brain is functioning

The imaging tools help the physician find the blockage and tangle of blood vessels, as well as see how much damage may have been done by the condition.

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