Moyamoya disease is usually diagnosed by a doctor who specializes in conditions of the brain, called a neurologist. The neurologist reviews your symptoms and your family and medical history. The neurologist also may perform a physical exam. Several tests are generally needed to diagnose moyamoya disease and any underlying conditions.
Tests may include:
Your neurologist may recommend a perfusion MRI. This type of imaging can measure the amount of blood passing through the vessels. It can show if there is a decrease in blood supply to the brain.
If necessary, your neurologist may order other tests to rule out other conditions.
Healthcare professionals evaluate your condition and determine the treatment that is right for you. Treatment doesn't cure moyamoya disease. But treatment can help prevent strokes.
The goal of treatment is to reduce your symptoms and improve blood flow to the brain. Treatment also aims to lower your risk of complications. Complications include ischemic stroke caused by a lack of blood flow, bleeding in your brain and death.
The outlook for moyamoya disease, also called the prognosis, depends on several factors, including:
Your treatment may include medicine, surgery and therapy.

Mayo Clinic healthcare professionals provide comprehensive treatment for people with moyamoya.
Medicines may be prescribed to manage symptoms, to reduce the risk of a stroke or to aid in seizure control. Medicines may include:
Early surgical treatment can help slow progression of moyamoya disease. Your neurologist may recommend revascularization surgery if you develop symptoms or strokes. Surgery also may be recommended if tests show evidence of low blood flow to your brain.
In revascularization surgery, surgeons bypass blocked arteries. They do this by connecting blood vessels on the outside of the skull to the inside of the skull to help restore blood flow to your brain. This may include direct or indirect revascularization procedures. Or it may include a combination of both.
Direct bypass surgery may be difficult to perform in children due to the size of the blood vessels. But it's the preferred option in adults. This intervention can be performed safely and effectively by an experienced surgical team that treats people with moyamoya disease daily.
Indirect revascularization procedures include encephaloduroarteriosynangiosis. This also is called EDAS. They include encephalomyosynangiosis, also called EMS. Or they include a combination of both.
In EDAS, a surgeon makes a small temporary opening on the scalp to expose the artery. Then the surgeon makes an opening in your skull directly beneath the artery. The surgeon lays the intact scalp artery onto the surface of your brain, which allows blood vessels from the artery to grow into your brain over time. The surgeon then replaces the bone and closes the opening in your skull.
In EMS, your surgeon separates a muscle in the temple region of your forehead and places it onto the surface of your brain through an opening in your skull. This helps restore blood flow.
Your surgeon may perform EMS with EDAS. In this procedure, your surgeon separates a muscle in the temple region of your forehead. The surgeon places it onto the surface of your brain after attaching the scalp artery to the surface of your brain. The muscle helps to hold the artery in place as blood vessels grow into your brain over time.
Possible surgery risks of revascularization procedures for moyamoya disease include changes in pressure in the blood vessels in the brain. This can cause headaches, bleeding and seizures. However, the benefits of surgery largely outweigh the risks.
Some people with moyamoya disease develop a bulge or ballooning of a blood vessel in the brain known as a brain aneurysm. If this happens, surgery may be necessary to prevent or treat a ruptured brain aneurysm.

In a direct revascularization procedure, your surgeon connects a scalp artery, known as a superficial temporal artery, directly to the middle brain artery, known as a middle cerebral artery. This increases blood flow to the brain.
To address the physical and mental effects of a stroke on you or your child, your healthcare professional may recommend an evaluation by a psychiatrist or therapist. Without surgery, moyamoya disease can cause cognitive decline due to narrowing blood vessels. A psychiatrist may look for signs of problems with thinking and reasoning skills. The psychiatrist also may monitor you or your child for signs that those problems are worsening.
Cognitive behavioral therapy can help address emotional issues related to having moyamoya disease, such as how to cope with fears and uncertainties about future strokes.
Physical and occupational therapy can help regain any lost physical function caused by a stroke.
If you or your child has been diagnosed with moyamoya disease, you'll most likely be referred to a doctor who specializes in brain conditions, known as a neurologist.
Here's some information to help you get ready for your appointment.
Your time with your healthcare team is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For moyamoya disease, some basic questions to ask include:
Your healthcare professional is likely to ask a number of questions, such as: