Moyamoya Disease

A healthcare provider will perform a physical examination and ask you about your symptoms. If they suspect moyamoya disease, you may need the following tests:

• Cerebral arteriography: Your provider inserts a small tube called a catheter into an artery in your arm or leg. They then use it to inject iodine contrast dye into your bloodstream. Next, they take X-ray scans of the dye in your blood vessels. This technique can reveal how much your blood vessels have narrowed and map blood flow patterns.
• Magnetic resonance angiography (MRA): In this pain-free test, your provider uses a magnetic field, radio waves and a computer to look at your blood vessels.
• Magnetic resonance imaging (MRI): MRI uses similar technology to take pictures inside your body and can help assess the effect of moyamoya disease on your brain.

What are the stages of moyamoya disease?

Moyamoya disease is progressive. That means it will gradually get worse without treatment. Healthcare providers use the “Suzuki” stages to describe the severity of the disease. They’ll use the MRA test to help determine what stage of the disease you’re in. Suzuki stages include:

• Stage 1 — Narrowing of carotid fork: The narrowing or blockage is only affecting the internal part of your carotid artery.
• Stage 2 — Initiation and appearance of basal moyamoya vessels: The narrowing is affecting all the terminal branches of your internal carotid artery, and deep moyamoya blood vessels are starting to become visible on the angiogram.
• Stage 3 — Intensification of basal moyamoya vessels: The deep moyamoya blood vessels are intensified on the angiogram, and the “puff of smoke” appearance can be seen.
• Stage 4 — Minimization of basal moyamoya vessels: On the angiogram, the deep moyamoya blood vessels start to regress. Other blood vessels called transdural collateral vessels start to appear.
• Stage 5 — Reduction of moyamoya vessels: On the angiogram, the deep moyamoya blood vessels continue to regress, and more transdural collateral vessels begin to appear.
• Stage 6 — Disappearance of moyamoya vessels: All the deep moyamoya blood vessels have vanished, and there’s a complete narrowing or blockage of the internal carotid artery.