MOYAMOYA DISEASE

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Moyamoya disease is a rare, progressive cerebrovascular disorder caused by blocked arteries at the base of the brain in an area called the basal ganglia. The term "moyamoya" means "puff of smoke" in Japanese, describing the tangled appearance of tiny blood vessels that form to compensate for the blockage.

Moyamoya disease is more common in Asian countries, particularly Japan, Korea, and China, but it can occur in people of any ethnicity. It typically affects children, but adults can also develop the condition. The disease is slightly more prevalent in females than in males.

The symptoms of Moyamoya disease vary depending on the age of onset and the severity of the blood vessel blockage. Common symptoms include:

• Transient ischemic attacks (TIAs) or mini-strokes
• Strokes
• Headaches
• Seizures
• Weakness or paralysis in a limb
• Visual disturbances
• Cognitive and developmental delays in children
• Difficulty with speech or understanding language
• Involuntary movements

Diagnosing Moyamoya disease involves several steps:

• Medical History and Physical Exam: Your doctor will review your symptoms and perform a neurological examination.
• Imaging Tests: Various imaging techniques are used to detect the characteristic blood vessel changes:
  • MRI (Magnetic Resonance Imaging) and MRA (Magnetic Resonance Angiography): Provide detailed images of the brain and blood vessels, showing blockages and the "puff of smoke" appearance.
  • CT Scan (Computed Tomography) and CTA (Computed Tomography Angiography): Can help visualize blood vessel abnormalities and detect any bleeding in the brain.
  • Cerebral Angiography: The gold standard for diagnosing Moyamoya disease, where a contrast dye is injected into the blood vessels, allowing for detailed imaging of the cerebral circulation.
  • Electroencephalogram (EEG): May be used to detect abnormal electrical activity in the brain, especially if seizures are present.

Treatment for Moyamoya disease aims to improve blood flow to the brain and reduce the risk of strokes. Options include:

• Medications: Drugs such as blood thinners (anticoagulants) and antiplatelet agents can help prevent blood clots and reduce the risk of strokes. Medications may also be prescribed to manage symptoms like headaches and seizures.
• Revascularization Surgery: The primary treatment for Moyamoya disease, aiming to restore adequate blood flow to the brain. There are two main types of surgical procedures:
  • Direct Bypass: This involves connecting a scalp artery directly to a brain artery to bypass the blocked vessel and restore blood flow.
  • Indirect Bypass: This technique promotes the growth of new blood vessels by placing tissues with a rich blood supply (like the scalp or muscle) onto the brain surface. Over time, new blood vessels grow and improve blood flow.

There are different surgical techniques for treating Moyamoya disease:

• Direct Bypass (STA-MCA Bypass): The superficial temporal artery (STA) from the scalp is connected to the middle cerebral artery (MCA) in the brain. This method provides immediate improvement in blood flow.
• Indirect Bypass Procedures:
  • Encephaloduroarteriosynangiosis (EDAS): An artery from the scalp is placed onto the surface of the brain, encouraging the growth of new blood vessels.
  • Encephalomyosynangiosis (EMS): Muscle tissue from the scalp is laid onto the brain surface to stimulate new blood vessel formation.
  • Multiple Burr Hole Surgery: Small holes are drilled in the skull to promote new blood vessel growth from the scalp to the brain.

Early detection and treatment of Moyamoya disease can significantly improve outcomes and prevent serious complications. If you experience symptoms or have concerns about Moyamoya disease, it's important to consult your healthcare provider for a thorough evaluation.