Moyamoya Syndrome, a Rare Medical Complication

Moyamoya Syndrome, a Rare Medical Complication

Moyamoya syndrome
Moyamoya syndrome (sometimes referred as Moyamoya disease also) is predominantly a problem observed in kids. It is a rare medical complexity when the walls of carotid arteries, which are responsible for blood supply to the brain, become thick. Due to the thickness of walls, less space is available for proper and uninterrupted blood supply to the body. It results in lower oxygen levels, and the patient has increased risk of complete blockage or suffering from a stroke.

As a natural reflex when the supply of oxygen is low, body attempts to overcome the situation by forming supplementary blood vessels so that enough supply of blood reaches the brain. These tiny blood vessels look like a puff of smoke (the word Moyamoya means exactly that in Japanese) with many curls and twists when observed on an angiogram. However, these vessels are extremely fragile and tender. They always have a risk of puncturing and bleeding off, which is called haemorrhage.


Moyamoya exhibits itself in various symptoms camouflaging with several other diseases and often goes unnoticed until the disease progresses. Hence, exact diagnosis gets delayed. In a few patients, transient ischemic attacks (also known as mini-strokes) occur. Other common symptoms are:

    • Weakness on either side of the body
    • Vision problems like blurred or distorted vision, sudden increase in number
    • Headache
    • Difficulty in speaking, slurred speech
    • Seizure

In Some Patients Brain Haemorrhage Occurs Without Any Prior Warning. In a Few Cases, Following Symptoms May be Seen:

  • Nausea and vomiting
  • Severe headaches
  • Fatigue
  • Numbness in the body
  • Change in vision


Since it is a progressive disease, no treatment can reverse the damage the disease causes to the brain because of short supply of blood. Symptomatic treatment can be given to manage the problem.

  • Medication: Aspirin is prescribed to prevent clotting of blood. It reduces the risk of stroke. Calcium channel blockers prevent entry of calcium in the blood vessels and cells of the heart. As a result, blood pressure drops and the risk of transient ischemic attacks get reduced. Patients feel relief in headache and nausea/vomiting sensation also.
  • Surgical procedures: Doctors decide to perform surgery with two objectives. Either they bypass the narrowed arteries or create additional blood supplies in the severely affected regions of the brain. There are two types of surgeries:
  • Direct: It is called a cerebral bypass procedure. Surgeons reroute the blood supply by connecting an external blood vessel from the brain to an internal blood vessel. This connection substitutes the damaged artery. Typically, a blood vessel from the scalp region is connected to the middle cerebral artery. This procedure improves blood supply significantly in three to four months.
  • Indirect: Surgeons prefer indirect procedures, especially in case of very young patients. Since the arteries are very small, it is not possible to perform a bypass in such cases. There are many indirect procedures available:
  1. Omental transposition procedure (OTP): In this procedure, lining of abdominal organs (known as omentum) are used. These linings are removed from the abdominal organs and placed on top of the brain. Subsequently, they grow and start supplying blood in adequate quantity.
  2. Encephalo-Duro-Arterio-Synangiosis (EDAS): In this procedure, doctors take temporal arteries and stitch them to the superficial tissues of the brain. These temporal arteries develop in some time and start supplying blood to the brain.
  3. Encephalo-Myo-Synangiosis (EMS): Temporal vessels are taken from temporal of either side of the head and placed on the surface of the brain.
  4. Dural inversion: In this surgical process, flaps of dural tissues are flipped on a large artery of the skull known as meningeal vessel. The blood vessels on the other surface of dural tissue supply adequate quantity of brain.

The exact cause behind this less known yet fatal disease is still unknown. However, a lot of research has been done for providing effective treatment for those who contract it. Modern medical science brings new hopes for patients and their family members. The procedures are definitely complicated and risky, but surgeons take the utmost precaution to mitigate the risks up to the maximum extent.

Reviewed By:

Dr. Kaushal M. Bhavsar (MBBS, MD)

Assistant Professor in Pulmonary Medicine, GMERS Medical College, Ahmedabad