About the disease

Moyamoya disease, also known as Moyamoya syndrome, is a pediatric condition, when carotid arteries become thickened and are not able to supply sufficient amount of blood to the brain vessels. As a result, child does not receive enough oxygen-rich blood and there is increased risk of clot formation in the brain. Such risk exists because the brain, trying to compensate for the lack of blood supply, creates new blood vessels, which start to clot together. The most dangerous complication of Moyamoya disease is a stroke, which can be caused by such cerebrovascular disorder, as this syndrome.

According to Boston Children's Hospital,  Moyamoya disease is a rare condition, affecting only several hundred children worldwide annually. Most commonly this disease is diagnosed at the age of 7, although in rare cases it can first manifest itself in adulthood after many years of unnoticed progression.

Moyamoya disease is believed to be caused by genetic defects. Some of the children with this condition also have Down syndrome and other congenital conditions. It is more common in girls. In some children the first indicator of Moyamoya disease is a brain hemorrhage, while in others - mini stroke. Nonetheless, this syndrome develops very slowly and before there is a real danger of stroke, child has pronounced symptoms of this disease, which usually allows the doctor to carry out diagnosis on time.   

Symptoms

• Recurrent headaches
• Slurred speech
• Fatigue
• Weakness on right/left side of the body
• Seizures
• Nausea
• Blurred vision
• Irritability
• Changes in behaviour

Diagnosis

• MRI is the most commonly used diagnostic measure for this type of disease. it creates the image of the brain, which allows the doctor to see if there is an excessive number of blood vessels.
• CT scan is a more precise imaging test, which creates the three-dimensional image of the brain and determines if there is insufficient supply of oxygen-rich blood through carotid arteries.
• Angiogram is also an imaging test, which shows the carotid artery and helps doctor determine the extent of its narrowing and thickness.

Treatment

Surgery is the only possible treatment for this disease, as it is impossible to fully stop the process of artery narrowing by anti-clotting drugs or any other blockers. Most often, medications in this case are used only to prepare the child for surgery, which aims to restore normal blood flow to the brain.

• Arterial bypass surgery restores the blood flow by joining blood vessel from the scalp directly to the brain.
• Shunt overlay with interpolation is a surgery, during which hollow tube is placed in the brain to redirect the blood flow and normalize the supply of oxygen-rich blood to the brain. 

Authors: Dr. Nadezhda Ivanisova, Dr. Sergey Pashchenko