Special Considerations in Management of Moyamoya Disease in Children

Young Children

• Infarct without warning: In children younger than 3 years of age, Moyamoya Disease frequently manifests with cerebral infarction without preceding TIA. The progression of cerebral ischemia can be much faster, and the frequency of perioperative ischemia-related complications is higher than in older children. Urgent revascularization surgery is often recommended.
• Bilateral infarcts: Within a few months of the initial infarct a contralateral cerebral infarction may occur, which carries the risk of profound neurological compromise. When the area of initial cerebral infarction is wide, saving the contralateral intact hemisphere is of utmost concern (27).
• Post-operative infarcts: In contrast to the older children, new infarction may occur on the surgical hemisphere, even in a delayed fashion (1 week) after surgery. This mandates careful examination of the children during the recovery period.

Pregnancy and Delivery

• Revascularization drops risk to normal population: For females diagnosed with Moyamoya Disease and subsequently successfully treated by revascularization surgery, the risk of stroke related to pregnancy and delivery does not appear to be significantly increased. However, those who are newly diagnosed with moyamoya and who have not been treated with revascularization may be at higher risk of intracranial stroke or hemorrhage during pregnancy. Special attention should be paid to maintenance of blood pressure within a safe range (56).

Hyperthyroidism

• Hyperthyroidism: When present, this needs treatment prior to revascularization: Hyperthyroidism provokes symptoms of Moyamoya Disease. Treatment of hyperthyroidism often leads to amelioration of Moyamoya Disease symptoms and may reduce the perioperative risk of ischemia-related complications (21).