Follow-up for Moyamoya Disease in Children

Frequency of Office Visits

• Time of initial postoperative visit: At two weeks after surgery, office visit is recommended for postoperative check-up: neurological symptoms, wound status, etc.
• Time of the first follow-up visit: The interval between the first surgery and the second one is different according to the hemodynamic status and age. For those with marginal reserve of cerebral perfusion and young age patients, the recommended interval is short, about 4 weeks. For those with good reserve of cerebral perfusion, the second operation may be performed later than postoperative 2-3 months when revascularization is well developed at the sites of the first operation. When bilateral operations were done, initial follow-up is recommended at 6 months to 1 year after surgery.
• Frequency of subsequent visits: If the patient shows stable course, office visits are recommended for every 1-5 years depending on age or unoperated areas. Less frequent visits are recommended for older children because of slow progression of disease if present. If the patient already had surgery on all sites (bilateral STA areas, bilateral occipital artery areas and bifrontal area) and confirmed good revascularization, long interval is acceptable. When some sites were not operated on because of lack of hemodynamic disturbance at the areas at the time of previous surgery, progressive ischemic involvement of these area should be monitored according to the age. Again, older children do not need frequent visits. Female patients are recommended to visit before pregnancy and delivery to confirm hemodynamic status. At the visit of all patients, blood pressure is measured to screen hypertension.

Frequency of Imaging

• Peri-operative imaging: Immediate postoperative CT scan is recommended. When there are frequent or long lasting TIAs, additional CT scan is recommended to rule out the postoperative hematomas. If hematoma of significant amount is found, surgical evacuation should be considered. Otherwise treatments for ischemic condition are recommended: avoidance of adverse factors such as hyperventilation, hypovolemia, anemia, or hypotension and correction of hemodynamic parameters. When postoperative frequent or long lasting TIAs persist or fixed neurological deficits developed, MRI including diffusion MRI is recommended at postoperative 7 days in our institute.
• Timing of baseline scan: The first postoperative imaging (MRI, MRA, perfusion MRI) is recommended at 6 months to 1 year after last surgery according to the age of the patient. Young patients need early follow-up.
• Frequency of imaging: We recommend imaging every 1-5 years until adulthood depending on the age and non-operated areas. An additional imaging is recommended for female patients who plan the first pregnancy.

Other Investigations Required

• Stenosis of other systemic arteries: Some of the patients have narrowing of other systemic arteries. When suspected, appropriate tests should be performed with adequate specialist consultation.
• Screening test for family members: Mutation of RNF 213 is suggested as a potential screening marker in selected populations. However, its clinical value is still under investigation.