Characteristics of brain magnetic resonance images at symptom onset in children with moyamoya disease.

Objectives: To clarify the characteristics of brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) at symptom onset in patients with childhood moyamoya disease (MD) according to developmental stage.
Methods: In 26 childhood MD patients who underwent brain MRI and MRA within 3 months from symptom onset, MRA scores and grades and MRI findings from symptomatic hemispheres were summarized according to developmental stage: infancy (0-1 years, three patients), toddlerhood/preschool age (2-5 years, nine patients), school age (6-10 years, seven patients), and adolescence (11-18 years, seven patients).
Results: Mean MRA score was 5.6, which was higher in adolescents (6.9). The most common MRA grade was grade 3, particularly in those under 10 years. Acute ischemic infarction presented in 17 patients (65%), was more common in patients below 5 years (83%) and was mainly in a gyral pattern (47%). Most hemorrhagic infarctions occurred in adolescents. Moyamoya vessels in the Sylvian valleys were apparent in 22 patients (85%), which were the most sensitive non-ischemic findings on T2 weighted images. The signal void in the distal internal carotid artery was diminished in 73% and apparent signal voids in basal ganglia were seen in three patients. The ivy sign was positive in 81% on fluid attenuated inversion recovery images and 69% on contrast-enhanced T1-weighted images in 21 and 16 patients, respectively.
Conclusions: Brain MRIs and MRAs at symptom onset in childhood MD have characteristic findings, which differ in different developmental stage.
(Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)