Symptoms Do Not Predict White Matter Injury in the Watershed Regions in Children with Moyamoya

Abstract

ObjectiveTo assess if white matter injuries differ in symptomatic versus asymptomatic moyamoya-affected hemispheres using diffusion magnetic resonance imaging (dMRI) since there is controversy on when or if to revascularize children with asymptomatic moyamoya. Study designWe conducted a cross-sectional study of children with moyamoya who underwent dMRI prior to revascularization surgery as well as controls without moyamoya. We measured the fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) of white matter tracts in the watershed regions. Moyamoya-affected hemispheres were included if they did not have any visible stroke or infarct. Moyamoya-affected hemispheres were labeled “symptomatic” if transient ischemic attack (TIA), seizure, or movement disorder were localizable to that hemisphere, or if the child had headaches. Moyamoya-affected hemispheres were “asymptomatic” if the child did not have symptoms attributable to that hemisphere. Asymptomatic and symptomatic hemispheres were compared with each other and control children using ANOVA. ResultsWe included 17 children with moyamoya with 26 moyamoya-affected hemispheres and 27 control children. Compared with controls MD, RD, and AD were higher in both symptomatic and asymptomatic moyamoya-affected hemispheres but were not significantly different from each other. ConclusionChildren with moyamoya without stroke or silent infarct have unrecognized white matter injury that is similar in both symptomatic and asymptomatic moyamoya-affected hemispheres, suggesting that symptoms do not accurately reflect moyamoya severity.