Myelin damage and cortical atrophy in watershed regions in patients with moyamoya angiopathy

Abstract

BackgroundDespite it being known that chronic ischemia results in myelin damage and gray matter atrophy, data regarding patients with moyamoya angiopathy is limited. We hypothesized that chronic ischemia in moyamoya angiopathy leads to myelin damage, especially in anterior watershed regions, as well as cortical atrophy in these areas.Materials and methodsTwenty adult patients with moyamoya angiopathy and 17 age- and sex-matched healthy controls were evaluated using the T1w/T2w mapping method and surface-based MR-morphometry. The T1w/T2w signal intensity ratio, which reflects the white matter integrity, and the cortical thickness, were calculated in watershed regions and compared between the patients and controls. In the patients with moyamoya angiopathy, the correlations between these parameters and the Suzuki stage were also evaluated.ResultsThe regional T1w/T2w ratio values from centrum semiovale in patients with MMA were significantly lower than those in healthy controls (p < 0.05); there was also a downward trend in T1w/T2w ratio values from middle frontal gyrus white matter in patients compared with the controls (p < 0.1). The cortical thickness of the middle frontal gyrus was significantly lower in patients than in healthy controls (p < 0.05). There were negative correlations between the Suzuki stage and the T1w/T2w ratio values from the centrum semiovale and middle frontal white matter.ConclusionT1w/T2w mapping revealed that myelin damage exists in watershed regions in patients with moyamoya angiopathy, in association with cortical atrophy according to MR-morphometry. These changes were correlated with the disease stage.

White and Gray Matter Perfusion in Children with Moyamoya Angiopathy after Revascularization Surgery

“…Several studies have revealed myelin damage due to hypoperfusion within the hemispheric white matter in patients with MMA [28,29]. It is unclear, however, whether these changes are reversible [18,29].…”

“…To date, only a few studies dedicated to white matter perfusion changes in patients with MMA have been published [17]. However, white matter watershed regions (such as the semiovale center) are the most prone to chronic ischemic changes in MMA [18], and it is still unclear what changes can be found in these patients after bypass surgery. Thus, the purpose of this study was to estimate cerebral hemodynamic changes in gray matter and white matter in children with MMA after revascularization surgery.…”