Abstract 115: Periventricular But Not Subcortical White Matter Lesions Are Associated With Adult Moyamoya Disease

Abstract

Introduction: White matter hyperintensities (WMH) are reportedly increased in moyamoya disease (MMD); however, their clinical importance is not well-established owing to their pathophysiological heterogeneity by distribution. This study aimed to evaluate the burden and pattern of WMH and its clinical implications in the MMD trajectory. Methods: Adult MMD patients without significant structural lesions were 1:1 propensity score-matched with healthy controls for sex and vascular risk factors. The total, periventricular, and subcortical WMH volumes were segmented and quantified fully automatically. WMH volumes were detrended by age and compared between the two groups. MMD severity based on Suzuki stage and future ischemic events were assessed for their association with WMH volumes. Results: A total of 190 pairs of patients with MMD and controls were analyzed. MMD significantly correlated with increased total (B, 0.086; standard error [SE], 0.027; p=0.002) and periventricular WMH volumes (B, 0.079; SE, 0.025; p=0.002). In the MMD subgroup, advanced MMD had an independent positive association with the total (B, 0.124; SE, 0.034; p<0.001) and periventricular WMH volumes (B, 0.116; SE, 0.030; p<0.001). Periventricular WMH volume was associated with future ischemic events (adjusted hazard ratio [aHR], 4.96; 95% confidence intervals [CIs], 1.21-20.25) in medically followed-up MMD patients. However, no demonstrable association was found between subcortical WMH volume and MMD (B, 0.007; SE, 0.007; p=0.35), MMD severity (B, 0.010; SE, 0.011; p=0.37), or future ischemic events (aHR, 14.15; 95% CIs, 0.20-1022.96). Conclusions: Periventricular WMH, but not subcortical WMH, may represent the main pathophysiology of MMD. Periventricular WMH may be used as a marker for ischemic vulnerability in patients with MMD.