Presurgical Magnetic Resonance Imaging Indicators of Revascularization Response in Adults With Moyamoya Vasculopathy

Abstract

Methods ParticipantsAll participants provided informed, written consent for this prospective, interventional study. All study components were 984Volume 56, No. 4

Cerebrovascular reactivity dispersion as a new biomarker of recent stroke symptomatology in moyamoya

“…Prior work has shown that the CVR metrics are improved by surgical revascularization and can indicate good versus poor response to revascularization in adult moyamoya patients, as verified from neoangiogenesis on catheter angiography. 22,23 Our findings support this notion by showing that CVR metrics are less impaired in asymptomatic hemispheres in a much larger moyamoya cohort (n=73) and also provide evidence that the temporal parameters of the hemodynamic response function are the most sensitive to the presence of recent ischemic symptoms and have the highest predictive power for such symptoms. The exemplar statistics we show in Figure 5 complement recent reports of CVR ranges in healthy control volunteers.…”

Choroid plexus vascular reactivity in moyamoya: Implications for choroid plexus regulation in ischemic stress

“…The aim of this procedure is to improve blood flow to the ischemic hemisphere through neoangiogenesis rather than simply bypass. 9,27,28 The improvement in blood flow is consistent with higher vascular density, improved perivascular pathways in the region of vascular growth, and ultimately reduced cortical ischemia. Consistent with these expectations, participants with prior surgical revascularization did not have a cortical reactivity dependency on the proximal arterial steno-occlusion, which is consistent with local angiogenesis improving the cortical reactivity in a manner that did not depend significantly on the more proximal arterial vasculopathy.…”

“…The indirect surgical EDAS procedure transposes a segment of the superficial temporal artery onto the surface of the brain to induce angiogenesis near the site of transposition. The aim of this procedure is to improve blood flow to the ischemic hemisphere through neoangiogenesis rather than simply bypass 9,27,28 . The improvement in blood flow is consistent with higher vascular density, improved perivascular pathways in the region of vascular growth, and ultimately reduced cortical ischemia.…”

“…The ChP receives its arterial supply from anterior as well as medial and lateral posterior choroidal arteries, which arise from the posterior circulation. While the EDAS procedure generally does not directly affect posterior circulation flow, it has been shown that posterior circulation is relevant to surgical outcomes in moyamoya, with more positive outcomes to EDAS being more likely in patients who had better presurgical posterior reactivity profiles (eg, higher reactivity magnitude and shorter reactivity delay) 28 . The lack of a ChP reactivity change between revascularized participants with different levels of vasculopathy supports the conclusion that previously reported changes in ChP perfusion 9 are unlikely to be modulated by exclusively vascular phenomena.…”

Editorial for “Pre‐Surgical Magnetic Resonance Imaging Indicators of Revascularization Response in Adults With Moyamoya Vasculopathy”

“…In this issue of JMRI, Waddle et al offer a glimpse of the future with personalized revascularization decision-making strategy. 5 In a carefully designed and implemented prospective study, the authors propose a novel approach to predict the revascularization outcome for adult MMD with MRI-based evaluation of the posterior flow-territory reactivity. The analysis is motivated by the central hypothesis that as MMD preferentially affects the anterior circulation, the posterior circulation would display a compensatory increase in flow reactivity.…”