Abstract 115: Presenting Symptoms and Neuroimaging Correlates in North American Moyamoya Vasculopathy

Abstract

Introduction: Moyamoya disease (MMD) is a steno-occlusion of the supraclinoid internal carotid arteries and proximal branches with the development of collateral vessels 1 . Once thought to affect primarily females of East Asian descent, more than 11,000 hospitalizations in patients with MMD of non-Asian ancestry are reported annually in the USA, with the majority presenting with ischemic stroke. Here, we present frequent non-stroke symptomatology in North American MMD along with hemodynamic imaging profiles at presentation. Methods: Participants provided informed consent and underwent anatomical MRI with hypercapnic blood oxygenation level-dependent 2 ; time regression was applied to quantify cerebrovascular reactivity (CVR) and reactivity delay time (CVR DELAY ) 3 in right and left MCA territories. A logistic regression analysis based on the Huber-White sandwich estimator compared the CVR metrics between cohorts. Significance criterion: Bonferroni corrected two-sided p<0.05. Results: 74 patients (age=11-77 years; Asian=6%, White=65%, Black=29%) diagnosed with MMD with symptom durations spanning hours to years prior to presentation were enrolled. Non-stroke symptoms and frequency prior to stroke are listed in Table 1. In more than 1/3 rd of patients, unprovoked headaches preceded stroke-like symptoms. In patients exhibiting ischemic symptoms within six months of neuroimaging, cerebrovascular reserve capacity was reduced (p=0.007), and cerebrovascular reactivity delay time increased (p<0.001), in the flow territory from which symptoms were derived compared to the contralateral flow territory. Discussion: North American MMD is being observed with increasing frequency and increasing the awareness of non-stroke MMD presentations may lead to early diagnosis that can lead to proactive revascularization to minimize the risk of first stroke in these patients.