Abstract TP247: High Prevalence of Moyamoya Syndrome in Appalachia: Increased Frequency of Autoimmune Disorders

Abstract

Introduction: Moyamoya is a chronic cerebrovascular condition of unclear etiology characterized by progressive occlusion of one or both internal carotid arteries with neovascular collateral formation. With both a congenital juvenile form and a likely secondary adult form (moyamoya syndrome), it can cause ischemic and hemorrhagic stroke. Recent findings in the region have challenged traditional estimates of its incidence in US populations. Using the Kentucky Appalachian Stroke Registry (KApSR), our aim was to further characterize its incidence as a cause of stroke, and to understand the particular patient population in our region. Methods: A retrospective review was performed of patients identified with moyamoya within the KApSR database. Data collected included demographics, risk factors, comorbidities and healthcare encounters from January 1, 2012 to December 31, 2017. Statistical analyses were completed in SPSS 24 (IBM Corp., Armonk, NY, USA). Results: Sixty-seven patients were identified; 36 (53.7%) resided in Appalachian counties. The cohort accounted for 125 of 6305 stroke admissions, representing a prevalence of 1983 per 100000 stroke admissions. Most patients presented with ischemic strokes rather than hemorrhagic (OR 5.50, 95% CI:2.74-11.04, p<0.0001). Eleven patients (16.4%) exhibited autoimmune disorders. Compared to the general population autoimmune disorder prevalence of 4.5%, the presence of autoimmunity within the cohort was significantly higher (p<0.0001). Comparing Appalachian to non-Appalachian, Appalachian patients tended to present with lower frequencies of tobacco use (p=0.073), diabetes mellitus (p=0.086), hypertension (p=0.141) and autoimmunity (p=0.322). Conclusion: The prevalence of moyamoya accounts for a significant portion of stroke admissions in Appalachia and these patients were more likely to develop an ischemic stroke than hemorrhagic. Autoimmune disorders were more prevalent in moyamoya patients compared to the general population. Finally, the reduced frequency of risk factors within the Appalachian group suggests an etiology distinct to the population.