Abstract 3596: National Estimates of Down Syndrome Prevalence in Patients with Moyamoya Disease

Abstract

Background: An association between Moyamoya disease and Down syndrome appears to exist based on reported anectdotal cases in the literature. Objective: We performed this study to determine the prevalence of Down syndrome associated with Moyamoya disease in inpatients and to identify the clinical features of Moyamoya disease that may be unique when associated with Down syndrome. Methods: We analyzed data from patients entered in the Nationwide Inpatient Sample between 2002 and 2009, using International Classification of Diseases codes for Moyamoya disease and Down syndrome for patient identification. Data including patient age, gender, ethnicity, secondary diagnosis, medical complications, hospital costs, and patient outcomes was obtained. Results: From 2002 to 2009, an estimated 518 patients (mean age [±SD] 16.2 [± 1.68] years) with co-existing Moyamoya disease and Down syndrome were admitted as inpatients. The estimated prevalence was 3.76% (3760 per 100,000) among patients admitted with Moyamoya disease and 10.6% (10,600 per 100,000) among patients aged under 15 years. Patients admitted with Moyamoya disease and Down syndrome were most frequently Caucasian and Hispanic (p=0.015). They were more likely to present with symptoms of ischemic stroke and less commonly with hemorrhagic stroke, 15.3% and 2.7%(p < 0.05), respectively. The average length of hospital stay was 8.7 days (3.0 - 14.4). The majority were discharged home, 6.9% to nursing facilities, and 1.8% died in the hospital. Conclusion: This is the first study to estimate the prevalence of Down syndrome in patients with Moyamoya disease. The 300 fold greater prevalence of Down syndrome in patients with Moyamoya disease compared with prevalence among live births (12 per 100,000) highlight the need for better understanding of common pathophysiology of both conditions .