접수번호:33O10323    Risk factor, etiology and outcome of ischemic stroke in Korean young adults: a single center study   Seol-Hee BAEK, Kyung-Hee CHO Department of neurology, Korea University College of medicine, Seoul, Korea   Background & Objectives : The stroke is the second common cause of death and one of the most important causes of disability in Korea. Although most of stroke occurs in elderly, some of them affects younger than 50 years. The stroke has effect on the life of patients and their families. Especially, the stroke in young adults has a big impact on their life because young adults are main agents of economic activity. However, there is limited information about clinical manifestations of stroke in young adults. Therefore, we aimed to evaluate risk factors, etiology, and outcome of stroke in Korean young adults. Method : We reviewed stroke registry for 2187 patients with stroke or transient ischemic attack (TIA) who admitted to Korea University Hospital between September 2007 and March 2013 (total 66 months), retrospectively. We enrolled patients aged 18 to 50 years with an ischemic stroke only if the stroke lesion was documented by magnetic resonance imaging. We collected the following data during this study period: demographics, risk factors (hypertension, diabetes mellitus, dyslipidemia, cardiac problems, smoking, previous stroke history, and family history), the results of laboratory test (fasting blood sugar, LDL-cholesterol, triglyceride, C-reactive pretein, homocystein, and fibrinogen). The stroke was classified three groups; anterior circulating, posterior circulating, and both, according to the location of stroke lesion. The etiology of stroke was classified by the trial of ORG 10172 in acute stroke treatment (TOAST) classification. We also collected the data of the National Institutes of Healthy stroke scale (NIHSS) score at admission and the modified Rankin Scale (mRS) score at three months. According to the mRS score, we divided into two groups; favorable (mRS 0-2) and unfavorable (mRS 3-6). Results : Among the 2187 patients included in stroke registry, 200 patients (200/2187, 9.15%) aged 18 to 50 years with ischemic stroke were identified. The patients with TIA (n=41) or hemorrhagic stroke (n=8) were excluded. Fourteen patients became lost to follow up and 29 patients were lack of the mRS score at 3 months. Finally, we analyzed the clinical date of 108 young adults (81 men, 27 women) with ischemic stroke. The age ranged from 19 to 50 years (mean ± standard deviation, 42.75 ± 7.12 years). Most common risk factors in young adults were smoking (n=72, 66.7%) and hypertension (n=45, 41.7%). On the other hand, only 8 patients had previous stroke history (7.4%). Large artery atherosclerosis (n=39, 36.1%) was the most common cause of the stroke in young adults. Other causes were small vessel occlusion (n=25, 23.1%), cardioembolism (n=15, 8.3%), others determined etiology (n=9, 8.3%), 2 or more etiology (n=4, 3.7%), and undetermined etiology (n=16, 14.8%). Clinical outcome at three months was favorable in 89.8% and unfavorable in 10.2%. Three patients were expired. Stroke caused by cardioembolism had worse outcome than other causes (p=0.023). The initial NIHSS score of unfavorable outcome group (IQR 3-11) had higher than the favorable outcome group (IQR 1-4) (p=0.006). Logistic regression analysis revealed that the previous stroke history, the NIHSS score at admission were independent predictors of an unfavorable outcome (p=0.016, p=0.008 respectively). Conclusion : In Korean young adults, ischemic stroke occurred predominantly in male and was mainly caused by large artery atherosclerosis. Although most of young adult stroke had a good prognosis, about 10% of patients had a poor prognosis. Finally, our study suggests that previous stroke history and high NIHSS score at admission could be prognosis precursors of ischemic stroke in Korean young adults.