前言：腦中風在近年已成為台灣前三大死因之一，其中以腦梗塞為主要。台灣過去研究顯示年輕人腦梗塞比率約占6.8%，國外報告則由5%到15%不等，且有明顯上升的趨勢。由於國內目前對於年輕人腦梗塞的流行病學研究不多，因此本研究擬針對此一族群腦梗塞之危險因子做一流行病學探討。 方法：本研究採回溯性方式，蒐集自2009年1月至2010年12月共2年間，因腦梗塞於南部某醫學中心住院之病患。所有住院病人，都紀錄腦梗塞類型、部位、過去病史、發病時間、臨床症狀、神經學檢查及出院後追蹤。腦梗塞型態，依照TOAST準則分成小血管阻塞、大動脈動脈硬化、心臟來源的栓塞、其他確定原因、未知原因所造成等五個主要類別。對於腦梗塞嚴重度及預後的追蹤評估，使用了NIHSS、巴氏量表以及mRS。 結果：最終納入研究的個案有2,175人，其中18到45歲的年輕人有91名(4.18%)。男性的年齡較輕(p<0.001)，發病時間以上午六點到十二點間較多。女性有高血壓及糖尿病的比例較高；有吸菸、喝酒以及腦梗塞家族史的比例則以男性較高。發現年輕人腦梗塞之病人有高血壓、糖尿病、心臟疾病史及陳舊腦梗塞病史較少(p<0.05)，但是年輕人腦梗塞病人有腦梗塞家族病史者則較多(p<0.05)、有吸菸及喝酒者也較多(p<0.001)。在腦梗塞型態的比較上，年輕的病人在小血管阻塞及大動脈動脈硬化者較少，但其他確定原因甚至未知原因者的比例則明顯較高。 結論：年輕人腦梗塞與中老年腦梗塞病人明顯不同，有必要針對此一族群做進一步的研究，才能找出更明確的危險因子，以提供預防醫學之參考。 Background: Stroke has become one of the three major causes of death in Taiwan in recent years. The rate of young stroke was 6.8% in northern Taiwan in 2000, and 5% to 15% in foreign countries. Recently, the prevalence of young stroke has increased dramatically according to the American Stroke Association. The incidence and etiology of young stroke were different in different ethnic groups and different years. We conducted this study to identify the risk factors for cerebral infarction in a young population in hope of providing a preventive strategy. Methods: In this retrospective study, we collected cases of stroke patients from January 1, 2009 to December 31, 2010 in the Chi-Mei hospital stroke registry. In total, 2,175 patients were included in our study, 4.18% of whom were between 18 and 45 years old. We collected data from the registry and medical records including type and location of stroke, history of hypertension, diabetes, cardiovascular disease, previous stroke, uremia, smoking/ alcohol consumption, time of onset and prognosis. Laboratory data including chest X-ray, electrocardiogram, blood pressure, blood glucose, lipid profiles, brain CT or MRI reports, and intracranial artery ultrasound or echocardiography were collected for the diagnosis and classification of stoke. According to the TOAST criteria, cerebral infarction was classified in five categories: (1) small-vessel occlusion, (2) large-artery atherosclerosis, (3) cardioembolism, (4) stroke of other determined etiology, and (5) stroke of undetermined etiology. We used the National Institute of Health Stroke Scale, Barthel Index and Modified Ranking Scale to determine the prognosis. Results: Overall, most strokes occurred between 6AM and 12PM. Females had a higher proportion of hypertension and diabetes and males had a higher proportion of smoking, alcohol consumption and a family history of ischemic stroke. Young ischemic stroke patients had less hypertension, diabetes, or a history of heart disease or ischemic stroke (p<0.05); however, they did have more family histories of ischemic stroke (p<0.05), smoking and alcohol consumption (p<0.001). In terms of the type of ischemic stroke, there was less small-vessel occlusion and largeartery atherosclerosis in young ischemic stroke patients and more stroke of other determined etiology and stroke of undetermined etiology. Conclusions: We found that the prevalence of young ischemic stroke was elatively small; however, there were significant differences between young ischemic stroke patients and older ones. Further research in this population is necessary to identify more clearly the risk factors involved.