A prospective cohort study in Canada revealed that in patients with transient ischemic attack (TIA)/nondisabling stroke, CT evidence of acute ischemia alone or acute ischemia with chronic ischemia or microangiopathy was associated with increased subsequent stroke risk within 90 days. A total of 2028 patients that had CT scanning within 24 hours of presentation were included; 814 had ischemic changes on CT. Subsequent stroke rate was 3.4% at 90 days and 1.5% at ≤2 days. Logistic regression found acute+chronic ischemia, acute ischemia+microangiopathy, or acute+chronic ischemia+microangiopathy was associated with a greater risk at 90 days and at ≤2 days. Acute ischemia alone was associated with a greater risk at >2 days. TIA has recently been redefined by the American Heart Association as an episode of transient neurological dysfunction caused by ischemia without acute infarction. Source: http://stroke.ahajournals.org/加拿大的一项前瞻性群组研究发现短暂性脑缺血发作（TIA）/非致残性中风患者中，CT显示急性缺血或急性缺血合并慢性缺血或微血管病变与随后90天内中风风险的增加有关。该研究共包括2028例发病24小时内有CT扫描的患者; 814例CT显示缺血性改变。随后的中风率分别为90天3.4％和≤2天1.5％。 逻辑回归发现急性缺血+慢性缺血，急性缺血+微血管病变，急性缺血+慢性缺血+微血管病变与90天以及≤2天时较大的中风风险有关。仅急性缺血亦显示与> 2天时较大的风险有关。 美国心脏协会最近重新定义TIA为缺血引起的短暂神经功能障碍发作而无急性脑梗死。来源：http://stroke.ahajournals.org/
