BACKGROUND Current guidelines limit thrombolytic treatment of stroke to those patients who present within 4.5 h to minimize the risk of hemorrhagic complications. Risk of hemorrhage increases with increasing blood-brain barrier (BBB) disruption. This study aimed to determine, in a cohort of patients presenting outside of an IV-tPA treatment window, whether disruption of the BBB is time dependent, and what proportion of patients could be safely treated. METHODS We analyzed untreated stroke patients, seen between 2011 and 2015, who had MRI studies in the time window of 4 to 24 h from symptoms onset. Permeability of the BBB was measured within the ischemic tissue using an application of dynamic susceptibility contrast imaging. Patients were dichotomized into two groups based on a 20% threshold of BBB disruption and compared using logistic regression. RESULTS Of the 222 patients included in the final analysis, over half, 129 (58%), had preserved BBB integrity below the 20% threshold. There was no relationship between time imaged after symptom onset and the amount of BBB disruption (p = 0.138) across the population; BBB disruption varied widely. CONCLUSIONS Estimating BBB integrity may help to expand the treatment window for stroke patients by identifying those individuals for whom thrombolytic therapy can be considered.

中文翻译：

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中风患者的血脑屏障完整性在延长的时间范围内出现。

背景技术当前的指南将中风的溶栓治疗限于在4.5小时内出现的那些患者，以使出血并发症的风险最小化。出血风险随着血脑屏障（BBB）破坏的增加而增加。这项研究旨在确定在IV-tPA治疗窗口之外出现的一组患者中，BBB的破坏是否与时间有关，以及可以安全治疗的患者比例。方法我们分析了2011年至2015年之间未经治疗的中风患者，他们在症状发作后4到24小时的时间内进行了MRI研究。使用动态磁化率对比成像技术测量缺血组织内血脑屏障的通透性。根据血脑屏障破坏的20％阈值将患者分为两组，并使用逻辑回归进行比较。结果在最终分析的222例患者中，超过一半的129例（58％）的BBB完整性保持在20％阈值以下。症状发作后的影像时间与整个人群的血脑屏障破坏量（p = 0.138）之间没有关系。BBB破坏差异很大。结论估计BBB完整性可以通过确定可以考虑溶栓治疗的个体来帮助扩大中风患者的治疗范围。