Normobaric hyperoxia reduces MRI diffusion abnormalities and infarct size in experimental stroke
Normobaric hyperoxia reduces MRI diffusion abnormalities and infarct size in experimental stroke
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DOI：
10.1212/wnl.58.6.945
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发表时间：
2002-03-26
期刊：
影响因子：
9.9
通讯作者：
Lo, EH
中科院分区：
文献类型：
--
作者：
Singhal, AB;Dijkhuizen, RM;Lo, EH
背景：高压氧治疗被认为是一种重要的脑卒中治疗策略。目的：确定常压氧是否有神经保护作用，如果有，治疗的时间窗是什么。方法：实验1：将大鼠随机分为FiO(2) 30%（缺氧）和FiO(2) 100%（高氧）两组，在大脑中动脉细丝闭塞（MCAO）后进行连续弥散和灌注加权MRI （DWI和PWI）检查。实验2-48小时MCAO大鼠的损伤体积分析，MCAO后15、30、45分钟开始，再灌注后15分钟结束，随机分为常氧或高氧组。结果：实验一：常氧动物病变表观扩散系数（ADC）持续偏低。在高氧处理的大鼠中，皮质边缘区的ADC值显示从高氧前对侧的66 +/- 3%逐渐恢复到2小时后的104 +/- 20%。纹状体ADC值显示早期但不持久的改善。常氧组ADC病变体积逐渐增大。在高氧组，开始高氧后ADC病变体积有减小的趋势；然而，后来病变的大小增加，2小时病变体积与基线没有显著差异。所有动物PWI均显示稳定的右MCA灌注不足。实验2：脑卒中后48小时，30分钟内高氧可显著降低脑卒中总损伤体积和皮质损伤体积。高氧-15组纹状体损伤体积明显减少。结论：在短暂性脑卒中大鼠中，30分钟内给予100%的氧气可以挽救缺血脑组织，特别是大脑皮层。缩短治疗时间可提高神经保护程度。
Background: Hyperbaric oxygen therapy is considered an important stroke treatment strategy. Objective: To determine whether normobaric oxygen is neuroprotective, and, if so, what the therapeutic time window is. Methods: Experiment 1-Serial diffusion- and perfusion-weighted MRI (DWI and PWI) was performed after middle cerebral artery filament occlusion (MCAO) in rats randomized to FiO(2) 30% (normoxia) or FiO(2) 100% (hyperoxia). Experiment 2-48-hour lesion volumes were analyzed in rats subjected to 2-hour MCAO and randomized to normoxia or hyperoxia starting 15, 30, or 45 minutes after MCAO and ending 15 minutes after reperfusion. Results: Experiment I-Lesion apparent diffusion coefficient (ADC) values were persistently low in normoxic animals. In hyperoxia-treated rats, ADC values in cortical border zones showed progressive recovery from 66 +/- 3% of contralateral before hyperoxia, to 104 +/- 20% at similar to2 hours. Striatal ADC values showed early but ill-sustained improvement. ADC lesion volumes increased progressively in the normoxia group. In the hyperoxia group, ADC lesion volumes tended to decrease after starting hyperoxia; however, lesions later increased in size, and 2-hour lesion volumes were not significantly different from baseline. PWI showed stable right MCA hypoperfusion in all animals. Experiment 2-Hyperoxia within 30 minutes significantly reduced total and cortical lesion volumes at 48 hours after stroke. Striatal lesion volumes were significantly reduced in the hyperoxia-15 group. Conclusion: In rats subjected to transient stroke, 100% oxygen administered within 30 minutes salvages ischemic brain tissue, especially in the cerebral cortex. Reducing the time to treatment enhances the degree of neuroprotection.