ICU, Instituto de Pesquisa Clínica Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
J Cereb Blood Flow Metab. 2010 Feb;30(2):440-8. doi: 10.1038/jcbfm.2009.215. Epub 2009 Oct 21.
Brain dysfunction is frequently observed in sepsis as a consequence of changes in cerebral structure and metabolism, resulting in worse outcome and reduced life-quality of surviving patients. However, the mechanisms of sepsis-associated encephalopathy development and a better characterization of this syndrome in vivo are lacking. Here, we used magnetic resonance imaging (MRI) techniques to assess brain morphology and metabolism in a murine sepsis model (cecal ligation and puncture, CLP). Sham-operated and CLP mice were subjected to a complete MRI session at baseline, 6 and 24 h after surgery. Accumulation of vasogenic edematic fluid at the base of the brain was observed in T(2)-weighted image at 6 and 24 h after CLP. Also, the water apparent diffusion coefficients in both hippocampus and cortex were decreased, suggesting a cytotoxic edema in brains of nonsurvival septic animals. Moreover, the N-acetylaspartate/choline ratio was reduced in brains of septic mice, indicating neuronal damage. In conclusion, noninvasive assessment by MRI allowed the identification of new aspects of brain damage in sepsis, including cytotoxic and vasogenic edema as well as neuronal damage. These findings highlight the potential applications of MRI techniques for the diagnostic and therapeutic studies in sepsis.
脑功能障碍在脓毒症中经常观察到，这是由于脑结构和代谢的变化所致，导致预后更差，存活患者的生活质量降低。然而，脓毒症相关脑病发展的机制以及在体内更好地描述这种综合征的方法仍然缺乏。在这里，我们使用磁共振成像 (MRI) 技术来评估脓毒症小鼠模型 (盲肠结扎和穿刺，CLP) 中的脑形态和代谢。假手术和 CLP 小鼠在手术前、手术后 6 小时和 24 小时进行了完整的 MRI 检查。在 CLP 后 6 小时和 24 小时，T2 加权图像上观察到基底脑的血管源性水肿液积聚。此外，海马体和皮质中的水表观扩散系数降低，提示非存活脓毒症动物的脑中有细胞毒性水肿。此外，脓毒症小鼠的 N-乙酰天门冬氨酸/胆碱比降低，表明神经元损伤。总之，MRI 的非侵入性评估可识别脓毒症中脑损伤的新方面，包括细胞毒性和血管源性水肿以及神经元损伤。这些发现强调了 MRI 技术在脓毒症诊断和治疗研究中的潜在应用。
