Department of Pediatrics, Drexel University College of Medicine, St Christopher's Hospital for Children, Philadelphia, PA.
Department of Electrical and Computer Engineering, Villanova University, Villanova, PA.
Pediatr Res. 2018 Feb;83(2):484-490. doi: 10.1038/pr.2017.264. Epub 2017 Dec 6.
BackgroundDevelopment of cerebral edema after brain injury carries a high risk for brain damage and death. The present study tests the ability of a noninvasive cerebral edema monitoring system that uses near-infrared spectroscopy (NIRS) with water as the chromophore of interest to detect brain edema following hypoxia.MethodsVentilated piglets were exposed to hypoxia for 1 h, and then returned to normal oxygen levels for 4 h. An NIRS sensor was placed on the animal's head at baseline, and changes in light attenuation were converted to changes in HO. Cerebral water content and aquaporin-4 protein (AQP4) expression were measured.ResultsThe system detected changes in NIRS-derived water signal as early as 2 h after hypoxia, and provided fivefold signal amplification, representing a 10% increase in brain water content and a sixfold increase in AQP4, 4 h after hypoxia. Changes in water signal correlated well with changes in cerebral water content (R=0.74) and AQP4 expression (R=0.97) in the piglet brain.ConclusionThe data show that NIRS can detect cerebral edema early in the injury process, thus providing an opportunity to initiate therapy at an earlier and more effective time-point after an insult than is available with current technology.
脑损伤后发生脑水肿会极大增加脑损伤和死亡的风险。本研究旨在测试一种使用近红外光谱（NIRS）以水为感兴趣的发色团的非侵入性脑水肿监测系统，该系统能否在缺氧后检测脑水肿。
对通气的小猪进行 1 小时的缺氧暴露，然后恢复正常氧水平 4 小时。在基线时将 NIRS 传感器放置在动物头部，测量光衰减的变化以转化为 HO 的变化。测量脑水含量和水通道蛋白-4 蛋白（AQP4）的表达。
该系统早在缺氧后 2 小时即可检测到 NIRS 衍生水信号的变化，并提供五倍的信号放大，代表脑水含量增加 10%，AQP4 增加 6 倍，缺氧 4 小时后。水信号的变化与猪脑水含量（R=0.74）和 AQP4 表达（R=0.97）的变化密切相关。
数据表明，NIRS 可以在损伤过程中早期检测到脑水肿，从而为在当前技术更有效的时间点之前更早开始治疗提供机会。
