Tian Fenghua, Sepulveda Pollieanna, Kota Srinivas, Liu Yulun, Das Yudhajit, Liu Hanli, Zhang Rong, Chalak Lina
Department of Bioengineering, University of Texas at Arlington, Arlington, TX, USA.
Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Pediatr Res. 2021 Mar;89(4):882-888. doi: 10.1038/s41390-020-0992-5. Epub 2020 Jun 3.
Neuromonitoring at the bedside is the key to understand the pathophysiological mechanisms of brain injury associated with neonatal encephalopathy. The current practice is to monitor the forehead using a noninvasive cerebral oximetry-it remains unknown to what extent cerebral hemodynamics in other brain regions is different to the frontal region.
A multichannel near-infrared spectroscopy (NIRS) system was used to monitor neonates (n = 14) with fetal acidosis and mild neonatal encephalopathy at four brain regions (the frontal, posterior, left temporal, and right temporal lobes). The data were compared to delineate the regional difference in (1) cerebral hemodynamics and (2) pressure autoregulation. For both analyses, wavelet transform coherence was applied.
We observed frontal-posterior heterogeneity as indicated by significantly lower coherence between these two regions (p = 0.02). Furthermore, areas with regional magnetic resonance imaging (MRI)-detected lesions showed greater hemodynamic variations compared to non-affected areas (p = 0.03), while cerebral autoregulation was not affected and showed no difference.
Cerebral hemodynamics in mild neonatal encephalopathy is heterogeneous across different brain regions, while cerebral autoregulation remains intact. These findings indicate the robustness of the wavelet measure of cerebral autoregulation in this population, but need to be further investigated in the presence of severe injury.
This proof-of-concept study is the first to investigate the regional difference of cerebral hemodynamics and autoregulation in mild neonatal encephalopathy. Study findings confirm that brain functions are complex in the developing neonatal brain and that cerebral hemodynamics are region specific in newborns with frontal-posterior heterogeneity among brain regions probed by multichannel NIRS. Regional MRI lesions were associated with differences across NIRS regional channels among the affected side. Cerebral autoregulation with multichannel NIRS is not affected by regional MRI abnormalities.
床边神经监测是了解新生儿脑病相关脑损伤病理生理机制的关键。目前的做法是使用无创脑氧饱和度仪监测前额——其他脑区的脑血流动力学与额叶区域的差异程度仍不清楚。
使用多通道近红外光谱（NIRS）系统监测14例患有胎儿酸中毒和轻度新生儿脑病的新生儿的四个脑区（额叶、枕叶、左颞叶和右颞叶）。比较数据以描绘（1）脑血流动力学和（2）压力自动调节方面的区域差异。对于这两种分析，均应用小波变换相干分析。
我们观察到额叶和枕叶之间存在异质性，这两个区域之间的相干性显著降低（p = 0.02）。此外，与未受影响区域相比，区域磁共振成像（MRI）检测到病变的区域显示出更大的血流动力学变化（p = 0.03），而脑自动调节未受影响且无差异。
轻度新生儿脑病中的脑血流动力学在不同脑区之间存在异质性，而脑自动调节保持完整。这些发现表明该人群中脑自动调节的小波测量方法具有稳健性，但在存在严重损伤的情况下需要进一步研究。
这项概念验证研究首次调查了轻度新生儿脑病中脑血流动力学和自动调节的区域差异。研究结果证实，发育中的新生儿大脑功能复杂，脑血流动力学具有区域特异性，在通过多通道NIRS探测的脑区中存在额叶-枕叶异质性。区域MRI病变与患侧NIRS区域通道之间的差异有关。多通道NIRS的脑自动调节不受区域MRI异常的影响。
