Background

Spectral-based EEG is used to monitor anaesthetic state during surgical procedures in adults. Spectral EEG features that can resemble the patterns seen in adults emerge in children after the age of 10 months and cannot distinguish wakefulness and anaesthesia in the youngest children. There is a need to explore alternative EEG measures. We hypothesise that functional connectivity is one of the measures that can help distinguish between consciousness states in children.

Methods

An EEG data set of children undergoing sevoflurane general anaesthesia (age 0–3 yr) was reanalysed using debiased weighted phase lag index as a measure of functional connectivity in wakefulness (n=38) and anaesthesia (n=73). Network topology measures were compared between states in 0- to 6-, 6- to 10-, and >10-month-old children.

Results

Functional connectivity was reduced in anaesthesia vs wakefulness in delta band (n=cluster of 17 significant connections; P=0.013; 58% connections surviving thresholding in wakefulness and 49% in anaesthesia). Network density and node degree were lower in anaesthesia even in the youngest children (0.57 in wakefulness; 0.48 in anaesthesia; t [9]=3.39; P=0.029; G=0.98; confidence interval [CI] [0.25–1.77]). Modularity was higher in anaesthesia (0–6 months: 0.16 in wakefulness and 0.19 in anaesthesia, t [9]=–2.95, P=0.04, G=–0.85, CI [–1.60 to –0.16]; >10 months: 0.16 vs 0.21, t [13]=–6.45, P<0.001, G=–1.62, CI [–2.49 to –0.85]) and decreased with age (ρ [73]=–0.456; P<0.001).

Conclusions

Anaesthesia modulates functional connectivity. Increased segregation into a more modular structure in anaesthesia decreases with age as adult-like features develop. These findings advance our understanding of the network architecture underlying the effects of anaesthesia on the developing brain.

中文翻译：

---

人类大脑发育过程中七氟烷麻醉期间出现的功能连接模式

背景

基于频谱的脑电图用于监测成人手术过程中的麻醉状态。与成人模式相似的脑电图特征出现在 10 个月大的儿童身上，并且无法区分最小儿童的清醒和麻醉状态。有必要探索替代脑电图措施。我们假设功能连接是可以帮助区分儿童意识状态的措施之一。

方法

使用去偏加权相位滞后指数对接受七氟烷全身麻醉的儿童（0-3 岁）的脑电图数据集进行了重新分析，作为清醒状态（n = 38）和麻醉状态（n = 73）的功能连通性的测量。比较了 0 到 6 个月、6 到 10 个月和 >10 个月大儿童的状态之间的网络拓扑测量。

结果

在 delta 带中，麻醉与清醒状态下的功能连接性降低（ n = 17 个重要连接的集群；P = 0.013；58% 的连接在清醒状态下存活阈值，49% 在麻醉状态下存活）。即使在最小的儿童中，网络密度和节点度在麻醉时也较低（清醒时为 0.57；麻醉时为 0.48；t [9]=3.39；P =0.029；G =0.98；置信区间 [CI] [0.25–1.77]）。麻醉中的模块化更高（0-6 个月：清醒时 0.16，麻醉时 0.19，t [9]=–2.95，P =0.04，G =–0.85，CI [–1.60 至 –0.16]；>10 个月：0.16对比0.21，t [13]=–6.45, P <0.001, G =–1.62, CI [–2.49 to –0.85]) 并且随着年龄的增长而降低 (ρ [73]=–0.456; P <0.001)。

结论

麻醉调节功能连接。随着成人特征的发展，随着年龄的增长，麻醉中越来越多的分离成更模块化的结构。这些发现促进了我们对麻醉对大脑发育影响的网络结构的理解。