脑电功率谱密度及功能连接分析在新生儿缺氧缺血性脑病中的意义初探

The significance of EEG power spectral density and functional connectivity analysis in neonatal hypoxic-ischemic encephalopathy

目的探讨脑电功率谱密度(power spectral density,PSD)及功能连接分析对不同程度新生儿缺氧缺血性脑病(hypoxic-ischemic encephalopathy,HIE)早期大脑皮层功能的评估作用。方法选择2016年1月至2019年3月南通大学附属常州儿童医院新生儿科收治的轻、中度HIE患儿进行前瞻性研究,选择同期收治的无脑损伤足月儿为对照组。3组患儿生后72~96 h采集脑电图(electroencephalogram,EEG),分析4个频段(delta、theta、alpha、beta)各通道平均PSD谱密度及全脑PSD,于8个频段(delta、theta、alpha1、alpha2、beta1、beta2、beta3、beta4)使用孤立有效相关(the imaginary part of coherency,ICOH)进行功能连接分析,将PSD和ICOH值在3组间进行比较。结果共纳入轻度HIE组20例、中度HIE组15例及对照组30例。PSD分析显示,中度HIE组theta、alpha、beta频段在FP1、FP2、C3、C4、Fz、Cz、Pz、F3、P4通道较轻度组和对照组显著降低(P<0.05),而delta频段在以上各通道未见类似改变(P>0.05);轻度HIE组仅在P4通道theta频段、Cz通道alpha频段低于对照组(P<0.05);中度HIE组全脑平均PSD在各频段均较对照组显著降低(P<0.05);轻度HIE组全脑平均PSD与对照组比较差异无统计学意义(P>0.05)。ICOH分析显示,中度HIE组脑功能连接低于对照组,主要集中在delta频段;与轻度HIE组比较,中度HIE组功能连接在delta、theta、alpha1及alpha2频段明显减低;而轻度HIE组与对照组比较,仅在delta、alpha1频段有较少的ICOH差异。结论新生儿delta、theta、alpha频段PSD及ICOH可以定量分析HIE患儿脑功能状态,中度HIE患儿早期出现明显的皮层功能落后。

Objective To study the clinical significances of electroencephalogram(EEG)power and functional connectivity analysis in the assessment of early cerebral cortex function among neonates with different degrees of hypoxic-ischemic encephalopathy(HIE).Method From January 2016 to March 2019,children with mild and moderate HIE admitted to the neonatology department of our hospital were selected for the prospective study.Infants without brain injury during the same period were selected as the control group.All infants received EEG examination at 72~96 h after birth.The power spectral density(PSD)of each channel and the mean PSD of whole brain in four frequency bands(delta,theta,alpha and beta)were analyzed.The imaginary part of coherency(ICOH)was used to analyze the functional connectivity in eight frequency bands(delta,theta,alpha 1,alpha 2,beta 1,beta 2,beta 3,beta 4).Result A total of 20 term neonates in mild HIE group,15 in moderate HIE group and 30 in control group were enrolled.PSD study showed that the theta,alpha and beta frequency bands of channel FP1,FP2,C3,C4,Fz,Cz,Pz,F3 and P4 in the moderate HIE group were significantly lower than the mild HIE group and the control group(P<0.05)and no significant difference existed for delta frequency band in the above channels(P>0.05).In the mild HIE group,only the theta frequency band of P4 channel and alpha frequency band of Cz channel were significantly lower than the control(P<0.05).The whole brain mean PSD in moderate HIE group showed significant decrease in all frequency bands(P<0.05).However,no significant difference existed in the whole brain mean PSD of mild HIE group(P>0.05).ICOH analysis showed that brain functional connectivity in moderate HIE group was significantly less than the control group,mainly in delta frequency band.and also significantly less than the mild HIE group in delta,theta,alpha1 and alpha2 frequency bands.The differences of ICOH between mild HIE group and control group in delta and alpha1 frequency bands were statistically significant.Conclusion PSD and ICOH of delta,theta and alpha frequency bands can be used to evaluate the brain function of HIE infants.Moderate HIE infants may have significant cortical dysfunction in early stage after birth.