Objectives: To study the correlation of electroencephalogram (EEG) background evolution with the degree of brain injury in neonates with hypoxic-ischemic encephalopathy (HIE).
Methods: A retrospective analysis was performed for 56 neonates with HIE who underwent continuous video electroencephalogram (cVEEG) and brain magnetic resonance imaging (MRI) examinations. According to clinical symptoms, they were divided into a mild group with 3 neonates, a moderate group with 36 neonates, and a severe group with 17 neonates. EEG background grading and MRI score were determined for each group to analyze the correlation of EEG background evolution with the degree of brain injury.
Results: Compared with the moderate group, the severe group had significantly lower gestational age and Apgar score at 5 minutes after birth, a significantly higher resuscitation score, significantly lower base excess in umbilical cord blood or blood gas within 1 hour, a significantly higher proportion of neonates on mechanical ventilation, and a significantly higher incidence rate of short-term adverse outcomes (P<0.05). For the neonates in the mild and moderate groups, MRI mainly showed no brain injury (67%, 2/3) and watershed injury (67%, 16/24) respectively, and EEG showed mild abnormality in 62% (13/21) of the neonates on the 3rd day after birth. For the neonates in the severe group, MRI mainly showed basal ganglia/thalamus + brainstem injury (24%, 4/17) and whole brain injury (71%, 12/17), and EEG showed moderate or severe abnormalities on the 3rd day after birth. EEG background grading was correlated with clinical grading, MRI score, and short-term outcome on days 1, 2, 3 and 7-14 after birth (P<0.01). The highest correlation coefficient between EEG grading and MRI score was observed on the 3rd day after birth (rs=0.751, P<0.001), and the highest correlation coefficients between EEG grading and clinical grading (rs=0.592, P=0.002) and between EEG grading and short-term outcome (rs=0.737, P<0.001) were observed 7-14 days after birth. Among the neonates with severe abnormal EEG, the neonates without brain electrical activity had the highest MRI score, followed by those with status epileptics and persistent low voltage (P<0.05).
Conclusions: There is a good correlation between EEG background grading and degree of brain injury in neonates with HIE, which can help to evaluate the degree and prognosis of brain injury in the early stage.
目的: 探讨新生儿缺氧缺血性脑病（hypoxic-ischemic encephalopathy，HIE）患儿脑电图（electroencephalogram，EEG）背景演变与脑损伤程度之间的相关性。方法: 回顾性研究56例确诊为HIE并完善了连续视频脑电监测（continuous video electroencephalogram，cVEEG）与头部磁共振（magnetic resonance imaging，MRI）的患儿，根据临床症状分为轻度组（3例）、中度组（36例）、重度组（17例），各组进行EEG背景分度及MRI脑损伤评分，分析EEG背景演变与脑损伤程度之间的关系。结果: 与中度组患儿相比，重度组胎龄小、生后5 min Apgar评分低、复苏评分高、脐动脉血或生后1 h内动脉血剩余碱低、机械通气比例高及短期不良结局发生率高（P<0.05）。轻中度组患儿头部MRI以无脑损伤（67%，2/3）和分水岭区损伤（67%，16/24）为主，62%（13/21）EEG在生后第3天内改善至轻度异常；重度组患儿头部MRI以基底节/丘脑+脑干（24%，4/17）和全脑型损伤（71%，12/17）为主，至生后第3天仍均为中重度异常。在生后第1天、第2天、第3天及第7~14天4个时间段EEG背景分度与临床症状分度、MRI评分及短期结局均具有相关性（P<0.01）。EEG分度与MRI评分的相关系数在生后第3天最高（rs=0.751，P<0.001），与临床症状分度（rs=0.592，P=0.002）及短期结局（rs=0.737，P<0.001）的相关系数在生后第7~14天最高；重度异常EEG患儿中无脑电活动者MRI评分最高，惊厥持续状态者次之，持续低电压者最低，差异有统计学意义（P<0.05）。结论: HIE患儿的EEG背景分度与脑损伤程度之间有良好的相关性，可帮助早期评估脑损伤程度及预后。.
Keywords: Brain injury; Electroencephalogram background; Hypoxic-ischemic encephalopathy; Magnetic resonance imaging; Neonate.