目的：探究不同严重程度孤独症谱系障碍（autism spectrum disorders，ASD）儿童事件相关电位P300的反应特征，分析其潜伏期和波幅与ASD儿童严重程度之间的关系。

方法：将 2022 年 10 月～2023 年 10 月至深圳市罗湖区妇幼保健院就诊的 100 例 ASD 儿童纳入研究。根据儿童孤独症评定量表（Childhood Autism Rating Scale，CARS）评分结果分为轻至中度组和重度组，探讨 2 组 ASD 儿童中线位点（Fz、Cz、Pz）的事件相关电位 P300 潜伏期及波幅的特征，分析其潜伏期和波幅与ASD儿童疾病严重程度之间的关系。

结果：共纳入 100 例 ASD 儿童，其中轻至中度组 59 例，重度组 41 例。2 组患儿的年龄、性别、家族史和药物治疗史的差异无统计学意义（P>0.05）。单因素 logistic 分析结果显示，Fz、Cz、Pz 中线位点 P300 潜伏期值（P 值分别为<0.001、0.008 和 0.004）及 Cz、Pz 中线位点P300 波幅值（P 值分别为<0.001 和 0.004）与 ASD 儿童疾病严重程度相关。多因素 logistic回归分析结果显示，Fz 位点 P300 潜伏期值可能是 ASD 严重程度的独立危险因素［OR＝1.018（95% CI：1.008～1.028），P<0.001］，Cz 位点 P300 波幅值可能是 ASD 严重程度的保护因素［OR＝0.505（95% CI：0.352～0.726），P<0.001］。根据入组 ASD 儿童的 CARS 评分进行相关性分析发现，ASD 儿童各中线位点 P300 潜伏期值与 CARS 评分呈正相关（P<0.01），ASD儿童Cz和Pz中线位点P300波幅值与CARS评分呈负相关（P<0.001）。

结论：不同严重程度ASD儿童事件相关电位P300的表现存在显著差异，病情严重程度高的ASD 儿童各中线位点的 P300 潜伏期更长，Cz 和 Pz 中线位点的 P300 波幅更低；Fz 位点P300潜伏期值可能是ASD严重程度的独立危险因素，Cz位点P300波幅值可能是ASD严重程度的保护因素。事件相关电位P300的潜伏期和波幅检测能够为评估ASD儿童的病情严重程度提供一种神经电生理学的客观依据。

Objective: To explore the characteristics of P300 event-related potential in children with autism spectrum disorders (ASD) of different severity levels and to analyze the correlation between its latency or amplitude and the severity of ASD.

Methods: The study included 100 children with ASD who visited the Shenzhen Luohu District Maternal and Child Health Hospital from October 2022 to October 2023. Children with ASD were divided into 2 groups (mild to moderate group and severe group) according to the scoring results of the Childhood Autism Rating Scale (CARS). We compared the characteristics of P300 event-related potential latency and amplitude at midline sites (Fz, Cz and Pz) between the two groups. We explored the relationship between latency or amplitude and the severity of ASD in children.

Results: The study included a total of 100 children with ASD, including 59 in the mild to moderate group and 41 in the severe group. There was no statistically significant difference in age, gender, family history, and medication treatment history between the two groups. (P>0.05). Factors such as the latency of P300 at the Fz, Cz, and Pz midline loci (P values of <0.001, 0.008, and 0.004, respectively) and the amplitude of P300 at the Cz and Pz midline loci (P values of <0.001 and 0.004, respectively) were statistically significant between the two groups according to the univariate logistic analysis. The latency value of Fz locus P300 might be a risk factor for the severity of ASD [OR＝1.018 (95% CI: 1.008-1.028), P<0.001], while the amplitude value of Cz locus P300 might be a protective factor for the severity of ASD [OR＝0.505 (95% CI: 0.352-0.726), P<0.001] based on the multiple logistic regression analysis. The P300 latency values of various midline loci in ASD children were positively correlated with CARS scores (all P<0.01), and the P300 amplitude values of Cz and Pz midline loci in ASD children were negatively correlated with CARS scores (all P<0.001) according to the correlation analysis of CARS scores of enrolled ASD children.

Conclusion: There are significant differences in the expression of P300 event-related potential in children with ASD of different severity levels. Children with ASD of higher severity have lower P300 latency at each midline locus, and lower P300 amplitude at Cz and Pz midline loci; The latency value of Fz locus P300 may be a risk factor for the severity of ASD, while the amplitude value of Cz locus P300 may be a protective factor for the severity of ASD. The latency and amplitude detection of P300 event-related potential can provide an objective neurophysiological basis for evaluating the severity of ASD in children.