铅中毒儿童的智力改变及事件相关电位P_300的研究

Studies on Intelligence and P_300 Event-related Potentials in the Lead Poisoned Children

目的：研究儿童铅中毒的智力改变及事件相关电位P300的改变，探索儿童铅中毒的神经毒性和心理行为改变的电生理依据。方法：通过测定血铅及社会家庭情况问卷调查，在排除了影响智力的几个重要因素后，把6～12岁的45例符合条件的儿童分为高铅组（血铅值≥100μg／L）和正常组（血铅值〈100μg／L），进行韦氏智力量表（WISC）的测定及事件相关电位（ERP）P300的检测。评价铅中毒对儿童智力及高级神经功能的损害。结果：铅中毒儿童的总智商和言语智商较正常儿童显著降低，有统计学上的显著性差异。操作智商虽也有降低，但与正常对照组相比无统计学显著性差异。铅中毒儿童的P300外源性成分P100及N200的波幅较正常儿童明显降低，潜伏期也明显延长。结论：本研究为儿童铅中毒的神经毒性和认知心理行为的异常提供了具有客观性的电生理依据，为儿童铅中毒的神经毒性的预防、诊断和治疗的观察提供了电生理依据。

Objective To probe into the basis of brain electrophysiology of the neuropsychological and behavioral toxicity, the lead poisoned children＇s changes of the intelligence and P300 Event-related Potentials were studied in this article. Methods According to the blood lead level and questionnaire about personal, social and family, some factors related to intelligence were excluded. The 45 children aged 6 to 12 were divided into two groups： the high lead group （Pb 〉/100μg/L） and the low lead group （Pb 〈 100μg/L）. The two groups were measured the Weschsier Intelligence Scales （WISC） and the P300 Event-related Potentials （ERP） separately. Results This article reported that General IQ and Verbal IQ were significantly lower in high lead group than in low lead group. The studies of ERP in lead poisoned children indicated the amplitude of N200, P300 decreased and the latency of N200, P300 increased. Conclusion The WISC was widely used as a standard of IQ. P300 Event-related Potentials could directly reflect cerebral function： P300 was widely used as an assessment of human advanced mental function. Through these studies, the fundament of neuro-electrophysiology and the evidence for prevention, diagnosis and therapy of neurotoxicity and neuropsychological deficit in lead poisoned children was provided.