轻、中度缺氧对事件相关电位的影响及不同刺激模式的比较

Effects of Mild and Moderate Hypoxia on Event related Potentials and the Comparison of Different Stimulus Paradigms.

目的观察轻、中度缺氧对脑事件相关电位（ＥＲＰ）的影响，比较不同刺激模式诱发的ＥＲＰ对缺氧的敏感性。方法１２名受试者在地面、２５００ｍ和４３００ｍ模拟高度（吸入低氧混合气）分别进行视觉Ｏｄｄｂａｌ、Ｓｔｅｒｎｂｅｒｇ记忆量（ＭＳＥＴ）为１和ＭＳＥＴ为３的任务测试，记录ＥＲＰ的Ｐ３潜伏期、波幅和反应时（ＲＴ）及反应错误率（ＥＲ）。结果４３００ｍ高度缺氧时Ｐ３潜伏期显著延长，任务难度较大时（Ｓｔｅｒｎｂｅｒｇ模式ＭＳＥＴ＝３）ＥＲ增高；２５００ｍ高度缺氧时各指标无明显改变；以Ｓｔｅｒｎｂｅｒｇ模式ＭＳＥＴ＝１诱发的ＥＲＰ波形清晰，缺氧时Ｐ３潜伏期延长显著。结论４３００ｍ高度缺氧对ＥＲＰ有明显影响，Ｐ３潜伏期是评定缺氧时脑认知能力降低的敏感指标。Ｓｔｅｒｎｂｅｒｇ模式ＭＳＥＴ＝１诱发的ＥＲＰ对缺氧敏感，是一种较为理想的刺激模式。

Objective To investigate the effects of mild and moderate hypoxia on event related potentials (ERP), and to compare the sensitivity of different stimulus paradigms to hypoxia. Methods Twelve subjects performed visual Oddball and memory set size (MSET) 1 and MSET 3 of Sternberg tasks on the ground and at the simulated altitudes of 2500m and 4300m by breathing low oxygen mixtures. P 3 latency and amplitude of ERP, reaction time (RT) and response error rate (ER) were recorded. Results During hypoxia at the altitude of 4300m, P 3 latency significantly delayed, and ER was high when the difficulty of task increased (Sternberg paradigm with MSET 3). In contrast, at the altitude of 2500m no changes were observed. Sternberg paradigm with MSET 1, in comparison with others, could elicit clearer ERP waves, and P 3 latency was slower during hypoxia. Conclusion Hypoxia at the altitude of 4300m has strong influence on ERP.P 3 latency can be used as a sensitive index in evaluating the decrement of brain cognitive capacity during hypoxia. ERP elicited by Sternberg paradigm with MSET 1 was more sensitive to hypoxia.