脑干缺血对听觉脑干反应影响的实验研究

EFFECT OF BRAINSTEM ISCHEMIA ON AUDITORY BRAINSTEM RESPONSE IN CATS

目的 :探讨脑干缺血模型ABR变化特点及其在脑缺血早期诊断中的应用价值。方法 :阻断猫基底动脉不同部位血流 ,观察记录阻断血流后不同时间ABR变化特点及其规律。结果 :①夹闭基底动脉上、下段或小脑下前动脉 10min左右 ,ABRP3 ,P4振幅明显减小 (P <0 .0 1,P <0 .0 5 ) ,60min恢复夹前水平 ;②夹闭基底动脉上段 10～60minP5明显减小 (P <0 .0 5 ) ,直到 12 0min尚未恢复至夹前状态。结论 :①猫的ABRP3脑区的血供主要来自小脑下前动脉 ,P1,P2产生部位基本不依赖基底动脉供血 ;②轻度暂短性脑缺血时ABR振幅比潜伏期更敏感 ,振幅减小的程度与脑干缺血的程度密切相关 ;③ABR可用于脑缺血定位诊断及脑功能动态观察的电生理检测。

Aim:To study the effects of brainstem ischemia on auditory brainstem response (ABR) and its value to early diagnosis of brain ischemia.Methods: Changes of ABR for phases was observed after different pans of basllar artery were blocked. Results:(1)The amplitude of P 3 and P 4 in ABR was decreased distinctly after superior,inferior of basilar artery or anterior inferior cerebellar anery were clamped for 10 min and recovered to normal level 60 min later.(2)The amplitude of P 5 in ABR was reduced clearly after superior of basilar artery was blocked for 10 60 min( P <0.05) and didn't recover to the normal level until 120 min. Conciusion:(1) Blood supply of P 3 in ABR was mainly supplied by anterior inferior cerebellar anery. P 1 and P 2 region in ABR was independent on blood supply of basilar artery. (2) The changes of amplitude of ABR during brain ischemia were more sensitive than that of latency P.(3) ABR could be used to brain ischemia location diagnosis and dynanlic observ ation of brainstem function.