兔脑缺血的视觉和听觉诱发电位的变化

Changes of the visual and auditory evoked potential inn acute brain ischemic rabbits

阻断兔双侧椎动脉（ＢＶＡ）和左颈总动脉（ＬＣＣＡ）后，夹闭右颈总动脉（ＲＣＣＡ）３、５、７ｍｉｎ，松开ＲＣＣＡ再灌流，记录听觉脑干诱发电位（ＢＡＥＰ＿ｓ）、中潜伏期听觉诱发电位（ＭＡＥＰ＿ｓ）以及视觉诱发电位（ＶＥＰ＿ｓ）。发现不全阻断脑血流后２．５ｍｉｎＭＡＥＰ＿ｓＮ０消失；４．５ｍｉｎ，ＶＥＰ＿ｓＮ＿１和ｐ＿２消失，ＢＡＦＰ＿３Ｉ～Ｖ波峰值潜伏期延长，而振幅无明显变化。完全阻断脑血流１．５ｍｉｎ，ＭＡＥＰ＿ｓＮ０消失，２．５ｍｉｎ，ＶＥＰ＿ｓＮ＿１和Ｐ＿２消失；４．５ｍｉｎ，ＢＡＦＰ＿ｓ各波不易辨认，近于消失。完全阻断脑血流３ｍｉｎ及不全阻断３、５、７ｍｉｎ再灌流后，三种诱发电位均逐渐恢复；完全阻断５、７ｍｉｎ，动物于再灌流短期内死亡。结果表明，脑不同部位对缺血敏感性不同；保证一定量的脑血流供应，有利于脑功能的维持与恢复。

Bilateral vertebrartery(BVA)and left common carotid artery(LCCA) wereoccluded in 36 rabbits under chloralose anesthesia, then right common carotid artery(RCCA)was cliped 3, 5 or 7 minutes respectively. Finally, rabbit brain was reperfused byloosing RCCA. The changes of brainstem auditory evoked potential( BAEP_s),middlelantency auditory evoked potential(MAEP_s)and visual evoked potential(VEP_s )werestudied. The resuIts indicated that( l)2.5 minutes after incomplete occlusion of brainarteries, N0 components of MAEP_s disappeared; and at 4.5 minutes N_1 and P_2 componentsof VEP_s disappeared; t the moment I V of BAEP_s had longer latencies but the amplitudeof BAEP_s had no change.(2 )After complete brain arteries occlusion,1.5 minutes N0disappeared;2.5 minutes N_1 and P_2 disappeared;4.5 minutes all components of BAEP_sbecame unrecognizable.(3)By reperfusing of brain after 3 minutes complete or 3,5,7minutes incomplete brain arteries occlulsion ,evoked potentials recovered gradually, butin groups of 5 or 7 minutes complete blocking. animals died shortly after reperfusion.