脑缺血再灌注期间脑电功率谱的变化及亚低温对其的影响

Effect of mild hypothermia on EEG frequency power spectrum during cerebral ischemia reperfusion in gerbils

目的 研究亚低温对脑缺血再灌注后脑电变化及脑缺血损伤严重程度的影响。方法 沙土鼠全脑缺血再灌注模型 ,分为假手术组、常温组和亚低温组。监测脑电 SEF、BIS和α、β、θ、δ比率的变化 ,以海马 CAI区锥体细胞坏死数目来判断脑缺血损伤的严重程度。结果 在再灌注 30分时 ,常温组δ波比率较缺血前增高近一倍 (P<0 .0 1) ,α波比率下降至缺血前的 75 % (P<0 .0 5 )。亚低温组δ比率增高程度和α波比率下降的程度均小于常温组 (P<0 .0 5 )。脑缺血后 7天 ,常温组海马 CAI区存活锥体细胞数明显少于亚低温组。结论 亚低温可降低脑缺血再灌注后 EEGδ波比率增高程度和减少海马 CAI区锥体细胞死亡数目。

Objective To evaluate the effect of mild hypothermia on EEG changes and ischemia/reperfusion injury during gerbils global ischemia reperfusion.Methods The global cerebral ischemic modles of gerbils were induced by occlusion of bilateral carotid artery.Animals were divided into three groups:sham operation,normothermic brain temperature,and hypothermic brain temperature groups.EEG frequency power spectrum(SEF,BIS,α,β,δ,θ)was continuously monitored during whole procedures.The extent of reperfusion injury was assessed by accounting the number of surviving pyramidal cells in hippocampus CAI after cerebral ischemic 7 days.Results At the 30th min reperfusion,the δ ratio in normothermia group increased at two fold of preischemic values(P<0 01),and α ratio decreased to 75% of preischemic values(P<0.05).The increased and decreased degrees of δ and α ratios in mild hypothermic group were significantly smaller than those in normothermic group.The surviving number of pyramidal cells in hippocampus CAI in normothermic group was much less than that in mild hypothermic group Conclusion The mild hypothermia can inhibit the increased extent of δ ratio and mitigate the cerebral ischemia reperfusion injury.