脑缺血后体感诱发电位和脑电图波谱特征变化及其与细胞凋亡的关系

目的探讨大鼠全脑缺血／再灌注（I／R）后体感诱发电位（SEP）和脑电图波谱特征的变化及其与神经元分布的关系。方法SD大鼠35只，采用随机数字表法分为正常组、假手术组、全脑I／R3、12、24、48和72h组。采用四血管夹闭方法建立全脑I／R模型，末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）及吖啶橙／溴化乙锭（AO／EB）荧光比色法检测神经元凋亡；记录I／R后不同时间脑电图和SEP的变化，观察海马、额叶皮质和顶叶皮质神经元凋亡数量。结果脑缺血后大鼠脑电图波幅较假手术组显著下降（P均〈0．05），8波构成比明显增加（P均〈0．05）；伤后SEP的P1波波峰潜伏期较假手术组显著延长（P均〈0．05），P1～N1波波幅显著下降（P均〈0．05）；这些变化与伤后神经元凋亡以及自海马逐渐向额叶皮质和顶叶皮质扩展的结果相吻合。结论脑电图和SEP结合分析可以反映脑缺血损伤后神经元凋亡的发生过程，对临床脑缺血患者的病情和预后判断有参考价值。

Changes in electroencephalograph and somatosensory evoked potential and their relationship with neuron apoptosis in rat after ischemic insult to brain

OBJECTIVE: To study the changes in electroencephalograph (EEG) and somatosensory evoked potential (SEP) and their relationship with neuron apoptosis in rat after ischemic insult to the brain. METHODS: Thirty-five SD rats were randomly divided into normal, sham operated and 3, 12, 24, 48, 72 hours after ischemia/reperfusion (I/R) groups with 5 rats in each group. The ischemia of brain was produced by clamping 4 vessels to the brain for various periods of time. Changes in EEG and SEP were recorded at different time after I/R, and the amounts of apoptotic neurons in hippocampus and cortex after I/R were assessed with terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labeling (TUNEL) and acridine orange ethidium bromide (AO/EB) fluorescence examination techniques. RESULTS: Compared with sham operated group, EEG amplitude decreased significantly (all P<0.05), and the proportion of Delta wave increased significantly after ischemia of the brain (all P<0.05). The latent period of P1 wave crest extended markedly (all P<0.05), and P1-N1 amplitude decreased significantly after I/R (all P<0.05). EEG and SEP changes were correlated with the apoptosis and loss of neurons, which started in the hippocampus and extended to frontal cortex and parietal cortex. CONCLUSION: The combined analysis of EEG and SEP can reflect the process of neuron apoptosis, which is helpful for the diagnosis and evaluation of prognosis of patients suffering from cerebral ischemia.