缺血性脑梗塞CT表现与梗塞后神经细胞凋亡及坏死的相关性

目的 探讨实验性缺血性脑梗塞早期CT表现与神经细胞损伤的相关性及与临床诊断、治疗、预后的关系。方法 将新西兰大白兔经颈总动脉注入PVA栓子栓塞大脑中动脉,在不同的时间点(2~36h)对兔脑进行CT扫描,并取脑组织经HE染色、Nissle染色、免疫组化(TUNEL法)进行观察。结果 CT分期Ⅰ期(脑梗塞后2~8h),神经细胞首先出现缺血改变,随后细胞周围出现水肿;基底节周围及大脑皮质可见少量TUNEL阳性细胞。CT分期Ⅱ期(梗塞后12~18h),以神经细胞溶解消失为主;基底节周围及大脑皮质可见较多TUNEL阳性细胞。CT分期Ⅲ期(梗塞后24~36h),脑水肿改变十分显著,基底节呈明显的坏死区,神经细胞坏死,结构消失,大脑皮质可见大量TUNEL阳性细胞。神经元具有凋亡及坏死的双重形态学特征。结论 缺血性脑梗塞后神经细胞损伤形态上有水肿、凋亡及坏死等多样性,CT扫描显示缺血性脑梗塞的进展与实际病理变化有高度相关性。

CT findings of ischemic infarction in relation to neuronal damage in rabbits

Objective To explore the early changes in CT findings of ischemic infarction in relation to neuronal damage in rabbits. Methods Thirty-two rabbits were divided into control group and experiment groups and scanned with CT 2, 4, 8, 12, 18, 24, and 36 h after ischemic cerebral infarction induced by PVA embolization of the middle cerebral artery (MCA), respecti- vely. The brain specimen were stained with HE, Nissle and TUNEL techniques for pathological examination. Results In stage Ⅰ (2-8 h after MCA occlusion) by CT staging, the neurons exhibited ischemic change followed by cell edema. A small number of TUNEL-positive cells were found in the basal ganglia and cortex. In stage Ⅱ (12-18 h after MCA occlusion), neuronal swelling and lysis were observed with greater number of TUNEL-positive neurons in the basal ganglia and cortex. In stage Ⅲ (24-36 h after MCA obstruction), cerebral edema became obvious and ischemic cores were distinct, with numerous necrotic neurons seen and destruction of the cell structure. Numerous TUNEL-positive cells were seen in the ischemic penumbra and cortex. Conclusion The damaged neurons after ischemic cerebral infarction showed varied morphology including cell edema, apoptosis, necrosis, and necrosis-apoptosis continuum. CT manifestations are strongly associated with the progression of ischemia and the pathological changes.