经颅重频磁刺激对大鼠脑缺血再灌流损伤早期运动皮层兴奋性和神经功能的影响

目的 观察经颅重频磁刺激（rTMS）对大鼠脑缺血再灌流损伤早期运动皮层兴奋性和神经功能的影响。方法测定Wistar大鼠右后肢运动阚值（MT）．制作左侧大脑中动脉栓塞（MCAO）再灌流模型．给予rTMS（1次／d）。再灌流72h处死取脑。比较大鼠MCAO再灌流损伤不同时间MT、神经功能评分，脑梗死体积的变化及rTMS的影响。结果MCAO再灌流损伤使大鼠出现局灶性梗死灶，MT升高；神经功能障碍且其程度随损伤时间延长而愈加明显．表现为功能评分升高；rTMS可改善大鼠MCAO再灌流损伤72h的MT和功能障碍程度。减小梗死体积。尤其改善神经功能障碍的程度与对照组比较差异有显著性（P=0．004）。结论rTMS可能对早期缺血脑组织有保护作用．对缺血性脑卒中有进一步研究、应用前景。

Effects of Repetitive Transcranial Magnetic Stimulation on Rats Motor Cortical Excitability and Neurofunction of Acute Stage of Cerebral Ischemia Reperfusion

Objective To investigate the effects of repetitive transcranial magnetic stimulation(rTMS) on rats motor cortical excitability and neurofunction in acute stage of cerebral ischemia-reperfusion injury.Methods Wistar rats were used as research model.After determined awake resting motor threshold(MT) of right hind limbs,rats were introduced to middle cerebral artery occlusion for 1 h and reperfusion for 72 h;rTMS were(applied) to them at the beginning and 12 h after the reperfusion,and then repeated every 24 h.Control group was set without rTMS,other experimental conditions were just as same as the rTMS group.At 24 h,72 h after reperfusion,the extent of neurological deficits graded as scores by 2 examinations were evaluated.At 72 h after reperfusion,rats were decapitated rapidly and infarct volumes were measured,MT was evaluated again before the death.Changes in these parameters and effects of rTMS on them were analyzed.Results In addition increasing MT,(ischemia)-reperfusion injury produced distinct focal infarction and neurological deficits,which expressed as the growing of neurofunction scores,and deteriorated along with the prolongation of reperfusion time.rTMS could lessen the extent of upregulation of MT,reduce neurological scores,infarct volume,and improve neurofunction.Especially at 72 h after reperfusion,the neurological scores of rats receiving rTMS were statistically better than control group(P=0.004).Conclusions rTMS may provide neuroprotective role in acute stage of cerebral ischemia-reperfusion,should be explored further for its corresponding mechanisms in order to find new therapeutic strategy for ischemic stroke.