实验性大鼠内囊出血后H反射的改变及意义

目的　观察大鼠内囊出血后H反射的改变及意义。方法　将大鼠动脉血定向注入内囊以建立脑出血模型 ;检测左右侧腓肠肌H反射的变化 ;同时观察大鼠运动功能缺损和皮层血流量的改变情况。结果　大鼠右侧内囊出血后 ,左侧腓肠肌H反射波幅显著升高且明显高于右侧 (P <0 .0 1) ;左侧H反射的潜伏时明显缩短且明显低于右侧 (P <0 .0 5 ) ;相反 ,右侧H反射的波幅及潜伏时与出血前差异无显著性 (P >0 .0 5 )。大鼠左侧肢体出现了明显偏瘫体征。代表肢体的皮层局部血流量在出血后 7d右侧低于左侧。结论大鼠内囊出血可以引起支配对侧肢体的大鼠脊髓运动神经元兴奋性升高、脊髓单突触牵张反射增强。

Changes of H-reflex following experimental internal capsule hemorrhage in rats

Objective To observe the changes of H- re flex following experimental internal capsule hemorrhage in rats. Methods Models of cerebral hemorrhage were established by injection of arterial blood collected from the tail artery of rat into the right internal capsule of 14 rats. H- reflex was recorded bilaterally from the gastrocnemius m uscles. Meanwhile, neurological deficiency and the sensorimotor cortical blood f low were observed. Results Following the right intern al capsule hemorrhage, left side hemiplegia was observed in all the rats. The am plitude of H- reflex in the left side was significantly increased and higher th an those of the right side ( P <0.05). However, the amplitude and latency of H - reflex obtained in the right side remained unchanged as compared with those b efore the hemorrhage ( P >0.05). The latency of H- reflex of the left side wa s decreased significantly when compared with that of the right side( P <0.05). With regard to the blood flow, it was significantly reduced in the right sensor imotor cortex on 7 days post- hemorrhage as compared to that of the left side. Conclusion The results suggested that internal capsul e hemorrhage resulted in increase of excitability of the contralateral anterior horn motoneurons causing enhancement of monosynaptic stretch reflexes.