腰神经根与其支配肌群的电生理定位实验

Functional motor innervation of lumbar nerve roots of rats by electrophysiological method

目的:观察电生理方法定位腰神经根主要支配肌群的可行性,为临床术中电生理定位监测提供参考依据。方法:实验于2005-04/05在北京大学人民医院创伤骨科实验室完成,选择9只5月龄Wistar雌性大鼠,通过电生理的方法,依次电刺激L2～L5脊神经根部,分别记录双侧大鼠下肢主要肌肉的复合肌肉动作电位,测量下肢四组肌肉(股四头肌、股二头肌、胫骨前肌和腓肠肌)复合肌肉动作电位的波幅峰值。结果:9只大鼠全部进入结果分析。①刺激腰神经根于下肢所记录的典型肌电波形以双相波和三相波为主。②刺激L2脊神经根,于下肢四组肌肉记录到的复合肌肉动作电位最大波幅平均值均<1mV,以在股四头肌记录到的波幅峰值最高(0.89±1.05)mV,显著高于其他3组肌肉(P<0.05)。③刺激L3脊神经根,于股四头肌记录到的波幅峰值为(23.79±13.22)mV,显著高于其他各组肌肉(P<0.01)。④刺激L4脊神经根,于下肢四组肌肉记录到的复合肌肉动作电位最大波幅平均值均明显>1mV,股四头肌和胫骨前肌记录到的波幅峰值显著高于股二头肌和腓肠肌[(15.88±12.28),(12.75±4.97),(7.11±3.60),(8.06±5.29)mV,P<0.01]。⑤刺激L5脊神经根,于股二头肌、腓肠肌记录到的波幅峰值为(23.92±15.05),(13.1±7.05)mV,显著高于其他各肌群(P<0.01)。结论:电刺激不同脊神经根,在大鼠下肢不同肌肉记录到的复合肌肉动作电位的波幅峰值存在差异,综合分析记录到的复合肌肉动作电位的波幅峰值,可基本确定所刺激的腰神经根节段。

AIM： To observe the feasibility of locating the major muscle innervation of lumbar nerve roots by electrophysiological method. METHODS： The experiment was conducted in the laboratory of Department of Orthopedics and Trauma, People＇s Hospital, Peking University from April to May 2005. Nine female Wistar rats aged 5 months were selected and the L2-L5 never roots were stimulated by turns with electrophysiological method to record the amplitudes of the compound muscle action petentia （CMAP） and the maximum amplitudes of four groups of muscles （quadriceps and biceps muscles of thigh, anterior tibial muscle and gastrocnemius muscle） of bilateral lower limbs. RESULTS： All the 9 rats entered the result analysis. ①The typical waveform of the recorded CMAP were mostly diphase or triphasic wave. ②When stimulating L2, the average of the maximum amplitudes were 〈 1 mV, and the highest value was recorded in quadriceps femoris （0.89±1.05） mV, which was significantly higher than in other muscles （P 〈 0.05）.③When stimulating L3, the maximum amplitudes was that recorded in quadriceps femoris （23.79±13.22） mV, which was significantly higher than in other muscles （P 〈 0.01）. ④When stimulating L4 the average of the maximum amplitudes were 〉 1 mV, and the maximum amplitudes recorded in quadriceps femoris and tibialis anterior were obviously higher than in biceps femoris and gastmenemius [（15.88 ±12.28）, （12.75±4.97）, （7.11 ±3.60）, （8.06±5.29） mV, P 〈 0.01]. ⑤When stimulating L5 the maximum amplitudes recorded in biceps femoris and gastrocnemius were .（23.92±15.05） and （13.1±7.05） mV, which were significantly higher than in other muscles （P 〈 0.01）. CONCLUSION： There are significant differences in maximum amplitudes of CMAP recorded in different muscles of lower limbs after stimulating different lumbar never roots. We can identify the segment of the stimulated lumbar nerve roots by analyzing the recorded maximum amplitudes of CMAP.