不同术式切断C7神经根后对神经支配肌影响的实验研究

目的　研究切断大鼠 C7神经根不同纤维束组后其支配肌的肌电图变化 ,为临床选择性 C7神经根移位术提供理论根据。方法　 SD大鼠 2 4只 ,按手术术式不同随机分成 3组 ,每组 8只鼠。A组 :单纯切断上干 ;B组 :切断上干及部分中干 ( C7前股前外侧部分 ) ;C组 :切断上干及全中干。左侧为实验侧 ,右侧为自身正常对照组。术后 4周 ,各组大鼠测定双侧背阔肌、肱三头肌、指总伸肌的复合肌肉动作电位 ( CMAP) ,并计算其潜伏期和波幅。所得数据进行统计学处理。结果　与对照组相比 ,C组背阔肌、肱三头肌及指总伸肌 CMAP的波幅及潜伏期均有明显的变化 ,波幅衰减、潜伏期延长 ;以背阔肌受的影响最为显著。A、B两组上述肌肉 CMAP的波幅及潜伏期均无明显改变。结论　单纯上干损伤后切取 C7神经根前股前外侧束组对 C7神经根主要支配肌 (背阔肌、肱三头肌、指总伸肌 )并无多大影响 ;而 C7全干切断后对上述肌肉影响较大

An experimental study of the influence on the C_7 innervating muscles after transection of different C_7 fascicles

Objective To investigate the electrophysiological changes after transection of different ipsilateral C 7 fascicles in rats with upper trunk injuries, and provide theoretic evidence for selective C 7 transfer using the anteriolateral fascicles of the anterior division. Methods 24 Sprague Dawley rats were randomized into three groups. In group A, the upper trunk of the brachial plexus was transected. In group B, the upper trunk and a part of the middle trunk (the anteriolateral fascicles of the anterior division ) were transected. In group C, the upper trunk and the whole middle trunk were transected. The operations were done on the left side while the right side served as control. The brachial plexus on both sides were exposed in four weeks to exam. The compound muscle action potential (CMAP) of latissimus dorsi, triceps brachii and extensor digiti communis muscles and record the latent period and the amplitude. All data were statistically analyzed. Results Compared with the control side, there was obvious change in CMAP of latissimus dorsi, triceps brachii and extensor digiti communis muscles in group C, which was manifested as decreased amplitude and prolonged latent period. The latissimus dorsi was most affected. In group B and A, there was no obvious change in the latent period and the amplitude of CMAP in the above mentioned muscles. Conclusions When the upper trunk of the brachial plexus was injured, transection of partial fascicles of the anterior division of C 7 (the anteriolateral fascicles) didn't lead to obvious impairment of the C 7 innervating muscles. There was obvious impairment of muscle function after transection of whole middle trunk