Hamjian J A, Walker F O
Department of Neurology, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina 27157-1078.
Muscle Nerve. 1994 Dec;17(12):1385-92. doi: 10.1002/mus.880171207.
To characterize the time course of intramuscular botulinum toxin-induced paresis, we serially performed electrophysiological measurements and recorded the sonographic size of an extensor digitorum brevis (EDB) muscle in 10 human subjects before and after injecting the EDB with 10 units of botulinum-A toxin. All EDB CMAPs decreased within 48 h, with peak decline at day 21 (8.3 +/- 3.1 mV to 3.0 +/- 0.9 mV). Decline of mean rectified voltage during maximal voluntary contraction of the EDB paralleled the change in CMAP amplitude. Average decrements to 2-Hz repetitive stimulation never exceeded 6% (day 42) and exercise failed to facilitate significantly CMAP amplitude. Atrophy peaked at day 42. The F-wave to M-wave ratio increased at day 2; silent periods did not change. Our findings confirm a primary peripheral action of the toxin, but a superimposed, transient central effect of the drug cannot be excluded. Intramuscular injections into EDB provide a useful model for studying chemodenervation effects.
为了描述肌内注射肉毒杆菌毒素所致轻瘫的时间进程，我们对10名人类受试者在向趾短伸肌（EDB）注射10单位A型肉毒杆菌毒素前后，连续进行了电生理测量，并记录了该肌肉的超声大小。所有EDB复合肌肉动作电位（CMAP）在48小时内均下降，在第21天下降至峰值（从8.3±3.1毫伏降至3.0±0.9毫伏）。EDB最大自主收缩时平均整流电压的下降与CMAP波幅的变化平行。2赫兹重复刺激的平均衰减在第42天从未超过6%，且运动未能显著促进CMAP波幅。萎缩在第42天达到峰值。F波与M波的比率在第2天增加；静息期无变化。我们的研究结果证实了毒素的主要外周作用，但不能排除药物叠加的短暂中枢效应。向EDB进行肌内注射为研究化学去神经作用提供了一个有用的模型。
