低强度超声促进周围神经损伤后的再生

目的：探讨低强度超声对周围神经损伤后再生的作用。方法：将64只大鼠右侧坐骨神经重度钳夹伤制作神经损伤模型，随机分为2组各32只。超声组造模侧神经损伤处以声强250mW／cm^2、频率1．0MHz的超声进行体外治疗，隔天1次；对照组相应部位予以未启动治疗系统的假治疗。术后不同时期进行电生理、坐骨神经功能指数等指标测定及组织学检查。结果：超声组损伤神经远侧Wallerian变性进程加速、雪旺细胞增殖、变性组织吸收，轴索及髓鞘再生、感觉传导速度及坐骨神经功能的恢复等与对照组比较均提前（P〈0．01或P〈0．05）。结论：低强度超声通过影响神经再生的多个环节而促进周围神经的再生和功能恢复。

Low-intensity Ultrasound for Regeneration of Peripheral Injured Nerve

Objective: To study the effect of low-intensity ultrasound (LIU) on regeneration of peripheral injured nerve. Methods: The right sciatic nerves of 64 adult Wistar rats were crushed with forceps to establish the experimental animal models. Then they were equally divided into ultrasound group and control group. The ultrasound group received the LIU exposure, and control group was subjected to sham exposure. LIU was applied every other day to the crush site of rats, which had a spatial peak, time-averaged intensity of 250 W/cm~2 operated at 1.0 MHz for 1 min per application. At various stages after operation, the sciatic nerve function index (SFI), the sensory nerve conduction velocity (SNCV) and its histology were detected. Results: The course of Wallerian degeneration, Schwann's cell proliferation, the thickness of myelin sheath, the regeneration of axon and medullary sheath and the recovery of SFI and SNCV in ultrasound group were significantly earlier than those in control group (P<0.01 or P<0.05). Conclusion: LIU could promote the regeneration and functional recovery of peripheral injured nerve through the modulation and effect of many links of nerve regeneration process.