Pathological changes of rabbit sciatic nerve caused by exposure to high intensity ultrasound / 中华物理医学与康复杂志

ABSTRACT

Objective To observe the pathologic changes of the rabbit sciatic nerves after the exposure of high intensity ultrasound(HIU) (7.1 MHz,45.86 W/cm2)and to establish the experimental base for protection of the nerves near the organs and tissues treated with HIU. Methods The rabbit sciatic nerves were exposed to HIU of different doses as defined by the action time of the ultrsound(0, 15, 25 and 50 seconds, respectively); The Pathological changes of the nerves were observed at different times after exposed to HIU(1 week,2 weeks,1 month,3 months and 6 months). Results In 0 s (45.86 W/cm2?0 s)group, no significant pathological changes were observed. In 15 s(45.86 W/cm2?15 s) group, slight deformation of the myelin sheath were observed and recovery took place at 2 weeks. In 25 s (45.86 W /cm2?25 s) group, the nerves became broken partly and recovered at 3 months. In 50 s(45.86 W/cm2?50 s) group, great part of the nerves got coagulation necrosis and had not recovered at 6 months. Conclusion The larger the dosage of HIU, the higher degree the injury of the sciatic nerve, the more difficult the nerves to get repaired.