The Effect of Low-intensity Remote Ultrasound on Sciatic Nerve Regeneration in Male Rats

Background: Ultrasonic therapy is used locally to repair damaged peripheral nerves. Objectives: This study was designed to examine the effect of low-intensity remote ultrasound on peripheral nerve regeneration. Materials & Methods: In the present study, ۲۴ male rats were randomly divided into three groups: Sham surgery (SS: No sciatic crush injury, no ultrasonic treatment, n=۸), control (C: Sciatic crush injury, without ultrasonic treatment, n=۸), and remote ultrasound (RU: Sciatic crush injury, ultrasonic treatment, n=۸). To induce nerve crush, the sciatic nerve was clamped ۱ cm above the bifurcation site for ۳۰ seconds. In the RU group, the opposite leg was treated with low-intensity ultrasound for ۱۰ minutes, ۳ times a week for ۴ weeks (۱.۱ MHz frequency with an intensity of ۰.۵ W/cm۲). Neurological evaluation was done by examining the sciatic nerve index (SFI) on days ۷, ۲۱, ۲۸, ۳۵, ۴۹, and ۵۶ after surgery. The samples were evaluated histologically, biochemically, and immunohistologically on days ۲۸ and ۵۶ after surgery. Results: The mean SFI, transverse diameter of muscle fibers, and the number of myelinated axons in the RU group were higher than those in the control group (P<۰.۰۵). Also, the mean plasma levels of total antioxidant capacity, malondialdehyde, interleukin-۶, and HSP۷۰ in the control group differed from the RU group on days ۲۸ and ۵۶ after surgery (P<۰.۰۵). Conclusion: The results of the present study show that low-intensity remote ultrasound has beneficial effects on the crushed sciatic nerve.