Wallerian Degeneration and Recovery of Motor Nerves after Multiple Focused Cold Therapies

INTRODUCTION A device has been developed to apply freezing temperatures to temporarily impede nerve conduction, resulting in inhibition of voluntary skeletal muscle contraction. This device was designed as an alternative to the neurotoxins usually used to treat movement disorders. METHODS We evaluated the effects of single and 3 repeat treatments with a cryoprobe device (-55°C) on a sciatic nerve rat model. Long-term effects of repeated treatment were evaluated through assessments of physiological function and histological analysis. RESULTS There was consistent weakening of physiological function after each treatment, with recovery of normal function by 8 weeks posttreatment. Histological findings showed axonal degeneration with no disruption to the epineurial or perineurial structures. Progressive axonal regeneration was followed by normal recovery by 24 weeks post-treatment. CONCLUSIONS Low-temperature treatment of motor nerves did not result in permanent or long-term changes to nerve function or structure.