Nerve enlargement after cold exposure: A pilot study with ultrasound imaging

ABSTRACT Introduction: Changes of electrophysiogical parameters with regard to cold have been studied intensively but not the morphology of nerves. We explored the effects of cold exposure on median nerve morphology. Methods: Cross‐sectional area (CSA) and depth of the right median nerve were assessed at the carpal tunnel and mid‐forearm levels before and after 15 min ice‐pack application in 34 healthy volunteers. Results: After cooling, mean CSA measurements increased at the carpal tunnel and mid‐forearm levels (from 8.00 to 8.85 and 6.64 to 7.55, respectively, P < 0.05); however, the depth values were similar. Conclusions: These preliminary results revealed that cold exposure may cause acute nerve swelling. Further studies with larger samples will be necessary to confirm our findings, to correlate them with electrophysiological data, and to explore when/how the nerve edema resolves. Muscle Nerve 49:502–505, 2014