Cold nerve injury is enhanced by intermittent cooling.

Clinically nonfreezing cold nerve injury (NFCNI) is often preceded by fluctuating ambient temperatures. To simulate this we exposed the sciatic nerve of Wistar rats to intermittent cooling and rewarming. This paradigm was contrasted with one in which the sciatic nerve was continuously cooled. Despite an identical duration and degree of sciatic nerve cooling in both experiments, the pathology, as assessed neurophysiologically and morphologically, was much more severe when the nerve was intermittently cooled. It is likely that this exaggerated pathology is a result of repeated reperfusion injury. These experimental results suggest the need for a trial of free radical scavengers or antioxidants in models of NFCNI.