Application of infrared thermography for the analysis of rewarming in patients with cold intolerance

Cold intolerance is a serious long-term problem after injury to the ulnar and median nerves, and its pathophysiology is unclear. We investigated the use of infrared thermography for the analysis of thermoregulation after injury to peripheral nerves. Four patients with injuries to the ulnar nerve and four with injuries to the median nerve (4-12 years after injury) immersed their hands in water at 15C for 5 minutes, after which infrared pictures were taken at intervals of 2-4 minutes. The areas supplied by the injured nerves could be identified easily in the patients with symptoms of cold intolerance. At baseline temperature distribution of the hand was symmetrical, but after testing the injured side warmed up much slower. We concluded that the infrared profile of the temperature of the hand after immersion in cold water is helpful to assess thermoregulation after injury to peripheral nerves.