Cold Intolerance in Upper Extremity Nerve Injury Patients

Cold intolerance is a frequent and invalidating finding after upper extremity nerve lesions. The pathogenesis of cold intolerance is still unclear. It is usually evaluated with a subjective questionnaire. The aim of this study was to clarify the pathogenesis of cold intolerance and to investigate thermoregulation in cold intolerance patients.

One hundred seven upper extremity nerve injury patients completed the CISS (Cold Intolerance Symptom Severity) questionnaire at different time intervals. Sensory recovery was assessed by Semmes Weinstein monofilaments. Based on the total score on the CISS questionnaire (CISS > 36), 12 patients were selected to investigate thermoregulation in both hands. After 5-min immersion of both hands in a 15 degree C water bath, infrared thermo images were obtained at 0, 2, 5, and 10 min. Furthermore, continuous thermo registration during immersion and re-warming were performed. Additionally, a large normative population study (n = 148)was performed to define a CISS score to classify cold intolerance.

Mean CISS of the normative study population was 13.8 (SD: 10.6). Mean CISS score of the median and ulnar nerve injuries was 38.4 (SD: 25.6). Thirty-six percent of the patients reported sufficient symptoms to be classified as cold intolerance (CISS 36 or higher). Symptoms of cold intolerance do not decrease over the years. ANOVA analysis, adjusted for age, gender, and lesion of the artery, showed a very close relationship between the level of sensory recovery and the level of cold intolerance (p < 0.01). No difference was found between patients with or without vascular injury (p = 0.48). Thermoregulation differed markedly between the affected and contralateral hand. The capacity to warm the hand appears to correlate with the reported degree of cold intolerance and degree of sensory recovery. All 12 patients with a CISS > 36 lost their protective sympathetic response (hunting reaction). Re-warming of the injured hand was delayed and seemed to be associated with level of sensory recovery and CISS score.

For upper extremity nerve injuries, a neurogenic cause of cold intolerance appears most likely. Detailed investigation of the sympathetic reponse will provide more information about the pathogenesis of cold intolerance.