Possible Use of Sympathetic Skin Response and Thermography in Assessing the Effects of Sympathectomy: A Case Report

Abstract

The objective assessment of sympathectomy is clinically difficult. Its success is usually judged in terms of patient's improvement. Aim: This study tested the hypothesis of possible use of Thermography and Sympathetic Skin Response (SSR) in assessing the effects of sympathectomy. Case history: A man suffering from chronic, disabling palmar hyperhidrosis underwent a bilateral, localised, endoscopic resection of the thoracic sympathetic chain, immediately below the second thoracic ganglion. After the operation he had a significant reduction of palmar hyperhidrosis, but he did not feel satisfied with the operation due to distal paresthesias associated with thermal allodynia in the upper limbs and excessive, troublesome compensatory sweating of the trunk and lower limbs. We evaluated him fifteen months after the operation and symptoms were still present. Standard neurological examination was normal apart from a mild heat hyperesthesia in the distal portions of upper limbs. Methods: SSR was evoked by auditory, alerting stimuli and recorded simultaneously from palm and sole bilaterally. We preferred to use auditory stimulation because of the low variability of SSR waveform usually obtained with this method. The amplitude of SSR in the palm and sole were measured and a palm/sole ratio was calculated. Total body thermography was also performed. Results: A clear reduction in SSR palm/sole ratio was observed. Thermography showed a thoracic thermal level with the upper part of the body being warmer than the lower. Conclusion: Judging from the results obtained in this single case, both SSR and Thermography appear to be objective, simple, noninvasive tools for assessment of thoracic simpathectomy effectiveness. Studies on a large population of patients are needed.