Clinical and electrophysiological characteristics of neuropathic pain in leprosy patients: A prospective cross-sectional study

Abstract

Introduction: Neuropathic pain is a common and disabling late complication of leprosy. We investigated the clinical and electrophysiological characteristics of neuropathic pain in leprosy patients by evaluating nerve conduction, sympathetic skin response (SSR) and A-waves. Methods: Twenty one leprosy patients with neuropathic pain validated by the Douleur Neuropathique en 4 (DN4)Questionnaire were selected for study. Pain intensity was measured by the visual analog scale. Demographic and clinical data were collected for all patients. Clinical data included appraisal of the median, ulnar, radial, tibial and common peroneal nerves, assessment of the sympathetic skin response and conventional electrophysiological recordings. Results: Among all electroneuromyographic presentations, multifocal mononeuropathy was still the most prevalent. Sensory loss was observed more frequently than motor deficits. As most patients presented advanced clinical forms of leprosy and were under treatment, this high mean was found and the ulnar nerve was most frequently affected. The sympathetic skin response was absent in 16 patients. Higher DN4 Questionnaire scores were observed in women and in those receiving corticosteroid therapy. These inferences are possible to be made, but our study's limitations don't allow us to be certain about it. The statistical significance found only permits us to evidence what we related on the textual part of the study. Limitations: The small number of patients studied, the lack of sophisticated diagnostic methods for leprosy, as well as the difficulties in assessing nerve conduction were the main limitations of this study. Conclusion: The neurophysiological and clinical findings in leprous neuropathy were modest despite the conspicuous neuropathic pain. Although electrophysiological studies are a vital tool to verify nerve damage, variations in the clinical presentation of leprosy neuropathic pain render the diagnosis challenging. Further studies are needed to describe the neurophysiological evolution of this disease.