A-waves associated are with neuropathic pain in leprosy.

INTRODUCTION/AIMS: A-wave is a late response related either to demyelination or early axonal regeneration. It may be helpful in the evaluation of some peripheral neuropathies. In leprosy, previous studies suggested that A-waves could be a neurophysiological marker of pain in patients during reactions. Herein, we attempted to further assess the profile and clinical correlates of A-waves by exploring a large leprosy cohort.

METHODS: Between 2015 and 2018, sixty-three patients with leprosy (47 men and 16 women) had A-waves in nerve conduction studies and were included in this study. We included patients regardless of whether or not they were experiencing leprosy reactions. We then compared clinical features in nerves with and without A-waves.

RESULTS: Mean age was 46.5 ± 12.3 years and most subjects had borderline leprosy. From this cohort, we assessed separately 83 motor nerves that demonstrated A waves (Group A+) and 29 motor nerves that did not demonstrate A waves (Group A-). Neuropathic pain (NP) was found in 66 out of 83 nerves in group A+, but only 5 out 29 in group A- (79.5 vs 17.2%, p<0.001). In contrast, no significant between-group difference emerged regarding presence of reactions, sensory function (based on Semmes-Weinstein evaluations) or muscle strength. A-waves were found in nerves with NP experiencing (39/66=59%) or not experiencing (27/66=41%) leprosy reactions.

DISCUSSION: These results show that A-waves are associated with neuropathic pain in leprosy patients, regardless of the nerves affected and the immune status (in reaction or not). This article is protected by copyright. All rights reserved.