Leprosy neuropathy evaluated by NCS is independent of the patient’s infectious state

[[[ Introduction: ]]] Leprosy causes nerve injury, which mimics clinical and neurophysiological conditions, rendering it an excellent model of peripheral neuropathy. [[[ Methods: ]]] A retrospective study including 822 nerve conduction studies (NCS) of 509 patients was developed to appraise the electrophysiological pattern of leprosy neuropathy. NCS of motor and sensory nerves performed before, during, and after multidrug therapy (MDT) were analyzed. [[[ Results: ]]] During the three periods of MDT, while NCS alterations were similar regarding extension, topography, damage severity, and type of lesion, NCS showed that sensory was more frequent (sural nerve) (92-96%) than motor impairment (70-77%) (ulnar nerve). [[[ Conclusion: ]]] Once axonal loss has been installed, nerve function is little affected by inflammatory, immune and/or bacterial events since chronic neuropathy has been established, inevitably leading to the well-known leprosy sequelae occurring at any time before and/or after leprosy diagnosis.