Neurophysiological patterns of ulnar nerve neuropathy in leprosy reactions

摘要

Background: Leprosy neuropathy, despite being primarily demyelinating,frequently leads to axonal loss. Neurophysiological examination of the nervesduring Type 1 (T1R) and Type 2 reactions (T2R) may give some insight into thepathophysiological mechanisms.Methods: Neurophysiological examinations were performed in 28 ulnar nervesduring a clinical trial of steroid treatment effectiveness, 19 patients with T1R and ninewith T2R. The nerves were monitored during a period of 6 months; there were eightassessments per nerve, for a total of 224 assessments. Nine neurophysiologicalparameters were assessed at three sites of the ulnar nerve. The compound motoraction potential amplitudes elicited at wrist, elbow and above, as well as theconduction velocity and temporal dispersion across the elbow, were chosen to focuson the changes occurring in the parameters at the elbow tunnel.Results and Conclusion: Neurophysiological changes indicating axonal anddemyelinating processes during both T1R and T2R were detected across theelbow. Changes in demyelination, i.e. a Conduction Block, as a primary event presentduring T2R, occurring as an acute phenomenon, were observed regularly; in T1RTemporal Dispersion, a subacute phenomenon, was seen. During treatmentremyelination occurred after both types of reactions