SEGMENTAL ULNAR NERVE-CONDUCTION VELOCITI ES IN HANSENS-DISEASE

In leprosy, ulnar neuritis is considered to be selectively localised a t the elbow and is often treated by surgical decompression when pain a nd/or neurological deficit occurs. The aim of this prospective study i s to assess the prevalence, localisation and severity of ulnar nerve d amage in leprosy. Motor nerve conduction velocity (MNC) was measured a t 3 different segments: arm, elbow and forearm, and was expressed both in meters/second and percentage of the mean normal values found in ou r laboratory or as reported in other studies. The patient group consis ted of 123 consecutive new leprosy sufferers (228 ulnar nerves only) w ho attended the Institut de Leprologie Appliquee de Dakar over the per iod of one year. Diagnosis and classification, were based on Ridley & Jopling's criteria, including skin and nerve biopsy. Mean MNC was redu ced by 13,5 m/s at the arm, 19,8 m/s at the elbow and 7,8 m/s at the f orearm as compared to the mean normal values. Increased distal latency as an isolated finding was rare (0.9 %). Mean MNC was more reduced in the BL, LL (lepromatous) than in the TT, BT (tuberculoid) subgroups, despite similar disease durations (22.3 +/- 18.7 months and 24.2 +/- 2 6.4 months respectively (n.s.). Using different normal MNC values did not affect the conclusion : we did not see any selective slowing of ul nar MNC at the elbow suggesting that nerve damage is not primarily rel ated to mechanical factors.