Peripheral neuropathy in leprosy among patients attending the Dermatology Clinic in a Tertiary Care Hospital in Sri Lanka: clinical, ultrasound measures and electrophysiological correlations

Abstract

Introduction: Leprosy primarily affects the peripheral nerves and subsequently spreads to the skin and its appendages. The aim of this study was to correlate clinical patterns of nerve abnormalities of ulnar and common peroneal nerves of leprosy patients with ultrasonography (USG) and findings of nerve conduction studies (NCS).
 Methods: 180 ulnar nerves (UN) and 180 common peroneal nerves (CPN) of 90 patients with leprosy were assessed clinically. Cross sectional area (CSA) of nerves was measured by ultrasonography. Motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV) were measured in NCS.
 Results: The correlation of clinical palpation and ultrasound measures were significant; r= 0.378 (p<0.01) in UN and r= 0.158 (p<0.01) in CPN. There was a significant correlation between clinical findings and NCS; MNCV of UN r= -0.44 (p<0.01), SNCV of UN r= -0.575 (p<0.01) and MNCV of CPN r= -0.254 (p<0.01). The correlation of maximum CSA and NCS was statistically significant in UN; MNCV r= -0.276 (p<0.01) and SNCV r = -0.412 (p<0.01).
 Conclusion: In leprosy patients, a significant positive correlation exists between clinical detection, ultrasound measures of nerve enlargement and slowing of MNCV and SNCV of UN and CPNs. In our study, USG was done using 4 - 11MHz linear transducer, which is available at any low resource setting. Therefore, ultrasonography without high resolution can be used to detect nerve enlargement in leprosy.