Multisegmental ultrasonography of peripheral nerves in leprosy neuropathy

Abstract

Introduction: Leprosy is the most common treatable peripheral neuropathy worldwide. The detection of peripheral nerve impairment is essential for its diagnosis and treatment. Objectives: To identify neural thickening through multisegmental ultrasonography (US). Methods: US measurements of cross-sectional areas (CSAs) of ulnar, median and tibial nerves at two points (in the osteofibrous tunnel and proximal to the tunnel), and also of the common fibular nerve at the fibular head. CSA index (ΔCSA) was calculated as the absolute difference between CSAs from the contralateral side. This is a cross-sectional study composed of 53 leprosy patients (LP) and 53 healthy volunteers (HV). Results: US evaluation detected a total of 138 enlarged nerves, implying neural impairment in 71.7% (38/53) of LP (3.6 enlarged nerves/LP). We detected only mononeuropathy on patient in 23.7% (9/38), and multiple mononeuropathy in 76.3% (29/53). The ulnar and tibial were the most frequently affected nerves. The mean values of CSA of all nerves were significantly higher in LP. We also observed higher ΔCSA measurements for all nerves in LP, with significantly higher values for the ulnar and tibial nerves, both in the tunnel and proximal to the tunnel points. All clinical forms of leprosy evaluated showed neural enlargement through US. Conclusion: The multisegmental US is a useful method for diagnosing leprosy neuropathy, revealing that asymmetry and irregular thickening are characteristics of the disease. Furthermore, that neural involvement is common in different clinical forms of leprosy, reinforcing the importance of including US evaluation of peripheral nerves in the investigation of all leprosy patients.