Exploring the Utility of High-Resolution Ultrasonography and Color Doppler of Peripheral Nerves in Monitoring Response to Treatment in Leprosy Patients: A Prospective, Observational Study.

Diagnosis and monitoring of nerve function impairment (NFI) presents an ongoing challenge in global leprosy control. This was a prospective, observational study in leprosy patients receiving treatment with cutaneous and neurological examinations done every 3 months for 1 year. High-resolution ultrasonography and color Doppler (HRUS-CD) was performed in all patients at baseline, completion of treatment, and anytime during the study period if a patient had deterioration of nerve function noted clinically. All peripheral nerves were assessed, and parameters studied were cross-sectional area (CSA), length of thickening, endoneural flow signals (ENFS), and distortion in fascicular symmetry. Of 54 treatment-naive leprosy patients, loss of sensation was noted in 37 (68.5%), paresthesia in 20 (37.0%), and neuropathic pain in 7 (12.9%) at baseline presentation. At end of treatment of leprosy, maximum improvement in NFI across all clinical criteria was seen in ulnar and radial nerves (P <0.05). The number of impairments on HRUS-CD decreased consistently, significantly for ulnar (P = 0.009 right ulnar, P = 0.012 left ulnar) and right radial (P = 0.025) nerves, and significant improvements in CSA and ENFS were seen across multiple nerves, which correlated with improvement in NFI as well. Abnormal HRUS-CD findings in the target nerves were significantly associated with multibacillary cases (odds ratio [OR]: 4.33; 95% CI: 0.62-30.31), those in reaction (OR: 9.42; 95% CI: 1.51-58.66), and those older than 40 years (OR: 3.14; 95% CI: 0.49-19.93). This study provides objective evidence of improvement in NFI with anti-leprosy treatment, supporting integration of HRUS-CD imaging in monitoring nerve involvement in leprosy.