P-NJ003. Sonographic pattern of median nerve enlargement in hansen’s neuropathy

Abstract

Introduction . Median nerve enlargement in leprosy using high-resolution ultrasound seems to be more proximal than in carpal tunnel syndrome (CTS), which might be an important discriminating sign, but has not been studied systematically. The aim of this study is to compare the sites of median nerve enlargement in patients with leprosy with that of patients with CTS. Methods . Transverse sections of the median nerve were recorded from wrist until the forearm (at distal wrist crease, and at 2-cm: M1, 4-cm: M2, 6-cm: M3, 8-cm: M4 and 10-cm: M5, proximal to the distal wrist crease in the forearm) and at mid arm and forearm in patients with leprosy, CTS and healthy subjects. Results . Twenty-six patients each with leprosy and CTS were compared with healthy controls. Patients with leprosy included 6 (23%), 7 (26.9%), 7 (26.9%) and 6 (23.1%) patients with borderline-tuberculoid, borderline-borderline, borderline-lepromatous and lepromatous leprosy respectively. Cross-sectional area (CSA) of median nerve was increased in all patients with leprosy as compared to healthy controls at all points of measurement. CSA was higher among patients with leprosy as compared to CTS at all points except at the wrist. In patients with leprosy, the maximal enlargement was noted 2-cm (M1) proximal to the wrist crease with gradual tapering of the CSA proximally (p < 0.05). In contrast, in patients with CTS the median nerve was maximally enlarged at the distal wrist crease (p < 0.05). Conclusion . Enlargement of median nerve 2-cm proximal to the distal wrist crease is a characteristic feature that distinguishes leprosy from CTS. This important finding can be used at point-of-care ultrasound to identify patients with leprosy.