High-Resolution Sonography as an Additional Diagnostic and Prognostic Tool to Monitor Disease Activity in Leprosy: A Two-Year Prospective Study.

PURPOSE: Early diagnosis and treatment of leprosy and leprosy reactions are essential to prevent stigmatizing deformities and disability. Although the incidence of leprosy has decreased enormously, grade 2 disability due to nerve injury has remained the same. New tools are needed to better diagnose and monitor leprosy reactions and associated neuritis and this study assessed whether high-resolution sonography (HRUS) can be used as such a tool. MATERIALS AND METHODS: During a prospective follow-up period of 2 years at regular intervals, we performed clinical examination to assess sensory and motor function and HRUS of the four main peripheral nerves in 57 patients, of whom 36 were with reactions and 21 were without reactions. Normative data of the cross-sectional area (CSA) of these nerves were obtained from 55 healthy subjects (HS). Color Doppler (CD) was used to study blood flow in the nerves. RESULTS: At the baseline visit and during follow-up, all four nerves were significantly thicker in patients with leprosy reactions in comparison to HS (p < 0.0001) and to a lesser extent also in comparison to patients without reactions ranging from a p-value of < 0.05 to < 0.0001 in the different nerves tested. During follow-up, the nerve size did not change significantly in patients without reactions, while it decreased significantly in patients with reactions. At baseline, endoneural blood flow was present only in patients with reactions. This occurred in 20 of the 36 (55 %) patients (49 nerves) and decreased to only 1 patient (2.7 %) at the end of the follow-up period. CONCLUSION: This prospective study demonstrates the ability of HRUS to monitor disease activity and the effect of treatment in patients with leprosy reactions by determining changes in nerve size and vascularity, which are indicators of peripheral nerve involvement and damage.

High-resolution sonography: a new technique to detect nerve damage in leprosy.

BACKGROUND: Leprosy is the most common treatable peripheral nerve disorder worldwide with periods of acute neuritis leading to functional impairment of limbs, ulcer formation and stigmatizing deformities. Since the hallmarks of leprosy are nerve enlargement and inflammation, we used high-resolution sonography (US) and color Doppler (CD) imaging to demonstrate nerve enlargement and inflammation. METHODOLOGY/PRINCIPAL FINDINGS: [corrected] We performed bilateral US of the ulnar (UN), median (MN), lateral popliteal (LP) and posterior tibial (PT) nerves in 20 leprosy patients and compared this with the clinical findings in these patients and with the sonographic findings in 30 healthy Indian controls. The nerves were significantly thicker in the leprosy patients as compared to healthy controls (p<0.0001 for each nerve). The two patients without nerve enlargements did not have a type 1 or type 2 reaction or signs of neuritis. The kappa for clinical palpation and nerve enlargement by sonography was 0.30 for all examined nerves (0.32 for UN, 0.41 for PN and 0.13 for LP). Increased neural vascularity by CD imaging was present in 39 of 152 examined nerves (26%). Increased vascularity was observed in multiple nerves in 6 of 12 patients with type 1 reaction and in 3 of 4 patients with type 2 reaction. Significant correlation was observed between clinical parameters of grade of thickening, sensory loss and muscle weakness and US abnormalities of nerve echotexture, endoneural flow and cross-sectional area (p<0.001). CONCLUSIONS/SIGNIFICANCE: We conclude that clinical examination of enlarged nerves in leprosy patients is subjective and inaccurate, whereas sonography provides an objective measure of nerve damage by showing increased vascularity, distorted echotexture and enlargement. This damage is sonographically more extensive and includes more nerves than clinically expected.

Lower touch sensibility in the extremities of healthy Indians: further deterioration with age.

Touch sensibility testing is a cost-effective, psychophysical measure of peripheral nerve function and impairment. However, there is limited information regarding the natural variability in touch sensibility across different populations and different age groups. We studied 568 healthy Indian volunteers without any clinical evidence of peripheral nerve disease. Touch sensibility was evaluated bilaterally in palms, feet, and heels, using Semmes-Weinstein monofilaments, with target forces ranging from 0.008 to 300 g. No differences were observed between the right and the left limbs. The lowest target force detected ranged from 0.4 to 2 g in the palms and 1.4 to 15 g in the feet. These values showed further increase with age. Women compared with men had higher sensibility in the palms in most age groups. Touch sensibility thresholds recorded in a large group of Indians were higher than that reported in other populations. These findings have clinical implications for the diagnosis of early nerve impairment in the elderly and in disease states drawing attention to geographic variations in touch sensation.