High-resolution ultrasound in the assessment of peripheral nerves in leprosy: A comparative cross-sectional study

Abstract

Background: Detection of peripheral nerve thickening and nerve function impairment is crucial in the diagnosis and the management of leprosy. Aims and objectives: (1) To document the cross-sectional area, echotexture and blood flow of peripheral nerves in healthy controls and leprosy cases using high-resolution ultrasound, (2) to compare the sensitivities of clinical examination and high-resolution ultrasound in detecting peripheral nerve thickening in leprosy. Methods: Peripheral nerves of 30 leprosy patients and 30 age- and sex-matched controls were evaluated clinically and by high-resolution ultrasound. When the cross-sectional area of a peripheral nerve on high-resolution ultrasound in a leprosy patient was more than the calculated upper bound of the 95% confidence interval for mean for that specific nerve in controls, that particular peripheral nerve was considered to be enlarged. Results: Cross-sectional areas more than 7.1 mm2 for the radial nerve, 8.17 mm2 for ulnar, 10.17 mm2 for median, 9.50 mm2 for lateral popliteal and 11.21mm2 for the posterior tibial nerve were considered as nerve thickening on high-resolution ultrasound. High-resolution ultrasound detected 141/300 (47%) nerves enlarged in contrast to the 60 (20%) diagnosed clinically by palpation (P < 0.001). Clinical examination identified thickening in 31/70 (44.3%) nerves in cases with impairment of nerve function and 29/230 (12.6%) in the absence of nerve function impairment. High-resolution ultrasound detected thickening in 50/70 (71.4%) nerves with impairment of function and in 91/230 (39.6%) nerves without any impairment of function. Limitation: A single-centre study design was the major study limitation. Conclusion: High-resolution ultrasound showed greater sensitivity than clinical examination in detecting peripheral nerve thickening in leprosy cases. High-resolution ultrasound, may therefore improve the sensitivity of the diagnostic criterion of peripheral nerve enlargement in the diagnosis and classification of leprosy.

Peripheral nerve sonography, a novel technique for improving the diagnosis of Hansen’s neuropathy

“…6 Recently, Sreejith et al also reported a lack of good agreement between clinical and sonographic examination for the detection of thickened nerves with a kappa of −0.04 for the median nerve to 0.215 for the common peroneal nerve. 7 These data clearly indicate clinical examination alone is inadequate and HRUS identifies a greater number of patients with abnormal nerves even in the presence of normal electrophysiological testing. 8 Sonographically enlarged nerves correlate with clinical and electrophysiological abnormalities.…”

“…8 Sonographically enlarged nerves correlate with clinical and electrophysiological abnormalities. 7,9 Being non-invasive and well tolerated by the patients, HRUS can be used to identify 'silent' neuropathy in patients with isolated cutaneous manifestations and normal neurological examination, as well as to screen household contacts. With technological advances, smaller ultrasound machines are available which can be used at the point-of-care.…”

A review of nutrition in neuropathic pain of leprosy

“…Presence of hypo- or anaesthetic hypopigmented lesions during assessment, and thickened peripheral nerves identified via palpation or ultrasonography, are key diagnostic features of leprosy. 73 – 75 Confirmatory laboratory testing to detect acid-fast bacilli in slit skin smears or biopsies using Fite staining and light microscopy or polymerase chain reaction (PCR) amplification can also be completed. Diagnostic specimens are preferentially collected from persistent and active lesions typically located in cooler parts of the body.…”

Treatment and Evaluation Advances in Leprosy Neuropathy

“…Recently, high-frequency ultrasound with color Doppler (HFUS with CD) have been used to describe characteristic changes in leprosy neuropathy to further facilitate diagnosis and treatment. Studies have described nerve thickening at entrapment sites, cross-sectional area difference between tuberculoid and lepromatous diseases, and increased intraneural or perineural vascularization [161][162][163][164][165].…”