Comparison of High Resolution Ultrasonography with Clinical Examination in the Assessment of Peripheral Nerve...

Assessment of peripheral nerves in leprosy by clinical methods is subject to considerable inter-observer variability. High resolution ultrasonography (HRUS) can assess peripheral nerves more objectively.

To compare the findings of peripheral nerve involvement in newly diagnosed cases of leprosy by clinical and sonological methods.

Cross sectional study in a tertiary care teaching hospital.

Four pairs of peripheral nerves of 40 newly diagnosed patients with leprosy were examined clinically and by HRUS.

Agreement between clinical examination and HRUS using kappa statistic; sensitivity; specificity; and predictive values.

Of the 320 nerves examined, 71 (22.18%) were abnormal clinically and 63 (19.7%) sonologically. Sonological abnormalities were increased cross sectional area (n = 63; 100%), hypoechogenicity with loss of fascicular architecture (n = 46; 73%) and increased vascularity (n = 35; 55.6%). There was moderate agreement (Cohen's Ḳ = 0.59) between clinical and sonological findings. HRUS findings were abnormal in 18 (7.2%) nerves that were clinically normal. HRUS was normal in 26 (36.6%) nerves which were clinically abnormal. Sensitivity of HRUS compared to clinical examination was 63%; specificity 92.7%; positive predictive value 71.4%; and negative predictive value 89.9%. Increased cross sectional area agreed with clinical findings the most.

HRUS has low sensitivity (63%) and high specificity (92.7%) to identify abnormal peripheral nerves in leprosy, compared to clinical examination. It could detect abnormality of some (n = 18, 7.2%) clinically normal nerves, but showed normal findings of some nerves (n = 26, 36.6%), which were considered clinically abnormal.