P-NU003. Estimation of cross-sectional area reference values of nerves in the upper and lower extremities using ultrasonography in the Indian population

Abstract

Introduction. High resolution ultrasonography (HRU) permits direct assessment of the morphology of the nerve, unlike electrophysiology that assesses the functionality of the nerves. Normative data of nerves in a population is crucial in differentiating from pathological conditions and hence this study was conducted. Methods. The demographics, physical characteristics and HRU of median, radial, ulnar, fibular, tibial, sural, and superficial fibular nerves at defined sites of 60 adult healthy volunteers were evaluated and recorded. Nerve conduction study (NCS) of ulnar and common peroneal nerves were done to rule out subclinical neuropathy. The estimated cross-sectional area (CSA) reference values and their correlations with the age, weight, height, body mass index (BMI) were evaluated. Results. The mean age of the population was 35.6 (SD-11.1) years, height = 161.4 (SD-8.3) centimeters, weight = 57.4 (SD-9.5) kilograms and BMI = 21.99 (SD-2.9) kilograms/m2. The M:F ratio = 1.2:1. The NCS of ulnar and common peroneal nerves were within normal limits. The normal reference values for each nerve were as follows: median nerve at wrist = 7.1±2.8 mm2, at mid forearm level = 4.8±1.6 mm2, at elbow = 7.4±2.8 mm2, ulnar nerve at wrist = 4.3±1.4 mm2, at mid forearm level = 4.4±1.4 mm2, at elbow = 5.3±2.1 mm2, radial nerve at spiral groove = 4.2±1.3 mm2, tibial nerve at popliteal fossa = 19.5±8.6 mm2, at the medial malleolus = 9.3 ± 3.8 mm2, common peroneal nerve at fibular head = 9.2±4.2 mm2, sural nerve above the lateral malleolus = 1.8±0.8 mm2. Positive correlation was seen between height and median nerve at wrist and elbow, radial nerve at spiral groove, tibial nerve at popliteal fossa and medial malleolus, between weight and median nerve at elbow, ulnar nerve at forearm and elbow, tibial nerve at popliteal fossa and medial malleolus and common peroneal nerve at fibular, between BMI and median nerve at elbow, tibial and common peroneal nerves. Conclusion. The reference values for the upper and lower limb peripheral nerves were recorded. These values could be used for comparison of normal versus abnormal nerves in peripheral neuropathies and could also help in selecting the nerve for biopsy.