Ulnar Nerve Cross-sectional Area among Ulnar Neuropathy Patients and Healthy Subjects - A Study in Hospital-based Population of Eastern India.

Introduction: Ultrasound (US) examinations of the ulnar nerve and measurement of cross-sectional area (CSA) are now used to diagnose cases of ulnar neuropathy. However, the CSA values vary across the population. The present study was planned to prepare a preliminary dataset of ulnar CSA among the symptomatic ulnar neuropathy patients diagnosed by electrodiagnostic studies at our institute and compare the values with those of healthy volunteers. Materials and Methods: A hospital-based case-control study was conducted, which included 20 diseased upper limbs diagnosed with ulnar neuropathy and 40 non-neuropathic upper limbs as controls. They all underwent an US examination of the ulnar nerve in both upper limbs. The demographic data, nerve CSA at five predetermined locations, swelling and flattening ratios were compared and analyzed. Results: The mean values of ulnar CSA at the medial epicondyle, 5 cm proximal and distal to it, at mid-forearm, and at the wrist were 11.5 ± 2.38 mm2, 7.43 ± 1.47 mm2, 6.17 ± 1.42 mm2, 5.78 ± 2.53 mm2, and 4.67 ± 2.3 mm2, respectively, in ulnar neuropathy patients. All the values were statistically significantly higher in cases than in controls. The swelling and flattening ratios were statistically significantly higher in ulnar neuropathy cases than in controls. Conclusion: This study presents a data set of ulnar nerve CSA and some other parameters for the ulnar neuropathy patients and the normative values of ulnar nerve CSA in healthy subjects for the population of West Bengal (Eastern India). This data might be helpful for the diagnosis and management of ulnar neuropathy in this region.