NORMATIVE VALUES FOR SHORT-SEGMENT NERVE CONDUCTION STUDIES AND ULTRASONOGRAPHY OF THE ULNAR NERVE AT THE ELBOW

Introduction: In patients with ulnar neuropathy at the elbow (UNE), short-segment nerve conduction studies (NCS) are rarely performed due to unclear reference values. We excluded controls with subclinical UNE, calculated normative values, and tested them in UNE patients. Methods: Clinical examination, ultrasonography (US), and 2-cm short-segment ulnar motor NCS across the elbow were performed in 49 controls and 67 UNE patients. In controls, subclinical UNE was diagnosed if at least 2 studies were outside the reference limits in the same 2-cm segment. Results: Exclusion of controls with subclinical UNE produced less stringent normative values (2-cm conduction velocity: 25 to 31 m/s; US cross-sectional area: 11.6 to 9.6 mm(2)), which raised diagnostic sensitivity (short-segment NCS: 76% to 90%; 10-cm NCS: 72% to 85%, US: 43% to 79%). Conclusions: We propose the use of our normative values in patients with clinically definite and probable UNE after exclusion of alternative diagnoses. Muscle Nerve, 2015 Muscle Nerve 51: 370-377, 2015