SENSORY AND MIXED NERVE-CONDUCTION STUDIES IN THE EVALUATION OF ULNARNEUROPATHY AT THE ELBOW

The relative sensitivities of sensory, mixed nerve, and motor conducti on studies in assessing ulnar neuropathy at the elbow have not yet bee n established. Using surface electrodes, we performed conduction studi es across the elbow segment in 43 patients with symptoms referable to the ulnar nerve and 40 control subjects. Segmental slowing of motor co nduction localized the lesion to the elbow in 14 of 21 patients (67%) with clear evidence of ulnar neuropathy on physical examination but on ly in 2 of 22 (9%) with subtle or no physical examination abnormalitie s. The diagnostic yield was increased by the finding of segmental slow ing of sensory or mixed nerve conduction across the elbow to 86% and 6 8%, respectively, for each of the groups. We conclude that surface-rec orded sensory and mixed nerve conduction studies appear to be more sen sitive than motor studies in the electrodiagnosis of ulnar neuropathy at the elbow and are especially valuable in patients with subtle clini cal involvement. (C) 1994 John Wiley and Sons, Inc.