Interexaminer Repeatability of Antidromic Ulnar Sensory Nerve Conduction Velocity Measurements

Abstract

Schuhfried O, Angst M, Herceg M, Paternostro-Sluga T. Interexaminer repeatability of antidromic ulnar sensory nerve conduction velocity measurements. Objective To determine the interexaminer repeatability of the ulnar antidromic sensory nerve conduction velocity (NCV). Design Test-retest design. Based on a randomization list of various combinations and sequences from 2 of a total of 3 examiners, the measurement was repeated within half an hour by a second examiner blinded to the results of the first examiner. Setting Outpatient department. Participants Twenty-four consecutive healthy subjects (mean age, 38y). Interventions Not applicable. Main Outcome Measures The intraclass correlation coefficient (ICC) and the coefficient of repeatability (CR) were determined for the below elbow to wrist (BE-to-W), above elbow to below elbow (AE-to-BE), and axilla to above elbow (AX-to-AE) segments. Results The ICC was .42 for the BE-to-W, .15 for the AE-to-BE, and −.05 for the AX-to-AE segment. The CR was 12.2m/s for the BE-to-W, 16.2m/s for the AE-to-BE, and 21.4m/s for the AX-to-AE segment. Conclusions During the assessment of the antidromic sensory NCV of the ulnar nerve, a moderate amount of interexaminer variability must be taken into account for the BE-to-W segment. More proximally, an extremely large amount of interexaminer variability must be taken into account. This calls into question the usefulness of the antidromic ulnar sensory NCV for the AX-to-AE and AE-to-BE segments.