Interexaminer Repeatability of Antidromic Ulnar Sensory Nerve Conduction Velocity Measurements

Schuhfried O, Angst M, Herceg M, Paternostro-Sluga T. Interexaminer repeatability of antidromic ulnar sensory nerve conduction velocity measurements.ObjectiveTo determine the interexaminer repeatability of the ulnar antidromic sensory nerve conduction velocity (NCV).DesignTest-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.SettingOutpatient department.ParticipantsTwenty-four consecutive healthy subjects (mean age, 38y).InterventionsNot applicable.Main Outcome MeasuresThe 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.ResultsThe 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.ConclusionsDuring 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.