Ocular and Cervical Vestibular Evoked Myogenic Potentials (VEMPs) in healthy volunteers: the intra-, interobserver, and the test re-test reliability

OBJECTIVE: The aims of the study are to determine the intra-, interobserver, and the test re-test reliability of the cervical and ocular vestibular evoked myogenic potentials (VEMPs). METHODS: Twenty healthy subjects underwent acoustically and forehead tap elicited cervical and ocular VEMPs. The measurements were repeated one week later. RESULTS: The intra- and interobserver reliability of both ocular and cervical VEMPs is excellent. The test re-test reliability of the raw p13n23 peak-to-peak amplitudes of the cervical VEMPs is excellent (ICC: 0.76, 0.87) and the p13 latencies show a good reliability (ICC: 0.56, 0.73). The raw n1p1 peak-to-peak amplitudes of the ocular VEMPs show a fair-to-good test re-test reliability (ICC: 0.51, 0.64) and the n1 and p1 latencies show a poor reliability (ICC: -0.17 <= x <= 0.44). CONCLUSIONS: The intra- and interobserver reliability of the cervical and ocular VEMPs is excellent. The raw ocular and cervical VEMP peak-to-peak amplitudes are the most reliable parameters, followed by the cervical VEMP latencies. The ocular VEMP latencies shows a poor test re-test reliability. The individual VEMP results, however, remained within normal limits despite the test re-test variability.