Test-Retest Reliability of Vestibular Evoked Myogenic Potentials Parameters

Abstract

Vestibular evoked myogenic potentials (VEMPs) have been used to evaluate the functioning of the saccule and inferior vestibular nerve. However there are discrepancies in literature regarding the test-retest reliability of VEMPs. Hence the present study aimed at evaluating the test-retest reliability of VEMP parameters. In the present study, VEMPs were measured in 80 subjects with normal audio-vestibular system using AC- and BC- stimulation under rectified and unrectified conditions. The rectified VEMPs were recorded by using a visual monitoring device and the unrectified VEMPs were recorded by using a specially fabricated device at maximum intensities and threshold. Descriptive statistics was done to see the effects of stimulus level on VEMP parameters and Cronbach’s Alpha test was done to measure the test-retest reliability of VEMP. Results revealed an increasing trend for amplitudes with increase in stimulus levels in all conditions. Latency measures also showed a tendency to increase with intensity but were not statistically significant. The test-retest reliability of amplitudes was higher than the latency measures, AC was more reliable than BC, unrectified method had higher reliability than rectified, VEMP thresholds had comparable reliability across all conditions and the reliability of VEMP parameters at thresholds were generally poor.