Side-difference of vestibular evoked myogenic potentials in healthy subjects

Abstract

The aim of this study was to investigate the side-difference of vestibular evoked myogenic potentials (VEMPs) in relation to the provocation rates, latencies and amplitudes using binaural acoustic stimulation with bilateral recording. Fourteen healthy volunteers underwent a serial VEMP testings elicited binaurally by a sequence of alternating stimulus intensities, that is, 95–95 (right–left), 85–95, 95–85, and 85–85 dBHL tone burst, respectively. The provocation rates as well as the mean latencies of p13 and n23 for the VEMPs demonstrated no significant side-difference despite using 95–95, 85–95, 95–85 and 85–85 dBHL binaural acoustic stimulation. In contrast, nine (64%) of the 14 subjects showed side-difference of absolute p13–n23 amplitude, including right side dominant in five subjects, and left side dominant in four subjects. However, there was no significant side-difference in terms of relative amplitude despite using 95–95, 85–95, 95–85 and 85–85 dBHL binaural acoustic stimulation. Furthermore, the relative amplitude or interaural amplitude difference (IAD) ratios between those with and without side-difference of p13–n23 amplitude did not differ significantly. Hence, this study provides a potentially important method for adjusting the side difference of p13–n23 amplitudes by using a relative amplitude or IAD ratio adjustment. It also adds confidence to the successful use of binaural stimulation and recording of VEMPs under conditions of bilateral SCM muscular contractions.