Comparing vestibular evoked myogenic potential response parameters in young Black African and Caucasian adults

Abstract

Objective: The aim of this study was to compare cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) in young gender- and age-matched black African and Caucasian male and female adults. Design: A quasi-experimental between-subjects research design was utilised. This study was comparative in nature, thus data was collected in a cross-sectional manner from two age- and gender-matched racial groups, namely black African and Caucasian, and compared. Furthermore, interactions of gender and race were also examined in this research study. Methods: Sixty healthy age- and gender-matched participants (30 black African, 30 Caucasian) between the ages of 18 25 years participated in this study. Fifteen males and fifteen females, within one year of the age of their racial participant counterparts, were included in each racial group. Latencies, peak-to-peak amplitudes and asymmetry ratios were analysed for both groups in these tests. Furthermore, auditory brainstem response (ABR) and electromyography (EMG) testing were conducted to investigate whether possible racial differences in VEMP tests could be attributed to differences in neural or muscular function. Results: Black African participants demonstrated significantly shorter latencies of the n23 component of the cVEMP and the p15 component of the oVEMP, as well as larger peakto- peak amplitude of the oVEMP response. Highly significant differences were found in all EMG measurements between the two racial groups, suggesting that these racial VEMP differences are primarily based on differences in muscular function between black Africans and Caucasians. Significant gender differences were observed in all tests conducted, with females predominantly displaying shorter latencies, while males had larger amplitudes. Conclusions: Young black African adults demonstrated significant differences in both cVEMP and oVEMP responses, namely shorter latencies and larger amplitudes, in comparison to young Caucasian adults. Correlations with differences in EMG measurements suggest that these differences are primarily due to differences in muscular function as opposed to neural function. Future research is required to confirm and expand on these findings.