Clinical correlates of different forms of endolymphatic hydrops

Abstract

Abstract Background The aim of this study is to explore the different kinds of endolymphatic hydrops and the sensitivity of vestibular evoked myogenic potentials (VEMP) and electrocochleography in their diagnosis. Three groups of patients were selected according to the diagnosis, definitive MD (DMD), cochlear MD (CMD), and recurrent vestibulopathy (RV) groups. A basic audiological evaluation was carried out. It included pure tone audiometry, speech audiometry, acoustic immittancemetry testing and electrocochleography, cervical VEMP (c-VEMP), and ocular VEMP (o-VEMP). Results The overall sample was 40 cases, 13 with DMD, 10 with CMD, and 17 with RV. The mean age is variable between groups (p-value < 0.001) with the highest in the DMD group (38.3 ± 7.4 years) and the lowest in the CMD group (25.2 ± 4.6 years). The male to female ratio is variable between groups of the study (p-value = 0.03) with the highest ratio 9:4 in the DMD group. There was a significant difference between groups (p < 0.001) regarding dizziness. Asymmetric response of c-VEMP was seen in nine (69.2%) of DMD cases, in 14 (82.4%) of RV cases, and only in three (30%) of CMD cases (p-value < 0.001). Low amplitude of o-VEMP was seen in 11 (84.6%) of DMD cases, 9 (90%) of CMD cases, 15 (88.2%) of RV cases, and only two (25%) of normal cases (p-value = 0.002). A significant difference was found between definitive and cochlear Meniere’s as regards o-VEMP inter-aural amplitude difference (IAD) (p-value = 0.032) only. There was a significant positive strong correlation between age and EcochG SP/AP ratio left ear, o-VEMP IAD, and o-VEMP left ear n1. In addition, there is a significant positive weak correlation between duration and EcochG SP/AP ratio left ear and c-VEMP left ear n1. Conclusions Asymmetric response of c-VEMP can be used as a diagnostic tool to differentiate different kinds of MD: DMD, RV, and CMD.