Value of Vestibular Evoked Myogenic Potentials in IdentifyingDifferent Forms of Endolymphatic Hydrops: A Cross-Sectional Study

Abstract

AbstractBackground: Meniere’s disease is idiopathic Endolym-phatic Hydrops. Vestibular evoked myogenic potential is aneurophysiological assessment technique that is used determinethe function of the otolith organs of the inner ear. Usingvestibular evoked myogenic potential tests may identify thedifferent forms of the Endolymphatic Hydrops.Aim of Study: The aim of this study is to explore the roleof vestibular evoked myogenic potentials (VEMP) in diagnosis of the different kinds of Meniere’s disease (MD).Patients and Methods: Three groups of patients that wereselected according to the diagnosis, definitive MD (DMD),cochlear MD (CMD) and recurrent vestibulopathy (RV) group.Basic audiological evaluation was carried out. It includedPure tone audiometry, speech audiometry, acoustic immittancetesting and electrocochleography. Otolith function assessmentwas carried out in the form of:Cervical VEMP (c-VEMP) and ocular VEMP (o-VEMP).Vestibular assessment was carried out: The test protocolincluded spontaneous nystagmus, gaze test, oculomotor tests,positioning test (Dixhallpike), positional nystagmus, andcaloric testing. The three groups were compared for all demo-graphic variables as well as clinic-pathologic variables, andtests results.Results: The overall sample was 40 cases; 13 with DMD,10 with CMD and 17 with RV. The mean age is variablebetween groups (p-value <0.001) with the highest in the DMDgroup (38.3±7.4 years) and the lowest in the CMD group (25.2±4.6 years). The male to female ratio is variable betweengroups of the study (p-value=0.03) with the highest ratio 9:4in the DMD group. There was a significant difference betweengroups (p < 0.001) regarding dizziness. Asymmetric responseof c-VEMP was seen in nine (9/13) (69.2%) of DMD cases, (14/17) (82.4%) of RV cases and only in three (3/10) (30%)of CMD cases, (p-value <0.001). Low amplitude of o-VEMPwas seen in (11/13) (84.6%) of DMD cases, (9/10) (90%) ofCMD cases, (15/17) (88.2%) of RV cases, and only in two (25%) of normal cases, (p-value=0.002). A significant differ-ence 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 strongcorrelation between age and EchoG sp/ap ratio left ear, o-VEMP IAD and o-VEMP left ear n1. In addition, there is asignificant positive weak correlation between duration andEchoG sp/ap ratio left ear and c-VEMP left ear n1.Conclusion: Asymmetric response of c-VEMP can beused as a diagnostic tool to differentiate different kinds ofMD: DMD, RV and CMD.