Vestibular evoked myogenic potentials: Test-retest reliability and normative values obtained with a feedback method for the sternocleidomastoid muscle contraction

Article type: Research Article

Authors: Vanspauwen, R.^{a; *} | Wuyts, F.L.^{a; b} | Van de Heyning, P.H.^{a; c}

Affiliations: [a] Antwerp University Research Center for Equilibrium and Aerospace, Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, University of Antwerp, Antwerpen, Belgium | [b] Department of Biomedical Physics, University of Antwerp, Antwerpen, Belgium | [c] Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, University of Antwerp, Antwerpen, Belgium

Correspondence: [*] Corresponding author: Robby Vanspauwen, Antwerp University Research Center for Equilibrium and Aerospace, Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, University of Antwerp, Wilrijkstraat 10, 2650 Edegem, Antwerpen, Belgium. Tel.: +32 496 17 29 70; Fax: +32 3 821 44 51; E-mail: [email protected], [email protected]

Abstract: Objective:To determine normal limits and to analyse the test-retest reliability of the vestibular evoked myogenic potentials (VEMPs) parameters. Methods:The VEMP procedure was repeated on different test days to analyze test-retest differences. We calculated several reliability parameters: intraclass reliability coefficient (ICC), method error (ME), coefficient of variation of the method error (CVME), standard error of measurement (SEM) and minimal difference (MD) for test-retest measurements. Normal values for left-right differences, based on the interaural ratio (IAR), were determined. Results:For each VEMP parameter, the ICC values indicated excellent reliability, except for p13 and corrected amplitude (fair to good reliability). The CVME values were less than 7% for p13, n23, threshold, MRVfemales and MRVmales. For the parameters corrected amplitude and raw amplitude, the CVME values exceeded 15%. The 95% IAR prediction intervals (PIs) were also largest for the parameters raw amplitude and corrected amplitude. Conclusion:In order to evaluate a VEMP outcome in a patient, the VEMP parameters and IAR values can be compared with the 95% PI of the normal values. When successive measurements are performed within the same subjects, the minimal difference (MD) serves as a tool to decide whether these differences are clinically relevant or not.

Keywords: Contraction feedback method, vestibular evoked myogenic potential, saccule, test-retest reliability, normal values

DOI: 10.3233/VES-2009-0358

Journal: Journal of Vestibular Research, vol. 19, no. 3-4, pp. 127-135, 2009