Appraisal of the signal-to-noise-ratio of uni- and bipolar recordings of ocular vestibular evoked myogenic potentials

Article type: Research Article

Authors: Ertl, M.^{a; b; *} | Kirsch, V.^{a; b; c} | Gerb, J.^a | Boegle, R.^{a; c} | Krafczyk, S.^{a; c} | Dieterich, M.^{a; b; c; d}

Affiliations: [a] Department of Neurology, Ludwig-Maximilians University, Munich, Germany | [b] Graduate School of Systemic Neuroscience, Ludwig-Maximilians University, Munich, Germany | [c] German Center for Vertigo and Balance Disorders (IFB^LMU), Ludwig-Maximilians University, Munich, Germany | [d] Munich Cluster for Systems Neurology (SyNergy), Munich, Germany

Correspondence: [*] Corresponding author: Matthias Ertl, Klinikum Großhadern der Universität München, Feodor-Lynen-Straße 19, 81377 München, Germany. Tel.: +49 089/7095 7825; Fax: +49 089/7095 4801; E-mail: matthias.ertl@med.uni-muenchen.de.

Abstract: Ocular vestibular evoked myogenic potentials (oVEMPs) are a non-invasive method to investigate otolith function mediated via the superior vestibular nerve. However, the herein used recordings and protocols may alter within different studies. In particular the diverging use of electrode configuration regarding polarity or even electrode position varies across studies. Therefore, a systematic analysis and appraisal of the different electrode configuration seems mandatory. In this study we compared the quality of uni- and bipolar recordings based on the signal to noise ratio (SNR). We recoded oVEMPs using a uni- and bipolar electrode configuration simultaneously and compared the recorded amplitudes and latencies and calculated the SNR. The amplitudes recorded by the unipolar configurations were significantly (p < 0.01) increased compared to the bipolar configuration. However, the SNR of the bipolar setup was significantly better (p < 0.05) when compared to the unipolar setup. Additionally, we estimated a transfer function that enabled a comparison of uni- and bipolar recordings. To conclude, the variety of setups used for oVEMP recording hinder a comparison of results and unipolar electrode configurations have clear disadvantages.

Keywords: Ocular vestibular evoked myogenic potential, oVEMP, transfer function, asymmetry ratio

DOI: 10.3233/VES-150545

Journal: Journal of Vestibular Research, vol. 25, no. 1, pp. 9-14, 2015