gms | German Medical Science

Fourth International Symposium and Workshops: Objective Measures in Cochlear Implants

Medical University of Hannover

01.06. bis 04.06.2005, Hannover

Exploration of electrode position to optimise the signal-to-noise ratio of the Auditory Steady State Response in infants

Meeting Abstract

Suche in Medline nach

  • corresponding author C. van der Reijden - Department of Otorhinolaryngology, University Medical Centre Nijmegen, the Netherlands P.O. Box 9101, 6500 HB Nijmegen, the Netherlands
  • L.H.M. Mens - Department of Otorhinolaryngology, University Medical Centre Nijmegen, the Netherlands
  • A.F.M. Snik - Department of Otorhinolaryngology, University Medical Centre Nijmegen, the Netherlands

Medical University of Hannover, Department of Otolaryngology. Fourth International Symposium and Workshops: Objective Measures in Cochlear Implants. Hannover, 01.-04.06.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05omci092

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/omci2005/05omci092.shtml

Veröffentlicht: 31. Mai 2005

© 2005 van der Reijden et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Introduction

To identify EEG derivations that yield high signal to noise ratios of the Auditory Steady State Response (ASSR) in infants aged 0 to 5 months.

Materials and Methods

The ASSR was recorded simultaneously from ten EEG derivations in a monopolar montage in 20 sleeping infants. Stimuli were tones of 0.5 or 2 kHz which were 100% amplitude modulated (AM) and 20% frequency modulated, presented at 65 dB SPL for 4.4 minutes in either the right or the left ear. An AM of 90 Hz (left ear) or 94 Hz (right ear) was used. All 45 bipolar derivations were calculated from the 10 measured monopolar ones mounting up to 55 EEG derivations. EEG derivations were selected in the preferred set if they had the largest SNRs within subjects and if they were obtained significantly more frequently across subjects than was expected by chance (Monte Carlo simulation and Wilcoxon signed ranks test).

Results

The preferred set of derivations consisted of the left and right mastoid with Cz as common reference. This set improved SNRs compared to each of several conventional EEG derivations between 0-69% (500 Hz, left ear), 0-132% (500 Hz, right ear), 0-193% (2 kHz, left ear) and 0-105% (2kHz, right ear). In contrast to results reported earlier for adults, high SNRs were not found at the inion-Cz derivation in these infants.

Conclusions

High SNRs were obtained in infants aged younger than six months if the ASSR was recorded from the mastoids ipsilateral to the ear of stimulation referenced to Cz.