J Am Acad Audiol 2020; 31(01): 069-075
DOI: 10.3766/jaaa.18077
Articles
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

When Can Stable AutoNRT Thresholds be Expected? A Clinical Implication When Fitting Young Children

Andreas Björsne
*   Unit of Audiology, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
†   Hearing Organization, Habilitation & Health, Region Västra Götaland, Sweden
,
Lennart Magnusson
*   Unit of Audiology, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
‡   Department of ENT, Sahlgrenska University Hospital, Gothenburg, Sweden
› Author Affiliations
Further Information

Publication History

15 October 2018

Publication Date:
25 May 2020 (online)

Abstract

Background:

Objective measurements are important for programming cochlear implants in young children and other individuals who cannot participate in behavioral measurements. AutoNRT, the automatic method used to record responses from the auditory nerve in the Cochlear Ltd., implant system, is often used as a basis for estimating the threshold level and comfort level (C-level) for these patients. However, it has not been sufficiently established if AutoNRT measurements remain consistent over time.

Purpose:

This study aimed to determine if/when AutoNRT thresholds stabilize.

Research Design:

The study design was a longitudinal prospective study.

Study Sample:

AutoNRT thresholds were obtained from 52 young children and 80 adults. All subjects received the same implant (CI24RE Contour Advance).

Data Collection and Analysis:

AutoNRT thresholds were measured on all intracochlear electrodes during the surgery and at the initial activation. During the following year, children were measured at 1, 3, 6, and 12 months, and adults were measured at 6 and 12 months. The results were analyzed based on mean values, correlation, and absolute mean differences.

Results:

There were large variations for all electrodes between the intraoperative and postoperative AutoNRT thresholds of both children and adults. For children, the thresholds were considered to be stable from 1 month. The correlations obtained between the last two measurements, 6 and 12 months, for both children and adults were generally high for all electrodes.

Conclusion:

The present results demonstrate the importance of repeating the AutoNRT measurement postoperatively, at about 1 month after initial activation, to obtain reliable and stable thresholds for estimating the T- and C-level profiles.

This research was partly supported by a grant from Cochlear Nordic AB, Sweden.


Parts of the results in this study were presented at the World Congress of Audiology, Cape Town, South Africa, October 28–31, 2018.


Supplementary Material

 
  • REFERENCES

  • Botros A, Psarros C. 2010; Neural response telemetry reconsidered: I. The relevance of ECAP threshold profiles and scaled profiles to cochlear implant fitting. Ear Hear 31: 367-379
  • Botros A, Van Dijk B, Killian M. 2007; Autonrt: an automated system that measures ECAP thresholds with the nucleus freedom cochlear implant via machine intelligence. Artif Intell Med 40: 15-28
  • Brown CJ, Abbas PJ, Etler CP, O’brien S, Oleson JJ. 2010; Effects of long-term use of a cochlear implant on the electrically evoked compound action potential. J Am Acad Audiol 21: 5-15
  • Brown CJ, Hughes ML, Luk B, Abbas PJ, Wolaver A, Gervais J. 2000; The relationship between eap and eabr thresholds and levels used to program the nucleus 24 speech processor: data from adults. Ear Hear 21: 151-163
  • Cafarelli Dees D, Dillier N, Lai WK, Von Wallenberg E, Van Dijk B, Akdas F, Aksit M, Batman C, Beynon A, Burdo S, Chanal JM, Collet L, Conway M, Coudert C, Craddock L, Cullington H, Deggouj N, Fraysse B, Grabel S, Kiefer J, Kiss JG, Lenarz T, Mair A, Maune S, Muller-Deile J, Piron JP, Razza S, Tasche C, Thai-Van H, Toth F, Truy E, Uziel A, Smoorenburg GF. 2005; Normative findings of electrically evoked compound action potential measurements using the neural response telemetry of the nucleus CI24M cochlear implant system. Audiol Neurotol 10: 105-116
  • Gärtner L, Lenarz T, Joseph G, Büchner A. 2010; Clinical use of a system for the automated recording and analysis of electrically evoked compound action potentials (ECAPs) in cochlear implant patients. Acta Oto-Laryngol 130: 724-732
  • Gordin A, Papsin B, James A, Gordon K. 2009; Evolution of cochlear implant arrays result in changes in behavioral and physiological responses in children. Otol Neurotol 30: 908-915
  • Hughes ML, Vander Werff KR, Brown CJ, Abbas PJ, Kelsay DM, Teagle HF, Lowder MW. 2001; A longitudinal study of electrode impedance, the electrically evoked compound action potential, and behavioral measures in nucleus 24 cochlear implant users. Ear Hear 22: 471-486
  • Lai WK, Aksit M, Akdas F, Dillier N. 2004; Longitudinal behaviour of neural response telemetry (NRT) data and clinical implications. Int J Audiol 43: 252-263
  • Lai WK, Dillier N, Weber BP, Lenarz T, Battmer R, Gantz B, Brown C, Cohen N, Waltzman S, Skinner M, Holden L, Cowan R, Busby P, Killian M. 2009; TNRT profiles with the nucleus research platform 8 system. Int J Audiol 48: 645-654
  • Mckay CM, Fewster L, Dawson P. 2005; A different approach to using neural response telemetry for automated cochlear implant processor programming. Ear Hear 26: 38s-44s
  • Smoorenburg GF, Willeboer C, Van Dijk JE. 2002; Speech perception in nucleus CI24M cochlear implant users with processor settings based on electrically evoked compound action potential thresholds. Audiol Neurotol 7: 335-347
  • Spivak L, Auerbach C, Vambutas A, Geshkovich S, Wexler L, Popecki B. 2011; Electrical compound action potentials recorded with automated neural response telemetry: threshold changes as a function of time and electrode position. Ear Hear 32: 104-113
  • Tavartkiladze G, Bakhshinyan V, Irwin C. 2015; Evaluation of new technology for intraoperative evoked compound action potential threshold measurements. Int J Audiol 54: 347-352
  • Van Dijk B, Botros AM, Battmer RD, Begall K, Dillier N, Hey M, Lai WK, Lenarz T, Laszig R, Morsnowski A, Muller-Deile J, Psarros C, Shallop J, Weber B, Wesarg T, Zarowski A, Offeciers E. 2007; Clinical results of autonrt, a completely automatic ECAP recording system for cochlear implants. Ear Hear 28: 558-570