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Fourth International Symposium and Workshops: Objective Measures in Cochlear Implants

Medical University of Hannover

01.06. bis 04.06.2005, Hannover

Objective measures and amplification outcome in subjects with Connexin 26 gene mutations (Cochlear implant and hearing aid users)

Meeting Abstract

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  • corresponding author N. Kamal - Ainshams University, Cairo
  • N. Said - Ainshams University, Cairo
  • D. Hassan - Ainshams University, Cairo

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. Doc05omci055

The electronic version of this article is the complete one and can be found online at:

Published: May 31, 2005

© 2005 Kamal et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




Objective: To study the performance of Connexin 26 gene mutations -GJB2 related deafness -with amplification (cochlear implant "CI" and hearing aid users).

Materials and Methods

It comprised two sub-groups. Group "A": 18 children proved to have positive GJB2 mutations. They had severe to profound SNHL. 14 were regular hearing aid users while 4 were implanted with Nucleus CI24. Group "B": 19 children with definite heredofamilial etiology not related to GJB2 gene mutation. Four of them were implanted with Nucleus CI24. All of them were subjected to aided and unaided threshold testing for pure tone and Arabic speech perception test using either digital hearing aids or cochlear implants Nucleus CI24. In addition, electrophysiological tests were applied on the cochlear implant children in the form of Neural Response Telemetry "NRT" and Electrical Auditory Brain stem Response "EABR".


Children with GJB2 related deafness had higher pure tone thresholds even while using hearing aids. They scored also poorer aided speech perception scores. CI improved significantly the aided thresholds and the speech performance but unexpectedly did not reach the level achieved by the CI children with definite heredofamilial etiology not related to GJB2 gene mutation.NRT revealed lower thresholds and better resolution in CI users with GJB2 related deafness. On the other hand, EABR test results showed no obvious difference.


The authors speculated that the dendrite extensions are relatively still intact despite the extensive destruction of the hair cells structure known in GJB2 related deafness with the likelihood of damage at other sites of auditory pathway .Cochlear implantation is the most suitable means for amplification and rehabilitation for children with GJB2 related deafness that should be started as early as possible.