gms | German Medical Science

65th Annual Meeting of the German Society of Neurosurgery (DGNC)

German Society of Neurosurgery (DGNC)

11 - 14 May 2014, Dresden

Restoration of hearing and speech perception by auditory brainstem implants in Neurofibromatosis type 2

Meeting Abstract

  • Cordula Matthies - Department of Neurosurgery, Julius-Maximilians-University Wuerzburg, Germany
  • Stefan Brill - Department of Otorhinolaryngology, Julius-Maximilians-University Wuerzburg
  • Laszlo Solymosi - Department of Neuroradiology, Julius-Maximilians-University Wuerzburg
  • Robert Mlynski - Department of Otorhinolaryngology, Julius-Maximilians-University Wuerzburg
  • Rudolf Hagen - Department of Otorhinolaryngology, Julius-Maximilians-University Wuerzburg
  • Wafaa Shehata-Dieler - Department of Otorhinolaryngology, Julius-Maximilians-University Wuerzburg

Deutsche Gesellschaft für Neurochirurgie. 65. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Dresden, 11.-14.05.2014. Düsseldorf: German Medical Science GMS Publishing House; 2014. DocDI.18.08

doi: 10.3205/14dgnc248, urn:nbn:de:0183-14dgnc2483

Published: May 13, 2014

© 2014 Matthies 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 improve auditory quality obtained by auditory brainstem implants (ABI) after loss of auditory nerves in Neurofibromatosis Type 2 (NF2).

Method: In a consecutive series of 27 patients with NF2, ABI implantation was performed under multimodality monitoring including mapping of the dorsal cochlear nucleus for electrical auditory brainstem responses (E-ABR). Clinical outcome was evaluated by standardized syllable and word tests and HSM (Hochmair-Schulz-Moser) sentence test at auditory-only and audio-visual conditions.

Results: Out of 27 implanted patients, there were 24 successful hearing restorations. Causes of failures were radiotherapy, anatomical variation or fast disease progress. In 17 patients open set speech perception could be documented at a range of 10% to 99% correct understanding of unknown text in auditory-only mode, mean 44%. Patients’ ages, tumor extensions and tumor volumes were no negative predictors. Positive predictors for open speech perception were a minimal number of 6 active electrodes and a maximal duration of deafness below 2 years (P<0.1).

Conclusions: This study documents that open set speech recognition in pure auditory mode is now a realistic goal by ABI. Pre-conditions to optimize results are exact ABI placing under electropyhsiological mapping, and adequate timing within the first two years of deafness.