gms | German Medical Science

61st Annual Meeting of the German Society of Neurosurgery (DGNC) as part of the Neurowoche 2010
Joint Meeting with the Brazilian Society of Neurosurgery on the 20 September 2010

German Society of Neurosurgery (DGNC)

21 - 25 September 2010, Mannheim

Auditory brainstem implants in neurofibromatosis type 2: How to optimize results

Meeting Abstract

  • Cordula Matthies - Neurochirurgische Klinik und Poliklinik, Julius-Maximilians-Universität Würzburg, Deutschland
  • Stefan Brill - Klinik für HNO-Heilkunde, Julius-Maximilians-Universität Würzburg, Deutschland
  • Csanad Varallyay - Abteilung für Neuroradiologie, Julius-Maximilians-Universität Würzburg, Deutschland
  • Laszlo Solymosi - Abteilung für Neuroradiologie, Julius-Maximilians-Universität Würzburg, Deutschland
  • Ralf-Ingo Ernestus - Neurochirurgische Klinik und Poliklinik, Julius-Maximilians-Universität Würzburg, Deutschland
  • Joachim Müller - Klinik für HNO-Heilkunde, Julius-Maximilians-Universität Würzburg, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 61. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC) im Rahmen der Neurowoche 2010. Mannheim, 21.-25.09.2010. Düsseldorf: German Medical Science GMS Publishing House; 2010. DocV1669

DOI: 10.3205/10dgnc142, URN: urn:nbn:de:0183-10dgnc1426

Published: September 16, 2010

© 2010 Matthies et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Objective: Auditory brainstem implants (ABI) provide a realistic chance for some hearing rehabilitation in patients with neurofibromatosis type 2. In view of recent technological developments and discussion of ideal site of stimulation, the current prospective study was undertaken to optimize clinical outcome and analyze advantageous as well as critical factors in this respect.

Methods: 18 patients with Neurofibromatosis Type 2 were the focus of this analysis with 19 ABI operations being performed under multi-modality neuro-monitoring. Functional outcome was evaluated at 3 to 6 months intervals by monosyllabic word recognition at audiologic and audio-visual mode (MTPa, MTPav) and by open set speech recognition in the Hochmair sentence test (HSM). Factors investigated for their impact on functional outcome were gender, age, duration of deafness, tumour extension and volume, tumorous nerve changes, related paresis and brainstem deformation.

Results: Functional results were available for 16 ABI implantations as two patients had no hearing sensation and one died due to other tumour progression. Four patients achieved very good open speech understanding (HSM 60% to 99%), 3 patients had some open set understanding (10% to 28%), 6 patients had very useful understanding with lip-reading (MTPav 100%). No auditory perception occurred after radiation and in an anatomic variant. Correlation analysis showed that neither patients’ ages nor tumour volume exerted any negative influences. A significant impact on hearing quality was identified for duration of deafness up to one year and for the number of active electrodes where less than 6 electrodes were never associated with open set audiologic understanding.

Conclusions: Different to other reports, this study did not identify severe brainstem compression as a negative predictor, but demonstrated that also patients with previous bilateral severe brainstem compression and large tumor volumes do experience very favourable auditory results. Factors such as functional intra-operative implant placing and short periods of deafness are more relevant than tumour size.