gms | German Medical Science

63rd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Japanese Neurosurgical Society (JNS)

German Society of Neurosurgery (DGNC)

13 - 16 June 2012, Leipzig

Differences and supplemental use of transtympanic electrocochleography and auditory brainstem response audiometry for intraoperative neuromonitoring

Meeting Abstract

  • S.M. Krieg - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München
  • L. Kempf - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München
  • D. Dröse - Klinik für Anaesthesiologie, Klinikum rechts der Isar, Technische Universität München
  • J. Lehmberg - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS). Leipzig, 13.-16.06.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. DocFR.05.02

DOI: 10.3205/12dgnc195, URN: urn:nbn:de:0183-12dgnc1950

Published: June 4, 2012

© 2012 Krieg et al.
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Outline

Text

Objective: Resection of lesions within the cerebellopontine angle is widely performed using auditory brainstem response audiometry (ABR) for intraoperative neuromonitoring (IOM). Detection of those potentials via transtympanic electrocochleography (ECochG) is also routinely used but particularly for ear and cochlear surgery. Thus, this study evaluates the value of the combined use and differences between both modalities concerning pre- and postoperative hearing impairment.

Methods: Between 2006 and 2011 we performed 125 consecutive surgeries within the cerebellopontine angle under IOM by ABR and ECochG. The monitoring data were reviewed and related to pre- and postoperative hearing deficit.

Results: MEP monitoring was successful in 114 cases (91.2%). Postoperatively, 42.0% of patients showed any degree of new hearing deficit while 3.7% even improved. We recognized a higher variability and oscillation of EChoG potentials. Moreover, amplitudes of EChochG monitoring were significantly higher (0.18 ± 0.04 µV) compared to ABR potentials (0.08 ± 0.006 µV). (p < 0.05).

Conclusions: ABR and ECochG monitoring of the hearing system show significant differences. However, for optimal monitoring it seems feasible to combine the more stable ABR with the better detectable ECochG.