gms | German Medical Science

55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

25. bis 28.04.2004, Köln

Multi-modality monitoring of the auditory pathway in cerebellopontine angle (CPA) surgery

Multi-modales Monitoring der Hörbahn in der Kleinhirnbrückenwinkel-Chirurgie

Meeting Abstract

Suche in Medline nach

  • corresponding author Cordula Matthies - Neurochirurgische Klinik, Klinikum Hannover Nordstadt, Lehrkrankenhaus der Med. Hochschule Hannover, Hannover
  • S. Mirzai - Neurochirurgische Klinik, Klinikum Hannover Nordstadt, Lehrkrankenhaus der Med. Hochschule Hannover, Hannover
  • P. Vorkapic - Neurochirurgische Klinik, Klinikum Hannover Nordstadt, Lehrkrankenhaus der Med. Hochschule Hannover, Hannover
  • M. Samii - International Neuroscience Institute, Hannover

Deutsche Gesellschaft für Neurochirurgie. Ungarische Gesellschaft für Neurochirurgie. 55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie. Köln, 25.-28.04.2004. Düsseldorf, Köln: German Medical Science; 2004. DocMO.05.06

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2004/04dgnc0058.shtml

Veröffentlicht: 23. April 2004

© 2004 Matthies et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective

Multi-Modality monitoring of the auditory pathway in CPA surgery is intended to increase the safety and the speed of recordings. Hereby, the useful feedback to the surgeon may be improved and enable a modification of the microsurgical procedure in time.

Methods

Besides conventional ear to vertex recording of auditory evoked potentials by averaging 250 sweeps two further recording modalities are applied: A non-invasive electrocochleography is performed by placing a ball electrode in the external auditory canal onto the tympanon. A nearfield brainstem recording is performed by using a neurosurgical retractor with small tubes in the sides of the blade; through these tubes small ball electrodes are inserted with their cables and pushed through up to the retractor tip; when brain retraction is performed as usual, the electrodes become placed on the brainstem and in the vicinity of cranial nerves and nuclei.

Results

In 269 patients conventional AEP and non-invasive electrocochleography were applied, in 80 of these additional nearfield recording was performed. The sensitivity of EAC_ECoch and of Nearfield AEP was superior to conventional AEP, with regard to demonstrating relevant changes as well as to obtain responses of reduced number of active neurons. Hearing was preserved in 119 of the 269 cases. In 7 cases conventional AEP was false negative at the end of surgery while EAC-ECoch demonstrated contained function; the same was true for 2 cases with retained Nearfield AEP, but lost conventional AEP. The shape and size of the retractor blade is unchanged to the previous one. The small ball electrodes reach the brainstem or cranial nerves without occupying any further space and without the risk of dislocation. Near-field recording of evoked potentials is enabled at various sites, especially at the skull base or in deep-seated targets. Recording time is reduced to 2 to 5 seconds in view of the large amplitude of EAC_ECoch and Nearfield AEP.

Conclusions

The recording in the immediate vicinity of potential generators, for example the cochlear nucleus, provides large potentials and allows reliable monitoring information in very short periods.