gms | German Medical Science

64th Annual Meeting of the German Society of Neurosurgery (DGNC)

German Society of Neurosurgery (DGNC)

26 - 29 May 2013, Düsseldorf

Optimized preoperative mapping of language regions by navigated transcranial magnetic stimulation: a multicentric comparison study in awake surgery

Meeting Abstract

  • Sandro M. Krieg - Neurochirurgische Klinik, Klinikum rechts der Isar, Technische Universität München, Germany
  • Phiroz E. Tarapore - Department of Neurological Surgery, University of California, San Francisco, CA, USA
  • Thomas Picht - Neurochirurgische Klinik, Charité - Universitätsmedizin, Berlin, Germany
  • Peter Vajkoczy - Neurochirurgische Klinik, Charité - Universitätsmedizin, Berlin, Germany
  • Bernhard Meyer - Neurochirurgische Klinik, Klinikum rechts der Isar, Technische Universität München, Germany
  • Mitchel S. Berger - Department of Neurological Surgery, University of California, San Francisco, CA, USA
  • Florian Ringel - Neurochirurgische Klinik, Klinikum rechts der Isar, Technische Universität München, Germany

Deutsche Gesellschaft für Neurochirurgie. 64. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Düsseldorf, 26.-29.05.2013. Düsseldorf: German Medical Science GMS Publishing House; 2013. DocDI.05.11

doi: 10.3205/13dgnc204, urn:nbn:de:0183-13dgnc2044

Published: May 21, 2013

© 2013 Krieg 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

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Objective: Navigated transcranial magnetic stimulation (nTMS) in presurgical brain mapping showed a high correlation to direct cortical stimulation (DCS) within the primary motor cortex. Moreover, repetitive nTMS (rTMS) combined with a picture naming task can identify speech-sensitive cortical areas.

Method: Thirty-two patients with left-sided perisylvian tumors were examined by rTMS prior to awake surgery. Twenty patients underwent rTMS 300 ms after picture presentation whereas another 12 patients received rTMS pulses with no time delay. These rTMS results were then evaluated for correlation with intraoperative DCS as gold standard.

Results: In and adjacent to Broca's area, there were no differences in sensitivity (0 ms: 100%, 300 ms: 100%), negative predictive value (NPV) (0 ms: 100%, 300 ms: 100%), and positive predictive value (PPV) (0 ms: 55%, 300 ms: 54%) for both protocols compared to DCS. Yet, specificity differed significantly (0 ms: 67%, 300 ms: 28%). In contrast, functional inhibition by early pulse onset showed favorable results in supramarginal gyrus, angular gyrus and dorsal superior temporal gyrus. While sensitivity was comparable (0 ms: 75%, 300 ms: 70%), NPV (0 ms: 92%, 300 ms: 57%), PPV (0 ms: 75%, 300 ms: 30%) and specificity differed significantly (0 ms: 92%, 300 ms: 20%).

Conclusions: Repetitive nTMS correlates well with DCS especially in the Broca region, particularly with regard to negatively mapped areas. However, an immediate application of rTMS pulses shows a more intense effect on posterior language regions. Thus, the immediate rTMS onset has to be favored in the future. Moreover, with this study we are able to provide evidence for the first time that results on language networks obtained by TMS are highly comparable and correlated with the gold standard DCS. By establishing these ties, the results of this study are unique in the literature up to now.