gms | German Medical Science

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

German Society of Neurosurgery (DGNC)

26 - 29 May 2013, Düsseldorf

Comparison of nTMS with functional MRI of healthy subjects and patients with tumors in the language cortex

Meeting Abstract

  • Sandro M. Krieg - Neurochirurgische Klinik, Klinikum Rechts der Isar, Technische Universität München, München, Germany
  • Sebastian Ille - Neurochirurgische Klinik, Klinikum Rechts der Isar, Technische Universität München, München, Germany
  • Nico Sollmann - Neurochirurgische Klinik, Klinikum Rechts der Isar, Technische Universität München, München, Germany
  • Annette Förschler - Abteilung für Neuroradiologie, Klinikum Rechts der Isar, Technische Universität München, München, Germany
  • Bernhard Meyer - Neurochirurgische Klinik, Klinikum Rechts der Isar, Technische Universität München, München, Germany
  • Florian Ringel - Neurochirurgische Klinik, Klinikum Rechts der Isar, Technische Universität München, 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.05.10

doi: 10.3205/13dgnc203, urn:nbn:de:0183-13dgnc2030

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

Text

Objective: Navigated transcranial magnetic stimulation (nTMS) has already shown good results in comparison with direct cortical stimulation (DCS) of the motor cortex and speech-sensitive cortical regions. Nevertheless, functional MRI (fMRI) is still the gold standard in the clinical application of preoperative brain mapping.

Method: 20 patients with tumors in or close to speech-related cortical areas and 40 healthy subjects underwent language mapping, using navigated TMS and naming task functional MRI. We compared the results of both applications in each group. Here we described fMRI, the current gold standard in preoperative language mapping, as the “true” reference level in healthy subjects and DCS in patients.

Results: In the group “healthy subjects” the data of nTMS partially correlated with those of the functional MRI (PPV 92%). In contrast to this, fMRI showed less precision compared to DCS than nTMS especially when a tumor was located in the specific brain region.

Conclusions: Though we showed a fairly good correlation between nTMS and fMRI in healthy subjects with regard to the positive predictive values, they are not as good as those of the comparison with DCS. This tendency was confirmed by the analysis related to tumor localization. However, we have to keep in mind, that fMRI, i.e. its BOLD signal is frequently altered by the tumor and the local change of oxygenation. In case of a tumor in the anatomic Broca´s area or close to it, we could support former data, that nTMS is more valuable for preoperative language mapping than fMRI. The same applies to the dorsal language areas. In the context of preliminary findings in other studies, we advocate that nTMS is a more reliable method for non-invasive language mapping in selected cases.