gms | German Medical Science

66th Annual Meeting of the German Society of Neurosurgery (DGNC)
Friendship Meeting with the Italian Society of Neurosurgery (SINch)

German Society of Neurosurgery (DGNC)

7 - 10 June 2015, Karlsruhe

Article

Send article

Function-based DTI fibertracking of subcortical language tracts by rTMS

Meeting Abstract

Search Medline for

  • Chiara Negwer - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar der TU München; TUM-Neuroimaging Center
  • Sebastian Ille - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar der TU München; TUM-Neuroimaging Center
  • Nico Sollmann - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar der TU München; TUM-Neuroimaging Center
  • Theresa Hauck - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar der TU München; TUM-Neuroimaging Center
  • Bernhard Meyer - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar der TU München
  • Sandro M. Krieg - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar der TU München; TUM-Neuroimaging Center

Deutsche Gesellschaft für Neurochirurgie. 66. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Karlsruhe, 07.-10.06.2015. Düsseldorf: German Medical Science GMS Publishing House; 2015. DocP 115

doi: 10.3205/15dgnc513, urn:nbn:de:0183-15dgnc5134

Published: June 2, 2015

© 2015 Negwer et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.

Outline

Text

Objective: Diffusion tensor imaging fiber tracking (DTI FT) is commonly used in glioma surgery to visualize subcortical fiber tracts, especially within the neuronavigation. Yet, there is no standardized protocol at hand, which visualizes all language-involved fiber tracts reliably. Thus, this study investigates the value of using language-related cortical areas identified via repetitive navigated transcranial magnetic stimulation (rTMS) as seed regions for DTI-FT of subcortical language tracts.

Method: Language mapping by rTMS was performed in 38 patients (23 male, 15 female) with left-hemispheric perisylvian lesions from 05/2011 to 08/2014. Language positive stimulation spots were integrated in the tractography software (Brainlab, iPlanNet 3.0) as individual objects via DICOM standard and used as seed regions for DTI-FT. Deterministic tractography was then performed in each individual patient with 77 different settings of fiber lengths (40 - 100 mm) and fractional anisotropy (FA) (0.01 - 0.5) to detect language-relevant fiber tracts.

Results: By performing rTMS-based DTI-FT it was possible to identify language-related fiber tracts such as the corticonuclear tract, arcuate fascicle, uncinate fascicle, superior longitudinal fascicle, inferior longitudinal fascicle, arcuate fibers, commissural fibers, corticothalamic fibers, and frontooccipital fascicle in all 38 patients. In 33 patients every above-named fiber tract could be visualized (87%). A fiber length of 60 mm and an FA of 0.2 were proved optimal by requiring a mean of 58 ± 26 traced individual fibers for one visualized language tract.

Conclusions: With this study, we present the feasibility of rTMS-based DTI-FT for subcortical language tracts for the first time and show that it provides an easy and standardizable method for the visualization of every language tract in 87% of patients.