gms | German Medical Science

60th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Benelux countries and Bulgaria

German Society of Neurosurgery (DGNC)

24 - 27 May 2009, Münster

New aspects in presurgical mapping of language areas and connecting fiber tracts

Meeting Abstract

  • P. Grummich - Neurochirurgische Klinik, Universität Erlangen-Nürnberg
  • M. Buchfelder - Neurochirurgische Klinik, Universität Erlangen-Nürnberg
  • O. Ganslandt - Neurochirurgische Klinik, Universität Erlangen-Nürnberg

Deutsche Gesellschaft für Neurochirurgie. 60. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit den Benelux-Ländern und Bulgarien. Münster, 24.-27.05.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. DocMO.06-03

doi: 10.3205/09dgnc029, urn:nbn:de:0183-09dgnc0299

Published: May 20, 2009

© 2009 Grummich et al.
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Outline

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Objective: For planning and intraoperative guidance in case of surgery close to eloquent areas, it is useful to have individual localizations of the affected brain functions to avoid neurological impairment.First, particularly individual data are necessary because of individual differences in structure. Secondly the gyrus may be shifted by the lesion and difficult to identify. Thirdly, functions may have been transferred into new brain areas because of lesion influences (plasticity). Finally it is desirable to evaluate the hemispheric dominance of language function.

Methods: MEG measurements were carried out with a 2x37 channel biomagnetic system (Magnes II, 4-D Neuroimaging). Localization was performed by 1-dipole fit or beamformer algorithm. For fMRI we used a 1.5T MR scanner with echo planar imaging (Sonata, Siemens Medical Solutions) and a block paradigm with 180 measurements in 6 blocks (rest alternating with activation, 25 slices, 3mm thickness & resolution TR=2470, TE=60). We used visual stimulation with words and pictures.

Measurement position was identical for all paradigms of a measurement modality. Diffusion tensor imaging was performed with a resolution of 1.9mm.

Results: We obtained localizations of frontal and temporal language areas in all patients. Wernicke activity we found in the posterior supratemporal sulcus. In the supramarginal gyrus, an area for phonemic processing was localized. In the posterior inferior frontal cortex we found 3 language subsystems. By diffusion tensor imaging we received connections of the frontal language areas with the temporal areas: the inferior fronto-occipital fasciculus and the arcuate fasciculus. For the first time, we describe a fiber tract connecting the area for reading in the fusiform gyrus with the Wernicke area. We performed functional localization of language areas in 226 patients. Of these 144 patients were operated on. Following surgery, 27 patients experienced slight transient language disorders. One suffered from phonemic paraphasia; the others had naming disorders. All disturbances resolved within 2 months after surgery. Two patients, who had had preoperative language disorders had better performance following surgery than before (one an articulary disorder, the other a naming disorder).

Conclusions: Navigation which uses markers of functional areas and the fiber connections of these areas are a reliable tool for intraoperative guidance. It increases the amount of radical surgery and decreases morbidity.