gms | German Medical Science

56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
3èmes journées françaises de Neurochirurgie (SFNC)

Deutsche Gesellschaft für Neurochirurgie e. V.
Société Française de Neurochirurgie

07. bis 11.05.2005, Strasbourg

Extraoperative stimulation mapping of higher cortical functions via chronically implanted grid electrodes prior to surgery for gliomas in eloquent cortex

Extraoperative Funktionslokalisation durch die Stimulation von Gridelektroden vor der Gliomresektion in eloquentem Cortex

Meeting Abstract

  • corresponding author T. Kral - Klinik für Neurochirurgie, Universitätsklinikum Bonn
  • M. Kurthen - Klinik für Epileptologie, Universitätsklinikum Bonn
  • J. Schramm - Klinik für Neurochirurgie, Universitätsklinikum Bonn
  • H. Urbach - Klinik für Radiologie, Universitätsklinikum Bonn
  • B. Meyer - Klinik für Neurochirurgie, Universitätsklinikum Bonn

Deutsche Gesellschaft für Neurochirurgie. Société Française de Neurochirurgie. 56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3èmes journées françaises de Neurochirurgie (SFNC). Strasbourg, 07.-11.05.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc09.05.-17.07

The electronic version of this article is the complete one and can be found online at:

Published: May 4, 2005

© 2005 Kral et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




Because indications for surgery of gliomas in eloquent areas depend on a careful analysis of the risk/benefit ratio, we evaluated in this retrospective study whether preoperative mapping of higher-level (not sensory-motor) functions with subdural grid electrodes can help to maximize resection in functional areas and avoid permanent injury.


14 of 16 patients (female: n=7, male: n=9) with a mean age of 38 (range: 17 – 59 years) had a history of seizures and 2 of pharmacoresistent epilepsy. On presurgical MRI all tumours were located in the dominant hemisphere in or with contact to the following eloquent areas: F3 gyrus/Broca area (N=11), parietal lobe (N=4) and temporodorsal/Wernicke area (N=4). Additionally, a frontodorsal localization in/near the central sulcus was seen in 11 patients. To a) preoperatively define and b) intraoperative tailor the extent of resection, all patients had a presurgical grid implantation for functional brain mapping.


No permanent neurological deficit or death was observed after grid implantation and resective surgery. One bone flap had to be explanted because of infection. On postoperative MRI the resection was complete in 38% (N=6), between 80% and 100% in 19% (N=3) and between 50% and 80% in 31% (N=5). In 2 patients only biopsies were taken according to the results of mapping. All patients with high-grade gliomas (N=14) had adjuvant treatment with radiation and chemotherapy. After a mean follow-up of 20.4 months no tumour relapse or growth was seen in all resection cases.


Preoperative grid mapping is a safe and precise instrument to evaluate language and/or associated left perisylvian cognitive functions in patients with gliomas. It can be considered a valid alternative to awake craniotomy to maximize safe resection.