gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Mismatch of fMRI and intraoperative stimulation of the motor cortex (MEP) – a case report

Mismatch von fMRT und intraoperativer Motorkortexstimulation (MEP) – case report

Meeting Abstract

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  • corresponding author S. Schiffler - Neurochirurgische Klinik, Katharinenhospital, Klinikum Stuttgart
  • N. Hopf - Neurochirurgische Klinik, Katharinenhospital, Klinikum Stuttgart

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocP 04.55

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

Published: May 8, 2006

© 2006 Schiffler 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.



Objective: Presently, the most reliable method for intraoperative localization of the motor cortex is thought to be the direct stimulation (MEP). Preoperative imaging, such as functional MRI (fMRI) and diffusion tensor imaging (DTI) with fiber tracking are developed to substitute this time consuming and invasive method. However, reliable data on the correlation of these different techniques are still pending. We present a case of obvious mismatch between fMRI and intraoperative MEP.

Methods: A 37-year-old male with a progressive oligoastrocytoma (WHO grade II) in the right motor cortex region was investigated preoperatively with conventional MRI, fMRI, and DTI for fiber tracking. Data of the conventional MRI and DTI were used for neuronavigation with visualization of the corticospinal tracts. Intraoperatively, the motor cortex was identified by direct MEP. Resection of the tumor was performed with the help of intraoperative ultrasound.

Results: Preoperative fMRI data based on finger tapping localized the motor cortex posterior to the tumor, whereas fiber tracking data suggested it anterior to the tumor. Intraoperative MEP clearly revealed the motor cortex anterior to the tumor, correlating with the fiber tracking data. The tumor was resected completely under control of intraoperative ultrasound and sparing of the corticospinal tracts as visualized by the fiber tracking data. Postoperatively, the patient showed no motor deficit.

Conclusions: MEP is still the only method to reliably detect the motor cortex. Preoperative fMRI as well as DTI with fiber tracking seem to be helpful in selected cases. This case of obvious mismatch demonstrates, that reliability and limits of both methods need to be further evaluated in clinical trials.