gms | German Medical Science

59th Annual Meeting of the German Society of Neurosurgery (DGNC)
3rd Joint Meeting with the Italian Neurosurgical Society (SINch)

German Society of Neurosurgery (DGNC)

1 - 4 June 2008, Würzburg

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Prediction of visual field deficits by diffusion tensor imaging in temporal lobe epilepsy surgery

Diffusions-Tensor-Bildgebung zur Vorhersage von Gesichtsfelddefekten bei Temporallappenresektionen

Meeting Abstract

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  • corresponding author C. Nimsky - Neurochirurgische Universitätsklinik Erlangen, Erlangen, Deutschland
  • D. Weigel - Neurochirurgische Universitätsklinik Erlangen, Erlangen, Deutschland
  • X. Chen - Neurochirurgische Universitätsklinik Erlangen, Erlangen, Deutschland
  • O. Ganslandt - Neurochirurgische Universitätsklinik Erlangen, Erlangen, Deutschland
  • M. Buchfelder - Neurochirurgische Universitätsklinik Erlangen, Erlangen, Deutschland

Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocMO.11.02

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2008/08dgnc108.shtml

Published: May 30, 2008

© 2008 Nimsky 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

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Objective: To correlate and predict visual field defects in temporal lobe surgery for pharmaco-resistant epilepsy by comparing reconstructed pre-and intraoperative fiber bundles representing the optic radiation.

Methods: A single-shot spin-echo diffusion weighted echo planar sequence (with 6 diffusion gradients on a 1.5T MR scanner) was used for diffusion tensor imaging (DTI) based fiber tracking in 48 patients undergoing temporal lobectomy for pharmaco-resistant epilepsy. Pre- and intraoperative fiber tracking was used to visualize the optic radiation applying a standard tensor deflection approach (iPlan 2.5, BrainLAB, Feldkirchen, Germany). The differences between pre- and intraoperative reconstruction of the optic radiation were correlated with the visual field defects in a prospective double-blinded study.

Results: The course of the optic radiation could be successfully reconstructed by DTI based fiber tracking. There was a significant correlation between the fiber tracking estimation and the outcome of visual field deficits after surgery. The receiver operating characteristic (ROC) curve analysis confirmed the accuracy and validity of prediction of the post-operative visual field deficits comparing pre- and intra-operative fiber tracking results. The Spearman correlation analysis showed significant correlations of field loss (calculated as visual field defect grades) with optic radiation/Meyer’s loop injury fraction (P<0.001), with an r value of 0.889.

Conclusions: Pre- and intraoperative reconstruction of the optic radiation was possible in all patients. The differences between the reconstructed pre- and intraoperative fiber bundles correlated well with postoperative visual field defects. Blinded analysis of DTI data allowed a reliable prediction of visual field defects.