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

Usefulness of optic-tract fibre-tracking for mesial temporal surgery

Meeting Abstract

  • M. Thudium - Klinik für Neurochirurgie, Universitätsklinikum Bonn
  • A. Campos - Klinik für Neurochirurgie, Universitätsklinikum Bonn
  • H. Urbach - Neuroradiologie, Universitätsklinikum Bonn
  • H. Clusmann - Klinik für Neurochirurgie, Universitätsklinikum Bonn

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. DocMI.04-07

doi: 10.3205/09dgnc189, urn:nbn:de:0183-09dgnc1895

Published: May 20, 2009

© 2009 Thudium 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: Visual field deficits are a common complication of mesial temporal surgery. About 50% of cases suffer from postoperative upper quadranopia after transsylvian approaches. We attempted to minimize trauma to the optic tract by using a temporo-basal approach guided by navigated DTI fibre tracking of Meyer’s loop.

Methods: Ten patients with amygdalohippocampectomy to treat mesial temporal lobe epilepsy were prospectively included. Every patient underwent preoperative MRI (Neuronavigation and DTI sequences). Meyer’s loop was reconstructed using DTI fibre tracking with the BrainLab Vector Vision System. Preoperatively, the approach was planned strictly avoiding any compromise of the optic tract. Intraoperative visualisation via the navigation-bound microscope was provided.

Results: A temporo-basal approach was the only possible route in all cases to access the temporal horn without interfering with any parts of the optic tract. Two patients were operated using a basal transcortical approach and eight with a subtemporal trans-fusiform-gyrus approach. Eight patients (80%) did not show any visual field defects. One patient with a transcortical approach had a minimal scotoma, and one patient with a subtemporal approach suffered an incomplete contralateral quadranopia.

Conclusions: Meyer’s loop can be sufficiently reconstructed using this DTI fibre tracking algorithm. Preoperative approach planning proved to be useful to avoid any relevant damage to the optic tract. The use of basal approaches seems to be beneficial regarding post-operative visual field deficits.