Optic radiation tractography and vision in anterior temporal lobe resection
Version of Record online: 23 MAR 2012
Copyright © 2012 American Neurological Association
Annals of Neurology
Volume 71, Issue 3, pages 334–341, March 2012
How to Cite
Winston, G. P., Daga, P., Stretton, J., Modat, M., Symms, M. R., McEvoy, A. W., Ourselin, S. and Duncan, J. S. (2012), Optic radiation tractography and vision in anterior temporal lobe resection. Ann Neurol., 71: 334–341. doi: 10.1002/ana.22619
- Issue online: 23 MAR 2012
- Version of Record online: 23 MAR 2012
- Accepted manuscript online: 2 SEP 2011 01:43PM EST
- Manuscript Accepted: 26 AUG 2011
- Manuscript Revised: 19 AUG 2011
- Manuscript Received: 30 APR 2011
- Wellcome Trust Programme Grant. Grant Number: 083148
- Medical Research Council. Grant Number: G0802012
- Joint Cancer Research United Kingdom/Engineering and Physical Sciences Research Council grant. Grant Number: C1519/A10331
Anterior temporal lobe resection (ATLR) is an effective treatment for refractory temporal lobe epilepsy but may result in a contralateral superior visual field deficit (VFD) that precludes driving in the seizure-free patient. Diffusion tensor imaging (DTI) tractography can delineate the optic radiation preoperatively and stratify risk. It would be advantageous to incorporate display of tracts into interventional magnetic resonance imaging (MRI) to guide surgery.
We studied 20 patients undergoing ATLR. Structural MRI scans, DTI, and visual fields were acquired before and 3 to 12 months following surgery. Tractography of the optic radiation was performed on preoperative images and propagated onto postoperative images. The anteroposterior extent of the damage to Meyer's loop was determined, and visual loss was quantified using Goldmann perimetry.
Twelve patients (60%) suffered a VFD (10–92% of upper quadrant; median, 39%). Image registration took <3 minutes and predicted that Meyer's loop was 4.4 to 18.7mm anterior to the resection margin in these patients, but 0.0 to 17.6mm behind the resection margin in the 8 patients without VFD. The extent of damage to Meyer's loop significantly correlated with the degree of VFD and explained 65% of the variance in this measure.
The optic radiation can be accurately delineated by tractography and propagated onto postoperative images. The technique is fast enough to propagate accurate preoperative tractography onto intraoperative scans acquired during neurosurgery, with the potential to reduce the risk of VFD. ANN NEUROL 2012;