gms | German Medical Science

67th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Korean Neurosurgical Society (KNS)

German Society of Neurosurgery (DGNC)

12 - 15 June 2016, Frankfurt am Main

Resective surgery for medically refractory epilepsy using intraoperative MR imaging and functional neuronavigation: A single center experience of 415 patients

Meeting Abstract

  • Karl Rössler - Neurochirurgische Klinik, Erlangen, Germany
  • Andrea Hofmann - Neurochirurgische Klinik, Erlangen, Germany
  • Bjoern Sommer - Neurochirurgische Klinik, Erlangen, Germany
  • Hajo Martinus Hamer - Neuropathologisches Institut, Universitätsklinikum Erlangen, Germany
  • Ingmar Blümcke - Neurologische Klinik, Erlangen, Epilepsiezentrum, Germany
  • Michael Buchfelder - Neurochirurgische Klinik, Erlangen, Germany

Deutsche Gesellschaft für Neurochirurgie. 67. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 1. Joint Meeting mit der Koreanischen Gesellschaft für Neurochirurgie (KNS). Frankfurt am Main, 12.-15.06.2016. Düsseldorf: German Medical Science GMS Publishing House; 2016. DocDI.06.03

doi: 10.3205/16dgnc128, urn:nbn:de:0183-16dgnc1287

Published: June 8, 2016

© 2016 Rössler et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Objective: Intraoperative underestimation of resection amount in epilepsy surgery is a well-known problem, leading to an unfavourable seizure outcome. Intraoperative MR imaging combined with neuronavigation may help to avoid this pitfall and facilitate visualisation and targeting of the sometimes ill-defined heterogeneous lesions or epileptogenic zones and may increase numbers of complete resection leading to an improved seizure outcome.

Method: To investigate this hypothesis, we conducted a retrospective clinical study on consecutive epilepsy surgical procedures were we utilised neuronavigation combined with intraoperative magneto- resonance imaging (iopMRI) and functional imaging, magneto- encephalography (MEG) and electro-corticography (ECoG) for spike detection during a ten year period. Altogether, there were 415 patients (192 female, 223 male, mean age 37.2 years, 41% left sided and 84.9% temporal epileptogenic zones). The mean preoperative duration of epilepsy was 17.5 years.

Results: Altogether, in 11.8% (n=49) of surgeries, an intraoperative second look surgery (iopSLS) due to incomplete resection verified by intraoperative MR imaging had to be performed. Of those incomplete resections, most often long term epilepsy associated tumors (LEAT) were involved (in 40.9% of iopSLS, 29.9% of LEAT patients). Additionally, 37.5% (6/16) of the diffuse glioma group and 12.9% of focal cortical dysplasia patients had second look surgeries. Moreover, iopMRI had additional advantages during implantation of grid, strip and depth electrodes and allowed intraoperative correction of electrode position in 13.1% (3/23) of cases. Altogether, an excellent seizure outcome Engel class 1 was found in 72.7% of patients during a mean follow-up of 36 months (from 3 months to 10.8 years). Highest Engel class 1 outcome was found in cavernomas (83.7%), in hippocampal sclerosis (78.8%), and in LEAT (75.8%). Severe visual field defects were found in 5.2% of the patients, aphasia in 5.7% and hemiparesis in 2.7%, with altogether 0% mortality.

Conclusions: Neuronavigation combined with iopMR imaging was beneficially used during epilepsy surgical procedures and led to favourable seizure outcome having only few specific complications. Especially in lesional epilepsy involving LEAT or diffuse gliomas, a significant higher resection amount associated with a higher chance of favourable seizure outcome was found.