gms | German Medical Science

68th Annual Meeting of the German Society of Neurosurgery (DGNC)
7th Joint Meeting with the British Neurosurgical Society (SBNS)

German Society of Neurosurgery (DGNC)

14 - 17 May 2017, Magdeburg

Insular resections for drug-resistant epilepsy: results and prognostic factors

Meeting Abstract

  • Daniel Delev - Department of Neurosurgery, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Deutschland
  • Gerrit Haaker - Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Deutschland
  • Bernhard J. Steinhoff - Epilepsiezentrum Kork, Kehl-Kork, Deutschland
  • Christian Scheiwe - Freiburg, Deutschland
  • Julia M. Nakagawa - Department of Neurosurgery, Freiburg, Deutschland
  • Andreas Schulze-Bonhage - Universitätsklinikum Freiburg, Neurozentrum, Epilepsiezentrum, Freiburg, Deutschland
  • Josef Zentner - Universitätsklinikum Freiburg, Neurozentrum, Abteilung für Allgemeine Neurochirurgie, Freiburg, Deutschland

Deutsche Gesellschaft für Neurochirurgie. Society of British Neurological Surgeons. 68. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 7. Joint Meeting mit der Society of British Neurological Surgeons (SBNS). Magdeburg, 14.-17.05.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocDI.19.03

doi: 10.3205/17dgnc287, urn:nbn:de:0183-17dgnc2875

Published: June 9, 2017

© 2017 Delev et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at



Objective: Surgery is a widely accepted option for treatment of pharmacoresistant focal epilepsy. One of the greatest challenges, however, refers to patients in whom the epileptogenic zone encroaches upon areas of high functionality such as the insular cortex. The aim of this study was to analyze clinical and epileptological results and to provide prognostic factors influencing seizure outcome after insular resections for drug-resistant epilepsy.

Methods: This single-center study comprises a consecutive series of 53 patients, who underwent resective surgery of insular cortex due to pharmacoresistant epilepsy. Comprehensive data including preoperative diagnostic modalities, surgical treatment, histopathological evaluation, and clinical as well as epileptological outcome were analyzed with a particular focus on prognostic factors.

Results: Twenty-four patients underwent pure insular resections, whereas in the remaining 29 cases resection included parts of the temporal or frontal cortex. Histopathological evaluation of the operative specimens revealed tumors (n=24), focal cortical dysplasia (n=22), cavernomas (n=4) and gliosis (n=3). The resection in most patients with focal cortical dysplasia (n=18; 81%) comprised insular and neighboring frontal or temporal cortex, while the resection of most glial tumors (n=15; 68%) was restricted to the insular cortex only. Seizure outcome data were available from 49 patients. After a mean follow-up of 52 months, 28 patients (57%) were free from disabling seizures (Engel class I) and 35 patients (66%) had favorable seizure outcome (Engel classes I and II). There was no perioperative death. Permanent morbidity was encountered in 10 cases (19%) and included in most patients mild hemiparesis or dysphasia. The following prognostic factors were associated with excellent seizure outcome: MRI visible lesion (p=0.039), complete resection of the lesion (p=0.013) and younger age at surgery (<18 years) (p=0.032). Evaluation of histopathological findings revealed that glial tumors were associated with a poor seizure outcome (p=0.020).

Conclusion: Surgical treatment of pharmacoresistant epilepsy arising from the insular cortex provides satisfying results with seizure free rates of almost 60% and acceptable morbidity. Best epileptological outcome can be achieved in younger patients with dysplastic lesions that can be resected completely, while patients with glial tumors are less likely to become seizure free.