Document Type
Article
Publication Date
10-7-2024
Manuscript Version
vor
Abstract
Objective: Temporal lobe encephaloceles (TLEN) have been implicated as a cause of temporal lobe epilepsy (TLE), the treatment which is primarily surgical; however, there is no clear consensus on the optimal surgical approach, because it is unclear whether TLE related to TLEN can be addressed by a restricted encephalocele resection or if a more extensive resection is required. The aim of the current article is to report the clinical and electrophysiological profile of patients with TLE secondary to TLEN who underwent stereotactic electroencephalography (SEEG) implantation to identify the epileptogenic network. Methods: A retrospective review was performed of patients with TLE related to TLEN who underwent SEEG implantation. Medical charts were reviewed for demographic data, the results of noninvasive and invasive investigations, and operative details. Surgical outcomes were based on Engel classification with at least 6 months follow-up. Results: Nine patients were identified. The mean age at epilepsy onset was 28 years (range, 15–41 years), and 7/9 patients were female. Scalp EEG revealed interictal epileptiform activity most often maximum in the frontotemporal and/or temporal regions. A discrete TLEN was often not identified on initial imaging, but was identified during re-review or at the time of surgery. Seizure onset zones during SEEG were localized to the mesial temporal structures, the temporal pole, or both. One patient became seizure-free following SEEG and another refused further surgery. Of the 7 patients who underwent epilepsy surgery, 5/7 underwent an anterior temporal lobectomy—surgical outcomes were favorable, with 5/7 achieving Engel I outcomes. Significance: Invasive SEEG monitoring demonstrated ictal onsets may not be restricted to the TLEN, and often the temporal pole and mesial structures are involved at seizure onset. Ictal propagation patterns vary significantly, which may be related to the underlying pathology and explain the variability in semiology. These findings may inform surgical treatment options. Plain language summary: Temporal lobe encephaloceles can cause intractable epilepsy, although their presence may be missed on routine imaging. The management of encephaloceles is primarily surgical; however, the optimal surgical approach can be unclear. Invasive monitoring with SEEG may help characterize the epileptogenic network and result in more optimal surgical outcomes.
Keywords
case series, encephalocele, epilepsy, epileptogenic network, SEEG, temporal lobe
Publication Title
Epilepsia Open
Rights
© 2024 The Author(s). Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Zillgitt AJ, Mong ER, Manasseh AM, Guider HC, Baki N, Staudt MD. Exploration of epileptic networks in temporal lobe encephaloceles with stereotactic EEG: Electroclinical characteristics and surgical outcomes. Epilepsia Open. 2024; 9: 2395–2407. https://doi.org/10.1002/epi4.13063