Occult focal cortical dysplasia may predict poor outcome of surgery for drug-resistant mesial temporal lobe epilepsy.

Arkadiusz Nowak,Aleksandra Bala,Stéphane Charpier

doi:10.1371/journal.pone.0257678

Arkadiusz Nowak, Aleksandra Bala + Show 1 more

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https://doi.org/10.1371/journal.pone.0257678

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Journal: PloS one	Publication Date: Sep 30, 2021
Citations: 3	License type: CC BY 4.0

Affiliation: Medical University of Warsaw, University of Warsaw

Abstract

PurposeThe results of surgery in patients with mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) are favorable, with a success rate over 70% following resection. An association of HS with focal cortical dysplasia (FCD) in the temporal lobe is one of the potential causes for poor surgical outcome in MTLE. We aimed to analyzed seizure outcome in a population of MTLE patients and recognize the role of occult FCD in achieving postoperative seizure control.MethodsWe retrospectively analyzed postoperative outcomes for 82 consecutive adult patients with the syndrome of MTLE due to HS, who had no concomitant lesions within temporal lobe in MRI and who underwent surgical treatment in the years 2005–2016, and correlated factors associated with seizure relapse.ResultsAt the latest follow-up evaluation after surgery, 59 (72%) were free of disabling seizures (Engel Class I) and 48 (58,5%) had an Engel Class Ia. HS associated with FCD in neocortical structures were noted in 33 patients (40%). Analyzes have shown that dual pathology was the most significant negative predictive factor for Engel class I and Engel class Ia outcome.ConclusionsThe incidence of dual pathology in patients with temporal lobe epilepsy seems to be underestimated. An incomplete epileptogenic zone resection of occult focal temporal dysplasia within temporal lobe is supposed to be the most important negative prognostic factor for seizure freedom after epilepsy surgery in MTLE-HS patients. The study indicates the need to improve diagnostics for other temporal lobe pathologies, despite the typical clinical and radiological picture of MTLE-HS.

Highlights

Mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) is the most common focal, drug-resistant epilepsy syndrome requiring surgical treatment [1]
We retrospectively analyzed postoperative outcomes for 82 consecutive adult patients with the syndrome of MTLE due to HS, who had no concomitant lesions within temporal lobe in Magnetic Resonance Imaging (MRI) and who underwent surgical treatment in the years 2005–2016, and correlated factors associated with seizure relapse
Analyzes have shown that dual pathology was the most significant negative predictive factor for Engel class I and Engel class Ia outcome

Summary

Introduction

Mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) is the most common focal, drug-resistant epilepsy syndrome requiring surgical treatment [1]. Hippocampal sclerosis which is the most frequent neuropathologic finding in these patients, may be isolated or associated with a second principal lesion such as a tumor, focal cortical dysplasia (FCD) or vascular malformation. An association of hippocampal sclerosis with cortical dysplasia in the temporal lobe has been discovered as a quite common pathology and has come into the focus of interest. The authors analyzed the results of epilepsy surgery in a group of patients with drug-resistant MTLE epilepsy associated with hippocampal sclerosis, who underwent standard resection of the anterior temporal lobe. We aimed to recognize the role of occult FCD in achieving postoperative seizure control

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