Non-Lesional Epilepsy Does Not Predict Poor Outcomes After Invasive Monitoring Followed by Resection or Thermal Ablation
Abstract number :
1.236
Submission category :
4. Clinical Epilepsy / 4D. Prognosis
Year :
2021
Submission ID :
1826337
Source :
www.aesnet.org
Presentation date :
12/4/2021 12:00:00 PM
Published date :
Nov 22, 2021, 06:53 AM
Authors :
Stephanie Bustros, MD - University of Alabama at Birmingham; Nicole Bentley – University of Alabama at Birmingham; Zeenat Jaisani – University of Alabama at Birmingham; Manmeet Kaur – University of Alabama at Birmingham; Gerald McGwin – University of Alabama at Birmingham; Adeel Memon – University of Alabama at Birmingham; Kristen Riley – University of Alabama at Birmingham; Elizabeth Ritchey – University of Alabama at Birmingham; Jerzy Szaflarski – University of Alabama at Birmingham
Rationale: We aimed to compare outcomes including seizure free status at the last follow-up in patients with medically refractory focal epilepsy identified as lesional vs. non-lesional based on their magnetic resonance imaging (MRI) findings who underwent invasive evaluation followed by subsequent resection or thermal ablation (LiTT) in a single level 4 comprehensive epilepsy center.
Methods: We retrospectively reviewed 88 patients who underwent intracranial monitoring between 2014 and 2021 dichotomized as lesional and non-lesional epilepsy based on MRI findings. Forty-eight patients were excluded. Patient demographics, seizure characteristics, non-invasive interventions, intracranial monitoring, and surgical variables were compared between the 2 groups which consisted of 40 patients. Postsurgical seizure outcome at the last follow-up was rated according to the Engel classification, and postoperative seizure freedom was determined by Kaplan-Meyer survival analysis. Statistical analyses employed Fisher’s exact test for comparison of categorical variables, while t-test was used for continuous variables.
Results: 64% of the lesional group and 57% of the non-lesional group were offered surgical resection or LiTT after invasive monitoring (p=0.78). Both surgical groups were found to have similar baseline demographics and clinical characteristics except that the lesional group had significantly more PET positive results (p=0.0003). At the last follow-up, 78.5% of the patients with lesional MRI findings achieved Engel I outcomes compared to 66.7% of non-lesional patients (p= 0.45). Both lesional and non-lesional groups achieved similar Engel I outcomes when stratified according to temporal (p= 0.65) and extratemporal lobe epilepsy anatomical locations (p=1.0). Kaplan-Meier curves did not show a significant difference in seizure free duration between the lesional and non-lesional groups after surgical intervention (resection or LiTT) (p=0.49).
Conclusions: In our sample, the presence or absence of lesion is not associated with seizure outcomes in patients who undergo invasive intracranial monitoring followed by resection or thermal ablation. Absence of a lesion on MRI should not discourage the epileptologist from pursuing further workup and intervention. While we did not include patients who underwent surgery/LiTT following phase I evaluation, this study provides promising results to the epileptologist in setting appropriate goals and expectations during patient discussion regarding outcomes.
Funding: Please list any funding that was received in support of this abstract.: None.
Clinical Epilepsy