Ictal Source Imaging and Functional Connectivity on Intracranial EEG Localize the Seizure Onset and Predict Surgical Outcome in Pediatric Epilepsy
Abstract number :
1.336
Submission category :
9. Surgery / 9B. Pediatrics
Year :
2022
Submission ID :
2204682
Source :
www.aesnet.org
Presentation date :
12/3/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:26 AM
Authors :
Lorenzo Ricci, MD – University Campus Bio Medico in Rome; Margherita Matarrese, PhD student – University Campus Bio Medico in Rome; Jurriaan Peters, MD, PhD – Boston Children's Hospital; Eleonora Tamilia, PhD – Boston Children's Hospital; Joseph Madsen, MD – Boston Children's Hospital; Phillip Pearl, MD – Boston Children's Hospital; Christos Papadelis, PhD – Jane and John Justin Neurosciences Center – Cook Children's Health Care System, Fort Worth, TX
This abstract is a recipient of the Jack M. Pellock Pediatric Travel Award
This abstract has been invited to present during the Pediatric Epilepsy Highlights platform session
Rationale: Delineation of the seizure onset zone (SOZ) is required in children with medically refractory epilepsy (MRE) undergoing resective surgery. Intracranial EEG (iEEG) serves as the gold standard for this purpose but presents limitations due to its limited spatial sampling and risk of misleading the localization of the SOZ. Thus, more advanced methods are needed to interpret iEEG and improve SOZ localization for epilepsy surgery. The goal of this study is to assess the clinical utility of electrical source imaging (ESI) and functional connectivity (FC) using iEEG in localizing the SOZ in children with MRE prior to surgery. We hypothesize that ESI and FC can delineate the SOZ and predict the outcome of epilepsy surgery.
Methods: We analyzed iEEG-recorded seizures from 35 children with MRE who underwent epilepsy surgery. We performed ESI at ictal onset to localize the SOZ (ESI-SOZ) and FC analysis (using Granger Causality) to identify the iEEG contacts with the highest connectivity during seizures (Figure 1). Intracranial EEG contacts with FC values ≥ 70% of maximal threshold during the onset of seizures were considered as “highly connected SOZ electrodes” (i.e., FC-SOZ). We tested whether resection of ESI-SOZ and FC-SOZ predicted good surgical outcome (Engel 1a) using logistic regression and Receiver Operating Characteristic (ROC) curve analysis. We further compared the prediction performance of ESI-SOZ and FC-SOZ to those of conventional methods currently used in clinical practice, i.e., visually identifying iEEG-electrodes showing the earliest ictal activation (conv-SOZ).
Results: Twenty-one patients (60%) were seizure free after surgery. The anatomical concordance of ESI-SOZ (p=0.007; OR: 8) and FC-SOZ (p < 0.001; OR: 22) with the surgical resection has higher effect on the patient’s outcome (i.e. seizure freedom) than the proximity of conv-SOZ to the resection (p=0.17; OR: 1.7). ROC curve analysis showed that the resection of ESI-SOZ and FC-SOZ predicted good surgical outcome (AUC: 0.85 and 0.86; Sensitivity: 76% and 85%; Specificity: 100% and 78%; Accuracy: 84% and 83%, respectively; Figure 2).
Surgery