Authors :
Presenting Author: Sara Matthews, BS – UAB Heersink School of Medicine
Anastasia Smith, MPH, CCRP – University of Alabama at Birmingham
Curtis Rozzelle, MD – University of Alabama at Birmingham
Jeffrey Blount, MD – University of Alabama at Birmingham
Ismail Mohamed, MD – University of Alabama at Birmingham
Rationale:
Epilepsy affects 1% of the population, with about 30% of cases being drug-resistant. Surgical resection of the seizure onset zone (SOZ) can treat drug-resistant epilepsy. There is increasing use of stereo-electroencephalography (SEEG) for invasive SOZ localization in children due to its better tolerability. However, invasive EEG can fail to localize the SOZ in 10-15% of cases, leading to poor surgical outcome or repeat SEEG. We explore the benefits of additional electrodes to define the SOZ during the same hospitalization when initial SEEG is inconclusive in children.
Methods:
Pediatric epilepsy surgery cases at Children’s of Alabama from 2014 to 2024 were reviewed to identify patients who underwent SEEG. From this group, patients who received additional electrode placements during the same hospitalization were compiled. Charts were reviewed to obtain data of interest, including number of electrode arrays added, rationale for adding electrodes, length of hospital stay, complications and surgical outcomes.
Results:
13 patients underwent additional electrode placement during the same hospitalization. Age at SEEG placement ranged from 3.3-18.2 years (mean ± SD: 12 ± 5 years). Reasons for placing additional electrodes included defining surgical resection margin (6), inconclusive lobar localization (6), and inconclusive lateralization (1).
Initial electrode placement was bilateral in 4 patients and unilateral in the remaining 9 patients (right: 5 patients, left: 4 patients). Number of electrode arrays placed initially ranged from 7-19 (mean ± SD: 11 ± 3), with 1-4 additional arrays (mean ± SD: 3 ± 1) added during the same hospitalization. Duration of SEEG monitoring ranged from 3-13 days (mean ± SD: 7 ± 3 days) for initial electrode placement and ranged 1-7 days (mean ± SD: 3 ± 1 days) days after additional electrode implantation.
Additional electrodes captured seizures in 12 of 13 patients. Subsequent treatment included laser ablation in six patients and surgical resection in another six patients. One patient did not undergo any further treatment. One patient experienced a small, focal intra parenchymal hemorrhage after electrode removal that did not require evacuation.
At the last available follow-up after surgery, six patients were seizure-free, three had rare seizures, one experienced daily auras without impairment of consciousness, and two continued to have frequent seizures. Five of six patients who underwent additional electrode placement to define resection margins became seizure free and one had rare seizures after surgery.Conclusions:
Additional electrode placement during the same hospitalization in pediatric SEEG is well tolerated and is most beneficial when these electrodes are added to define surgical margins and could influence subsequent surgical strategy allowing more limited resections or laser ablations. These findings may help establish institutional best practices for additional electrode use in pediatric SEEG patients.
Funding:
UAB Heersink School of Medicine Physician Scientist Development Fellowship to Sara Matthews