Abstracts

Rationale: There are relatively few published reports on the safety and efficacy of stereoelectroencephalography (SEEG) in the presurgical evaluation of pediatric drug-resistant epilepsy. The objectives of this study were to describe our institutional experience with pediatric SEEG in terms of (1) insertional complications, (2) identification of the epileptogenic zone (EZ) and (3) ultimate seizure outcome following SEEG-tailored resections. Methods: Retrospective review of 29 patients pediatric drug resistant epilepsy patients referred to the Epilepsy Program at our institution between 2005 and 2018 who underwent presurgical SEEG. Patient demographics, non-invasive evaluation results, rationale for and coverage of SEEG are analyzed in the context of SEEG complications, identification of the EZ and seizure outcome (Engel scale) following SEEG-guided resections. Results: Twenty-nine patients (15 male; 12.4 ± 4.6 years, range: 3–17 years; mean age seizure onset 4.8 ± 3.3 years) who underwent SEEG were included in this study with mean follow-up of 6.0 ± 4.1 years (range: 0.4–13.2 years). SEEG-related complications occurred in 1/29 (3%)--neurogenic pulmonary edema (Jacob et al., 2010, Can J Neurol Sci., 37(6):885-7). A total of 190 multi-contact electrodes (mean of 7.0 ± 2.5 per patient) were implanted across 30 insertions (1 patient had further SEEG implantation following index case) which captured 437 electrographic seizures (mean 17.5 ± 27.6 per patient). The most common rationale for SEEG was normal MRI with surface EEG that failed to identify the EZ (16/29; 55%) followed by abnormal MRI with wide field identified on surface EEG (6/29; 21%) or abnormal MRI near eloquent cortical/subcortical areas (5/29; 17%). SEEG-tailored resections were performed in 24/29 (83%) patients including lesionectomy (n = 1), frontal cortical resections (n = 8) including four SMA resections and four orbitofrontal resections, occipital cortical resections (n = 4), anterior temporal lobectomy (n = 9) and selective amygdalohippocampectomy (n = 2). Engel I outcome was achieved following resections in 19/24 cases (79%), while 4/24 (17%) had improvement in seizure control (Engel II or III) with 5.9 ± 4.0 years of postoperative follow-up (range 0.9 – 12.8 years). Conclusions: Stereoelectroencephalography in presurgical evaluation of pediatric drug-resistant epilepsy is a safe and effective way to identify the epileptogenic zone permitting SEEG-tailored resections conveying freedom from seizures at long-term follow-up in 79%.  Funding: None