Authors :
Presenting Author: S. Katie Ihnen, MD, PhD – Cincinnati Children's Hospital Medical Center
Darcy Krueger, MD,PhD – Cincinnati Children's Hospital
Hansel Greiner, MD – University of Cincinnati College of Medicine; Cincinnati Children's Hospital Medical Center
Skoch Jesse, MD – University of Cincinnati College of Medicine; Cincinnati Children's Hospital Medical Center
Francesco Mangano, DO – University of Cincinnati College of Medicine; Cincinnati Children's Hospital Medical Center
Ravindra Arya, MD, DM – Cincinnati Children's Hospital Medical Center
Rationale:
Electrical stimulation for the induction of seizures (ESIS) using stereoelectroencephalography (sEEG) has been proven a valid adjunct for surgical planning in adults with drug-refractory epilepsy (DRE). Stimulated habitual (typical) seizures are a positive prognostic sign in adults1 and can reveal regions involved in seizure onset not implicated by spontaneous seizures2. Despite this, the relationship between induced seizures and surgical outcomes in children with DRE is not well-described.Methods:
This prospective study enrolled consecutive patients undergoing sEEG in a pediatric center. ESIS was performed at 1 and 50 Hz at all gray matter channels and induced seizures were recorded. Following multi-disciplinary conference, each patient’s (actual) surgical plan was classified as concordant or discordant with an (alternative) surgical plan informed by induced seizures. Binary surgical outcomes at 6 months or later (favorable vs. unfavorable) were evaluated for a relationship with two ESIS measures: a) stimulation of at least one habitual seizure and b) concordance between the actual surgical plan and the ESIS-informed plan. Patients with and without Tuberous Sclerosis Complex (TSC) were evaluated separatelyResults:
n=81 patients underwent ESIS; n=57 had surgery with at least 6 months of post-operative data and were included (ages 1-24y; 27F/30M; 19 TSC/38 not TSC). Habitual seizures were induced in 39/57 (0.68). In those without TSC, patients who had at least one induced habitual seizure were more likely to have favorable outcomes than those who did not (0.92 vs. 0.42; OR=16.8; p=0.002 by Fisher Exact Test). This relationship was absent in patients with TSC (Fig. 1). In those with TSC, patients whose actual and ESIS-informed surgical plans were concordant were more likely to have favorable outcomes than those with discordance (1.00 vs. 0.22; OR=0; p=0.003). In contrast, in patients without TSC, concordance was associated with a favorable outcome at chance, while discordance was unexpectedly associated with a favorable outcome (0.50 vs. 0.95; OR=0.06; p=0.01; Fig. 2). Conclusions:
In pediatric DRE, induced seizures have prognostic relevance for surgical outcomes. Interpretation depends on whether or not a patient has TSC. For children without TSC, failure to induce a habitual electroclinical seizure during ESIS may represent a red flag for surgical planning, consistent with work in adults2. For patients with TSC, discordance between induced seizures and other data informing surgical planning may represent a red flag. These findings may catalyze wider use and more accurate interpretation of ESIS in children with DRE.
1. Trebuchon A, Racila R, Cardinale F, et al. Electrical stimulation for seizure induction during SEEG exploration: a useful predictor of postoperative seizure recurrence? J Neurol Neurosurg Psychiatry. Oct 28 2020;doi:10.1136/jnnp-2019-322469
2. Cuello Oderiz C, von El lenrieder N, Dubeau F, et al. Association of Cortical Stimulation-Induced Seizure With Surgical Outcome in Patients With Focal Drug-Resistant Epilepsy. JAMA Neurol. Jun 10 2019;doi:10.1001/jamaneurol.2019.1464
Funding:
Child Neurologist Career Development Program K12 scholar, 2K12NS098482-06