Electrical stimulation for the induction of seizures is safe, well-tolerated and high-yield in children with drug-resistant epilepsy

Introduction: Drug-refractory epilepsy (DRE) affects one-third of children with epilepsy and can be treated with surgery. The surgical target is determined by recording spontaneous seizures during stereoelectroencephalography (sEEG). In adults, induced seizures help define the surgical target and predict favorable outcomes. No studies focus on the safety, tolerability, and yield of electrical stimulation for the induction of seizures (ESIS) in children. Methods: Stimulation at 1 Hz and 50 Hz was performed prospectively and comprehensively (all gray matter channels) during sEEG in children and young adults with DRE. Induced seizures were categorized as electroclinical habitual, clinical habitual (aura), subclinical and non-habitual. Primary safety outcome was rescue medication use. Tolerability was assessed by questionnaire. Yield was induced seizure rate. Results: Sixty-seven patients (n = 30 female) participated during 70 admissions. Patients were 1-21 years old (mean ± SD, 11.1 ± 5.7). n = 10,135 stimulation trials were performed, requiring 175 ± 61 min per patient. One seizure required rescue medication. Tolerability ratings were favorable and improved from pre- to post-session. At least one induced seizure was obtained in 62/70 (89 %) sessions, representing 283/10,135 trials (2.8 %). Combined, habitual seizures and habitual auras accounted for 58 % of induced seizures; non-habitual seizures were uncommon (12 %). Of those with induced seizures, multiple seizure types occur