SEEG guided mapping of primary motor cortex in children with epilepsy.

Background: Direct cortical electrical stimulation remains the gold standard for delineation of the primary motor cortex in patients with drug-resistant epilepsy (DRE) undergoing epilepsy surgery evaluation OBJECTIVE: This study aimed to explore the efficacy and safety of functional motor mapping through Stereo-EEG (SEEG) electrode contacts in children with DRE at our institute.

Methods: We performed a retrospective analysis of children who underwent SEEG evaluation and functional cortical mapping via bipolar electrical stimulation at our institution between July 2020 and June 2024. Detailed clinical, radiological and neurophysiological variable were extracted; qualitative and quantitative variables were summarized using appropriate descriptive statistics.

Results: A total of 29 patients underwent functional cortical motor mapping via SEEG with the mean age of 12.5 years (standard deviation, 4.1). Stimulation was performed using 50 Hz bipolar electrical stimulation. Succesful motor mapping was reported in 28 patients (96.6 %). The median lowest current threshold for a motor response was 2 mA. The spectrum of motor responses reported included: tonic/dystonic (26), clonic (6), and jerk/jitteriness (1). Afterdischarges were noted in 14 patients (48.3 %) and seizures were seen in 5 patients (17.2 %).

Conclusions: SEEG guided electrical stimulation of motor cortex is feasible and safe for functional cortical mapping in children with epilepsy.