Stimulation-Induced Seizures in Children Undergoing Stereo-EEG Evaluation

Area of Science:

• Pediatric Neurology
• Epileptology
• Neurophysiology

Background:

• Drug-resistant epilepsy in children poses significant management challenges.
• Stereo-electroencephalography (stereo-EEG) is crucial for localizing seizure foci.
• Stimulation-induced seizures (SIS) can aid in understanding epilepsy networks.

Purpose of the Study:

• To evaluate the initial experience of using low-frequency stimulation to provoke SIS in pediatric patients with drug-resistant epilepsy.
• To assess the feasibility and effectiveness of 1-Hz stimulation during stereo-EEG evaluations.
• To identify factors associated with successful SIS provocation.

Main Methods:

• Retrospective analysis of 14 children (aged 2-18 years) with drug-resistant focal epilepsy undergoing stereo-EEG.
• Extraoperative direct electrical cortical stimulation using 1-Hz biphasic square waveforms (1ms pulse width, 1-3mA current, 20s trains).
• Collection and summary of epilepsy-related, imaging, neurophysiology, and surgery-related variables.

Main Results:

• Four patients (28.6%) experienced habitual SIS, all with extratemporal origins.
• Focal cortical dysplasia was the etiology in three patients with SIS.
• Interictal high-frequency oscillations were observed at contacts provoking SIS in 75% of cases.
• Two patients achieved excellent seizure control (Class 1 ILAE outcome) after resection of SIS-generating regions.

Conclusions:

• Low-frequency (1-Hz) stimulation can provoke habitual SIS in a subset of pediatric epilepsy patients undergoing stereo-EEG.
• This approach may help delineate seizure networks and guide surgical interventions.
• Further research is needed to expand the understanding of low-frequency stimulation in pediatric epilepsy.