Electrical Stimulation for Seizure Induction and Functional Mapping in Stereoelectroencephalography

Area of Science:

• Neurosurgery
• Epileptology
• Neurophysiology

Background:

• Epilepsy surgery aims to resect the epileptogenic zone while preserving neurological function.
• Electrical stimulation (ES) is vital for precise identification of functionally critical cortical areas.
• Standardization of ES techniques and electrode types (grids vs. stereoelectroencephalography) is needed for reliable language and motor mapping.

Purpose of the Study:

• To discuss methodological aspects of ES influencing functional brain mapping, particularly for language.
• To explore the role of ES in triggering seizures for epilepsy localization.
• To emphasize the importance of correlating anatomical, electrophysiological, and clinical data in stereoelectroencephalography.

Main Methods:

• Review of methodological factors influencing ES-based functional mapping.
• Discussion of ES parameters, electrode types, and task variations.
• Analysis of ES-induced seizures versus spontaneous seizure recording for epileptogenic zone localization.

Main Results:

• ES parameters, electrode choice, and task design significantly impact functional mapping accuracy.
• Stereoelectroencephalography (SEEG) utilizes ES to differentiate between after-discharge and seizure networks.
• ES-induced seizures show varied responses in supra- and infra-sylvian epilepsies.

Conclusions:

• Integrating seizure triggering and functional mapping via ES is essential for epilepsy surgery.
• Determining the spatio-temporal overlap between epileptogenic and functional networks is key.
• Anatomo-electro-clinical correlations are fundamental in SEEG for precise epilepsy management.