Impact of Anesthesia With Propofol on Epileptic Discharges Recorded by Stereo-Electroencephalography in Pediatric Epilepsy Surgery.

OBJECTIVE

This study aimed to evaluate the influence of anesthesia with propofol on epileptic discharges recorded by stereo-electroencephalography (SEEG) during pediatric epilepsy surgery.

METHODS

We enrolled 30 pediatric patients (aged 2-14 years) undergoing epilepsy surgery between June 2022 and November 2023. SEEG recordings were obtained under different states of consciousness: awake, sleep, and anesthesia. We analyzed the power spectral density (PSD) across frequency bands and quantified the number of interictal spikes and high-frequency oscillations (HFO) including ripples and fast ripples (FRs).

RESULTS

There was a significant reduction in the number of spikes, particularly within the seizure onset zone (SOZ), while ripples and FRs increased under general anesthesia, but the extent of the increase did not differ between the SOZ and other detected brain regions (NSOZ). Analysis of PSD showed increased energy during anesthesia, particularly in high-frequency bands. Meanwhile, no statistical differences were observed in energy changes between the SOZ and NSOZ when compared to wakefulness or sleep. HFOs emerged as more robust and consistent interictal biomarkers for localizing the SOZ under propofol anesthesia, particularly in the frontal cortex and cingulate cortex, and were not influenced by age.

CONCLUSIONS

General anesthesia with propofol significantly affects the number and frequency of epileptic discharges, particularly by reducing spikes while increasing HFOs. Notably, HFOs-particularly in the frontal and cingulate cortices-emerged as reliable biomarkers for delineating the SOZ and guiding surgical resections. Furthermore, no significant age-related variability was identified, supporting the applicability of intra-operative electroencephalography in pediatric epilepsy surgery.