This arm encompasses patients with drug-resistant focal epilepsy who underwent intracranial monitoring via stereotactically implanted depth electrodes (SEEG) as part of their standard presurgical evaluation. During the monitoring period, these patients additionally underwent systematic Single-Pulse Electrical Stimulation (SPES) mapping. SPES was administered according to a standardized clinical protocol, involving the delivery of single, low-intensity electrical pulses to selected electrode contacts-including those located within or adjacent to the piriform cortex-while recording the evoked electrophysiological responses across the implanted SEEG network. The data collected in this arm include continuous intracranial EEG recordings, precise stimulation parameters (location, intensity), and the corresponding electrophysiological responses used to characterize cortico-cortical evoked potentials and network connectivity.

The intervention involves single-pulse electrical stimulation (SPES) applied during stereotactic electroencephalography (SEEG) monitoring. Low-intensity, standardized electrical pulses are delivered to targeted contacts within or near the piriform cortex via implanted depth electrodes, while simultaneous full-bandwidth SEEG recordings capture network-wide electrophysiological responses, allowing characterization of stimulation-evoked brain network activation and modulation patterns.

Quantified as the percentage reduction in the frequency of spikes and interictal epileptiform discharges (IEDs) during active stimulation compared to the baseline period.

The minimum current intensity (mA) required to elicit a reproducible response.

Amplitude (μV) and latency (ms) of the primary cortical evoked response (N1 wave).