[Utility of Presurgical Evaluation Using Stereoelectroencephalography(SEEG)].

Area of Science:

• Neurology
• Neurosurgery
• Epileptology

Background:

• Precise localization of the epileptogenic zone (EZ) is crucial for presurgical evaluation in drug-resistant focal epilepsy.
• Intracranial electroencephalography (iEEG) is necessary when noninvasive methods are inconclusive.
• Stereoelectroencephalography (SEEG) is a recently introduced iEEG technique, contrasting with the widely used subdural grid electrodes (SDG).

Purpose of the Study:

• To introduce the basics of SEEG methodology for presurgical evaluation.
• To highlight the importance of anatomo-electro-clinical correlations in SEEG.
• To present a representative case study illustrating SEEG application.

Main Methods:

• SEEG utilizes anatomo-electro-clinical correlations to guide electrode trajectory planning.
• Analysis of seizure semiology and noninvasive investigations informs the surgical hypotheses.
• Focus is placed on mapping epileptic networks, including deep brain structures, rather than anatomical lobes.

Main Results:

• Effective SEEG implantation strategy relies on accurate preimplantation hypotheses derived from detailed semiological analysis.
• SEEG can identify the EZ by investigating complex epileptic networks involving multiple brain regions.
• The theoretical basis of SEEG differs significantly from SDG, emphasizing network connectivity.

Conclusions:

• SEEG is a valuable tool for presurgical evaluation in drug-resistant focal epilepsy.
• Accurate SEEG requires a deep understanding of epilepsy semiology and network dynamics.
• This technique offers a distinct approach to EZ localization compared to traditional methods like SDG.