Theoretical stereoelectroencephalography density on the brain convexity

Area of Science:

• Neurosurgery
• Epileptology
• Medical Imaging

Background:

• Invasive electroencephalography (EEG) is crucial for drug-resistant epilepsy, with stereoelectroencephalography (SEEG) and subdural EEG (SDEEG) as key diagnostic tools.
• Debate exists regarding SEEG's efficacy in exploring the brain's convexity, where SDEEG is often preferred.
• Understanding SEEG's coverage is vital for optimizing epilepsy surgery planning.

Purpose of the Study:

• To evaluate the theoretical safe coverage of SEEG on the brain convexity.
• To compare the theoretical SEEG cortical density with the established SDEEG density.
• To provide data supporting the use of SEEG for convexity epilepsy cases.

Main Methods:

• A theoretical model was developed based on previously described SEEG techniques.
• The maximal number of safe entry points and inter-electrode distances were calculated for 10 hemispheres.
• Cortical density was assessed using mathematical formulas to compare SEEG and SDEEG coverage.

Main Results:

• The study identified an average of 132.8 safe SEEG entry points per hemisphere with a 2.5 mm safety margin.
• Theoretical SEEG safe electrode density on the convexity ranged from 0.46 to 0.69 electrodes/cm², averaging 0.59 electrodes/cm².
• The average distance between neighboring SEEG entry points was 11.47 mm, with maximal distances up to 27.23 mm.

Conclusions:

• Theoretical SEEG cortical density on the brain convexity is comparable to SDEEG.
• SEEG's safety profile and ability to explore deep structures support its increasing use over SDEEG.
• These findings advocate for SEEG's expanded application in diagnosing epilepsy involving the brain convexity.