Validating EEG source imaging using intracranial electrical stimulation.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Imaging

Background:

• Electrical source imaging (ESI) is crucial for localizing brain activity in presurgical epilepsy evaluation and cognitive neuroscience.
• Accurate source localization is vital for effective clinical decision-making and research.

Purpose of the Study:

• To assess the spatial accuracy of ESI using known electrical stimulation sources.
• To identify factors influencing localization error in ESI.

Main Methods:

• Simultaneous stereo-EEG and scalp EEG recordings were obtained during electrical stimulation in 11 epilepsy patients.
• ESI was performed using a dipole source model and finite element method head models with varying skull conductivities.
• Localization error was calculated as the distance between estimated dipoles and stimulation sites.

Main Results:

• Mean localization errors ranged from 10.3 to 26 mm, influenced by source depth and skull conductivity.
• Localization error increased with source depth and decreased with higher skull conductivity.
• High skull conductivities significantly reduced errors for deeper sources.

Conclusions:

• ESI demonstrates reliable spatial accuracy for known sources, supporting its clinical application.
• Optimizing skull conductivity in ESI models can minimize localization errors.
• Further research is needed to validate these findings with true neural signals.