Intracranial Voltage Profiles from Untangled Human Deep Sources Reveal Multisource Composition and Source Allocation...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Imaging

Background:

• Intracranial potentials serve as functional biomarkers for neural networks.
• Signal mixing and individual cortical variations complicate source localization.
• Accurate mapping of neural activity is crucial for understanding brain function and dysfunction.

Purpose of the Study:

• To disentangle mixed intracranial potentials using source separation techniques.
• To identify the number, location, contribution, and dynamics of coactive neural sources.
• To address interindividual differences in cortical architecture for precise functional mapping.

Main Methods:

• Application of source separation techniques to deep array recordings from epilepsy patients.
• Analysis of unique spatial profiles of separated generators.
• Integration with MRI for anatomical correlation and origin determination.
• 3D source coverage plotting across arrays.

Main Results:

• Discernment of dozens of stable, independent cortical areas per patient, even during seizures.
• Association of sources with specific cortical regions (sulci and gyri) using MRI.
• Identification of contributions from 3-5 local and distant generators to individual recording sites.
• Revealed significant bias and false positives in seizure origin localization using raw potentials and bipolar montage.

Conclusions:

• Source disentangling effectively reveals the multisource nature and far intracranial spread of human potentials.
• The method accurately addresses patient-specific anatomofunctional cortical divergence.
• Improved localization of neural sources and seizure origins is achievable.