Seizure localization using pre ictal phase-amplitude coupling in intracranial electroencephalography

Area of Science:

• Neuroscience
• Epilepsy research
• Brain dynamics

Background:

• Brain rhythm dynamics, especially phase-amplitude coupling (PAC), are altered during epileptic seizures.
• Neural processes preceding seizures remain poorly understood.
• Accurate prediction and localization of seizure onset are crucial for patient management.

Purpose of the Study:

• To investigate phase-amplitude coupling (PAC) dynamics before and after seizure onset.
• To understand the neural processes occurring in the pre-ictal period.
• To assess the utility of PAC for seizure detection and onset zone localization.

Main Methods:

• Analysis of stereoelectroencephalography (SEEG) recordings from 5 patients (30 seizures).
• Quantification of phase-amplitude coupling (PAC) dynamics.
• Comparison of PAC values in electrodes near and far from the seizure onset zone, before and after seizure onset.

Main Results:

• Electrodes identified as being near the seizure onset zone exhibited higher phase-amplitude coupling (PAC).
• Immediately preceding seizure onset, PAC values decreased significantly in these electrodes.
• Pre-ictal PAC levels dropped to resemble those observed in electrodes distant from the seizure onset zone.

Conclusions:

• Phase-amplitude coupling (PAC) dynamics provide valuable insights into pre-ictal brain activity.
• Monitoring PAC changes can aid in the early detection of epileptic events.
• PAC analysis can help delineate the seizure onset zone in patients undergoing epilepsy surgery.