Intraoperative microseizure detection using a high-density micro-electrocorticography electrode array

Area of Science:

• Neuroscience
• Biomedical Engineering
• Epilepsy Research

Background:

• One-third of epilepsy patients have drug-resistant seizures, necessitating surgical intervention.
• Current surgical outcomes for epilepsy are limited, with 30-70% of patients experiencing post-resection seizures.
• Accurate localization of epileptogenic tissue is crucial for improving surgical success rates.

Purpose of the Study:

• To investigate the utility of novel high-density micro-electrocorticographic (μECoG) electrode arrays for capturing and analyzing human epileptiform activity.
• To compare microseizure activity in epilepsy patients versus non-epileptic controls.
• To assess the impact of electrode contact size and density on microseizure detection.

Main Methods:

• Intraoperative μECoG recordings were performed in nine epilepsy patients and four non-epileptic controls using high-density thin-film electrode arrays.
• Microseizures were identified by a board-certified epileptologist.
• Simulations were conducted using spatial averaging to mimic recordings from larger electrode contacts.

Main Results:

• Epilepsy patients exhibited a significantly higher microseizure rate (2.01 events/min) compared to controls (0.01 events/min).
• Microseizure detection decreased substantially with larger electrode contact sizes and lower contact densities.
• The approximate onset region of microseizures could be identified when they were spatially distributed across multiple channels.

Conclusions:

• High-density μECoG arrays with broad coverage are essential for capturing microseizures in epilepsy.
• This technology holds promise for more precise localization of epileptogenic tissue, potentially improving surgical planning and targeted brain stimulation for epilepsy treatment.