Relationship between direct cortical stimulation and induced high-frequency activity for language mapping during SEEG...

Area of Science:

• Neuroscience
• Epileptology
• Clinical Neurophysiology

Background:

• Preoperative language mapping is crucial for epilepsy surgery.
• Task-induced high-frequency activity (HFA) is a potential biomarker for cognitive function.
• Previous studies primarily used electrocorticography (ECOG) to assess HFA for language networks.

Purpose of the Study:

• To evaluate the clinical relevance of preoperative task-induced HFA for language mapping in epilepsy patients undergoing stereoelectroencephalography (SEEG).
• To compare the spatial and functional relevance of HFA with direct cortical stimulation (DCS) for language mapping.

Main Methods:

• Analysis of 42 epilepsy patients who underwent SEEG with both HFA and DCS language mapping.
• Evaluation of the specificity and sensitivity of HFA and DCS in mapping language regions.
• Comparison of regional language network recruitment between HFA and DCS.

Main Results:

• Both HFA and DCS successfully mapped classic language regions, revealing a large, bilateral language network with HFA.
• HFA recruited more parietal sites, while DCS engaged more temporal sites.
• HFA demonstrated high specificity (92.4%) and negative predictive value (95.9%) in predicting DCS-induced language interference, but low sensitivity (8.9%).

Conclusions:

• DCS is more suitable for extensive temporal language mapping compared to HFA.
• HFA can serve as a complementary tool to DCS, helping to preselect stimulation sites and potentially reduce surgical procedure duration.
• The findings provide insights into the utility and limitations of HFA and DCS in clinical language mapping.