New Tactic May Improve Brain Mapping for Epilepsy Surgery

A study published in Annals of Neurology reports that naturalistic conversation may provide a reliable alternative to standard task-based procedures for electrical stimulation mapping (ESM) of the brain before epilepsy surgery. The new approach, called Behavior-iEEG-Spectral-Power Correlation (BESPoC), was tested in children and young adults and compared favorably with established methods whereby patients perform a series of tasks to identify areas critical to speech and language. The findings suggest that the BESPoC approach could reduce the burden of lengthy and complex mapping procedures while maintaining accuracy in identifying language-critical brain regions.

Traditional presurgical mapping often involves ESM with repetitive structured tasks, which can be difficult for young patients or those with developmental challenges. BESPoC differs by correlating intracranial EEG spectral power with natural behaviors, such as spontaneous conversations with family members. This approach does not depend on trial-based tasks and, according to the published article, can yield meaningful results in just a few minutes. The authors state that the BESPoC approach is more adaptable for patients who cannot complete standard evaluations.

In the study of 134 participants aged 2 to 29 years undergoing stereo-EEG monitoring:

• BESPoC demonstrated specificity of 0.79 to 0.83 and sensitivity of 0.64 to 0.86 in localizing high-gamma activity linked to language sites in the brain.
• BESPoC mapping matched traditional tasks in localizing both high-gamma modulation (HGM) and ESM language regions
• BESPoC outperformed high-gamma modulation in predicting neuropsychological outcomes after surgery and was equivalent to ESM.

Source: Cincinnati Children’s Hospital Medical Center. New method simplifies brain evaluations for planning epilepsy surgery. PRNMedia.PRNewswire.com. Published 4 September, 2025. Accessed 5 September, 2025. https://prnmedia.prnewswire.com/news-releases/new-method-simplifies-brain-evaluations-for-planning-epilepsy-surgery-302547229.html

Ervin B, Frink C, Buroker J, et al. Behavior-iEEG-Spectral-Power-Correlation: Defining Neural Substrates of Naturalistic Behavior. Ann Neurol. Published online August 16, 2025. doi:10.1002/ana.70002