Sample entropy analysis with high-density electroencephalography for non-invasive evaluation of hemispheric language dominance.

Background: Sample entropy analysis with electroencephalography (EEG) is an established diagnostic tool for neurological disorders. This study aimed to investigate the usefulness of sample entropy analysis of EEG for evaluating hemispheric language dominance during auditory tasks. Methods: Twenty-two patients scheduled for brain surgery were evaluated. High-density EEG data were recorded during four types of listening tasks: sound of the natural environment, classic music, sound of text reading, and reverse playback of that text reading. Sample entropy in the alpha, beta, and gamma bands was calculated. The Wada test was used to identify the language-dominant hemisphere. Results: While listening to the sound of text reading tasks, the sample entropy significantly decreased in the left anterior hemisphere for all oscillation bands, consistent with the language dominance evaluated using the Wada test. Conclusion: The sound of text reading tasks induces entropy decreases in the language-dominant hemisphere and can be used to evaluate language-dominant hemispheres. Our sample entropy analysis using the sound of text reading tasks can serve as a non-invasive evaluation technique for hemispheric language dominance.