Computational exploration of epidural cortical stimulation using a realistic head model. (August 2021)

• Record Type: Journal Article
• Authors: Seo, Hyeon; Jun, Sung Chan
• Is Part Of: Computers in biology and medicine. Volume 135(2021)
• Publication Date: 2021-08
• Subjects: Epidural cortical stimulation -- Motor cortex stimulation -- Field calculation -- Electrode modeling -- Computational modeling; Medicine -- Data processing -- Periodicals; Biology -- Data processing -- Periodicals; 610.285
• DOI: 10.1016/j.compbiomed.2021.104290
• Languages: English
• ISSNs: 0010-4825

Abstract

Abstract: Motor cortex stimulation, either non-invasively or with implanted electrodes, has been applied worldwide as a treatment for intractable neuropathic pain syndromes. Although computer simulations of non-invasive brain stimulation have been investigated largely to optimize protocols and improve our understanding of underlying mechanisms using a realistic head model, computational studies of invasive cortical stimulation are rare and limited to very simplified cortical models. In this paper, we present an anatomically realistic head model for epidural cortical stimulation that includes the most sophisticated epidural electrodes with an insulating paddle. The head model predicted the stimulus-induced field strengths according to two different stimulation techniques, bipolar and monopolar stimulations. We found that the stimulus-induced field focused on the precentral and postcentral gyri because of the epidural lead's invasiveness. Different stimulation configurations influenced the shape of the field markedly, and complex patterns of inward and outward directions of the radial field were observed in bipolar stimulation compared to those in monopolar stimulation. The spatial distributions of field strength showed that the optimal stimulation varied according to the target areas. In conclusion, we proposed an anatomically realistic head model and a sophisticated epidural lead to simulate epidural cortical stimulation-induced field strengths and identified the importance of such detailed modeling for epidural cortical stimulation because of the current's shunting through the cerebrospinal fluid. Highlights: We proposed the realistic full head modeling for epidural cortical stimulation. Stimulus configuration substantially influenced the spatial extent of field in the cortex. Bipolar stimulation showed complex patterns of radial field compared to those in monopolar stimulation. Our result informed the importance of sophisticated lead modeling for further computational study.