Constrained maximum intensity optimized multi-electrode tDCS targeting of human somatosensory network

Area of Science:

• Neuroscience
• Biomedical Engineering
• Computational Modeling

Background:

• Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique.
• Standard tDCS uses large electrodes, leading to widespread current distribution.
• Optimized multi-electrode tDCS aims for improved focality and intensity at the target region.

Purpose of the Study:

• To emphasize the importance of individualized target location and orientation for tDCS.
• To present a new constrained maximum intensity (CMI) optimization approach for multi-electrode tDCS.
• To simulate optimized excitatory and inhibitory tDCS montages for future experimental validation.

Main Methods:

• Combined electroencephalography and magnetoencephalography (EMEG) source analysis for individualized target localization and orientation.
• Individualized skull-conductivity calibrated finite element method (FEM) head models.
• Simulation of four different tDCS montages, including a novel CMI approach.

Main Results:

• The study identified the P20/N20 component generator in Brodmann area 3b, oriented posterior to anterior, as a target.
• Simulations generated optimized excitatory and inhibitory electrode montages.
• The CMI approach demonstrated potential for better current distribution and reduced skin sensations.

Conclusions:

• Individualized target location and orientation are crucial for effective tDCS.
• Optimized multi-electrode tDCS montages, particularly using the CMI approach, can enhance focality and reduce discomfort.
• These findings pave the way for more precise and comfortable tDCS applications in future research.