Cranial Sutures Alter Computational Models of Transcranial Electrical Stimulation

Area of Science:

• Neuroscience
• Biomedical Engineering
• Computational Modeling

Background:

• Realistic vOlumetric-Approach-based Simulator for Transcranial electric stimulation (ROAST) is vital for transcranial electrical stimulation (tES) research.
• Model precision in ROAST relies heavily on the anatomical accuracy of the input data.

Purpose of the Study:

• To compare ROAST models using only T1 MRI versus T1 and T2 MRI.
• To investigate the impact of varying skull conductivity and incorporating cranial sutures into tES models.
• To analyze electrical field distribution for common electroconvulsive therapy (ECT) montages.

Main Methods:

• Computational modeling using a T1 MRI-based head model in ROAST.
• Simulation of varying skull conductivities (0.01 S/m to 0.0126 S/m) and cranial sutures (0.32 S/m).
• Application of "disc" and "pad" electrodes with 1 mA current for bitemporal, bifrontal, and right unilateral montages.

Main Results:

• The T1-only model produced different electric field distributions compared to the T1 and T2 model.
• Altering skull conductivity and simulating cranial sutures modified electric current flow to cortical and subcortical areas.
• Cranial sutures had a more substantial effect on current distribution than skull conductivity variations.

Conclusions:

• Anatomically accurate head models are essential for precise ROAST simulations of tES.
• Incorporating in vivo skull conductivity values and cranial sutures improves the realism of tES electric field predictions.
• Accurate modeling enhances the reproducibility of tES study outcomes.