Left prefrontal neuronavigated electrode localization in tDCS: 10-20 EEG system versus MRI-guided neuronavigation

Area of Science:

• Neuroscience
• Medical Imaging
• Neuromodulation

Background:

• Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique used in neuropsychiatric research.
• Accurate electrode placement is critical for effective tDCS, but traditional methods like the 10-20 EEG system may lack precision due to individual brain variability.
• The left dorsolateral prefrontal cortex (DLPFC) is a common target for tDCS.

Purpose of the Study:

• To compare the accuracy of MRI-guided neuronavigation versus the 10-20 EEG system for localizing the left DLPFC in tDCS.
• To investigate the impact of different electrode localizations on tDCS-induced electrical field distributions.
• To identify the neural region targeted by a supraorbital reference electrode.

Main Methods:

• Forty participants underwent left DLPFC localization using both the 10-20 EEG system and MRI-guided neuronavigation.
• Electrical field modeling was performed for one participant to compare field distributions based on electrode placement.
• Analysis focused on the spatial accuracy of DLPFC targeting and resulting electric field patterns.

Main Results:

• MRI-guided neuronavigation localized the anode more latero-posteriorly compared to the 10-20 EEG system, targeting the middle prefrontal gyrus.
• Distinct electrode localizations resulted in significantly different tDCS-induced electrical field distributions.
• The right supraorbital region was identified as the target for the reference electrode.

Conclusions:

• MRI-guided neuronavigation provides more precise DLPFC targeting for tDCS than the 10-20 EEG system.
• Differences in electrode placement significantly alter tDCS electric field patterns, potentially affecting clinical outcomes.
• Further research comparing the clinical efficacy of different tDCS targeting methods is warranted.