On the importance of precise electrode placement for targeted transcranial electric stimulation

• Published in: NeuroImage (Orlando, Fla.) Vol. 181; pp. 560 - 567
• Main Authors: Opitz, Alexander, Yeagle, Erin, Thielscher, Axel, Schroeder, Charles, Mehta, Ashesh D., Milham, Michael P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2018; Elsevier Limited
• Subjects: Accuracy; Adult; Alzheimer's disease; Brain research; Cerebral Cortex - physiopathology; Computational neuroscience; Defects; Electric fields; Electrocorticography - instrumentation; Electrocorticography - methods; Electrocorticography - standards; Electrodes; Epilepsy; Epilepsy - physiopathology; Female; Humans; Inventors; Male; Mental disorders; Models, Theoretical; Patients; Review boards; Therapeutic applications; Transcranial Direct Current Stimulation - instrumentation; Transcranial Direct Current Stimulation - methods; Transcranial Direct Current Stimulation - standards
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2018.07.027

Transcranial electric stimulation (TES) is an increasingly popular method for non-invasive modulation of brain activity and a potential treatment for neuropsychiatric disorders. However, there are concerns about the reliability of its application because of variability in TES-induced intracranial electric fields across individuals. While realistic computational models offer can help to alleviate these concerns, their direct empirical validation is sparse, and their practical implications are not always clear. In this study, we combine direct intracranial measurements of electric fields generated by TES in surgical epilepsy patients with computational modeling. First, we directly validate the computational models and identify key parameters needed for accurate model predictions. Second, we derive practical guidelines for a reliable application of TES in terms of the precision of electrode placement needed to achieve a desired electric field distribution. Based on our results, we recommend electrode placement accuracy to be < 1 cm for a reliable application of TES across sessions. •Validation of computational models for TES•Investigation of electrode placement accuracy in 25 head models•Recommendation for electrode placements guidelines for TES