Imaging of current flow in the human head during transcranial electrical therapy
| Autor: | Aditya K. Kasinadhuni, Rosalind J. Sadleir, Michael Schär, Munish Chauhan, Aprinda Indahlastari, Thomas H. Mareci |
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| Rok vydání: | 2017 |
| Předmět: |
Male
tACS medicine.medical_treatment Finite Element Analysis Models Neurological Biophysics Transcranial Direct Current Stimulation tDCS Article lcsh:RC321-571 030218 nuclear medicine & medical imaging Young Adult 03 medical and health sciences 0302 clinical medicine MREIT Current density Electric Impedance medicine Humans Finite element modeling lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry Electrodes Evoked Potentials Physics Computational model Transcranial direct-current stimulation General Neuroscience Direct current Brain Reproducibility of Results Magnetic Resonance Imaging Magnetic flux Neuromodulation (medicine) Neurology (clinical) Current (fluid) Electric current 030217 neurology & neurosurgery MRI Biomedical engineering |
| Zdroj: | Brain Stimulation, Vol 10, Iss 4, Pp 764-772 (2017) |
| ISSN: | 1935-861X |
| Popis: | Background It has been assumed that effects caused by tDCS or tACS neuromodulation are due to electric current flow within brain structures. However, to date, direct current density distributions in the brains of human subjects have not been measured. Instead computational models of tDCS or tACS have been used to predict electric current and field distributions for dosimetry and mechanism analysis purposes. Objective/Hypothesis We present the first in vivo images of electric current density distributions within the brain in four subjects undergoing transcranial electrical stimulation. Methods Magnetic resonance electrical impedance tomography (MREIT) techniques encode current flow in phase images. In four human subjects, we used MREIT to measure magnetic flux density distributions caused by tACS currents, and then calculated current density distributions from these data. Computational models of magnetic flux and current distribution, constructed using contemporaneously collected T 1 -weighted structural MRI images, were co-registered to compare predicted and experimental results. Results We found consistency between experimental and simulated magnetic flux and current density distributions using transtemporal (T7-T8) and anterior-posterior (Fpz-Oz) electrode montages, and also differences that may indicate a need to improve models to better interpret experimental results. While human subject data agreed with computational model predictions in overall scale, differences may result from factors such as effective electrode surface area and conductivities assumed in models. Conclusions We believe this method may be useful in improving reproducibility, assessing safety, and ultimately aiding understanding of mechanisms of action in electrical and magnetic neuromodulation modalities. |
| Databáze: | OpenAIRE |
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