Transcranial Direct Current Stimulation Electrodes
Abstract
Electrodes serve as the interface between transcranial direct current stimulators and the human body. Electrodes are the method for delivering current from an electrical stimulator to the brain. If prepared poorly, they can significantly reduce the degree of brain stimulation delivered. The size, number, and relative location of electrodes control the distribution of current in the brain, whether stimulation is focal or broad, and levels of stimulation intensity within the tissue. Thus, careful consideration is required for how electrodes are prepared and applied in transcranial direct current stimulation. This chapter will discuss the typical construction of the electrode assembly, differences in commonly available electrodes, high definition versus conventional electrodes, and contact mediums commonly used for transcranial direct current stimulation. This chapter will also describe approaches for consistent preparation and placement of the electrode assembly on the head. This chapter will give special considerations to methods for avoiding oversaturation of electrodes, safety considerations for avoiding burns on the scalp, and methods for avoiding common mistakes in preparation and placement of electrodes that undermine the valid and consistent application of transcranial direct current stimulation.
Keywords
tDCS Electrode assembly Safety Design Tolerability ReproducibilityReferences
- Abram, S. E., Asiddao, C. B., & Reynolds, A. C. (1980). Increased skin temperature during transcutaneous electrical stimulation. Anesthesia and Analgesia, 59, 22–25.CrossRefGoogle Scholar
- Alam, M., Truong, D. Q., Khadka, N., & Bikson, M. (2016). Spatial and polarity precision of concentric high-definition transcranial direct current stimulation (HD-tDCS). Physics in Medicine and Biology, 61, 4506–4521. PubMedCrossRefGoogle Scholar
- Alonzo, A., Aaronson, S., Bikson, M., Husain, M., Lisanby, S., Martin, D., … Loo, C. (2016). Study design and methodology for a multicentre, randomised controlled trial of transcranial direct current stimulation as a treatment for unipolar and bipolar depression. Contemporary Clinical Trials, 51, 65–71. PubMedPubMedCentralCrossRefGoogle Scholar
- Ambrus, G. G., Antal, A., & Paulus, W. (2011). Comparing cutaneous perception induced by electrical stimulation using rectangular and round shaped electrodes. Clinical Neurophysiology, 122, 803–807. PubMedCrossRefGoogle Scholar
- Antal, A., Boros, K., Poreisz, C., Chaieb, L., Terney, D., & Paulus, W. (2008). Comparatively weak after-effects of transcranial alternating current stimulation (tACS) on cortical excitability in humans. Brain Stimulation, 1, 97–105. PubMedCrossRefGoogle Scholar
- Aparício, L. V. M., Guarienti, F., Razza, L. B., Carvalho, A. F., Fregni, F., & Brunoni, A. R. (2016). A systematic review on the acceptability and tolerability of transcranial direct current stimulation treatment in neuropsychiatry trials. Brain Stimulation, 9, 671–681.PubMedPubMedCentralCrossRefGoogle Scholar
- Balogun, J. A., Tang, S., He, Y., Hsieh, J. M., & Katz, J. S. (1996). Effects of high-voltage galvanic stimulation of ST36 and ST37 acupuncture points on peripheral blood flow and skin temperature. Disability and Rehabilitation, 18, 523–528. PubMedCrossRefGoogle Scholar
- Bikson, M., Datta, A., Rahman, A., & Scaturro, J. (2010). Electrode montages for tDCS and weak transcranial electrical stimulation: Role of “return” electrode’s position and size. Clinical Neurophysiology, 121, 1976–1978.PubMedPubMedCentralCrossRefGoogle Scholar
- Bikson, M., Grossman, P., Thomas, C., Zannou, A. L., Jiang, J., Adnan, T., … Woods, A. J. (2016). Safety of transcranial direct current stimulation: Evidence based update 2016. Brain Stimulation, 9, 641–661.Google Scholar
- Borckardt, J. J., Bikson, M., Frohman, H., Reeves, S. T., Datta, A., Bansal, V., … George, M. S. (2012). A pilot study of the tolerability and effects of high-definition transcranial direct current stimulation (HD-tDCS) on pain perception. The Journal of Pain, 13, 112–120. PubMedCrossRefGoogle Scholar
- Brunoni, A. R., Nitsche, M. A., Bolognini, N., Bikson, M., Wagner, T., Merabet, L., … Fregni, F. (2012). Clinical research with transcranial direct current stimulation (tDCS): Challenges and future directions. Brain Stimulation, 5, 175–195.PubMedCrossRefGoogle Scholar
- Cramp, A. F., Gilsenan, C., Lowe, A. S., & Walsh, D. M. (1999). The effect of high- and low-frequency transcutaneous electrical nerve stimulation upon cutaneous blood flow and skin temperature in healthy subjects. Clinical Physiology, 20, 150–157. doi: cph240 [pii].Google Scholar
- Dasilva, A. F., Volz, M. S., Bikson, M., & Fregni, F. (2011). Electrode positioning and montage in transcranial direct current stimulation. Journal of Visualized Experiments, e2744. Google Scholar
- Datta, A., Elwassif, M., Bikson, M. (2009). Bio-heat transfer model of transcranial DC stimulation: Comparison of conventional pad versus ring electrode. Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2009. EMBC 2009, 2009, pp. 670–673. Google Scholar
- Dmochowski, J. P., Datta, A., Bikson, M., Su, Y., & Parra, L. C. (2011). Optimized multi-electrode stimulation increases focality and intensity at target. Journal of Neural Engineering, 8, 46011. PubMedCrossRefGoogle Scholar
- Dundas, J. E., Thickbroom, G. W., & Mastaglia, F. L. (2007). Perception of comfort during transcranial DC stimulation: Effect of NaCl solution concentration applied to sponge electrodes. Clinical Neurophysiology, 118, 1166–1170. CrossRefGoogle Scholar
- Elwassif, M. M., Kong, Q., Vazquez, M., & Bikson, M. (2006). Bio-heat transfer model of deep brain stimulation-induced temperature changes. Journal of Neural Engineering, 3, 306–315. Google Scholar
- Ezquerro, F., Moffa, A. H., Bikson, M., Khadka, N., Aparicio, L. V., de Sampaio-Junior, B., … AR, B. (2017). The influence of skin redness on blinding in transcranial direct current stimulation studies: A crossover trial. Neuromodulation, 20, 248–255. CrossRefGoogle Scholar
- Fernández-Corazza, M., Turovets, S., Luu, P., Anderson, E., & Tucker, D. (2016). Transcranial electrical neuromodulation based on the reciprocity principle. Frontiers in Psychiatry, 7. Google Scholar
- Fertonani, A., Ferrari, C., & Miniussi, C. (2015). What do you feel if I apply transcranial electric stimulation? Safety, sensations and secondary induced effects. Clinical Neurophysiology, 126, 2181–2188. PubMedCrossRefGoogle Scholar
- Feurra, M., Bianco, G., Santarnecchi, E., Del Testa, M., Rossi, A., & Rossi, S. (2011a). Frequency-dependent tuning of the human motor system induced by transcranial oscillatory potentials. The Journal of Neuroscience, 31, 12165–12170. PubMedCrossRefGoogle Scholar
- Feurra, M., Paulus, W., Walsh, V., & Kanai, R. (2011b). Frequency specific modulation of human somatosensory cortex. Frontiers in Psychology, 2, 13. Google Scholar
- Feusner, J. D., Madsen, S., Moody, T. D., Bohon, C., Hembacher, E., Bookheimer, S. Y., & Bystritsky, A. (2012). Effects of cranial electrotherapy stimulation on resting state brain activity. Brain and Behavior: A Cognitive Neuroscience Perspective, 2, 211–220. PubMedPubMedCentralCrossRefGoogle Scholar
- Galletta, E. E., Cancelli, A., Cottone, C., Simonelli, I., Tecchio, F., Bikson, M., & Marangolo, P. (2015). Use of computational modeling to inform tDCS electrode montages for the promotion of language recovery in post-stroke aphasia. Brain Stimulation, 8, 1108–1115. PubMedCrossRefGoogle Scholar
- Gholami-Boroujeny, S., Mekonnen, A., Batkin, I., & Bolic, M. (2015). Theoretical analysis of the effect of temperature on current delivery to the brain during tDCS. Brain Stimulation, 8, 509–514. PubMedCrossRefGoogle Scholar
- Guarienti, F., Caumo, W., Shiozawa, P., Cordeiro, Q., Boggio, P. S., Benseñor, I. M., … Brunoni, A. R. (2014). Reducing transcranial direct current stimulation-induced erythema with skin pretreatment: Considerations for sham-controlled clinical trials. Neuromodulation, 18, 261–265. CrossRefGoogle Scholar
- Guleyupoglu, B., Febles, N., Minhas, P., Hahn, C., & Bikson, M. (2014). Reduced discomfort during high-definition transcutaneous stimulation using 6% benzocaine. Frontiers in Neuroengineering, 7, 28. Google Scholar
- Hahn, C., Rice, J., Macuff, S., Minhas, P., Rahman, A., & Bikson, M. (2013). Methods for extra-low voltage transcranial direct current stimulation: Current and time dependent impedance decreases. Clinical Neurophysiology, 124, 551–556. PubMedCrossRefGoogle Scholar
- Hill, A. T., Rogasch, N. C., Fitzgerald, P. B., & Hoy, K. E. (2017). Effects of prefrontal bipolar and high-definition transcranial direct current stimulation on cortical reactivity and working memory in healthy adults. NeuroImage, 152, 142–157. PubMedCrossRefGoogle Scholar
- Kasschau, M., Sherman, K., Haider, L., Frontario, A., Shaw, M., Datta, A., … Charvet, L. (2015). A protocol for the use of remotely-supervised transcranial direct current stimulation (tDCS) in multiple sclerosis (MS). Journal of Visualized Experiments. (106):e53542. .Google Scholar
- Kessler, S. K., Minhas, P., Woods, A. J., Rosen, A., Gorman, C., & Bikson, M. (2013). Dosage considerations for transcranial direct current stimulation in children: A computational modeling study. PLoS One, 8, e76112. PubMedPubMedCentralCrossRefGoogle Scholar
- Kessler, S. K., Turkeltaub, P. E., Benson, J. G., & Hamilton, R. H. (2012). Differences in the experience of active and sham transcranial direct current stimulation. Brain Stimulation, 5, 155–162. PubMedCrossRefGoogle Scholar
- Khadka, N., Borges, H., Paneri, B., Boateng, A., Jang, J., Kim, B., … Bikson, M. (2017a). Dry electrodes for transcranial direct current stimulation (tDCS). Brain Stimulation, 10, e32. CrossRefGoogle Scholar
- Khadka, N., Rahman, A., Sarantos, C., Truong, D. Q., & Bikson, M. (2015a). Methods for specific electrode resistance measurement during transcranial direct current stimulation. Brain Stimulation, 8, 150–159. PubMedCrossRefGoogle Scholar
- Khadka, N., Truong, D. Q., & Bikson, M. (2015b). Principles of within electrode current steering. Journal of Medicine Devices, 9, 020947–020947-2. Google Scholar
- Khadka, N., Zannou, A. L., Zunara, F., Truong, D. Q., Dmochowski, J., & Bikson, M. (2017b). Minimal heating at the skin surface during transcranial direct current stimulation. Neuromodulation Technol Neural Interface. Google Scholar
- Klem, G. H., Lüders, H. O., Jasper, H. H., & Elger, C. (1999). The ten-twenty electrode system of the international federation. The International Federation of Clinical Neurophysiology. Electroencephalography and Clinical Neurophysiology Supplement, 52, 3–6.Google Scholar
- Knotkova, H., Riggs, A., Patel, V., Truong, D., Arce, D., Bernstein, H., … Bikson, M. (2017). Proceedings #24. A novel approach to determining M1 tDCS montage without Neuronavigational measurements, suitable for patients in home settings. Brain Stimulation, 10, e78–e80. CrossRefGoogle Scholar
- Kronberg, G., & Bikson, M. (2012). Electrode assembly design for transcranial direct current stimulation: A FEM modeling study. Conference Proceedings of Annual Intenational Conference on IEEE Engineering Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2012, 891–895. Google Scholar
- Kuo, H. I., Bikson, M., Datta, A., Minhas, P., Paulus, W., Kuo, M. F., & Nitsche, M. A. (2013). Comparing cortical plasticity induced by conventional and high-definition 4 ?? 1 ring tDCS: A neurophysiological study. Brain Stimulation, 6, 644–648. Google Scholar
- Lagopoulos, J., & Degabriele, R. (2008). Feeling the heat: The electrode–skin interface during DCS. Acta Neuropsychiatrica, 20, 98–100. CrossRefGoogle Scholar
- Merrill, D. R., Bikson, M., & Jefferys, J. G. R. (2005). Electrical stimulation of excitable tissue: Design of efficacious and safe protocols. Journal of Neuroscience Methods, 141, 171–198. PubMedCrossRefGoogle Scholar
- Minhas, P., Bansal, V., Patel, J., Ho, J. S., Diaz, J., Datta, A., & Bikson, M. (2010). Electrodes for high-definition transcutaneous DC stimulation for applications in drug delivery and electrotherapy, including tDCS. Journal of Neuroscience Methods, 190, 188–197. PubMedPubMedCentralCrossRefGoogle Scholar
- Minhas, P., Bikson, M., Woods, A. J., Rosen, A. R., & Kessler, S. K. (2012). Transcranial direct current stimulation in pediatric brain: A computational modeling study. Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2012, 859–862. Google Scholar
- Minhas, P., Datta, A., & Bikson, M. (2011). Cutaneous perception during tDCS: Role of electrode shape and sponge salinity. Clinical Neurophysiology, 122, 637–638. PubMedCrossRefGoogle Scholar
- Monte-Silva, K., Kuo, M.-F., Liebetanz, D., Paulus, W., & Nitsche, M. A. (2010). Shaping the optimal repetition interval for cathodal transcranial direct current stimulation (tDCS). J Neurophysiol, 103, 1735–1740.PubMedCrossRefGoogle Scholar
- Nitsche, M. A., Doemkes, S., Karaköse, T., Antal, A., Liebetanz, D., Lang, N., … Paulus, W. (2007). Shaping the effects of transcranial direct current stimulation of the human motor cortex. Journal of Neurophysiology, 97, 3109–3117. PubMedPubMedCentralCrossRefGoogle Scholar
- Nitsche, M. A., & Paulus, W. (2000). Excitability changes induced in the human motor cortex by weak transcranial direct current stimulation. The Journal of Physiology, 527(Pt 3), 633–639. doi: PHY_1055 [pii].Google Scholar
- Oostenveld, R., & Praamstra, P. (2001). The five percent electrode system for high-resolution EEG and ERP measurements. Clinical Neurophysiology, 112, 713–719.PubMedCrossRefGoogle Scholar
- Opitz, A., Paulus, W., Will, S., Antunes, A., & Thielscher, A. (2015). Determinants of the electric field during transcranial direct current stimulation. NeuroImage, 109, 140–150. PubMedCrossRefGoogle Scholar
- Paneri, B., Adair, D., Thomas, C., Khadka, N., Patel, V., Tyler, W. J., … Bikson, M. (2016). Tolerability of repeated application of transcranial electrical stimulation with limited outputs to healthy subjects. Brain Stimulation, 9, 740–754. PubMedPubMedCentralCrossRefGoogle Scholar
- Poreisz, C., Boros, K., Antal, A., & Paulus, W. (2007). Safety aspects of transcranial direct current stimulation concerning healthy subjects and patients. Brain Research Bulletin, 72, 208–214. PubMedPubMedCentralCrossRefGoogle Scholar
- Russowsky Brunoni, A. I., Sampaio-Junior, B. I., Henrique Moffa, A., III, Borrione, L., Nogueira, B. S., Aparício, L. V., … Benseñor, I. M. (2015). The escitalopram versus electric current therapy for treating depression clinical study (ELECT-TDCS): Rationale and study design of a non-inferiority, triple-arm, placebo-controlled clinical trial. São Paulo Medical Journal, 133, 252–263. PubMedCrossRefGoogle Scholar
- Santarnecchi, E., Feurra, M., Barneschi, F., Acampa, M., Bianco, G., Cioncoloni, D., … Rossi, S. (2014). Time course of corticospinal excitability and autonomic function interplay during and following monopolar tDCS. Frontiers in Psychiatry, 5, 86. Google Scholar
- Scudds, R. J., Helewa, A., & Scudds, R. A. (1995). The effects of transcutaneous electrical nerve stimulation on skin temperature in asymptomatic subjects. Physical Therapy, 75, 621–628. PubMedCrossRefGoogle Scholar
- Seibt, O., Brunoni, A. R., Huang, Y., & Bikson, M. (2015). The pursuit of DLPFC: Non-neuronavigated methods to target the left dorsolateral pre-frontal cortex with symmetric bicephalic transcranial direct current stimulation (tDCS). Brain Stimulation, 8, 590–602. PubMedCrossRefGoogle Scholar
- Shen, B., Yin, Y., Wang, J., Zhou, X., Mcclure, S. M., & Li, J. (2016). High-definition tDCS alters impulsivity in a baseline-dependent manner. NeuroImage, 143, 343–352. PubMedCrossRefGoogle Scholar
- Turi, Z., Ambrus, G. G., Ho, K. A., Sengupta, T., Paulus, W., & Antal, A. (2014). When size matters: Large electrodes induce greater stimulation-related cutaneous discomfort than smaller electrodes at equivalent current density. Brain Stimulation, 7, 460–467. PubMedCrossRefGoogle Scholar
- Turi, Z., Ambrus, G. G., Janacsek, K., Emmert, K., Hahn, L., Paulus, W., & Antal, A. (2013). Both the cutaneous sensation and phosphene perception are modulated in a frequency-specific manner during transcranial alternating current stimulation. Restorative Neurology and Neuroscience, 31, 275–285. Google Scholar
- Wagner, T., Fregni, F., Fecteau, S., Grodzinsky, A., Zahn, M., & Pascual-Leone, A. (2007). Transcranial direct current stimulation: A computer-based human model study. NeuroImage, 35, 1113–1124. PubMedPubMedCentralCrossRefGoogle Scholar
- Woods, A. J., Antal, A., Bikson, M., Boggio, P. S., Brunoni, A. R., Celnik, P., … Nitsche, M. A. (2016). A technical guide to tDCS, and related non-invasive brain stimulation tools. Clinical Neurophysiology, 127, 1031–1048.PubMedPubMedCentralCrossRefGoogle Scholar
- Woods, A. J., Bryant, V., Sacchetti, D., Gervits, F., & Hamilton, R. (2015). Effects of electrode drift in transcranial direct current stimulation. Brain Stimulation, 8, 515–519. PubMedCrossRefGoogle Scholar