Highlights
- •Deep targets can be reached with intensities comparable to the cortical surface.
- •Multi-electrode montages increase intensity with the same current limits per electrode.
- •High-definition and intersectional pulsed stimulation are largely equivalent.
- •Interferential stimulation is generally weaker than conventional stimulation.
Abstract
To reach a deep target in the brain with transcranial electric stimulation (TES),
currents have to pass also through the cortical surface. Thus, it is generally thought
that TES cannot achieve focal deep brain stimulation. Recent efforts with interfering
waveforms and pulsed stimulation have argued that one can achieve deeper or more intense
stimulation in the brain. Here we argue that conventional transcranial stimulation
with multiple current sources is just as effective as these new approaches. The conventional
multi-electrode approach can be numerically optimized to maximize intensity or focality
at a desired target location. Using such optimal electrode configurations we find
in a detailed and realistic head model that deep targets may in fact be strongly stimulated,
with cerebro-spinal fluid guiding currents deep into the brain.
Keywords
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Brain Stimulation: Basic, Translational, and Clinical Research in NeuromodulationAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Gyri-precise head model of transcranial direct current stimulation: improved spatial focality using a ring electrode versus conventional rectangular pad.in: Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation. 2. 2009: 201-207 (4)
- Electrodes for high-definition transcutaneous dc stimulation for applications in drug delivery and electrotherapy, including tdcs.J Neurosci Meth. 2010; 190: 188-197
- Optimized multi-electrode stimulation increases focality and intensity at target.J Neural Eng. 2011; 8: 046011
- Targeted transcranial direct current stimulation for rehabilitation after stroke.Neuroimage. 2013; 75: 12-19
- Physiological and modeling evidence for focal transcranial electrical brain stimulation in humans: a basis for high-definition tdcs.Neuroimage. 2013; 74: 266-275
- Noninvasive deep brain stimulation via temporally interfering electric fields.Cell. 2017; 169: 1029-1041
- Direct effects of transcranial electric stimulation on brain circuits in rats and humans.Nat Commun. 2018; 9: 483
- Noninvasive neuromodulation goes deep.Cell. 2017; 169: 977-978
- Brain stimulation is all the rage–but it may not stimulate the brain.February 2018
- The New York head–a precise standardized volume conductor model for eeg source localization and tes targeting.Neuroimage. 2016; 140: 150-162
- Measurements and models of electric fields in the in vivo human brain during transcranial electric stimulation.eLife. 2017; 6
- Optimal use of eeg recordings to target active brain areas with transcranial electrical stimulation.Neuroimage. 2017; 157: 69-80
- Optimization of focality and direction in dense electrode array transcranial direct current stimulation (tdcs).J Neural Eng. 2016; 13: 036020
- Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields.Neuroimage. 2014; 89: 216-225
- Target optimization in transcranial direct current stimulation.Front Psychiatr. 2012; 3: 90
- How to target inter-regional phase synchronization with dual-site transcranial alternating current stimulation.Neuroimage. 2017; 163: 68-80
- An optimization approach for well-targeted transcranial direct current stimulation.SIAM J Appl Math. 2016; 76: 2154-2174
- Tolerability of repeated application of transcranial electrical stimulation with limited outputs to healthy subjects.in: Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation. 9. 2016: 740-754 (5)
- Interferential current therapy.Br J Sports Med. 1990; 24: 87
- Classification of methods in transcranial electrical stimulation (tes) and evolving strategy from historical approaches to contemporary innovations.J Neurosci Meth. 2013; 219: 297-311
- The point spread function of the human head and its implications for transcranial current stimulation.Phys Med Biol. 2012; 57: 6459
- Evidence of transcranial direct current stimulation-generated electric fields at subthalamic level in human brain in vivo.in: Brain Stimulation. 2018
- Optimized tDCS for targeting multiple brain regions: an integrated implementation.in: 40th annual international conference of the IEEE engineering in medicine and biology society, Honolulu, HI. Jul. 2018
- Stimulus: noninvasive dynamic patterns of neurostimulation using spatio-temporal interference.(bioRxiv)2017
- Considerations of quasi-stationarity in electrophysiological systems.Bull Math Biophys. 1967; 29: 657-664
- Capacitive properties of body tissues.Circ Res. 1957; 5: 439-443
- The dielectric properties of biological tissues: ii. measurements in the frequency range 10 hz to 20 ghz.Phys Med Biol. 1996; 41: 2251
- The electrical conductivity of human cerebrospinal fluid at body temperature.IEEE (Inst Electr Electron Eng) Trans Biomed Eng. 1997; 44: 220-223
- The dielectric properties of biological tissues: I. literature survey.Phys Med Biol. 1996; 41: 2231
- Oct. 1993. 3D statistical neuroanatomical models from 305 MRI volumes.in: Nuclear science symposium and medical imaging conference, 1993. vol. 3. IEEE Conference Record, 1993: 1813-1817
- Symmetric atlasing and model based segmentation: an application to the hippocampus in older adults.in: Medical image computing and computer-assisted intervention: MICCAI: International Conference on Medical Image Computing and Computer-Assisted Intervention. 9. 2006: 58-66 (Pt 2)
- Realistic volumetric-approach to simulate transcranial electric stimulation – roast – a fully automated open-source pipeline.(bioRxiv)2017
Article info
Publication history
Published online: September 26, 2018
Accepted:
September 16,
2018
Received in revised form:
August 3,
2018
Received:
April 18,
2018
Identification
Copyright
© 2018 Elsevier Inc. All rights reserved.
