S.K. Kessler, A.J. Woods, P. Minhas, A.R. Rosen, C. Gorman, M. Bikson. Dosage considerations for transcranial direct current stimulation in children: a computational modeling study. PLoS ONE 8(9): e76112. doi:10.1371/journal.pone.0076112

Free online access here

Abstract:

Transcranial direct current stimulation (tDCS) is being widely investigated in adults as a therapeutic modality for brain disorders involving abnormal cortical excitability or disordered network activity. Interest is also growing in studying tDCS in children. Limited empirical studies in children suggest that tDCS is well tolerated and may have a similar safety profile as in adults. However, in electrotherapy as in pharmacotherapy, dose selection in children requires special attention, and simple extrapolation from adult studies may be inadequate. Critical aspects of dose adjustment include 1) differences in neurophysiology and disease, and 2) variation in brain electric fields for a specified dose due to gross anatomical differences between children and adults. In this study, we used high-resolution MRI derived finite element modeling simulations of two healthy children, ages 8 years and 12 years, and three healthy adults with varying head size to compare differences in electric field intensity and distribution. Multiple conventional and high-definition tDCS montages were tested. Our results suggest that on average, children will be exposed to higher peak electrical fields for a given applied current intensity than adults, but there is likely to be overlap between adults with smaller head size and children. In addition, exposure is montage specific. Variations in peak electrical fields were seen between the two pediatric models, despite comparable head size, suggesting that the relationship between neuroanatomic factors and bioavailable current dose is not trivial. In conclusion, caution is advised in using higher tDCS doses in children until 1) further modeling studies in a larger group shed light on the range of exposure possible by applied dose and age and 2) further studies correlate bioavailable dose estimates from modeling studies with empirically tested physiologic effects, such as modulation of motor evoked potentials after stimulation.

Three papers published in Frontiers of Neuroscience by CCNY Neural Engineering addressing current issues, idea, and challenges in non-invasive brain stimulation:

Berker AO, Bikson M, Bestmann S. Predicting the behavioural impact of transcranial direct current stimulation: issues and limitations Frontiers of Human Neuroscience 2013; doi 10.3389/fnhum.2013.00613 Journal Link

Rahman A, Bikson M. Origins of specificity during tDCS: anatomical, activity-selective, and input-bias mechanisms Frontiers of Human Neuroscience 2013; doi 10.3389/fnhum.2013.00688 Journal Link

Reato D, Rahman A, Bikson M, Parra LC. Effects of weak transcranial Alternating Current Stimulation on brain activity – a review of known mechanisms from animal studies. Frontiers of Human Neuroscience 2013; doi 10.3389/fnhum.2013.00687 Journal Link  PDF: Bikson_tACSreview

Prof. Marom Bikson was among scientists recognized at the 2013 Biomedical Engineering Society Meeting for the Wallace H Coulter foundation Translational Award. Dr. Bikson was supported by the Coulter Foundation to develop High-Definition transcranial Direct Current Stimulation which was commercialized by Soterix Medical Inc.

Nature. 2013 Sep 12;501(7466):167. doi: 10.1038/501167b.

Neuroscience: Transcranial devices are not playthings.

Bikson M, Bestmann S, Edwards D.

Comment on: Brain blast. [Nature. 2013]

Read full text here: Transcranial devices are not playthings_Nature 2013

Journal of Neuroscience Methods 219 (2013) p297-311

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Berkan Guleyupoglu, Pedro Schestatsky, Dylan Edwards, Felipe Fregni, Marom Bikson

Full text: JNeuroscienceMethods_TEShistory_2013

Abstract: Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and techni- cal review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of trans- cranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimu- lation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.

NYC Neuromodulation 2013 brings together pioneers and emerging innovations in Transcranial Electrical Stimulation. Cutting edge research, clinical trials, and techniques are introduced in a dynamic and interactive format. Learn how the field developed to its current state and the outlook for the next five years. Technologies covered include transcranial Direct Current Stimulation (tDCS), transcranial Alternating Current Stimulation (tACS), transcranial Random Noise Stimulation (tRNCS), and High-Definition transcranial Direct Current Stimulation (HD-tDCS). Topics covered include design of clinical trials, integration with monitoring technologies (EEG), and deployable technology. Broad opportunities to network, sponsor exhibits, two large poster sessions, two panel discussions, social event and a certification course provide plenty of networking and educational opportunities. The conference is chaired by Dr. Marom Bikson and hosted at the historic City College of New York in New York City.

More info here. Conference WILL sell out to reserve your space ASAP  LINK

Special CCNY BME Seminar: William J. Tyler,  Ph.D., Assistant Professor, Virginia Tech Carilion Research Institute and Assistant  Professor, School of Biomedical Engineering and Sciences, Virginia Tech

“A Cellular Mechanical Approach to Non-Invasively Modulating Brain Activity With Transcranial Pulsed Ultrasound.” 

 The seminar will be held on September 11, 2013 at 3:00 PM in Steinman Hall, Room ST-402.   Department of Biomedical Engineering, Grove School of Engineering  The City College of New York, 160 Convent Avenue New York, NY 10031

The Journal Club is back! Every Friday at 2pm in the conference room on the 5th floor in Steinman Hall.

Archy O. De Berker (1), Marom Bikson (2) and Sven Bestmann (1)

• 1 Sobell Department for Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, United Kingdom

• 2 Department of Biomedical Engineering, The City College of New York of CUNY, US

Abstract

The transcranial application of weak currents to the human brain has enjoyed a decade of success, providing a simple and powerful tool for non-invasively altering human brain function. However, our understanding of current delivery and its impact upon neural circuitry leaves much to be desired. We argue that the credibility of conclusions drawn with tDCS is contingent upon realistic explanations of how tDCS works, and that our present understanding of tDCS limits the technique’s use to localize function in the human brain. We outline two central issues where progress is required: the localization of currents, and predicting their functional consequence. We encourage experimenters to eschew simplistic explanations of mechanisms of transcranial current stimulation. We suggest the use of individualized current modelling, together with computational neurostimulation to inform mechanistic frameworks in which to interpret the physiological impact of tDCS. We hope that through mechanistically richer descriptions of current flow and action, insight into the biological processes by which transcranial currents influence behaviour can be gained, leading to more effective stimulation protocols and empowering conclusions drawn with tDCS.

Frontier link

This article is part of a special issue in Frontiers edited by Marom Bikson and Shennan Weiss.

M. F. Villamar, P. Wivatvongvana, J.Patumanond, M. Bikson, D.Q. Truong, A. Datta, F. Fregni. Focal modulation of primary motor cortex in Fibromyalgia using 4×1-Ring High-Definition Transcranial Direct Current Stimulation (HD-tDCS): Immediate and delayed analgesic effects of cathodal and anodal stimulation. J Pain, 2013; 14(4): 371-83 – Can be downloaded here: Villamar_Bikson_Focal_Modulation_HDtDCS_Pain_2013

H.I. Kuo, A. Datta, M. Bikson, P. Minhas. W. Paulus, M.F. Kuo, M.A. Nitsche Comparing cortical plasticity induced by conventional and high-definition 4×1 ring tDCS: a neurophysiological study. Brain Stimulation. 2013 6(4):644-8  Can be downloaded here: Kuo_Bikson_HDtDCS_Cortical_Plasticity_BrainStimulation_2013

and

Watch the new HD-tDCS methods video

HERE: JOVE

M.F. Villamar, M.S. Volz, A. Datta, M. Bikson, A.F. DaSilva, F. Fregni. Technique and Considerations in the Use of 4×1 Ring High-definition Transcranial Direct Current Stimulation (HD-tDCS) JOVE 2013 (77) doi: 10.3791/50309.

Jacek P. Dmochowski, Abhishek Datta, Yu Huang, Jessica D. Richardson, Marom Bikson, Julius Fridriksson, Lucas C. Parra

City College of New York, New York, NY, USA, Soterix Medical, New York, NY, USA, University of South Carolina, Columbia, SC, USA

Abstract: Transcranial direct current stimulation (tDCS) is being investigated as an adjunctive technique to behavioral rehabilitation treatment after stroke. The conventional “dosage”, consisting of a large (25 cm2) anode over the target with the cathode over the contralateral hemisphere, has been previously shown to yield broadly distributed electric fields whose intensities at the target region are less than maximal. Here, we report the results of a systematic targeting procedure with small “high-definition” electrodes that was used in preparation for a pilot study on 8 stroke patients with chronic aphasia. We employ functional and anatomical magnetic resonance imagery (fMRI/MRI) to define a target and optimize (with respect to the electric field magnitude at the target) the electrode configuration, respectively, and demonstrate that electric field strengths in targeted cortex can be substantially increased (63%) over the conventional approach. The optimal montage exhibits significant variation across subjects as well as when perturbing the target location within a subject. However, for each displacement of the target co-ordinates, the algorithm is able to determine a montage which delivers a consistent amount of current to that location. These results demonstrate that MRI-based models of current flow yield maximal stimulation of target structures, and as such, may aid in reliably assessing the efficacy of tDCS in neuro-rehabilitation.

Read the full paper here

Prof. Marom Bikson of The City College of New York lecture at the 2013 Harvard Medical School tDCS course on tDCS dose and mechanism. Topics include High-Definition tDCS (HD-tDCS), TDCS in children and in stroke, targeting, and optimization.

Part 1

Part 2

Jeremy Hill will speak on “Real-time interaction with brain processes”.

1 pm Aug 16th, BME Conference Room, 5th Floor, Grove School of Engineering

Brain Stimulation 6(3) 433-439

J. Medina, J. Beauvais, A. Datta, M. Bikson, H.B. Coslett, R.H. Hamilton.

Background

Previous research on hemispatial neglect has provided evidence for dissociable mechanisms for egocentric and allocentric processing. Although a few studies have examined whether tDCS to posterior parietal cortex can be beneficial for attentional processing in neurologically intact individuals, none have examined the potential effect of tDCS on allocentric and/or egocentric processing.

Objective/hypothesis

Our objective was to examine whether transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique that can increase (anodal) or decrease (cathodal) cortical activity, can affect visuospatial processing in an allocentric and/or egocentric frame of reference.

Methods

We tested healthy individuals on a target detection task in which the target – a circle with a gap – was either to the right or left of the viewer (egocentric), or contained a gap on the right or left side of the circle (allocentric). Individuals performed the task before, during, and after tDCS to the posterior parietal cortex in one of three stimulation conditions – right anodal/left cathodal, right cathodal/left anodal, and sham.

Results

We found an allocentric hemispatial effect both during and after tDCS, such that right anodal/left cathodal tDCS resulted in faster reaction times for detecting stimuli with left-sided gaps compared to right-sided gaps.

Conclusions

Our study suggests that right anodal/left cathodal tDCS has a facilitatory effect on allocentric visuospatial processing, and might be useful as a therapeutic technique for individuals suffering from allocentric neglect.

Read the Full Paper here

Keywords:

• Transcranial direct current stimulation;

• Neglect;

• Egocentric;

• Allocentric;

• Current density modeling

Brain Stimulation 6 (2013): 704-705

Marom Bikson, Jacek Dmochowski, Asif Rahman

From the articles ” Computational models of transcranial stimulation predict brain current flow patterns for dose optimization. Translational animal models aim at elucidating the cellular mechanisms of neuromodu- lation. Here we identify and define a ubiquitous assumption under- lying both computational and animal models, referred to herein as the “quasi-uniform assumption”. Though we attempt to rationalize the biophysical plausibility for the quasi-uniform assumption based on the limited electric field gradients generated during stimulation, our goal is neither to justify nor repudiate it, but rather emphasize its implicit use in a majority of modeling and animal studies. ”

Read the whole thing here

Cranial electrotherapy stimulation and transcranial pulsed current stimulation: A computer based high-resolution modeling study

Abhishek Datta, Jacek P. Dmochowski, Berkan Guleyupoglu, Marom Bikson, Felipe Fregni

Neuroimage. 2013 Jan 15;65:280-7. doi: 10.1016/j.neuroimage.2012.09.062. Epub 2012 Oct 5

Highlights:

► CES-induced current passes the skull and reaches cortical and subcortical areas.

► CES induced brain electric fields ranges from 0.2 to 0.6 V/m depending on the model.

► CES induced electrical current varies according to the electrode montage.

► Peak electric fields in some subcortical areas were similar to cortical regions.

► CES induced currents in the mid-brain exceed cortical values in some montages.

Download PDF 

Picture from Davide Reato.

Computational modeling of transcranial direct current stimulation (tDCS) in obesity: Impact of head fat and dose guidelines

NeuroImage: Clinical 2 (2013) 759–766

Dennis Q. Truong, Greta Magerowski, George L. Blackburn, Marom Bikson,Miguel Alonso-Alonso

Full PDF

Abstract

Recent studies show that acute neuromodulation of the prefrontal cortex with transcranial direct current stim- ulation (tDCS) can decrease food craving, attentional bias to food, and actual food intake. These data suggest po- tential clinical applications for tDCS in the field of obesity. However, optimal stimulation parameters in obese individuals are uncertain. One fundamental concern is whether a thick, low-conductivity layer of subcutaneous fat around the head can affect current density distribution and require dose adjustments during tDCS adminis- tration. The aim of this study was to investigate the role of head fat on the distribution of current during tDCS and evaluate whether dosing standards for tDCS developed for adult individuals in general are adequate for the obese population. We used MRI-derived high-resolution computational models that delineated fat layers in five human heads from subjects with body mass index (BMI) ranging from “normal-lean” to “super-obese” (20.9 to 53.5 kg/m2). Data derived from these simulations suggest that head fat influences tDCS current density across the brain, but its relative contribution is small when other components of head anatomy are added. Cur- rent density variability between subjects does not appear to have a direct and/or simple link to BMI. These results indicate that guidelines for the use of tDCS can be extrapolated to obese subjects without sacrificing efficacy and/ or treatment safety; the recommended standard parameters can lead to the delivery of adequate current flow to induce neuromodulation of brain activity in the obese population.

Methods to focalize noninvasive electrical brain stimulation: principles and future clinical development for the treatment of pain

Expert Rev. Neurother. 13(5), 465-7 (2013)

Cano T, Morales-Quezada JL, Bikson M, Fregni F.

PMID: 23621302

Read the PDF

-Tuesday May 21, 2012, Steinman Lecture Hall –

Please join us for a very special event at the Grove School of Engineering on Tuesday, May 21, 2013 – the 3rd Annual Kaylie Prize for Entrepreneurship at The City College of New York.   In topics ranging from using online tools to change how we wait in lines, changing paper recycling with disappearing ink, to wall-climbing robots in the subway, to innovations in medical technology, the Kaylie semi-finalist teams will compete in fast-paced presentations and physical demonstrations – culminating in the selection of a winner.

The Kaylie Prize for Entrepreneurship was established in 2010 through an endowment by alumnus Harvey Kaylie.  Mr. Kaylie is president and founder of Mini-Circuits, a Brooklyn-based RF and microwave electronic components design, manufacture, and distribution company.  The Kaylie Prize for Entrepreneurship has developed into one of the most innovative and exciting entrepreneurship mechanisms in New York City. It has facilitated rapid acceleration of commercialization of student-generated ideas. The prize is directed by Prof. Marom Bikson.

This event is an opportunity to experience an intensive one-day competition and join a network of NYC area business and engineering leaders.

 So please join us in the Steinman Lecture Hall:

3:30 pm               Opening remarks by President Coico, Mr. Kaylie and Dean Barba

3:44 pm               Introduction of teams by Prof. Marom Bikson

3:45 – 4:45 pm     Short presentations by each of the 5 teams
4:45 – 6:45 pm     Reception and judging

6:45 – 7:00 pm     Announcement of the winners by Mr. Kaylie