Textbook of Neuromodulation
Principles, Methods and Clinical Applications

Springer. ISBN: 978-1-4939-1407-4 

 

Methods and Technologies for Low-Intensity Transcranial Electrical Stimulation: Waveforms, Terminology, and Historical Notes
Page 7-16. Berkan Guleyupoglu, Pedro Schestatsky, Felipe Fregni, Marom Bikson

PDF: 10-1007978-1-4939-1408-12

 

A Role of Computational Modeling in Customization of Transcranial Direct Current Stimulation for Susceptible Populations
Dennis Truong, Preet Minhas, Albert Mokrejs, Marom Bikson

PDF: 10-1007978-1-4939-1408-110

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Direct current stimulation over the anterior temporal areas boosts semantic processing in primary progressive aphasia.

Teichmann M, Lesoil C, Godard J, Vernet M, Bertrand A, Levy R, Dubois B, Lemoine L, Truong DQ, Bikson M, Kas A, Valero-Cabré A. Ann Neurol. 2016 Nov;80(5):693-707. doi: 10.1002/ana.24766.

Download PDF: teichmann-et-al_annals-of-neurology_2016

Abstract: Objective: Noninvasive brain stimulation in primary progressive aphasia (PPA) is a promising approach. Yet, applied to single cases or insufficiently controlled small-cohort studies, it has not clarified its therapeutic value. We here address the effectiveness of transcranial direct current stimulation (tDCS) on the semantic PPA variant (sv-PPA), applying a rigorous study design to a large, homogeneous sv-PPA cohort. Methods: Using a double-blind, sham-controlled counterbalanced cross-over design, we applied three tDCS condi- tions targeting the temporal poles of 12 sv-PPA patients. Efficiency was assessed by a semantic matching task orthogonally manipulating “living”/”nonliving” categories and verbal/visual modalities. Conforming to predominantly left-lateralized damage in sv-PPA and accounts of interhemispheric inhibition, we applied left hemisphere anodal- excitatory and right hemisphere cathodal-inhibitory tDCS, compared to sham stimulation. Results: Prestimulation data, compared to 15 healthy controls, showed that patients had semantic disorders predomi- nating with living categories in the verbal modality. Stimulation selectively impacted these most impaired domains: Left- excitatory and right-inhibitory tDCS improved semantic accuracy in verbal modality, and right-inhibitory tDCS improved processing speed with living categories and accuracy and processing speed in the combined verbal 3 living condition. Interpretation: Our findings demonstrate the efficiency of tDCS in sv-PPA by generating highly specific intrasemantic effects. They provide “proof of concept” for future applications of tDCS in therapeutic multiday regimes, potentially driv- ing sustained improvement of semantic processing. Our data also support the hotly debated existence of a left temporal- pole network for verbal semantics selectively modulated through both left-excitatory and right-inhibitory brain stimulation.

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Contemp Clin Trials. 2016 Nov;51:65-71. doi: 10.1016/j.cct.2016.10.002. Epub 2016 Oct 15.

Study design and methodology for a multicentre, randomised controlled trial of transcranial direct current stimulation as a treatment for unipolar and bipolar depression.

Alonzo A, Aaronson S, Bikson M, Husain M, Lisanby S, Martin D, McClintock SM, McDonald WM, O’Reardon J, Esmailpoor Z, Loo C.

Download PDF: 10-1016j-cct-2016-10-002

Abstract: Transcranial Direct Current Stimulation (tDCS) is a new, non-invasive neuromodulation approach for treating depression that has shown promising efficacy. The aim of this trial was to conduct the first international, multicentre randomised controlled trial of tDCS as a treatment for unipolar and bipolar depression. The study recruited 120 participants across 6 sites in the USA and Australia. Participants received active or sham tDCS (2.5mA, 20 sessions of 30min duration over 4weeks), followed by a 4-week open label active treatment phase and a 4-week taper phase. Mood and neuropsychological outcomes were assessed with the primary antidepressant outcome measure being the Montgomery-Asberg Depression Rating Scale (MADRS). A neuropsychological battery was administered to assess safety and examine cognitive effects. The study also investigated the possible influence of genetic polymorphisms on outcomes. The trial was triple-blinded. Participants, tDCS treaters and study raters were blinded to each participant’s tDCS group allocation in the sham-controlled phase. Specific aspects of tDCS administration, device operation and group allocation were designed to optimise the integrity of blinding. Outcome measures will be tested using a mixed effects repeated measures analysis with the primary factors being Time as a repeated measure, tDCS condition (sham or active) and Diagnosis (unipolar or bipolar). A restricted number of random and fixed factors will be included as required to account for extraneous differences. As a promising treatment, tDCS has excellent potential for translation into widespread clinical use, being cost effective, portable, easy to operate and well tolerated.

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Using Soterix Medical 1×1 CT platform: link      tdcsct_02-s4

[Nov 18, 2016 Update: Proceeding of WorkShop Published: Download PDF: 23657]

Dr. Marom Bikson will speak at the

Forum on Neuroscience and Nervous System Disorders

Hosted by the National Academies. Event Page

Slides here: QuantificationOfNeuromodulationDose_Bikson

When: June 14, 2016 – June 15, 2016 (1:30 PM Eastern). Dr. Bikson lectures on June 15 at 9:55 AM

Where: Keck Center • 500 Fifth St. NW, Washington, DC 20001

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New Paper: Tolerability of Repeated Application of Transcranial Electrical Stimulation with Limited Outputs to Healthy Subjects

tolerability_limited_output_paper

Brain Stimulation 2016 May 24. pii: S1935-861X(16)30104-8. doi: 10.1016/j.brs.2016.05.008. [Epub ahead of print]

Abstract: The safety and tolerability of limited output tES in clinical populations support a non-significant risk designation. The tolerability of long-term use in a healthy population had remained untested. We tested the tolerability and compliance of two tES waveforms, tDCS and modulated high frequency transcranial pulsed current stimulation (MHF-tPCS) compared to sham-tDCS, applied to healthy subjects for three to five days (17–20 minutes per day) per week for up to six weeks in a communal setting. MHF-tPCS consisted of asymmetric high-frequency pulses (7–11 kHz) having a peak amplitude of 10–20 mA peak, adjusted by subject, resulting in an average current of 5–7 mA. A total of 100 treatment blind healthy subjects were randomly assigned to one of three treatment groups: tDCS (n = 33), MHF-tPCS (n = 30), or sham-tDCS (n = 37). In order to test the role of waveform, electrode type and montage were fixed across tES and sham-tDCS arms: high-capacity self-adhering electrodes on the right lateral forehead and back of the neck. We conducted 1905 sessions (636 sham-tDCS, 623 tDCS, and 646 MHF-tPCS sessions) on study volunteers over a period of six weeks. Common adverse events were primarily restricted to influences upon the skin and included skin tingling, itching, and mild burning sensations. The incidence of these events in the active tES treatment arms (MHF-tPCS, tDCS) was equivalent or significantly lower than their incidence in the sham-tDCS treatment arm. Other adverse events had a rarity (<5% incidence) that could not be significantly distinguished across the treatment groups. Some subjects were withdrawn from the study due to atypical headache (sham-tDCS n = 2, tDCS n = 2, and MHF-tPCS n = 3), atypical discomfort (sham-tDCS n = 0, tDCS n = 1, and MHF-tPCS n = 1), or atypical skin irritation (sham-tDCS n = 2, tDCS n = 8, and MHF-tPCS n = 1). The rate of compliance, elected sessions completed, for the MHF-tPCS group was significantly greater than the sham-tDCS group’s compliance (p = 0.007). There were no serious adverse events in any treatment condition. We conclude that repeated application of limited output tES across extended periods, limited to the hardware, electrodes, and protocols tested here, is well tolerated in healthy subjects, as previously observed in clinical populations.

Electrode configurations and montages. Identical electrodes and montages were ...

Special CCNY BME Seminar Oct 26, 2016 featuring two Neural Engineering Lab researchers.

3 PM in the CCNY BME conference room. Steinman Hall Room 402

Modulating synaptic plasticity with tDCS

Mr. Greg Kronberg

Department of Biomedical Engineering, The City College of New York

Abstract: Synapses allow communication between neurons and guide the flow of information throughout the brain. Modification of synapses in response to experience, or synaptic plasticity, is thought to be a cellular mechanism for learning and memory. Noninvasive tools to alter synaptic plasticity are therefore highly desirable. Recently, transcranial direct current stimulation (tDCS), has received much attention as a such a tool. tDCS is the noninvasive application of weak DC electric current to the brain through electrodes on the scalp. In this talk I will discuss mechanisms by which tDCS may influence synaptic plasticity, and how this can inform tDCS protocols to improve learning and memory

Bio-sketch: Greg Kronberg is currently a PhD student in the Biomedical Engineering department at The City College of New York (CCNY), where he works under Lucas Parra. He received his BS in Biology from the University of Maryland and his MS in Biomedical Engineering from CCNY. His research focuses on the use of electrical brain stimulation to improve learning and memory.

Measurements and models of electric fields in the in vivo human brain during transcranial electric stimulation

Yu (Andy) Huang, Ph.D.

Department of Biomedical Engineering, The City College of New York

Abstract: Transcranial electric stimulation aims to stimulate the brain by applying weak electrical currents at the scalp. However, the magnitude and spatial distribution of electric fields in the human brain are unknown. Here we measure electric potentials intracranially in ten patients and estimate electric fields across the entire brain by leveraging calibrated current-flow models. Electric field magnitudes at the cortical surface reach values of 0.4 V/m, which is at the lower limit of effectiveness in animal studies. When individual anatomy is taken into account, the predicted electric field magnitudes match the recorded values with r=0.77. Modeling white matter anisotropy and different skull compartments does not improve accuracy, but correct magnitude estimates require an adjustment of conductivity values used in the literature. This is the first study to validate and calibrate current-flow models with in vivo intracranial recordings in humans, providing a solid foundation for targeting and interpretation of clinical trials.

Biosketch: Yu (Andy) Huang received his Ph.D. from Department of Biomedical Engineering, City College of New York. His research focuses on neuroimaging, image segmentation and computational modeling of image data. He received his B.S. and M.S. from University of Electronic Science and Technology of China, both in Biomedical Engineering.

3rd BIC Symposium event website

The Brain Imaging Center at Icahn School of Medicine at Mount Sinai
Davis Auditorium (2nd floor) Hess Center for Science and Medicine
October 19, 2016

1:55-2:20 Lucas Parra, PhD (CCNY) – “On Brainwaves and Videos and Video Games”

3:15-3:40 Marom Bikson, PhD (CUNY) – “Non-invasive Brain Stimulation and Imaging” Download slides: marombikson_brainstimwithimaging_2016

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Marom Bikson lectures at the Interdisciplinary Late-Summer School on Non-Invasive Brain Stimulation in Freiburg, Germany (Oct 12-16, 2016). Event details here

Download Bikson’s slides on “Translational aspects of tDCS: from rodent to humans” –  bikson_nibs_summerschool_2016

Download Bikson slides on “Modeling tDCS current flow: Hand-on practical” modelingworkshop_summer

 

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Neuromodulation: Technology at the Neural Interface, Clinical Research

The Influence of Skin Redness on Blinding in Transcranial Direct Current Stimulation Studies: A Crossover Trial

Fernando Ezquerro, Adriano H. Moffa, Marom Bikson, Niranjan Khadka, Luana V. M. Aparicio, Bernardo de Sampaio-Junior, Felipe Fregni, Isabela M. Bensenor, Paulo A. Lotufo, Alexandre Costa Pereira, Andre R. Brunoni

Abstract:

Objective
To evaluate whether and to which extent skin redness (erythema) affects investigator blinding in transcranial direct current stimulation (tDCS) trials.
Material and Methods
Twenty-six volunteers received sham and active tDCS, which was applied with saline-soaked sponges of different thicknesses. High-resolution skin images, taken before and 5, 15, and 30 min after stimulation, were randomized and presented to experienced raters who evaluated erythema intensity and judged on the likelihood of stimulation condition (sham vs. active). In addition, semi-automated image processing generated probability heatmaps and surface area coverage of erythema. Adverse events were also collected.
Results
Erythema was present, but less intense in sham compared to active groups. Erythema intensity was inversely and directly associated to correct sham and active stimulation group allocation, respectively. Our image analyses found that erythema also occurs after sham and its distribution is homogenous below electrodes. Tingling frequency was higher using thin compared to thick sponges, whereas erythema was more intense under thick sponges.
Conclusions
Optimal investigator blinding is achieved when erythema after tDCS is mild. Erythema distribution under the electrode is patchy, occurs after sham tDCS and varies according to sponge thickness. We discuss methods to address skin erythema-related tDCS unblinding.

Full PDF: Erythema and tDCS

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Nature Scientific Reports

In-vivo Imaging of Magnetic Fields Induced by Transcranial Direct Current Stimulation (tDCS) in Human Brain using MRI

Mayank V. Jog, Robert X. Smith, Kay Jann, Walter Dunn, Belen Lafon, Dennis Truong, Allan Wu, Lucas Parra, Marom Bikson & Danny J. J. Wang

Transcranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation technique that applies mA currents at the scalp to modulate cortical excitability. Here, we present a novel magnetic resonance imaging (MRI) technique, which detects magnetic elds induced by tDCS currents. This technique is based on Ampere’s law and exploits the linear relationship between direct current and induced magnetic elds. Following validation on a phantom with a known path of electric current and induced magnetic eld, the proposed MRI technique was applied to a human limb (to demonstrate in- vivo feasibility using simple biological tissue) and human heads (to demonstrate feasibility in standard tDCS applications). The results show that the proposed technique detects tDCS induced magnetic elds as small as a nanotesla at millimeter spatial resolution. Through measurements of magnetic elds linearly proportional to the applied tDCS current, our approach opens a new avenue for direct in-vivo visualization of tDCS target engagement.

Full PDF: srep34385

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