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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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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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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Our new review is published:

Jackson MP, Rahman A, Lafon B, Kronberg G, Ling D, Parra LC, Bikson M, Animal Models of transcranial Direct Current Stimulation: Methods and Mechanisms, Clinical Neurophysiology, doi:10.1016/j.clinph.2016.08.016

Full PDF here: animalmodelstdcs_2016

Abstract:  The objective of this review is to summarize the contribution of animal research using direct current stimulation (DCS) to our understanding of the physiological effects of transcranial direct current stimulation (tDCS). We comprehensively address experimental methodology in animal studies, broadly classified as: 1) transcranial stimulation; 2) direct cortical stimulation in vivo and 3) in vitro models. In each case advantages and disadvantages for translational research are discussed including dose translation and the overarching “quasi-uniform” assumption, which underpins translational relevance in all animal models of tDCS. Terminology such as anode, cathode, inward current, outward current, current density, electric field, and uniform are defined. Though we put key animal experiments spanning decades in perspective, our goal is not simply an exhaustive cataloging of relevant animal studies, but rather to put them in context of ongoing efforts to improve tDCS. Cellular targets, including excitatory neuronal somas, dendrites, axons, interneurons, glial cells, and endothelial cells are considered. We emphasize neurons are always depolarized and hyperpolarized such that effects of DCS on neuronal excitability can only be evaluated within subcellular regions of the neuron. Findings from animal studies on the effects of DCS on plasticity (LTP/LTD) and network oscillations are reviewed extensively. Any endogenous phenomena dependent on membrane potential changes are, in theory, susceptible to modulation by DCS. The relevance of morphological changes (galvanotropy) to tDCS is also considered, as we suggest microscopic migration of axon terminals or dendritic spines may be relevant during tDCS. A majority of clinical studies using tDCS employ a simplistic dose strategy where excitability is singularly increased or decreased under the anode and cathode, respectively. We discuss how this strategy, itself based on classic animal studies, cannot account for the complexity of normal and pathological brain function, and how recent studies have already indicated more sophisticated approaches are necessary. One tDCS theory regarding “functional targeting” suggests the specificity of tDCS effects are possible by modulating ongoing function (plasticity). Use of animal models of disease are summarized including pain, movement disorders, stroke, and epilepsy

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Dr. Lucas Parra, Dr. Jacek Dmochowski, and Dr. Marom Bikson are speakers at the National Institute of Health (NIH) workshop on Transcranial Electrical Stimulation. Sept 29-30, 2016. Dr. Bikson is also a co-organizer of the event.

Full event details here  (watch it on WebX)

Synaptic Plasticity Mechanism Explains the Specificity of tDCS- Lucas Parra, PhD– Download Parra talk slides: talk-plasticity-september-2016

Computational Modeling-assisted Design of tDCS Protocols- Marom Bikson, PhD. — Download Bikson talk slides: nih_2016_bikson

Targeted Stimulation of Active Brain Sources Using Electromagnetic Reciprocity- Jacek Dmochowski, PhD

 

D.Q. Truong. D. Adair, M. Bikson. Computer-based models of tDCS of tACS in Transcranial Direct Current Stimulation in Neuropsychiatric Disorders: Clinical Principles ed. M.Nitsche, C. Loo and A. Brunoni 2016 10.1007/978-3-319-33967-2_5 p.47-66 . PDF:computermodels_chapter

D. Ling, A. Rahman, M. Jackson M. Bikson Animal studies in the field of transcranial electric stimulation in Transcranial Direct Current Stimulation in Neuropsychiatric Disorders: Clinical Principles M.Nitsche, C. Loo and A. Brunoni 2016 10.1007/978-3-319-33967-2_5 p.67-83 PDF: animalstudies_chapter

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