New Paper: Design of Pivotal Trial of tDCS for Depression

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

Using Soterix Medical 1×1 CT platform: link

Neural Engineering
New Paper: Tolerability of Long-Term Application of tES in Healthy Subjects

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.

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Neural Engineering
Special BME seminar. Kronberg and Huang – Oct 26

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.

Neural Engineering
New Paper: Imaging tDCS current in MRI

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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Neural Engineering
New Paper: Review of Animal Models of tDCS

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 MechanismsClinical 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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Neural Engineering
Two Chapters in tDCS for in Neuropsychiatric Disorders books

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

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

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Neural Engineering
New Paper: Safety of tDCS, update 2016

Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016
Marom Bikson, Pnina Grossman, Chris Thomas, Adantchede Louis Zannou, Jimmy Jiang, Tatheer Adnan, Antonios P. Mourdoukoutas, Greg Kronberg, Dennis Truong, Paulo Boggio, André R. Brunoni, Leigh Charvet, Felipe Fregni, Brita Fritsch, Bernadette Gillick, Roy H. Hamilton, Benjamin M. Hampstead, Ryan Jankord, Adam Kirton, Helena Knotkova, David Liebetanz, Anli Liu, Colleen Loo, Michael A. Nitsche, Janine Reis, Jessica D. Richardson, Alexander Rotenberg, Peter E. Turkeltaub, Adam J. Woods
Brain Stimulation 2016, Vol. 9, Issue 5

Full PDF

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Neural Engineering
Farewell to Selin!

Since our lab is multidisciplinary, we have members from other fields than engineering. Selin Unal, is a medical student from Turkey that joined our lab for the summer and she is going to continue her research from Turkey remotely! See you soon Selin!

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Neural Engineering
Non-Invasive Neuromodulation Technology and Regulation Meeting

The “Non-invasive neuromodulation technology and regulation meeting” is a national meeting covering topics on the commercialization and regulation of non-invasive neuromodulation technology intended for medical and wellness use. This intensive one-day event is in direct response to the proliferation of clinical trials, popular press coverage, and now consumer-directed devices. The meeting is focused on transcranial Direct Current Stimulation (tDCS) but spans any investigational techniques or marketed technologies that apply electrical energy to the head. Ample time will be allowed for discussion with speakers.

Date: August 28, 2016
Location Center for Discovery and Innovation (CDI) Room Number – 4352

For more information visit the links below:
About this Meeting
Location
Speakers
Registration and Tickets
Program

Neural Engineering Lab members can ask for free registraton code from Dr. Marom Bikson or Bhaskar Paneri


Neural Engineering
New Paper: tDCS modulates Pattern Seperation

Transcranial direct current stimulation modulates pattern separation

Neuroreport 2016 DOI: 10.1097/WNR.0000000000000621

Full paper PDF

 

Marcus Cappiello, Weizhen Xie, Alexander David, Marom Bikson and Weiwei Zhang

Abstract: Maintaining similar memories in a distinct and nonoverlapping manner, known as pattern separation, is an important mnemonic process. The medial temporal lobe, especially the hippocampus, has been implicated in this crucial memory function. The present study thus examines whether it is possible to modulate pattern separation using bilateral transcranial direct current stimulation (tDCS) over the temporal lobes. Specifically, in this study, pattern separation was assessed using the Mnemonic Similarity Task following 15-min offline bilateral temporal lobe tDCS (left cathode and right anode or left anode and right cathode) or sham stimulation. In the Mnemonic Similarity Task, participants studied a series of sequentially presented visual objects. In the subsequent recognition memory test, participants viewed a series of sequentially presented objects that could be old images from study, novel foils, or lures that were visually similar to the studied images. Participants reported whether these images were exactly the same as, similar to, or different from the studied images. Following both active tDCS conditions, participants were less likely to identify lures as ‘similar’ compared with the sham condition, indicating a reduction in pattern separation resulting from temporal lobe tDCS. In contrast, no significant difference in overall accuracy was found for participants’ discrimination of old and new images. Together, these results suggest that temporal lobe tDCS can selectively modulate the pattern separation function without changing participants’ baseline recognition memory performance.

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Neural Engineering
Dr. Bikson speaks at NIH National Cancer Institute 6/13

Dr. Marom Bikson lectures at the National Institutes of Health (NIH) National Cancer Institute (NCI)

6/13/2016 NCI Shady Grove Campus Room TE406 9:30 AM

Medical Device Device for Innovative Cancer Therapies: Preclinical Evaluation, Clinical Trial Preparation, and a Prospective Clinical Trial of Intraoperative Real-Time Tissue Oxygenation Monitoring by Wireless Pulse Oximetry

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Neural Engineering
New Paper: Spatial and polarity precision of concentric high-definition transcranial direct current stimulation (HD-tDCS)

Alam M, Truong DQ, Khadka N , Bikson M
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Download: PDF Published in Physics in Medicine & Biology DOI 

Abstract:

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that applies low amplitude current via electrodes placed on the scalp. Rather than directly eliciting a neuronal response, tDCS is believed to modulate excitability—enhancing or suppressing neuronal activity in regions of the brain depending on the polarity of stimulation. The specificity of tDCS to any therapeutic application derives in part from how electrode configuration determines the brain regions that are stimulated. Conventional tDCS uses two relatively large pads (>25 cm2) whereas high-definition tDCS (HD-tDCS) uses arrays of smaller electrodes to enhance brain targeting. The 4  ×  1 concentric ring HD-tDCS (one center electrode surrounded by four returns) has been explored in application where focal targeting of cortex is desired. Here, we considered optimization of concentric ring HD-tDCS for targeting: the role of electrodes in the ring and the ring’s diameter. Finite element models predicted cortical electric field generated during tDCS. High resolution MRIs were segmented into seven tissue/material masks of varying conductivities. Computer aided design (CAD) model of electrodes, gel, and sponge pads were incorporated into the segmentation. Volume meshes were generated and the Laplace equation (  (σ  V)  =  0) was solved for cortical electric field, which was interpreted using physiological assumptions to correlate with stimulation and modulation. Cortical field intensity was predicted to increase with increasing ring diameter at the cost of focality while uni-directionality decreased. Additional surrounding ring electrodes increased uni-directionality while lowering cortical field intensity and increasing focality; though, this effect saturated and more than 4 surround electrode would not be justified. Using a range of concentric HD-tDCS montages, we showed that cortical region of influence can be controlled while balancing other design factors such as intensity at the target and uni-directionality. Furthermore, the evaluated concentric HD-tDCS approaches can provide categorical improvements in targeting compared to conventional tDCS. Hypothesis driven clinical trials, based on specific target engagement, would benefit by this more precise method of stimulation that could avoid potentially confounding brain regions.

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Neural Engineering