Transcranial Direct Current Stimulation (tDCS): What Pain Practitioners Need to Know
By Helena Knotkova, PhD, Adam J. Woods, PhD, Marom Bikson, PhD and Michael A. Nitsche, MD
Non-invasive brain stimulation with tDCS is an emerging tool for adjunctive treatment of pain syndromes. Its long-lasting analgesic effects are probably caused by alterations of activity in cerebral pain-processing networks.
Transcranial direct current stimulation in obsessive–compulsive disorder: emerging clinical evidence and considerations for optimal montage of electrodes
Expert Rev. Med. Devices, 1–11 (2015)
Full PDF: tDCSforOCD
Natasha M Senco, Yu Huang, Giordano D’Urso, Lucas C Parra, Marom Bikson, Antonio Mantovani, Roseli G Shavitt, Marcelo Q Hoexter, Eurıpedes C Miguel and Andre R Brunoni
Background: Neuromodulation techniques for obsessive–compulsive disorder (OCD) treatment have expanded with greater understanding of the brain circuits involved. Transcranial direct current stimulation (tDCS) might be a potential new treatment for OCD, although the optimal montage is unclear. Objective: To perform a systematic review on meta-analyses of repetitive transcranianal magnetic stimulation (rTMS) and deep brain stimulation (DBS) trials for OCD, aiming to identify brain stimulation targets for future tDCS trials and to support the empirical evidence with computer head modeling analysis. Methods: Systematic reviews of rTMS and DBS trials on OCD in Pubmed/MEDLINE were searched. For the tDCS computational analysis, we employed head models with the goal of optimally targeting current delivery to structures of interest. Results: Only three references matched our eligibility criteria. We simulated four different electrodes montages and analyzed current direction and intensity. Conclusion: Although DBS, rTMS and tDCS are not directly comparable and our theoretical model, based on DBS and rTMS targets, needs empirical validation, we found that the tDCS montage with the cathode over the pre-supplementary motor area and extra-cephalic anode seems to activate most of the areas related to OCD.
Soterix Medical HDExplore used.
Khadka N, Truong DQ, Bikson, M
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Download: PDF Published in Journal of Medical Devices DOI
Abstract
Within Electrode Current Steering (WECS) is a novel method that enhances reliability and tolerability of tDCS. The underlying assumption of WECS is steering current within electrodes but without altering current distribution in brain target. Through an exemplary case example of a realistic electrode and head geometry (FEM), we demonstrated how current flow in the brain is independent of current steering at the electrode. Three current split cases (even, partially uneven, and fully uneven), keeping total current (1 mA) fixed within the electrodes are tested. At the electrode-assembly interface with the skin, the current density distribution varied only incrementally across conditions (e.g. less than would be expected with even minor changes in electrode assembly or skin properties. There was no difference in the predicted electric filed at the brain target under all three cases. Thus, with such electrode assembly design, current steering to any functional electrode would not significantly increase current density in the skin (enhance tolerability during tDCS).
Behavioral and Cognitive Neuroscience Colloquium
Friday, 10:00 AM – 11:30 AM, May 8, 2015
Room C415A, The Graduate Center, 365 5th Ave, New York, NY 10016
Lucas Parra, City College, CUNY
“Brains on Video”
Abstract: Much of the research on human brain function studies the relationship between neural activity and specific events in the world (flashes, beeps, button pushes, and associated features such as contrast, frequency, reaction time, etc). We decided to abandon this conventional approach and look instead at responses of the brain to ongoing natural stimuli, and in particular, video. We found that when an audience watches video, their fast encephalographic brain responses are similar, however, only if the audience is paying attention! The effect is so strong that we can detect an audience’s attentional engagement in segments as short as 5 seconds. Indeed, similarity of encephalographic responses is predictive of a number of behaviors that presumably correlated with viewer’s attention, such as whether they continue watching a program, whether they ‘like’ certain ad segments, whether they decide to ‘tweet’ about it, and whether they remember the content weeks after they saw it. We believe that analyzing fast ongoing neural activity in response to natural stimuli has tremendous potential for basic inquiry into the functioning of the human brain, and has evident and important practical implications.
Special 200+ page issue of
The frontiers of clinical research on transcranial direct current stimulation (tDCS) in Neuropsychiatry
ready for FREE download here. We our work on the cover.
Includes our article
Inter-individual variation during transcranial direct current stimulation and normalization of dose using MRI-derived computational models
Available for individual download here
BME Day, May 01, 2015, Department of Biomedical Engineering, CCNY
Wireless Pulse Oximeter (WiPOX): Its Clinical Implications and Challenges
The WiPOX provides a tool for surgeons to objectively and reliably measure tissue viability during surgery rather than rely solely on their subjective visual inspection. Tissue ischemia is a major cause of wound dehiscence or anastomotic leakage resulting in significant morbidity and mortality occuring at a rate of 15 to 25%. Although measurement of systemic blood oxygenation status by finger-tip pulse oximetery is a mandatory requirement for every anesthetized patient, there is no standadrad procedure for intra-operative measurement of internal tissue oxygenation following complex resections and reconstructions.
Based on clinical experience gained in our trials, we present here the design of a second generation WiPOX that includes a reticulated pressure-sensitive head serving two related functions. First, the often-restricted and sensitive environment in which the device is employed constrains both the angle of approach and visibility, necessitating a self- correcting reticulated swiveling head that acts to improve the contact angle between the sensor head and the tissue. Second, because the devices is hand-held, the pressure on the tissue (often a membrane) is determined by the operator; too little pressure produces poor signal to noise ratio (SNR) while too much pressure can occlude blood flow, also reducing SNR and possibly yielding erroneously low oxygenation measurements. To address this, our sensor head includes a novel mounting for multiple “balloon” style pressure sensors that provide feedback on tissue contact pressure and contact angle. The reticulated head and pressure sensor features function in tandem to improve tissue contact and ensure
reliable measurements.
VENUE: Department of Biomedical Engineering, CCNY, ST 402
Harsh Baid, 17, of Bronx Science, wrote a piece of code that allows him to navigate the world of his favorite video game by moving his eyes.His project is enhancing gaming interfaces via gaze tracking. Baid approached Professor Lucas Parra, a professor of biomedical engineering at City College, to be his mentor.
Marom Bikson gives two lectures at Albert Einstein College of Medicine (Yeshiva University)
4/17/15
Kennedy Building Room 901. Map
2-3 PM Transcranial Direct Current Stimulation: How can one thing work for everything?
3-4 PM How electrotherapy devices work and why they fail to reach patients.
Niranjan Khadka presented a poster at the Minnesota Neuromodulation Symposium
Poster Title: Principles of Within Electrode Current Steering(WECS)
Department of Biomedical Engineering, The City College of New York, CUNY, 160 Convent Ave, New York, 10031, USA
Within Electrode Current Steering (WECS), a novel method, applies to non-invasive electrical stimulation with two or more electrodes to enhance reliability and tolerability during tDCS. The underlying assumption of WECS is steering current within electrodes (to compensate for any non-ideal conditions at the surface), but without altering current distribution in the brain target. This technology leverages our technique for independently isolating electrode impedance and over-potential during multi-channel stimulation. Through an exemplary case example of a realistic electrodes (metal-rivets embedded in an electrolyte (saline or gel)) and head geometry (FEM), we demonstrated how current flow in brain is independent of current steering at the electrode. Three current split cases (even, partially uneven, and fully uneven), keeping total current (1 mA) fixed within the electrodes are tested. At the electrode-assembly interface with the skin, the current density distribution varied only incrementally across conditions (e.g. less than would be expected) with even minor changes in electrode assembly or skin properties. There was no difference in the predicted electric filed at the brain target under all three cases. Thus, with such electrode assembly design, current steering to any functional electrode would not significantly increase current density in the skin; hence, not effecting tolerability.
Date & time: April 17, 2015 11:30-1:00 pm
Venue: University of Minnesota, Twin City, Minnesota
Niranjan Khadka presented a poster at the DMD Conference.
Poster Title: Design of Wireless Intraoperative Pulse Oximeter with Reticulated Pressure Sensitive Head
Link: KhadkaBiksonWiPOX
In order to provide a surgical tool that objectively and reliably measure tissue viability during surgery, we developed and validated a first generation compact handheld device for real time wireless monitoring of SPO2. Through the application of pressure sensor (provide feedback of real-time contact conditions of the device), reticulated shaft (facilitate flat contact with the tissue surface that are less visible), and systemic pulse rate input to signal tissue oxygenation through signal processing, this invention will enable surgeons to make treatment decision and measure the efficacy of the therapeutic interventions in real-time.
Date & time: April 15, 2015 5:30 – 7:00
Venue: McNamara Alumni Center, University of Minnesota, Minneapolis, MN
On the use of meta-analysis in neuromodulatory non-invasive brain stimulation
Brain Stimulation 2015 DOI: 10.1016/j.brs.2015.03.008
Michael A. Nitsche, MD, Marom Bikson, PhD, Sven Bestmann, PhD
Full PDF (in press version): MetaAnalysisinNeuromod105
In humans, non-invasive brain stimulation (NIBS) can modulate cortical excitability and activity. The buoyant use of this technique in basic and applied research requires further characterization of the basic mechanisms to divorce promising applications from those producing more heterogeneous outcomes. Here we outline some criteria and pitfalls for using published results to gain estimates about the effects of NIBS techniques through meta-analysis and related tools.
The Pursuit of DLPFC: Non-neuronavigated Methods to Target the Left Dorsolateral Pre-frontal Cortex With Symmetric Bicephalic Transcranial Direct Current Stimulation (tDCS)
Brain Stimulation 2015 doi: 10.1016/j.brs.2015.01.401
PDF (in press version): Bikson_Seibt_PursuitDLPFC_inpress2015 PubMED link
Ole Seibt, Andre R. Brunoni, Yu Huang, Marom Bikson
Abstract: The dose of transcranial direct current stimulation (tDCS) is defined by electrode montage and current, while the resulting brain current flow is more complex and varies across individuals. The left dorsolateral pre-frontal cortex (lDLPFC) is a common target in neuropsychology and neuropsychiatry applications, with varied approaches used to experimentally position electrodes on subjects. Objective: To predict brain current flow intensity and distribution using conventional symmetrical bicephalic frontal 1 1 electrode montages to nominally target lDLPFC in forward modeling studies. Methods: Six high-resolution Finite Element Method (FEM) models were created from five subjects of varied head size and an MNI standard. Seven electrode positioning methods, nominally targeting lDLPFC, were investigated on each head model: the EEG 10-10 including F3-F4, F5-F6, F7-8, F9-F10, the Beam F3- System, the 5-5 cm-Rule and the developed OLE-System were evaluated as electrode positioning methods for 5 5 cm2 rectangular sponge-pad electrodes. Results: Each positioning approach resulted in distinct electrode positions on the scalp and variations in brain current flow. Variability was significant, but trends across montages and between subjects were identified. Factors enhancing electric field intensity and relative targeting in lDLPFC include increased inter-electrode distance and proximity to thinner skull structures. Conclusion: Brain current flow can be shaped, but not focused, across frontal cortex by tDCS montages, including intensity at lDLPFC. The OLE-system balances lDLPFC targeting and reduced electric field variability, along with clinical ease-of-use.
Full Press Release link
Antonios Mourdoukoutas, a junior majoring in biomedical engineering in the Grove School of Engineering and Macaulay Honors College at The City College of New York, has been awarded a Goldwater Scholarship for 2015.
Mourdoukoutas, who has a 3.91 GPA, is a member of Professor Marom Bikson’s lab at City College. The Long Island resident helps model methods of noninvasive brain stimulation using electrodes placed on the skin surface to correct neurological disorders or facilitate the recovery of lost motor functions.
Mourdoukoutas is the third Goldwater Scholar from Professor Marom Bikson’s lab.
Kevin T. Jones, Jaclyn A. Stephens, Mahtab Alam, Marom Bikson, Marian E. Berryhill
Published: April 7, 2015
DOI: 10.1371/journal.pone.0121904 FREE ONLINE
Abstract: An increasing concern affecting a growing aging population is working memory (WM) decline. Consequently, there is great interest in improving or stabilizing WM, which drives expanded use of brain training exercises. Such regimens generally result in temporary WM benefits to the trained tasks but minimal transfer of benefit to untrained tasks. Pairing training with neurostimulation may stabilize or improve WM performance by enhancing plasticity and strengthening WM-related cortical networks. We tested this possibility in healthy older adults. Participants received 10 sessions of sham (control) or active (anodal, 1.5 mA) tDCS to the right prefrontal, parietal, or prefrontal/parietal (alternating) cortices. After ten minutes of sham or active tDCS, participants performed verbal and visual WM training tasks. On the first, tenth, and follow-up sessions, participants performed transfer WM tasks including the spatial 2-back, Stroop, and digit span tasks. The results demonstrated that all groups benefited from WM training, as expected. However, at follow-up 1-month after training ended, only the participants in the active tDCS groups maintained significant improvement. Importantly, this pattern was observed for both trained and transfer tasks. These results demonstrate that tDCS-linked WM training can provide long-term benefits in maintaining cognitive training benefits and extending them to untrained tasks.
Journal of Neurorestoratology 2015:3 73–82
Transcutaneous spinal stimulation as a therapeutic strategy for spinal cord injury: state of the art
PDF: BiksonFregniSpinalStim2015
Treatments for spinal cord injury (SCI) still have limited effects. Electrical stimu- lation might facilitate plastic changes in affected spinal circuitries that may be beneficial in improving motor function and spasticity or SCI-related neuropathic pain. Based on available animal and clinical evidence, we critically reviewed the physiological basis and therapeutic action of transcutaneous spinal cord stimulation in SCI. We analyzed the literature published on PubMed to date, looking for the role of three main noninvasive stimulation techniques in the recovery process of SCI and focusing mainly on transcutaneous spinal stimulation. This review discusses the main clinical applications, latest advances, and limitations of noninvasive electrical stimulation of the spinal cord. Although most recent research in this topic has focused on transcutaneous spinal direct current stimulation (tsDCS), we also reviewed the technique of transcutaneous electric nerve stimulation (TENS) and neuromuscular electrical stimulation (NMES) as potential methods to modulate spinal cord plasticity. We also developed a finite element method (FEM) model to predict current flow in the spinal cord when using different electrode montages. We identified gaps in our knowledge of noninvasive electrical stimulation in the modulation of spinal neuronal networks in patients with SCI. tsDCS, TENS, and NMES have a positive influence on the promotion of plasticity in SCI. Although there are no random- ized controlled studies of tsDCS in SCI, preliminary evidence is encouraging. FEMs predict that tsDCS electrode montage can be used to shape which spinal segments are modulated and what detailed areas of spinal anatomy can concentrate current density (eg, spinal roots). tsDCS is a technique that can influence conduction along ascending tracts in the spinal cord, so could modulate supraspinal activity. It may also be a promising new approach for a number of neu- ropsychiatric conditions.
Marom Bikson to be Inducted into Medical and Biological Engineering Elite
WASHINGTON, D.C.— The American Institute for Medical and Biological Engineering (AIMBE) has announced the pending induction of Marom Bikson, Ph.D., Professor of Biomedical Engineering, Department of Biomedical Engineering, City College of New York, to its College of Fellows. Dr. Bikson was nominated, reviewed, and elected by peers and members of the College of Fellows For outstanding contributions in the area of neuromodulation and the specific field of transcranial direct current stimulation of the brain.
The College of Fellows is comprised of the top two percent of medical and biological engineers in the country. The most accomplished and distinguished engineering and medical school chairs, research directors, professors, innovators, and successful entrepreneurs, comprise the College of Fellows.
AIMBE Fellows are regularly recognized for their contributions in teaching, research, and innovation. AIMBE Fellows have been awarded the Presidential Medal of Science and the Presidential Medal of Technology and Innovation and many also are members of the National Academy of Engineering, Institute of Medicine, and the National Academy of Sciences.
A formal induction ceremony will be held during AIMBE’s 2015 Annual Meeting at the National Academy of Sciences Great Hall in Washington, DC on March 16, 2015. Dr. Bikson will be inducted along with 150 colleagues who make up the AIMBE College of Fellows Class of 2015. For more information about the AIMBE Annual Meet, please visit www.aimbe.org.
AIMBE’s mission is to recognize excellence in, and advocate for, the fields of medical and biological engineering in order to advance society. Since 1991, AIMBE‘s College of Fellows has lead the way for technological growth and advancement in the fields of medical and biological engineering. Fellows have helped revolutionize medicine and related fields in order to enhance and extend the lives of people all over the world. They have also successfully advocated for public policies that have enabled researchers and business-makers to further the interests of engineers, teachers, scientists, clinical practitioners, and ultimately, patients.
Image. Dr. Marom Bikson with Dr. Gilda Barabino at the AIMBE induction ceremony at the National Academy of Science in Washington DC. Dr. Bikson is a new fellow for 2015. Dr. Barabino is the CCNY Grove School of Engineering Dean and the rising president of AIMBE.
Khadka N, Rahman A, Sarantos C, Truong DQ, Bikson M
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Download: PDF Published in Brain Stimulation DOI
Abstract:
Background: Monitoring of electrode resistance during tDCS is considered important for tolerability and safety. Conventional resistance measurement methods do not isolate individual electrode resistance and for HD-tDCS devices, cross talk across electrodes makes concurrent resistance monitoring unreliable. Objective: We propose a novel method to monitor individual electrode resistance during tDCS, using a super-position of direct current with a test-signal (low intensity and low frequency sinusoids with electrodeespecific frequencies) and a sentinel electrode (not used for DC).
Methods: We developed and solved lumped-parameter models of tDCS electrodes with or without a sentinel electrode to validate this methodology. Assumptions were tested and parameterized in partic- ipants using forearm stimulation combining tDCS (2 mA) and test-signals (38 and 76 mA pk-pk at 1 Hz, 10 Hz, & 100 Hz) and an in vitro test (creating electrode failure modes). DC and AC component voltages across the electrodes were compared and participants were asked to rate subjective pain.
Results: A sentinel electrode is required to isolate electrode resistance in a two-electrode tDCS system. Cross talk aggravated with electrode proximity and resistance mismatch in multi-electrode resistance tracking could be corrected using proposed approaches. Average voltage and pain scores were not significantly different across test current intensities and frequencies.
Conclusion: Using our developed method, a test signal can predict DC electrode resistance. Since unique test frequencies can be used at each tDCS electrode, specific electrode resistance can be resolved for any number of stimulating channels – a process made still more robust by the use of a sentinel electrode.
J Neurophysiol 113: 1334–1341, 2015. Full PDF: ReatoLastingEffectsoftDCS2
Lasting modulation of in vitro oscillatory activity with weak direct current stimulation
Davide Reato, Marom Bikson, Lucas C. Parra
Transcranial direct current stimulation (tDCS) is emerging as a versatile tool to affect brain function. While the acute neurophysiological effects of stimulation are well under- stood, little is know about the long-term effects. One hypothesis is that stimulation modulates ongoing neural activity, which then translates into lasting effects via physiological plasticity. Here we used carba- chol-induced gamma oscillations in hippocampal rat slices to establish whether prolonged constant current stimulation has a lasting effect on endogenous neural activity. During 10 min of stimulation, the power and frequency of gamma oscillations, as well as multiunit activity, were modulated in a polarity specific manner. Remarkably, the effects on power and multiunit activity persisted for more than 10 min after stimulation terminated. Using a computational model we propose that altered synaptic efficacy in excitatory and inhibitory pathways could be the source of these lasting effects. Future experimental studies using this novel in vitro preparation may be able to confirm or refute the proposed hypothesis.
March 11, Wed. 3-4:15pm in T-402 at CCNY Steinman Hall
Dr. Amy Kuceyeski: “The (dys)-connectome: quantifying brain network influences in disease and recovery“
How the human brain successfully completes varied and complex tasks is still largely unknown. In the past, brain-behavior relationships were derived from single subject studies wherein a focal lesion was linked to a corresponding impairment in a one-to-one manner. Recently developed neuroimaging methods, however, have allowed an unprecedented investigation of the workings of the human brain in health and disease. Neuroimaging methods are now able to measure the in vivo structural or functional connectivity between different brain regions. Studies of brain networks in health (the connectome) and disease (the dys-connectome) have begun to shed light on the true nature of brain-behavior relationships, which in most cases is many-to-many. This talk will present some recent work on statistical modeling of connectome-behavior relationships in disease as well as some preliminary work in mathematical modeling of network-level brain plasticity in recovery from injury. It is imperative that we understand the brain and its connectome if we aim to restore proper function after disease or injury.
Dr. Amy Kuceyeski is an assistant professor of Mathematics and Neuroscience in the Radiology Department and the Brain and Mind Research Institute at Weill Cornell Medical College.