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Simula S, Daoud M, Ruffini G, Biagi MC, Bénar CG, Benquet P, Wendling F, Bartolomei F. Transcranial current stimulation in epilepsy: A systematic review of the fundamental and clinical aspects. Front Neurosci 2022; 16:909421. [PMID: 36090277 PMCID: PMC9453675 DOI: 10.3389/fnins.2022.909421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose Transcranial electrical current stimulation (tES or tCS, as it is sometimes referred to) has been proposed as non-invasive therapy for pharmacoresistant epilepsy. This technique, which includes direct current (tDCS) and alternating current (tACS) stimulation involves the application of weak currents across the cortex to change cortical excitability. Although clinical trials have demonstrated the therapeutic efficacy of tES, its specific effects on epileptic brain activity are poorly understood. We sought to summarize the clinical and fundamental effects underlying the application of tES in epilepsy. Methods A systematic review was performed in accordance with the PRISMA guidelines. A database search was performed in PUBMED, MEDLINE, Web of Science and Cochrane CENTRAL for articles corresponding to the keywords “epilepsy AND (transcranial current stimulation OR transcranial electrical stimulation)”. Results A total of 56 studies were included in this review. Through these records, we show that tDCS and tACS epileptic patients are safe and clinically relevant techniques for epilepsy. Recent articles reported changes of functional connectivity in epileptic patients after tDCS. We argue that tDCS may act by affecting brain networks, rather than simply modifying local activity in the targeted area. To explain the mechanisms of tES, various cellular effects have been identified. Among them, reduced cell loss, mossy fiber sprouting, and hippocampal BDNF protein levels. Brain modeling and human studies highlight the influence of individual brain anatomy and physiology on the electric field distribution. Computational models may optimize the stimulation parameters and bring new therapeutic perspectives. Conclusion Both tDCS and tACS are promising techniques for epilepsy patients. Although the clinical effects of tDCS have been repeatedly assessed, only one clinical trial has involved a consistent number of epileptic patients and little knowledge is present about the clinical outcome of tACS. To fill this gap, multicenter studies on tES in epileptic patients are needed involving novel methods such as personalized stimulation protocols based on computational modeling. Furthermore, there is a need for more in vivo studies replicating the tES parameters applied in patients. Finally, there is a lack of clinical studies investigating changes in intracranial epileptiform discharges during tES application, which could clarify the nature of tES-related local and network dynamics in epilepsy.
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Affiliation(s)
- Sara Simula
- Aix Marseille Univ, INSERM, INS, Int Neurosci Syst, Marseille, France
| | - Maëva Daoud
- Aix Marseille Univ, INSERM, INS, Int Neurosci Syst, Marseille, France
| | | | | | | | | | | | - Fabrice Bartolomei
- Aix Marseille Univ, INSERM, INS, Int Neurosci Syst, Marseille, France
- APHM, Timone Hospital, Epileptology and Cerebral Rhythmology, Marseille, France
- *Correspondence: Fabrice Bartolomei
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2
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Kaufmann E, Hordt M, Lauseker M, Palm U, Noachtar S. Acute effects of spaced cathodal transcranial direct current stimulation in drug resistant focal epilepsies. Clin Neurophysiol 2021; 132:1444-1451. [PMID: 34023626 DOI: 10.1016/j.clinph.2021.03.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 02/28/2021] [Accepted: 03/13/2021] [Indexed: 01/04/2023]
Abstract
OBJECTIVE To evaluate the safety and temporal dynamic of the antiepileptic effect of spaced transcranial direct current stimulation (tDCS) in different focal epilepsies. METHODS Cathodal tDCS with individual electrode placement was performed in 15 adults with drug resistant focal epilepsy. An amplitude of 2 mA was applied twice for 9 minutes, with an interstimulation interval of 20 minutes. Tolerability was assessed via the Comfort Rating Questionnaire and the frequency of interictal epileptiform discharges (IEDs) was sequentially compared between the 24 hours before and after tDCS. RESULTS TDCS led to a significant reduction in the total number of IEDs/24 h by up to 68% (mean ± SD: -30.4 ± 21.1%, p = 0.001) as well as in seizure frequency (p = 0.041). The maximum IED reduction was observed between the 3rd and 21st hour after stimulation. Favorable clinical response was associated with structural etiology and clearly circumscribed epileptogenic foci but did not differ between frontal and temporal epilepsies. Overall, the tDCS treatment was well tolerated and did not lead to severe adverse events. CONCLUSIONS The spaced stimulation approach proved to be safe and well-tolerated in patients with drug-resistant unifocal epilepsies, leading to sustained IED and seizure frequency reduction. SIGNIFICANCE Spaced tDCS induces mediate antiepileptic effects with promising therapeutic potential.
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Affiliation(s)
- Elisabeth Kaufmann
- Epilepsy Center, Department of Neurology, University Hospital, LMU Munich, Munich, Germany.
| | - Mirjam Hordt
- Epilepsy Center, Department of Neurology, University Hospital, LMU Munich, Munich, Germany
| | - Michael Lauseker
- Institute for Medical Information Processing, Biometry, and Epidemiology, LMU Munich, Munich, Germany
| | - Ulrich Palm
- Department of Psychiatry and Psychotherapy, LMU Munich, Munich, Germany
| | - Soheyl Noachtar
- Epilepsy Center, Department of Neurology, University Hospital, LMU Munich, Munich, Germany
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3
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The visual system as target of non-invasive brain stimulation for migraine treatment: Current insights and future challenges. PROGRESS IN BRAIN RESEARCH 2020. [PMID: 33008507 DOI: 10.1016/bs.pbr.2020.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
The visual network is crucially implicated in the pathophysiology of migraine. Several lines of evidence indicate that migraine is characterized by an altered visual cortex excitability both during and between attacks. Visual symptoms, the most common clinical manifestation of migraine aura, are likely the result of cortical spreading depression originating from the extrastriate area V3A. Photophobia, a clinical hallmark of migraine, is linked to an abnormal sensory processing of the thalamus which is converged with the non-image forming visual pathway. Finally, visual snow is an increasingly recognized persistent visual phenomenon in migraine, possibly caused by increased perception of subthreshold visual stimuli. Emerging research in non-invasive brain stimulation (NIBS) has vastly developed into a diversity of areas with promising potential. One of its clinical applications is the single-pulse transcranial magnetic stimulation (sTMS) applied over the occipital cortex which has been approved for treating migraine with aura, albeit limited evidence. Studies have also investigated other NIBS techniques, such as repetitive TMS (rTMS) and transcranial direct current stimulation (tDCS), for migraine prophylaxis but with conflicting results. As a dynamic brain disorder with widespread pathophysiology, targeting migraine with NIBS is challenging. Furthermore, unlike the motor cortex, evidence suggests that the visual cortex may be less plastic. Controversy exists as to whether the same fundamental principles of NIBS, based mainly on findings in the motor cortex, can be applied to the visual cortex. This review aims to explore existing literature surrounding NIBS studies on the visual system of migraine. We will first provide an overview highlighting the direct implication of the visual network in migraine. Next, we will focus on the rationale behind using NIBS for migraine treatment, including its effects on the visual cortex, and the shortcomings of currently available evidence. Finally, we propose a broader perspective of how novel approaches, the concept of brain networks and the integration of multimodal imaging with computational modeling, can help refine current NIBS methods, with the ultimate goal of optimizing a more individualized treatment for migraine.
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4
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Gomez-Tames J, Asai A, Mikkonen M, Laakso I, Tanaka S, Uehara S, Otaka Y, Hirata A. Group-level and functional-region analysis of electric-field shape during cerebellar transcranial direct current stimulation with different electrode montages. J Neural Eng 2019; 16:036001. [DOI: 10.1088/1741-2552/ab0ac5] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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5
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Gomez-Tames J, Hirata A, Tamura M, Muragaki Y. Corticomotoneuronal Model for Intraoperative Neurophysiological Monitoring During Direct Brain Stimulation. Int J Neural Syst 2019; 29:1850026. [DOI: 10.1142/s0129065718500260] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Intraoperative neurophysiological monitoring during brain surgery uses direct cortical stimulation to map the motor cortex by recording muscle activity induced by the excitation of alpha motor neurons (MNs). Computational models have been used to understand local brain stimulation. However, a computational model revealing the stimulation process from the cortex to MNs has not yet been proposed. Thus, the aim of the current study was to develop a corticomotoneuronal (CMN) model to investigate intraoperative stimulation during surgery. The CMN combined the following three processes into one system for the first time: (1) induction of an electric field in the brain based on a volume conductor model; (2) activation of pyramidal neuron (PNs) with a compartment model; and (3) formation of presynaptic connections of the PNs to MNs using a conductance-based synaptic model coupled with a spiking model. The implemented volume conductor model coupled with the axon model agreed with experimental strength-duration curves. Additionally, temporal/spatial and facilitation effects of CMN synapses were implemented and verified. Finally, the integrated CMN model was verified with experimental data. The results demonstrated that our model was necessary to describe the interaction between frequency and pulses to assess the difference between low-frequency and multi-pulse high-frequency stimulation in cortical stimulation. The proposed model can be used to investigate the effect of stimulation parameters on the cortex to optimize intraoperative monitoring.
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Affiliation(s)
- Jose Gomez-Tames
- Department of Electromechanical Engineering, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Akimasa Hirata
- Department of Electromechanical Engineering, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Manabu Tamura
- Faculty of Advanced Techno-Surgery, Institute of Advanced Biomedical Engineering and Science, Tokyo Women’s Medical University, Shinjuku-ku, Tokyo 162-8666, Japan
- Department of Neurosurgery, Neurological Institute, Tokyo Women’s Medical University, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Yoshihiro Muragaki
- Faculty of Advanced Techno-Surgery, Institute of Advanced Biomedical Engineering and Science, Tokyo Women’s Medical University, Shinjuku-ku, Tokyo 162-8666, Japan
- Department of Neurosurgery, Neurological Institute, Tokyo Women’s Medical University, Shinjuku-ku, Tokyo 162-8666, Japan
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6
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Ciechanski P, Carlson HL, Yu SS, Kirton A. Modeling Transcranial Direct-Current Stimulation-Induced Electric Fields in Children and Adults. Front Hum Neurosci 2018; 12:268. [PMID: 30018543 PMCID: PMC6037769 DOI: 10.3389/fnhum.2018.00268] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 06/11/2018] [Indexed: 11/13/2022] Open
Abstract
Transcranial direct-current stimulation (tDCS) is a form of non-invasive brain stimulation that induces electric fields in neuronal tissue, modulating cortical excitability. Therapeutic applications of tDCS are rapidly expanding, and are being investigated in pediatrics for various clinical conditions. Anatomical variations are among a host of factors that influence the effects of tDCS, and pronounced anatomical differences between children and adults suggest that induced electric fields may be substantially different across development. The aim of this study was to determine the strength and distribution of tDCS-induced electric fields across development. Typically developing children, adolescents, and adults were recruited. Individualized finite-element method modeling of primary motor cortex (M1) targeting tDCS was performed. In the largest pediatric sample to date, we found significantly higher peak and mean M1 electric field strength, and more expansive electric field spread for children compared to adults. Electric fields were often comparable between adolescents and adults. Our results suggest that these differences may be associated with age-related differences in skull and extra-axial space thickness, as well as developmental changes occurring in gray and white matter. Individualized current modeling may be a valuable tool for personalizing effective doses of tDCS in future pediatric clinical trials.
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Affiliation(s)
- Patrick Ciechanski
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, AB, Canada.,Department of Neurosciences, University of Calgary, Calgary, AB, Canada
| | - Helen L Carlson
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, AB, Canada
| | - Sabrina S Yu
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, AB, Canada
| | - Adam Kirton
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, AB, Canada.,Departments of Pediatrics and Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
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Sridhar C, Bhat S, Acharya UR, Adeli H, Bairy GM. Diagnosis of attention deficit hyperactivity disorder using imaging and signal processing techniques. Comput Biol Med 2017; 88:93-99. [DOI: 10.1016/j.compbiomed.2017.07.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/21/2017] [Accepted: 07/06/2017] [Indexed: 12/21/2022]
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8
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Jankowska E. Spinal control of motor outputs by intrinsic and externally induced electric field potentials. J Neurophysiol 2017; 118:1221-1234. [PMID: 28539396 DOI: 10.1152/jn.00169.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/22/2017] [Accepted: 05/22/2017] [Indexed: 12/13/2022] Open
Abstract
Despite numerous studies on spinal neuronal systems, several issues regarding their role in motor behavior remain unresolved. One of these issues is how electric fields associated with the activity of spinal neurons influence the operation of spinal neuronal networks and how effects of these field potentials are combined with other means of modulating neuronal activity. Another closely related issue is how external electric field potentials affect spinal neurons and how they can be used for therapeutic purposes such as pain relief or recovery of motor functions by transspinal direct current stimulation. Nevertheless, progress in our understanding of the spinal effects of electric fields and their mechanisms has been made over the last years, and the aim of the present review is to summarize the recent findings in this field.
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Affiliation(s)
- Elzbieta Jankowska
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden
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9
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Manoli Z, Parazzini M, Ravazzani P, Samaras T. The electric field distributions in anatomical head models during transcranial direct current stimulation for post-stroke rehabilitation. Med Phys 2017; 44:262-271. [DOI: 10.1002/mp.12006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 11/01/2016] [Accepted: 11/12/2016] [Indexed: 11/10/2022] Open
Affiliation(s)
- Zoi Manoli
- Department of Physics; Aristotle University of Thessaloniki; Thessaloniki 54124 Greece
- THESS S.A.; Thessaloniki 57001 Greece
| | - Marta Parazzini
- National Research Council (CNR); Institute of Electronics; Computer and Telecommunication Engineering; Milano 20133 Italy
| | - Paolo Ravazzani
- National Research Council (CNR); Institute of Electronics; Computer and Telecommunication Engineering; Milano 20133 Italy
| | - Theodoros Samaras
- Department of Physics; Aristotle University of Thessaloniki; Thessaloniki 54124 Greece
- Department of Physics; University of Malta; Msida MSD 2080 Malta
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10
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Lee C, Jung YJ, Lee SJ, Im CH. COMETS2: An advanced MATLAB toolbox for the numerical analysis of electric fields generated by transcranial direct current stimulation. J Neurosci Methods 2016; 277:56-62. [PMID: 27989592 DOI: 10.1016/j.jneumeth.2016.12.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 12/12/2016] [Accepted: 12/13/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Since there is no way to measure electric current generated by transcranial direct current stimulation (tDCS) inside the human head through in vivo experiments, numerical analysis based on the finite element method has been widely used to estimate the electric field inside the head. In 2013, we released a MATLAB toolbox named COMETS, which has been used by a number of groups and has helped researchers to gain insight into the electric field distribution during stimulation. The aim of this study was to develop an advanced MATLAB toolbox, named COMETS2, for the numerical analysis of the electric field generated by tDCS. NEW METHOD COMETS2 can generate any sizes of rectangular pad electrodes on any positions on the scalp surface. To reduce the large computational burden when repeatedly testing multiple electrode locations and sizes, a new technique to decompose the global stiffness matrix was proposed. RESULTS As examples of potential applications, we observed the effects of sizes and displacements of electrodes on the results of electric field analysis. The proposed mesh decomposition method significantly enhanced the overall computational efficiency. COMPARISON WITH EXISTING METHODS We implemented an automatic electrode modeler for the first time, and proposed a new technique to enhance the computational efficiency. CONCLUSIONS In this paper, an efficient toolbox for tDCS analysis is introduced (freely available at http://www.cometstool.com). It is expected that COMETS2 will be a useful toolbox for researchers who want to benefit from the numerical analysis of electric fields generated by tDCS.
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Affiliation(s)
- Chany Lee
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea
| | - Young-Jin Jung
- Department of Radiological Science, Dongseo University, Busan, Republic of Korea
| | - Sang Jun Lee
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea
| | - Chang-Hwan Im
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea.
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11
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Gschwind M, Seeck M. Transcranial direct-current stimulation as treatment in epilepsy. Expert Rev Neurother 2016; 16:1427-1441. [DOI: 10.1080/14737175.2016.1209410] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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12
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Bocci T, Santarcangelo E, Vannini B, Torzini A, Carli G, Ferrucci R, Priori A, Valeriani M, Sartucci F. Cerebellar direct current stimulation modulates pain perception in humans. Restor Neurol Neurosci 2016; 33:597-609. [PMID: 25777683 DOI: 10.3233/rnn-140453] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE The cerebellum is involved in a wide number of integrative functions, but its role in pain experience and in the nociceptive information processing is poorly understood. In healthy volunteers we evaluated the effects of transcranial cerebellar direct current stimulation (tcDCS) by studying the changes in the perceptive threshold, pain intensity at given stimulation intensities (VAS:0-10) and laser evoked potentials (LEPs) variables (N1 and N2/P2 amplitudes and latencies). METHODS Fifteen subjects were studied before and after anodal, cathodal and sham tcDCS. LEPs were obtained using a neodymium:yttrium-aluminium-perovskite (Nd:YAP) laser and recorded from the dorsum of the left hand. VAS was evaluated by delivering laser pulses at two different intensities, respectively two and three times the perceptive threshold. RESULTS Cathodal polarization dampened significantly the perceptive threshold and increased the VAS score, while the anodal one had opposite effects. Cathodal tcDCS increased significantly the N1 and N2/P2 amplitudes and decreased their latencies, whereas anodal tcDCS elicited opposite effects. Motor thresholds assessed through transcranial magnetic stimulation were not affected by cerebellar stimulation. CONCLUSIONS tcDCS modulates pain perception and its cortical correlates. Since it is effective on both N1 and N2/P2 components, we speculate that the cerebellum engagement in pain processing modulates the activity of both somatosensory and cingulate cortices. Present findings prompt investigation of the cerebellar direct current polarization as a possible novel and safe therapeutic tool in chronic pain patients.
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Affiliation(s)
- Tommaso Bocci
- Department of Clinical and Experimental Medicine, Unit of Neurology, Pisa University Medical School, Pisa, Italy.,Department of Medical and Surgical Sciences and Neuroscience, University of Siena, Siena, Italy
| | - Enrica Santarcangelo
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Beatrice Vannini
- Department of Clinical and Experimental Medicine, Unit of Neurology, Pisa University Medical School, Pisa, Italy
| | - Antonio Torzini
- Department of Medical and Surgical Sciences and Neuroscience, University of Siena, Siena, Italy.,Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
| | - Giancarlo Carli
- Department of Medical and Surgical Sciences and Neuroscience, University of Siena, Siena, Italy
| | - Roberta Ferrucci
- Department of Neurological Sciences, University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Alberto Priori
- Department of Neurological Sciences, University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Massimiliano Valeriani
- Division of Neurology, Ospedale Bambino Gesù, IRCCS, Rome, Italy.,Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark
| | - Ferdinando Sartucci
- Department of Clinical and Experimental Medicine, Unit of Neurology, Pisa University Medical School, Pisa, Italy.,Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
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13
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Giraldo-Suarez E, Martinez-Vargas JD, Castellanos-Dominguez G. Reconstruction of Neural Activity from EEG Data Using Dynamic Spatiotemporal Constraints. Int J Neural Syst 2016; 26:1650026. [PMID: 27354190 DOI: 10.1142/s012906571650026x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We present a novel iterative regularized algorithm (IRA) for neural activity reconstruction that explicitly includes spatiotemporal constraints, performing a trade-off between space and time resolutions. For improving the spatial accuracy provided by electroencephalography (EEG) signals, we explore a basis set that describes the smooth, localized areas of potentially active brain regions. In turn, we enhance the time resolution by adding the Markovian assumption for brain activity estimation at each time period. Moreover, to deal with applications that have either distributed or localized neural activity, the spatiotemporal constraints are expressed through [Formula: see text] and [Formula: see text] norms, respectively. For the purpose of validation, we estimate the neural reconstruction performance in time and space separately. Experimental testing is carried out on artificial data, simulating stationary and non-stationary EEG signals. Also, validation is accomplished on two real-world databases, one holding Evoked Potentials and another with EEG data of focal epilepsy. Moreover, responses of functional magnetic resonance imaging for the former EEG data have been measured in advance, allowing to contrast our findings. Obtained results show that the [Formula: see text]-based IRA produces a spatial resolution that is comparable to the one achieved by some widely used sparse-based estimators of brain activity. At the same time, the [Formula: see text]-based IRA outperforms other similar smooth solutions, providing a spatial resolution that is lower than the sparse [Formula: see text]-based solution. As a result, the proposed IRA is a promising method for improving the accuracy of brain activity reconstruction.
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Affiliation(s)
- E. Giraldo-Suarez
- Department of Electrical Engineering, Universidad Tecnológica de Pereira, Colombia
| | - J. D. Martinez-Vargas
- Signal Processing and Recognition Group, Universidad Nacional de Colombia, Manizales, Colombia
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14
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Palm U, Segmiller FM, Epple AN, Freisleder FJ, Koutsouleris N, Schulte-Körne G, Padberg F. Transcranial direct current stimulation in children and adolescents: a comprehensive review. J Neural Transm (Vienna) 2016; 123:1219-34. [PMID: 27173384 DOI: 10.1007/s00702-016-1572-z] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 05/06/2016] [Indexed: 12/23/2022]
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that has shown promising results in various neuropsychiatric disorders in adults. This review addresses the therapeutic use of tDCS in children and adolescents including safety, ethical, and legal considerations. There are several studies addressing the dosage of tDCS in children and adolescents by computational modeling of electric fields in the pediatric brain. Results suggest halving the amperage used in adults to obtain the same peak electric fields, however, there are some studies reporting on the safe application of tDCS with standard adult parameters in children (2 mA; 20-30 min). There are several randomized placebo controlled trials suggesting beneficial effects of tDCS for the treatment of cerebral palsy. For dystonia there are mixed data. Some studies suggest efficacy of tDCS for the treatment of refractory epilepsy, and for the improvement of attention deficit/hyperactivity disorder and autism. Interestingly, there is a lack of data for the treatment of childhood and adolescent psychiatric disorders, i.e., childhood onset schizophrenia and affective disorders. Overall, tDCS seems to be safe in pediatric population. More studies are needed to confirm the preliminary encouraging results; however, ethical deliberation has to be weighed carefully for every single case.
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Affiliation(s)
- Ulrich Palm
- Department of Psychiatry and Psychotherapy, Klinikum der Universität München, Nußbaumstr. 7, 80336, Munich, Germany.
| | - Felix M Segmiller
- Department of Psychiatry and Psychotherapy, Klinikum der Universität München, Nußbaumstr. 7, 80336, Munich, Germany
| | | | | | - Nikolaos Koutsouleris
- Department of Psychiatry and Psychotherapy, Klinikum der Universität München, Nußbaumstr. 7, 80336, Munich, Germany
| | - Gerd Schulte-Körne
- Department of Childhood and Adolescent Psychiatry, Klinikum der Universität München, Munich, Germany
| | - Frank Padberg
- Department of Psychiatry and Psychotherapy, Klinikum der Universität München, Nußbaumstr. 7, 80336, Munich, Germany
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15
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van Dun K, Bodranghien FCAA, Mariën P, Manto MU. tDCS of the Cerebellum: Where Do We Stand in 2016? Technical Issues and Critical Review of the Literature. Front Hum Neurosci 2016; 10:199. [PMID: 27242469 PMCID: PMC4862979 DOI: 10.3389/fnhum.2016.00199] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/19/2016] [Indexed: 01/23/2023] Open
Abstract
Transcranial Direct Current Stimulation (tDCS) is an up-and-coming electrical neurostimulation technique increasingly used both in healthy subjects and in selected groups of patients. Due to the high density of neurons in the cerebellum, its peculiar anatomical organization with the cortex lying superficially below the skull and its diffuse connections with motor and associative areas of the cerebrum, the cerebellum is becoming a major target for neuromodulation of the cerebellocerebral networks. We discuss the recent studies based on cerebellar tDCS with a focus on the numerous technical and open issues which remain to be solved. Our current knowledge of the physiological impacts of tDCS on cerebellar circuitry is criticized. We provide a comparison with transcranial Alternating Current Stimulation (tACS), another promising transcranial electrical neurostimulation technique. Although both tDCS and tACS are becoming established techniques to modulate the cerebellocerebral networks, it is surprising that their impacts on cerebellar disorders remains unclear. A major reason is that the literature lacks large trials with a double-blind, sham-controlled, and cross-over experimental design in cerebellar patients.
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Affiliation(s)
- Kim van Dun
- Clinical and Experimental Neurolinguistics, Vrije Universiteit Brussel Brussels, Belgium
| | - Florian C A A Bodranghien
- Unité d'Etude du Mouvement, Laboratoire de Neurologie Expérimentale, Université libre de Bruxelles (ULB) Brussels, Belgium
| | - Peter Mariën
- Clinical and Experimental Neurolinguistics, Vrije Universiteit BrusselBrussels, Belgium; Department of Neurology and Memory Clinic, ZNA Middelheim General HospitalAntwerp, Belgium
| | - Mario U Manto
- Unité d'Etude du Mouvement, Laboratoire de Neurologie Expérimentale, Université libre de Bruxelles (ULB)Brussels, Belgium; Service des Neurosciences, Université de MonsMons, Belgium
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Modelling of the Electric Field Distribution in Deep Transcranial Magnetic Stimulation in the Adolescence, in the Adulthood, and in the Old Age. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2016; 2016:9039613. [PMID: 27069502 PMCID: PMC4812269 DOI: 10.1155/2016/9039613] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 02/03/2016] [Accepted: 02/15/2016] [Indexed: 12/04/2022]
Abstract
In the last few years, deep transcranial magnetic stimulation (dTMS) has been used for the treatment of depressive disorders, which affect a broad category of people, from adolescents to aging people. To facilitate its clinical application, particular shapes of coils, including the so-called Hesed coils, were designed. Given their increasing demand and the lack of studies which accurately characterize their use, this paper aims to provide a picture of the distribution of the induced electric field in four realistic human models of different ages and gender. In detail, the electric field distributions were calculated by using numerical techniques in the brain structures potentially involved in the progression of the disease and were quantified in terms of both amplitude levels and focusing power of the distribution. The results highlight how the chosen Hesed coil (H7 coil) is able to induce the maxima levels of E mainly in the prefrontal cortex, particularly for the younger model. Moreover, growing levels of induced electric fields with age were found by going in deep in the brain, as well as a major capability to penetrate in the deepest brain structures with an electric field higher than 50%, 70%, and 90% of the peak found in the cortex.
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Woods AJ, Antal A, Bikson M, Boggio PS, Brunoni AR, Celnik P, Cohen LG, Fregni F, Herrmann CS, Kappenman ES, Knotkova H, Liebetanz D, Miniussi C, Miranda PC, Paulus W, Priori A, Reato D, Stagg C, Wenderoth N, Nitsche MA. A technical guide to tDCS, and related non-invasive brain stimulation tools. Clin Neurophysiol 2015; 127:1031-1048. [PMID: 26652115 DOI: 10.1016/j.clinph.2015.11.012] [Citation(s) in RCA: 793] [Impact Index Per Article: 88.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 11/14/2015] [Accepted: 11/17/2015] [Indexed: 01/29/2023]
Abstract
Transcranial electrical stimulation (tES), including transcranial direct and alternating current stimulation (tDCS, tACS) are non-invasive brain stimulation techniques increasingly used for modulation of central nervous system excitability in humans. Here we address methodological issues required for tES application. This review covers technical aspects of tES, as well as applications like exploration of brain physiology, modelling approaches, tES in cognitive neurosciences, and interventional approaches. It aims to help the reader to appropriately design and conduct studies involving these brain stimulation techniques, understand limitations and avoid shortcomings, which might hamper the scientific rigor and potential applications in the clinical domain.
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Affiliation(s)
- A J Woods
- Center for Cognitive Aging and Memory, Institute on Aging, McKnight Brain Institute, Department of Aging and Geriatric Research, Department of Neuroscience, University of Florida, Gainesville, FL, USA.
| | - A Antal
- University Medical Center, Dept. Clinical Neurophysiology, Georg-August-University, Goettingen, Germany
| | - M Bikson
- Department of Biomedical Engineering, The City College of New York, USA
| | - P S Boggio
- Social and Cognitive Neuroscience Laboratory and Developmental Disorders Program, Center for Health and Biological Science, Mackenzie Presbyterian University, São Paulo, SP, Brazil
| | - A R Brunoni
- Service of Interdisciplinary Neuromodulation, Department and Institute of Psychiatry, University of São Paulo, São Paulo, Brazil
| | - P Celnik
- Department of Physical Medicine and Rehabilitation, Johns Hopkins Medical Institution, Baltimore, MD, USA
| | - L G Cohen
- Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - F Fregni
- Laboratory of Neuromodulation, Center for Clinical Research Learning, Department of Physical Medicine and Rehabilitation, Harvard University, USA
| | - C S Herrmann
- Experimental Psychology Lab, Center of excellence Hearing4all, Department for Psychology, Faculty for Medicine and Health Sciences, Carl von Ossietzky Universität, Ammerländer Heerstr, Oldenburg, Germany
| | - E S Kappenman
- Center for Mind & Brain and Department of Psychology, University of California, Davis, CA, USA
| | - H Knotkova
- MJHS Institute for Innovation in Palliative Care, New York, NY, USA
| | - D Liebetanz
- University Medical Center, Dept. Clinical Neurophysiology, Georg-August-University, Goettingen, Germany
| | - C Miniussi
- Neuroscience Section, Department of Clinical and Experimental Sciences, University of Brescia & Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - P C Miranda
- Institute of Biophysics and Biomedical Engineering (IBEB), Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - W Paulus
- University Medical Center, Dept. Clinical Neurophysiology, Georg-August-University, Goettingen, Germany
| | - A Priori
- Direttore Clinica Neurologica III, Università degli Studi di Milano, Ospedale San Paolo, Milan, Italy
| | - D Reato
- Department of Biomedical Engineering, The City College of New York, USA
| | - C Stagg
- Centre for Functional MRI of the Brain (FMRIB) Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; Oxford Centre for Human Brain Activity (OHBA), Department of Psychiatry, University of Oxford, Oxford, UK
| | - N Wenderoth
- Neural Control of Movement Lab, Dept. Health Sciences and Technology, ETH Zürich, Switzerland
| | - M A Nitsche
- University Medical Center, Dept. Clinical Neurophysiology, Georg-August-University, Goettingen, Germany; Leibniz Research Center for Working Environment and Human Factors, Dortmund, Germany; Department of Neurology, BG University Hospital Bergmannsheil, Ruhr-University Bochum, Germany
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Hirschauer TJ, Adeli H, Buford JA. Computer-Aided Diagnosis of Parkinson's Disease Using Enhanced Probabilistic Neural Network. J Med Syst 2015; 39:179. [PMID: 26420585 DOI: 10.1007/s10916-015-0353-9] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 09/18/2015] [Indexed: 01/01/2023]
Abstract
Early and accurate diagnosis of Parkinson's disease (PD) remains challenging. Neuropathological studies using brain bank specimens have estimated that a large percentages of clinical diagnoses of PD may be incorrect especially in the early stages. In this paper, a comprehensive computer model is presented for the diagnosis of PD based on motor, non-motor, and neuroimaging features using the recently-developed enhanced probabilistic neural network (EPNN). The model is tested for differentiating PD patients from those with scans without evidence of dopaminergic deficit (SWEDDs) using the Parkinson's Progression Markers Initiative (PPMI) database, an observational, multi-center study designed to identify PD biomarkers for diagnosis and disease progression. The results are compared to four other commonly-used machine learning algorithms: the probabilistic neural network (PNN), support vector machine (SVM), k-nearest neighbors (k-NN) algorithm, and classification tree (CT). The EPNN had the highest classification accuracy at 92.5% followed by the PNN (91.6%), k-NN (90.8%) and CT (90.2%). The EPNN exhibited an accuracy of 98.6% when classifying healthy control (HC) versus PD, higher than any previous studies.
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Affiliation(s)
- Thomas J Hirschauer
- Neuroscience Graduate Program and Medical Scientist Training Program, The Ohio State University College of Medicine, Columbus, OH, USA.
| | - Hojjat Adeli
- Departments of Biomedical Engineering, Biomedical Informatics, Neurology, Neuroscience, Electrical and Computer Engineering, Civil, Environmental, and Geodetic Engineering, and Biophysics Graduate Program, The Ohio State University, 470 Hitchcock Hall, 2070 Neil Avenue, Columbus, OH, 43210, USA.
| | - John A Buford
- Physical Therapy Division, School of Health and Rehabilitation Sciences, The Ohio State University, 453 W 10th Ave, Rm. 516E, Columbus, OH, 43210, USA.
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Laakso I, Tanaka S, Koyama S, De Santis V, Hirata A. Inter-subject Variability in Electric Fields of Motor Cortical tDCS. Brain Stimul 2015; 8:906-13. [PMID: 26026283 DOI: 10.1016/j.brs.2015.05.002] [Citation(s) in RCA: 219] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/28/2015] [Accepted: 05/01/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The sources of inter-subject variability in the efficacy of transcranial direct current stimulation (tDCS) remain unknown. One potential source of variations is the brain's electric field, which varies according to each individual's anatomical features. OBJECTIVE We employed an approach that combines imaging and computational modeling to quantitatively study the extent and primary causes of inter-subject variation in tDCS electric fields. METHODS Anatomically-accurate models of the head and brain of 24 males (age: 38.63 ± 11.24 years) were constructed from structural MRI. Finite-element method was used to computationally estimate the electric fields for tDCS of the motor cortex. Surface-based inter-subject registration of the electric field and functional MRI data was used for group level statistical analysis. RESULTS We observed large differences in each individual's electric field patterns. However, group level analysis revealed that the average electric fields concentrated in the vicinity of the primary motor cortex. The variations in the electric fields in the hand motor area could be characterized by a normal distribution with a standard deviation of approximately 20% of the mean. The cerebrospinal fluid (CSF) thickness was the primary factor influencing an individual's electric field, thereby explaining 50% of the inter-individual variability, a thicker layer of CSF decreasing the electric field strength. CONCLUSIONS The variability in the electric fields is related to each individual's anatomical features and can only be controlled using detailed image processing. Age was found to have a slight negative effect on the electric field, which might have implications on tDCS studies on aging brains.
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Affiliation(s)
- Ilkka Laakso
- Department of Computer Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
| | - Satoshi Tanaka
- Laboratory of Psychology, Hamamatsu University School of Medicine, Shizuoka 431-3192, Japan
| | - Soichiro Koyama
- School of Life Sciences, The Graduate University for Advanced Studies, Kanagawa 240-0193, Japan; Division of Cerebral Integration, National Institute for Physiological Sciences, Aichi 444-8585, Japan
| | - Valerio De Santis
- Department of Computer Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
| | - Akimasa Hirata
- Department of Computer Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
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DeMarse TB, Carney PR. Augmentation of cognitive function in epilepsy. Front Syst Neurosci 2014; 8:147. [PMID: 25177279 PMCID: PMC4132293 DOI: 10.3389/fnsys.2014.00147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 07/29/2014] [Indexed: 11/28/2022] Open
Affiliation(s)
- Thomas B DeMarse
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL, USA
| | - Paul R Carney
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL, USA ; Department of Pediatrics, University of Florida Gainesville, FL, USA
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