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Niemann F, Riemann S, Hubert AK, Antonenko D, Thielscher A, Martin AK, Unger N, Flöel A, Meinzer M. Electrode positioning errors reduce current dose for focal tDCS set-ups: Evidence from individualized electric field mapping. Clin Neurophysiol 2024; 162:201-209. [PMID: 38643613 DOI: 10.1016/j.clinph.2024.03.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/29/2024] [Accepted: 03/26/2024] [Indexed: 04/23/2024]
Abstract
OBJECTIVE Electrode positioning errors contribute to variability of transcranial direct current stimulation (tDCS) effects. We investigated the impact of electrode positioning errors on current flow for tDCS set-ups with different focality. METHODS Deviations from planned electrode positions were determined using data acquired in an experimental study (N = 240 datasets) that administered conventional and focal tDCS during magnetic resonance imaging (MRI). Comparison of individualized electric field modeling for planned and empirically derived "actual" electrode positions was conducted to quantify the impact of positioning errors on the electric field dose in target regions for tDCS. RESULTS Planned electrode positions resulted in higher current dose in the target regions for focal compared to conventional montages (7-12%). Deviations from planned positions significantly reduced current flow in the target regions, selectively for focal set-ups (26-30%). Dose reductions were significantly larger for focal compared to conventional set-ups (29-43%). CONCLUSIONS Precise positioning is crucial when using focal tDCS set-ups to avoid significant reductions of current dose in the intended target regions. SIGNIFICANCE Our results highlight the urgent need to routinely implement methods for improving electrode positioning, minimization of electrode drift, verification of electrode positions before and/or after tDCS and also to consider positioning errors when investigating dose-response relationships, especially for focal set-ups.
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Affiliation(s)
- Filip Niemann
- University Medicine Greifswald, Department of Neurology, Greifswald, Germany
| | - Steffen Riemann
- University Medicine Greifswald, Department of Neurology, Greifswald, Germany
| | - Ann-Kathrin Hubert
- University Medicine Greifswald, Department of Neurology, Greifswald, Germany
| | - Daria Antonenko
- University Medicine Greifswald, Department of Neurology, Greifswald, Germany
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark; Technical University of Denmark, Department of Health Technology, Kongens Lyngby, Denmark
| | - Andrew K Martin
- Kent University, School of Psychology, Canterbury, United Kingdom
| | - Nina Unger
- University Medicine Greifswald, Department of Neurology, Greifswald, Germany
| | - Agnes Flöel
- University Medicine Greifswald, Department of Neurology, Greifswald, Germany; German Center for Neurodegenerative Diseases (DZNE Site Greifswald), Greifswald, Germany
| | - Marcus Meinzer
- University Medicine Greifswald, Department of Neurology, Greifswald, Germany.
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2
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Norata D, Motolese F, Magliozzi A, Pilato F, Di Lazzaro V, Luzzi S, Capone F. Transcranial direct current stimulation in semantic variant of primary progressive aphasia: a state-of-the-art review. Front Hum Neurosci 2023; 17:1219737. [PMID: 38021245 PMCID: PMC10663282 DOI: 10.3389/fnhum.2023.1219737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/27/2023] [Indexed: 12/01/2023] Open
Abstract
The semantic variant of primary progressive aphasia (svPPA), known also as "semantic dementia (SD)," is a neurodegenerative disorder that pertains to the frontotemporal lobar degeneration clinical syndromes. There is currently no approved pharmacological therapy for all frontotemporal dementia variants. Transcranial direct current stimulation (tDCS) is a promising non-invasive brain stimulation technique capable of modulating cortical excitability through a sub-threshold shift in neuronal resting potential. This technique has previously been applied as adjunct treatment in Alzheimer's disease, while data for frontotemporal dementia are controversial. In this scoped review, we summarize and critically appraise the currently available evidence regarding the use of tDCS for improving performance in naming and/or matching tasks in patients with svPPA. Clinical trials addressing this topic were identified through MEDLINE (accessed by PubMed) and Web of Science, as of November 2022, week 3. Clinical trials have been unable to show a significant benefit of tDCS in enhancing semantic performance in svPPA patients. The heterogeneity of the studies available in the literature might be a possible explanation. Nevertheless, the results of these studies are promising and may offer valuable insights into methodological differences and overlaps, raising interest among researchers in identifying new non-pharmacological strategies for treating svPPA patients. Further studies are therefore warranted to investigate the potential therapeutic role of tDCS in svPPA.
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Affiliation(s)
- Davide Norata
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Università Campus Bio-Medico di Roma, Rome, Italy
- Neurological Clinic, Department of Experimental and Clinical Medicine (DIMSC), Marche Polytechnic University, Ancona, Italy
| | - Francesco Motolese
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Università Campus Bio-Medico di Roma, Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy
| | - Alessandro Magliozzi
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Fabio Pilato
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Università Campus Bio-Medico di Roma, Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy
| | - Vincenzo Di Lazzaro
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Università Campus Bio-Medico di Roma, Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy
| | - Simona Luzzi
- Neurological Clinic, Department of Experimental and Clinical Medicine (DIMSC), Marche Polytechnic University, Ancona, Italy
| | - Fioravante Capone
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Università Campus Bio-Medico di Roma, Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy
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3
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Williams EER, Sghirripa S, Rogasch NC, Hordacre B, Attrill S. Non-invasive brain stimulation in the treatment of post-stroke aphasia: a scoping review. Disabil Rehabil 2023:1-22. [PMID: 37828899 DOI: 10.1080/09638288.2023.2259299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 09/10/2023] [Indexed: 10/14/2023]
Abstract
PURPOSE Aphasia is an acquired language impairment that commonly results from stroke. Non-invasive brain stimulation (NIBS) might accelerate aphasia recovery trajectories and has seen mounting popularity in recent aphasia rehabilitation research. The present review aimed to: (1) summarise all existing literature on NIBS as a post-stroke aphasia treatment; and (2) provide recommendations for future NIBS-aphasia research. MATERIALS AND METHODS Databases for published and grey literature were searched using scoping review methodology. 278 journal articles, conference abstracts/posters, and books, and 38 items of grey literature, were included for analysis. RESULTS Quantitative analysis revealed that ipsilesional anodal transcranial direct current stimulation and contralesional 1-Hz repetitive transcranial magnetic stimulation were the most widely used forms of NIBS, while qualitative analysis identified four key themes including: the roles of the hemispheres in aphasia recovery and their relationship with NIBS; heterogeneity of individuals but homogeneity of subpopulations; individualisation of stimulation parameters; and much remains under-explored in the NIBS-aphasia literature. CONCLUSIONS Taken together, these results highlighted systemic challenges across the field such as small sample sizes, inter-individual variability, lack of protocol optimisation/standardisation, and inadequate focus on aphasiology. Four key recommendations are outlined herein to guide future research and refine NIBS methods for post-stroke aphasia treatment.
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Affiliation(s)
- Ellen E R Williams
- School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, Australia
- Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Sabrina Sghirripa
- School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, Australia
- Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Nigel C Rogasch
- School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, Australia
- Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
- Turner Institute of Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Australia
| | - Brenton Hordacre
- Innovation, IMPlementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, The University of South Australia, Adelaide, Australia
| | - Stacie Attrill
- Speech Pathology, School of Allied Health Science and Practice, The University of Adelaide, Adelaide, Australia
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Shah-Basak P, Boukrina O, Li XR, Jebahi F, Kielar A. Targeted neurorehabilitation strategies in post-stroke aphasia. Restor Neurol Neurosci 2023; 41:129-191. [PMID: 37980575 PMCID: PMC10741339 DOI: 10.3233/rnn-231344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
BACKGROUND Aphasia is a debilitating language impairment, affecting millions of people worldwide. About 40% of stroke survivors develop chronic aphasia, resulting in life-long disability. OBJECTIVE This review examines extrinsic and intrinsic neuromodulation techniques, aimed at enhancing the effects of speech and language therapies in stroke survivors with aphasia. METHODS We discuss the available evidence supporting the use of transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation, and functional MRI (fMRI) real-time neurofeedback in aphasia rehabilitation. RESULTS This review systematically evaluates studies focusing on efficacy and implementation of specialized methods for post-treatment outcome optimization and transfer to functional skills. It considers stimulation target determination and various targeting approaches. The translation of neuromodulation interventions to clinical practice is explored, emphasizing generalization and functional communication. The review also covers real-time fMRI neurofeedback, discussing current evidence for efficacy and essential implementation parameters. Finally, we address future directions for neuromodulation research in aphasia. CONCLUSIONS This comprehensive review aims to serve as a resource for a broad audience of researchers and clinicians interested in incorporating neuromodulation for advancing aphasia care.
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Affiliation(s)
| | - Olga Boukrina
- Kessler Foundation, Center for Stroke Rehabilitation Research, West Orange, NJ, USA
| | - Xin Ran Li
- School of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Fatima Jebahi
- Department of Speech, Languageand Hearing Sciences, University of Arizona, Tucson, AZ, USA
| | - Aneta Kielar
- Department of Speech, Languageand Hearing Sciences, University of Arizona, Tucson, AZ, USA
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5
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Chang WK, Park J, Lee JY, Cho S, Lee J, Kim WS, Paik NJ. Functional Network Changes After High-Frequency rTMS Over the Most Activated Speech-Related Area Combined With Speech Therapy in Chronic Stroke With Non-fluent Aphasia. Front Neurol 2022; 13:690048. [PMID: 35222235 PMCID: PMC8866644 DOI: 10.3389/fneur.2022.690048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 01/12/2022] [Indexed: 12/04/2022] Open
Abstract
OBJECTIVE High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) to the lesional hemisphere requires prudence in selecting the appropriate stimulation spot. Functional near-IR spectroscopy (fNIRS) can be used in both selecting the stimulation spot and assessing the changes of the brain network. This study aimed to evaluate the effect of HF-rTMS on the most activated spot identified with fNIRS and assess the changes of brain functional network in the patients with poststroke aphasia. METHODS A total of five patients received HF-rTMS to the most activated area on the lesional hemisphere, followed by 30 min of speech therapy for 10 days. The Korean version of the Western aphasia battery (K-WAB) and fNIRS evaluation were done 1 day before the treatment, 1 day and 1 month after the last treatment session. Changes of K-WAB and paired cortical interaction and brain network analysis using graph theory were assessed. RESULTS Aphasia quotient in K-WAB significantly increased after the treatment (P = 0.043). The correlation analysis of cortical interactions showed increased connectivity between language production and processing areas. Clustering coefficients of the left hemisphere were increased over a sparsity range between 0.45 and 0.58 (0.015 < p < 0.031), whereas the clustering coefficients of the right hemisphere, decreased over a sparsity range 0.15-0.87 (0.063 < p < 0.095). The global efficiency became lower over a network sparsity range between 0.47 and 0.75 (0.015 < p < 0.063). CONCLUSION Improvement of language function and changes of corticocortical interaction between language-related cortical areas were observed after HF-rTMS on the most activated area identified by fNIRS with combined speech therapy in the patients with poststroke aphasia.
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Affiliation(s)
| | | | | | | | | | | | - Nam-Jong Paik
- Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam-si, South Korea
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6
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High definition transcranial direct current stimulation modulates abnormal neurophysiological activity in post-stroke aphasia. Sci Rep 2020; 10:19625. [PMID: 33184382 PMCID: PMC7665190 DOI: 10.1038/s41598-020-76533-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 10/23/2020] [Indexed: 12/20/2022] Open
Abstract
Recent findings indicate that measures derived from resting-state magnetoencephalography (rsMEG) are sensitive to cortical dysfunction in post-stroke aphasia. Spectral power and multiscale entropy (MSE) measures show that left-hemispheric areas surrounding the stroke lesion (perilesional) exhibit pathological oscillatory slowing and alterations in signal complexity. In the current study, we tested whether individually-targeted high-definition transcranial direct current stimulation (HD-tDCS) can reduce MEG abnormalities and transiently improve language performance. In eleven chronic aphasia survivors, we devised a method to localize perilesional areas exhibiting peak MSE abnormalities, and subsequently targeted these areas with excitatory/anodal-tDCS, or targeted the contralateral homolog areas with inhibitory/cathodal-tDCS, based on prominent theories of stroke recovery. Pathological MEG slowing in these patients was correlated with aphasia severity. Sentence/phrase repetition accuracy was assessed before and after tDCS. A delayed word reading task was administered inside MEG to assess tDCS-induced neurophysiological changes in relative power and MSE computed on the pre-stimulus and delay task time windows. Results indicated increases in repetition accuracy, decreases in contralateral theta (4–7 Hz) and coarse-scale MSE (slow activity), and increases in perilesional low-gamma (25–50 Hz) and fine-scale MSE (fast activity) after anodal-tDCS, indicating reversal of pathological abnormalities. RsMEG may be a sensitive measure for guiding therapeutic tDCS.
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7
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Rodrigues de Almeida L, Pope PA, Hansen PC. Task load modulates tDCS effects on brain network for phonological processing. Cogn Process 2020; 21:341-363. [PMID: 32152767 PMCID: PMC7381442 DOI: 10.1007/s10339-020-00964-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 02/20/2020] [Indexed: 02/07/2023]
Abstract
Motor participation in phonological processing can be modulated by task nature across the speech perception to speech production range. The pars opercularis of the left inferior frontal gyrus (LIFG) would be increasingly active across this range, because of changing motor demands. Here, we investigated with simultaneous tDCS and fMRI whether the task load modulation of tDCS effects translates into predictable patterns of functional connectivity. Findings were analysed under the "multi-node framework", according to which task load and the network structure underlying cognitive functions are modulators of tDCS effects. In a within-subject study, participants (N = 20) performed categorical perception, lexical decision and word naming tasks [which differentially recruit the target of stimulation (LIFG)], which were repeatedly administered in three tDCS sessions (anodal, cathodal and sham). The LIFG, left superior temporal gyrus and their right homologues formed the target network subserving phonological processing. C-tDCS inhibition and A-tDCS excitation should increase with task load. Correspondingly, the larger the task load, the larger the relevance of the target for the task and smaller the room for compensation of C-tDCS inhibition by less relevant nodes. Functional connectivity analyses were performed with partial correlations, and network compensation globally inferred by comparing the relative number of significant connections each condition induced relative to sham. Overall, simultaneous tDCS and fMRI was adequate to show that motor participation in phonological processing is modulated by task nature. Network responses induced by C-tDCS across phonological processing tasks matched predictions. A-tDCS effects were attributed to optimisation of network efficiency.
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Affiliation(s)
| | - Paul A Pope
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Peter C Hansen
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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8
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Zito GA, Anderegg LB, Apazoglou K, Müri RM, Wiest R, Holtforth MG, Aybek S. Transcranial magnetic stimulation over the right temporoparietal junction influences the sense of agency in healthy humans. J Psychiatry Neurosci 2020; 45:271-278. [PMID: 32329986 PMCID: PMC7828927 DOI: 10.1503/jpn.190099] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/09/2019] [Accepted: 11/11/2019] [Indexed: 01/02/2023] Open
Abstract
Background The sense of agency is an important aspect of motor control. Impaired sense of agency has been linked to several medical conditions, including schizophrenia and functional neurological disorders. A complex brain network subserves the sense of agency, and the right temporoparietal junction is one of its main nodes. In this paper, we tested whether transcranial magnetic stimulation over the right temporoparietal junction elicited behavioural changes in the sense of agency. Methods In experiment 1, 15 healthy participants performed a behavioural task during functional MRI, with the goal of localizing the area relevant for the sense of agency in the right temporoparietal junction. In the task, the movement of a cursor (controlled by the participants) was artificially manipulated, and the sense of agency was either diminished (turbulence) or enhanced (magic). In experiment 2, we applied transcranial magnetic stimulation in 20 healthy participants in a sham-controlled, crossover trial with excitatory, inhibitory or sham (vertex) stimulation. We measured the summary agency score, an indicator of the sense of agency (lower values correspond to diminished sense of agency). Results Experiment 1 revealed a peak of activation during agency manipulation in the right temporoparietal junction (Montreal Neurological Institute coordinates x, y, z: 68, -26, 34). Experiment 2 showed that inhibition of the right temporoparietal junction significantly reduced the summary agency score in both turbulence (from -14.4 ± 11.4% to -22.5 ± 8.9%), and magic (from -0.7 ± 5.8% to -4.4 ± 4.4%). Limitations We found no excitatory effects, possibly because of a ceiling effect (because healthy participants have a normal sense of agency) or noneffectiveness of the excitatory protocol. Conclusion Our experiments showed that the network subserving the sense of agency was amenable to neuromodulation in healthy participants. This sets the ground for further research in patients with impaired sense of agency. Clinical trial identification: DRKS00012992 (German clinical trials registry).
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Affiliation(s)
- Giuseppe A Zito
- From the Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Anderegg, Müri, Holtforth, Aybek); the Support Centre for Advanced Neuroimaging (SCAN), University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Wiest); Department of Neuroscience, Faculty of Medicine, University of Geneva, Switzerland (Apazoglou); the Perception and Eye Movement Laboratory, Department of Neurology and Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland (Müri); and the Institute of Psychology, University of Bern, Bern, Switzerland (Holtforth)
| | - Laura B Anderegg
- From the Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Anderegg, Müri, Holtforth, Aybek); the Support Centre for Advanced Neuroimaging (SCAN), University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Wiest); Department of Neuroscience, Faculty of Medicine, University of Geneva, Switzerland (Apazoglou); the Perception and Eye Movement Laboratory, Department of Neurology and Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland (Müri); and the Institute of Psychology, University of Bern, Bern, Switzerland (Holtforth)
| | - Kallia Apazoglou
- From the Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Anderegg, Müri, Holtforth, Aybek); the Support Centre for Advanced Neuroimaging (SCAN), University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Wiest); Department of Neuroscience, Faculty of Medicine, University of Geneva, Switzerland (Apazoglou); the Perception and Eye Movement Laboratory, Department of Neurology and Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland (Müri); and the Institute of Psychology, University of Bern, Bern, Switzerland (Holtforth)
| | - René M Müri
- From the Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Anderegg, Müri, Holtforth, Aybek); the Support Centre for Advanced Neuroimaging (SCAN), University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Wiest); Department of Neuroscience, Faculty of Medicine, University of Geneva, Switzerland (Apazoglou); the Perception and Eye Movement Laboratory, Department of Neurology and Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland (Müri); and the Institute of Psychology, University of Bern, Bern, Switzerland (Holtforth)
| | - Roland Wiest
- From the Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Anderegg, Müri, Holtforth, Aybek); the Support Centre for Advanced Neuroimaging (SCAN), University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Wiest); Department of Neuroscience, Faculty of Medicine, University of Geneva, Switzerland (Apazoglou); the Perception and Eye Movement Laboratory, Department of Neurology and Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland (Müri); and the Institute of Psychology, University of Bern, Bern, Switzerland (Holtforth)
| | - Martin Grosse Holtforth
- From the Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Anderegg, Müri, Holtforth, Aybek); the Support Centre for Advanced Neuroimaging (SCAN), University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Wiest); Department of Neuroscience, Faculty of Medicine, University of Geneva, Switzerland (Apazoglou); the Perception and Eye Movement Laboratory, Department of Neurology and Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland (Müri); and the Institute of Psychology, University of Bern, Bern, Switzerland (Holtforth)
| | - Selma Aybek
- From the Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Anderegg, Müri, Holtforth, Aybek); the Support Centre for Advanced Neuroimaging (SCAN), University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (Zito, Wiest); Department of Neuroscience, Faculty of Medicine, University of Geneva, Switzerland (Apazoglou); the Perception and Eye Movement Laboratory, Department of Neurology and Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland (Müri); and the Institute of Psychology, University of Bern, Bern, Switzerland (Holtforth)
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9
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Sanches C, Levy R, Benisty S, Volpe-Gillot L, Habert MO, Kas A, Ströer S, Pyatigorskaya N, Kaglik A, Bourbon A, Dubois B, Migliaccio R, Valero-Cabré A, Teichmann M. Testing the therapeutic effects of transcranial direct current stimulation (tDCS) in semantic dementia: a double blind, sham controlled, randomized clinical trial. Trials 2019; 20:632. [PMID: 31747967 PMCID: PMC6868701 DOI: 10.1186/s13063-019-3613-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/23/2019] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Semantic dementia is a neurodegenerative disease that primarily affects the left anterior temporal lobe, resulting in a gradual loss of conceptual knowledge. There is currently no validated treatment. Transcranial stimulation has provided evidence for long-lasting language effects presumably linked to stimulation-induced neuroplasticity in post-stroke aphasia. However, studies evaluating its effects in neurodegenerative diseases such as semantic dementia are still rare and evidence from double-blind, prospective, therapeutic trials is required. OBJECTIVE The primary objective of the present clinical trial (STIM-SD) is to evaluate the therapeutic efficacy of a multiday transcranial direct current stimulation (tDCS) regime on language impairment in patients with semantic dementia. The study also explores the time course of potential tDCS-driven improvements and uses imaging biomarkers that could reflect stimulation-induced neuroplasticity. METHODS This is a double-blind, sham-controlled, randomized study using transcranial Direct Current Stimulation (tDCS) applied daily for 10 days, and language/semantic and imaging assessments at four time points: baseline, 3 days, 2 weeks and 4 months after 10 stimulation sessions. Language/semantic assessments will be carried out at these same 4 time points. Fluorodeoxyglucose positron emission tomography (FDG-PET), resting-state functional magnetic resonance imaging (rs-fMRI), T1-weighted images and white matter diffusion tensor imaging (DTI) will be applied at baseline and at the 2-week time point. According to the principle of inter-hemispheric inhibition between left (language-related) and right homotopic regions we will use two stimulation modalities - left-anodal and right-cathodal tDCS over the anterior temporal lobes. Accordingly, the patient population (n = 60) will be subdivided into three subgroups: left-anodal tDCS (n = 20), right-cathodal tDCS (n = 20) and sham tDCS (n = 20). The stimulation will be sustained for 20 min at an intensity of 1.59 mA. It will be delivered through 25cm2-round stimulation electrodes (current density of 0.06 mA/cm2) placed over the left and right anterior temporal lobes for anodal and cathodal stimulation, respectively. A group of healthy participants (n = 20) matched by age, gender and education will also be recruited and tested to provide normative values for the language/semantic tasks and imaging measures. DISCUSSION The aim of this study is to assess the efficacy of tDCS for language/semantic disorders in semantic dementia. A potential treatment would be easily applicable, inexpensive, and renewable when therapeutic effects disappear due to disease progression. TRIAL REGISTRATION ClinicalTrials.gov NCT03481933. Registered on March 2018.
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Affiliation(s)
- Clara Sanches
- Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Frontlab team, Paris, France.,Groupe de Dynamiques Cérébrales, Plasticité et Rééducation, FrontLab team, Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Richard Levy
- Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Frontlab team, Paris, France.,Department of Neurology, National Reference Center for « Rare or Early Onset Dementias », Pitié Salpêtrière Hospital, AP-HP, 47-83 Boulevard de l'Hôpital, 75013, Paris, France
| | | | | | - Marie-Odile Habert
- Department of Nuclear Medicine, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France.,CATI Multicenter Neuroimaging Platform, Paris, France.,Laboratoire d'Imagerie Biomédicale, Sorbonne Université, Inserm U1146, CNRS UMR, Paris, France
| | - Aurelie Kas
- Department of Nuclear Medicine, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France.,Laboratoire d'Imagerie Biomédicale, Sorbonne Université, Inserm U1146, CNRS UMR, Paris, France
| | - Sébastian Ströer
- Department of Neuroradiology, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France
| | - Nadya Pyatigorskaya
- Department of Neuroradiology, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France.,Institut du Cerveau et de la Moelle Epinière, Center for NeuroImaging Research - CENIR, Paris, France
| | - Anna Kaglik
- Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Frontlab team, Paris, France.,Groupe de Dynamiques Cérébrales, Plasticité et Rééducation, FrontLab team, Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France.,Unité de Recherche Clinique (URC) Pitié-Salpêtrière, Charles Foix, AP-HP, Paris, France
| | - Angelina Bourbon
- Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Frontlab team, Paris, France.,Groupe de Dynamiques Cérébrales, Plasticité et Rééducation, FrontLab team, Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Bruno Dubois
- Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Frontlab team, Paris, France.,Department of Neurology, National Reference Center for « Rare or Early Onset Dementias », Pitié Salpêtrière Hospital, AP-HP, 47-83 Boulevard de l'Hôpital, 75013, Paris, France
| | - Raffaella Migliaccio
- Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Frontlab team, Paris, France.,Department of Neurology, National Reference Center for « Rare or Early Onset Dementias », Pitié Salpêtrière Hospital, AP-HP, 47-83 Boulevard de l'Hôpital, 75013, Paris, France
| | - Antoni Valero-Cabré
- Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Frontlab team, Paris, France. .,Groupe de Dynamiques Cérébrales, Plasticité et Rééducation, FrontLab team, Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France. .,Laboratory for Cerebral Dynamics Plasticity and Rehabilitation, Boston University School of Medicine, Boston, MA, USA. .,Cognitive Neuroscience and Information Technology Research Program, Open University of Catalonia (UOC), Barcelona, Spain.
| | - Marc Teichmann
- Institut du Cerveau et de la Moelle Epinière, ICM, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Frontlab team, Paris, France. .,Department of Neurology, National Reference Center for « Rare or Early Onset Dementias », Pitié Salpêtrière Hospital, AP-HP, 47-83 Boulevard de l'Hôpital, 75013, Paris, France.
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Valero-Cabré A, Sanches C, Godard J, Fracchia O, Dubois B, Levy R, Truong DQ, Bikson M, Teichmann M. Language boosting by transcranial stimulation in progressive supranuclear palsy. Neurology 2019; 93:e537-e547. [PMID: 31270217 DOI: 10.1212/wnl.0000000000007893] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 03/22/2019] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE To explore whether transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) can improve language capacities in patients with progressive supranuclear palsy (PSP). METHODS We used a sham-controlled double-blind crossover design to assess the efficiency of tDCS over the DLPFC in a cohort of 12 patients with PSP. In 3 separate sessions, we evaluated the ability to boost the left DLPFC via left-anodal (excitatory) and right-cathodal (inhibitory) tDCS, while comparing them to sham tDCS. Tasks assessing lexical access (letter fluency task) and semantic access (category judgment task) were applied immediately before and after the tDCS sessions to provide a marker of potential language modulation. RESULTS The comparison with healthy controls showed that patients with PSP were impaired on both tasks at baseline. Contrasting poststimulation vs prestimulation performance across tDCS conditions revealed language improvement in the category judgment task following right-cathodal tDCS, and in the letter fluency task following left-anodal tDCS. A computational finite element model of current distribution corroborated the intended effect of left-anodal and right-cathodal tDCS on the targeted DLPFC. CONCLUSIONS Our results demonstrate tDCS-driven language improvement in PSP. They provide proof-of-concept for the use of tDCS in PSP and set the stage for future multiday stimulation regimens, which might lead to longer-lasting therapeutic effects promoted by neuroplasticity. CLASSIFICATION OF EVIDENCE This study provides Class III evidence that for patients with PSP, tDCS over the DLPFC improves performance in some language tasks.
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Affiliation(s)
- Antoni Valero-Cabré
- From Groupe de Dynamiques Cérébrales, Plasticité et Rééducation (A.V.-C., C.S., J.G., O.F.) and Frontlab Team (A.V.-C., C.S., J.G., O.F., B.D., R.L., M.T.), Institut du Cerveau et de la Moelle Epinière (ICM), INSERM 1127, CNRS, UMR 7225 and Sorbonne Université (SO), Paris, France; Laboratory for Cerebral Dynamics Plasticity and Rehabilitation (A.V.-C.), Boston University School of Medicine, MA; Cognitive Neuroscience and Information Technology Research Program (A.V.-C.), Open University of Catalonia (UOC), Barcelona, Spain; Department of Neurology (B.D., R.L., M.T.), National Reference Center for "PPA and Rare Dementias," Pitié Salpêtrière Hospital, AP-HP, Paris, France; and Neural Engineering Laboratory, Department of Biomedical Engineering (D.Q.T., M.B.), the City College of City University of New York, NY.
| | - Clara Sanches
- From Groupe de Dynamiques Cérébrales, Plasticité et Rééducation (A.V.-C., C.S., J.G., O.F.) and Frontlab Team (A.V.-C., C.S., J.G., O.F., B.D., R.L., M.T.), Institut du Cerveau et de la Moelle Epinière (ICM), INSERM 1127, CNRS, UMR 7225 and Sorbonne Université (SO), Paris, France; Laboratory for Cerebral Dynamics Plasticity and Rehabilitation (A.V.-C.), Boston University School of Medicine, MA; Cognitive Neuroscience and Information Technology Research Program (A.V.-C.), Open University of Catalonia (UOC), Barcelona, Spain; Department of Neurology (B.D., R.L., M.T.), National Reference Center for "PPA and Rare Dementias," Pitié Salpêtrière Hospital, AP-HP, Paris, France; and Neural Engineering Laboratory, Department of Biomedical Engineering (D.Q.T., M.B.), the City College of City University of New York, NY
| | - Juliette Godard
- From Groupe de Dynamiques Cérébrales, Plasticité et Rééducation (A.V.-C., C.S., J.G., O.F.) and Frontlab Team (A.V.-C., C.S., J.G., O.F., B.D., R.L., M.T.), Institut du Cerveau et de la Moelle Epinière (ICM), INSERM 1127, CNRS, UMR 7225 and Sorbonne Université (SO), Paris, France; Laboratory for Cerebral Dynamics Plasticity and Rehabilitation (A.V.-C.), Boston University School of Medicine, MA; Cognitive Neuroscience and Information Technology Research Program (A.V.-C.), Open University of Catalonia (UOC), Barcelona, Spain; Department of Neurology (B.D., R.L., M.T.), National Reference Center for "PPA and Rare Dementias," Pitié Salpêtrière Hospital, AP-HP, Paris, France; and Neural Engineering Laboratory, Department of Biomedical Engineering (D.Q.T., M.B.), the City College of City University of New York, NY
| | - Oriane Fracchia
- From Groupe de Dynamiques Cérébrales, Plasticité et Rééducation (A.V.-C., C.S., J.G., O.F.) and Frontlab Team (A.V.-C., C.S., J.G., O.F., B.D., R.L., M.T.), Institut du Cerveau et de la Moelle Epinière (ICM), INSERM 1127, CNRS, UMR 7225 and Sorbonne Université (SO), Paris, France; Laboratory for Cerebral Dynamics Plasticity and Rehabilitation (A.V.-C.), Boston University School of Medicine, MA; Cognitive Neuroscience and Information Technology Research Program (A.V.-C.), Open University of Catalonia (UOC), Barcelona, Spain; Department of Neurology (B.D., R.L., M.T.), National Reference Center for "PPA and Rare Dementias," Pitié Salpêtrière Hospital, AP-HP, Paris, France; and Neural Engineering Laboratory, Department of Biomedical Engineering (D.Q.T., M.B.), the City College of City University of New York, NY
| | - Bruno Dubois
- From Groupe de Dynamiques Cérébrales, Plasticité et Rééducation (A.V.-C., C.S., J.G., O.F.) and Frontlab Team (A.V.-C., C.S., J.G., O.F., B.D., R.L., M.T.), Institut du Cerveau et de la Moelle Epinière (ICM), INSERM 1127, CNRS, UMR 7225 and Sorbonne Université (SO), Paris, France; Laboratory for Cerebral Dynamics Plasticity and Rehabilitation (A.V.-C.), Boston University School of Medicine, MA; Cognitive Neuroscience and Information Technology Research Program (A.V.-C.), Open University of Catalonia (UOC), Barcelona, Spain; Department of Neurology (B.D., R.L., M.T.), National Reference Center for "PPA and Rare Dementias," Pitié Salpêtrière Hospital, AP-HP, Paris, France; and Neural Engineering Laboratory, Department of Biomedical Engineering (D.Q.T., M.B.), the City College of City University of New York, NY
| | - Richard Levy
- From Groupe de Dynamiques Cérébrales, Plasticité et Rééducation (A.V.-C., C.S., J.G., O.F.) and Frontlab Team (A.V.-C., C.S., J.G., O.F., B.D., R.L., M.T.), Institut du Cerveau et de la Moelle Epinière (ICM), INSERM 1127, CNRS, UMR 7225 and Sorbonne Université (SO), Paris, France; Laboratory for Cerebral Dynamics Plasticity and Rehabilitation (A.V.-C.), Boston University School of Medicine, MA; Cognitive Neuroscience and Information Technology Research Program (A.V.-C.), Open University of Catalonia (UOC), Barcelona, Spain; Department of Neurology (B.D., R.L., M.T.), National Reference Center for "PPA and Rare Dementias," Pitié Salpêtrière Hospital, AP-HP, Paris, France; and Neural Engineering Laboratory, Department of Biomedical Engineering (D.Q.T., M.B.), the City College of City University of New York, NY
| | - Dennis Q Truong
- From Groupe de Dynamiques Cérébrales, Plasticité et Rééducation (A.V.-C., C.S., J.G., O.F.) and Frontlab Team (A.V.-C., C.S., J.G., O.F., B.D., R.L., M.T.), Institut du Cerveau et de la Moelle Epinière (ICM), INSERM 1127, CNRS, UMR 7225 and Sorbonne Université (SO), Paris, France; Laboratory for Cerebral Dynamics Plasticity and Rehabilitation (A.V.-C.), Boston University School of Medicine, MA; Cognitive Neuroscience and Information Technology Research Program (A.V.-C.), Open University of Catalonia (UOC), Barcelona, Spain; Department of Neurology (B.D., R.L., M.T.), National Reference Center for "PPA and Rare Dementias," Pitié Salpêtrière Hospital, AP-HP, Paris, France; and Neural Engineering Laboratory, Department of Biomedical Engineering (D.Q.T., M.B.), the City College of City University of New York, NY
| | - Marom Bikson
- From Groupe de Dynamiques Cérébrales, Plasticité et Rééducation (A.V.-C., C.S., J.G., O.F.) and Frontlab Team (A.V.-C., C.S., J.G., O.F., B.D., R.L., M.T.), Institut du Cerveau et de la Moelle Epinière (ICM), INSERM 1127, CNRS, UMR 7225 and Sorbonne Université (SO), Paris, France; Laboratory for Cerebral Dynamics Plasticity and Rehabilitation (A.V.-C.), Boston University School of Medicine, MA; Cognitive Neuroscience and Information Technology Research Program (A.V.-C.), Open University of Catalonia (UOC), Barcelona, Spain; Department of Neurology (B.D., R.L., M.T.), National Reference Center for "PPA and Rare Dementias," Pitié Salpêtrière Hospital, AP-HP, Paris, France; and Neural Engineering Laboratory, Department of Biomedical Engineering (D.Q.T., M.B.), the City College of City University of New York, NY
| | - Marc Teichmann
- From Groupe de Dynamiques Cérébrales, Plasticité et Rééducation (A.V.-C., C.S., J.G., O.F.) and Frontlab Team (A.V.-C., C.S., J.G., O.F., B.D., R.L., M.T.), Institut du Cerveau et de la Moelle Epinière (ICM), INSERM 1127, CNRS, UMR 7225 and Sorbonne Université (SO), Paris, France; Laboratory for Cerebral Dynamics Plasticity and Rehabilitation (A.V.-C.), Boston University School of Medicine, MA; Cognitive Neuroscience and Information Technology Research Program (A.V.-C.), Open University of Catalonia (UOC), Barcelona, Spain; Department of Neurology (B.D., R.L., M.T.), National Reference Center for "PPA and Rare Dementias," Pitié Salpêtrière Hospital, AP-HP, Paris, France; and Neural Engineering Laboratory, Department of Biomedical Engineering (D.Q.T., M.B.), the City College of City University of New York, NY.
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Stimulation of Dorsolateral Prefrontal Cortex Enhances Adaptive Cognitive Control: A High-Definition Transcranial Direct Current Stimulation Study. J Neurosci 2017; 36:12530-12536. [PMID: 27974612 DOI: 10.1523/jneurosci.2450-16.2016] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/07/2016] [Accepted: 10/18/2016] [Indexed: 11/21/2022] Open
Abstract
Conflict adaptation is a hallmark effect of adaptive cognitive control and refers to the adjustment of control to the level of previously experienced conflict. Conflict monitoring theory assumes that the dorsolateral prefrontal cortex (DLPFC) is causally involved in this adjustment. However, to date, evidence in humans is predominantly correlational, and heterogeneous with respect to the lateralization of control in the DLPFC. We used high-definition transcranial direct current stimulation (HD-tDCS), which allows for more focal current delivery than conventional tDCS, to clarify the causal involvement of the DLPFC in conflict adaptation. Specifically, we investigated the regional specificity and lateralization of potential beneficial stimulation effects on conflict adaptation during a visual flanker task. One hundred twenty healthy participants were assigned to four HD-tDCS conditions: left or right DLPFC or left or right primary motor cortex (M1). Each group underwent both active and sham HD-tDCS in crossover, double-blind designs. We obtained a sizeable conflict adaptation effect (measured as the modulation of the flanker effect as a function of previous response conflict) in all groups and conditions. However, this effect was larger under active HD-tDCS than under sham stimulation in both DLPFC groups. In contrast, active stimulation had no effect on conflict adaptation in the M1 groups. In sum, the present results indicate that the DLPFC plays a causal role in adaptive cognitive control, but that the involvement of DLPFC in control is not restricted to the left or right hemisphere. Moreover, our study confirms the potential of HD-tDCS to modulate cognition in a regionally specific manner. SIGNIFICANCE STATEMENT Conflict adaptation is a hallmark effect of adaptive cognitive control. While animal studies have suggested causal involvement of the DLPFC in this phenomenon, such evidence is currently lacking in humans. The present study used high-definition transcranial direct current stimulation (HD-tDCS) to demonstrate that the DLPFC is causally involved in conflict adaptation in humans. Our study confirms a central claim of conflict monitoring theory, which up to now has predominantly relied on correlational studies. Our results further indicate an equal involvement of the left and right DLPFC in adaptive control, whereas stimulation of a control region-the primary motor cortex-had no effect on adaptive control. The study thus confirms the potential of HD-tDCS to modulate cognition in a regionally specific manner.
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12
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Lefebvre S, Liew SL. Anatomical Parameters of tDCS to Modulate the Motor System after Stroke: A Review. Front Neurol 2017; 8:29. [PMID: 28232816 PMCID: PMC5298973 DOI: 10.3389/fneur.2017.00029] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 01/23/2017] [Indexed: 01/19/2023] Open
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method to modulate the local field potential in neural tissue and consequently, cortical excitability. As tDCS is relatively portable, affordable, and accessible, the applications of tDCS to probe brain-behavior connections have rapidly increased in the last 10 years. One of the most promising applications is the use of tDCS to modulate excitability in the motor cortex after stroke and promote motor recovery. However, the results of clinical studies implementing tDCS to modulate motor excitability have been highly variable, with some studies demonstrating that as many as 50% or more of patients fail to show a response to stimulation. Much effort has therefore been dedicated to understand the sources of variability affecting tDCS efficacy. Possible suspects include the placement of the electrodes, task parameters during stimulation, dosing (current amplitude, duration of stimulation, frequency of stimulation), individual states (e.g., anxiety, motivation, attention), and more. In this review, we first briefly review potential sources of variability specific to stroke motor recovery following tDCS. We then examine how the anatomical variability in tDCS placement [e.g., neural target(s) and montages employed] may alter the neuromodulatory effects that tDCS exerts on the post-stroke motor system.
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Affiliation(s)
- Stephanie Lefebvre
- Neural Plasticity and Neurorehabilitation Laboratory, Chan Division of Occupational Science and Occupational Therapy, Division of Biokinesiology and Physical Therapy, Department of Neurology, Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Sook-Lei Liew
- Neural Plasticity and Neurorehabilitation Laboratory, Chan Division of Occupational Science and Occupational Therapy, Division of Biokinesiology and Physical Therapy, Department of Neurology, Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
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13
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Wilke S, List J, Mekle R, Lindenberg R, Bukowski M, Ott S, Schubert F, Ittermann B, Flöel A. No Effect of Anodal Transcranial Direct Current Stimulation on Gamma-Aminobutyric Acid Levels in Patients with Recurrent Mild Traumatic Brain Injury. J Neurotrauma 2017; 34:281-290. [DOI: 10.1089/neu.2016.4399] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Skadi Wilke
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Jonathan List
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Ralf Mekle
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig und Berlin, Berlin, Germany
| | - Robert Lindenberg
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Martin Bukowski
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Stefanie Ott
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Florian Schubert
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig und Berlin, Berlin, Germany
| | - Bernd Ittermann
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig und Berlin, Berlin, Germany
| | - Agnes Flöel
- Department of Neurology, Charité–University Hospital, Berlin, Germany
- Center for Stroke Research Berlin, Charité–University Hospital, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité–University Hospital, Berlin, Germany
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Abstract
PURPOSE OF REVIEW The review aims at highlighting the additional benefit that can be gained from combining noninvasive brain stimulation as well as repetitive sensory stimulation protocols with MRI techniques to account for the intersubject variability observed in those treatments. Potentially, this should help to identify predictive patterns in the individual receptiveness to the treatment. RECENT FINDINGS Knowledge about the underlying physiological principles of excitability changes as induced by noninvasive brain stimulation or repetitive sensory stimulation is accumulating, revealing strong associations with plasticity processes at the synaptic level. In this context, MRI techniques, such as magnetic resonance spectroscopy and functional MRI, emerged as valuable tools for the qualitative assessment of baseline states and induced changes. Those physiological readouts can help explain the interindividual heterogeneity found in behavioural and/or clinical responses to the specific stimulation protocols. This knowledge will eventually translate, first, into the preliminary classification of study participants into treatment groups according to their neurophysiological baseline state and expected responses to a particular stimulation. Subsequently, this should also aid the optimization of stimulation protocols according to the classification outcome, resulting in retuned protocols for particular groups of study participants. SUMMARY The consistent MRI-based monitoring of stimulation effects in the neural network promises a considerable gain for the customization of intervention protocols with improved therapeutic potential and rehabilitative predictions.
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15
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Darkow R, Martin A, Würtz A, Flöel A, Meinzer M. Transcranial direct current stimulation effects on neural processing in post-stroke aphasia. Hum Brain Mapp 2016; 38:1518-1531. [PMID: 27859982 DOI: 10.1002/hbm.23469] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 10/14/2016] [Accepted: 11/06/2016] [Indexed: 12/18/2022] Open
Abstract
Non-invasive transcranial direct current stimulation (tDCS) can enhance recovery after stroke. However, fundamental knowledge about how tDCS impacts neural processing in the lesioned human brain is currently lacking. In the present study, it was investigated how tDCS modulates brain function in patients with post-stroke language impairment (aphasia). In a cross-over, randomized trial, patients named pictures of common objects during functional magnetic resonance imaging (fMRI). Concurrently, excitatory (anodal-) or sham-tDCS (1 mA, 20 min, or 30 s, respectively) was administered to the left primary motor cortex, a montage with demonstrated potential to improve aphasic language. By choosing stimuli that could reliable be named by the patients, the authors aimed to derive a pure measure of stimulation effects that was independent of treatment or performance effects and to assess how tDCS interacts with the patients' residual language network. Univariate fMRI data analysis revealed reduced activity in domain-general regions mediating high-level cognitive control during anodal-tDCS. Independent component functional network analysis demonstrated selectively increased language network activity and an inter-correlated shift from higher to lower frequency bands, indicative of increased within-network communication. Compared with healthy controls, anodal-tDCS resulted in overall "normalization" of brain function in the patients. These results demonstrate for the first time how tDCS modulates neural processing in stroke patients. Such information is crucial to assure that behavioral treatments targeting specific neural circuits overlap with regions that are modulated by tDCS, thereby maximizing stimulation effects during therapy. Hum Brain Mapp 38:1518-1531, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Robert Darkow
- Department of Neurology, NeuroCure Clinical Research Center, and Center of Stroke Research Berlin, Berlin, Charité University Medicine, Berlin, 10117, Germany
| | - Andrew Martin
- The University of Queensland, Centre for Clinical Research, Brisbane Queensland, 4029, Australia
| | - Anna Würtz
- Department of Neurology, NeuroCure Clinical Research Center, and Center of Stroke Research Berlin, Berlin, Charité University Medicine, Berlin, 10117, Germany
| | - Agnes Flöel
- Department of Neurology, NeuroCure Clinical Research Center, and Center of Stroke Research Berlin, Berlin, Charité University Medicine, Berlin, 10117, Germany
| | - Marcus Meinzer
- Department of Neurology, NeuroCure Clinical Research Center, and Center of Stroke Research Berlin, Berlin, Charité University Medicine, Berlin, 10117, Germany.,The University of Queensland, Centre for Clinical Research, Brisbane Queensland, 4029, Australia
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17
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Electrical stimulation of the motor cortex enhances treatment outcome in post-stroke aphasia. Brain 2016; 139:1152-63. [DOI: 10.1093/brain/aww002] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 12/04/2015] [Indexed: 12/14/2022] Open
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