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Maeyama T, Okada H, Sakai S. The effects of rehabilitative interventions on reading disorders caused by homonymous visual field defects: a meta-analysis focusing on improvement in reading speed. Acta Neurol Belg 2024; 124:123-140. [PMID: 37572263 DOI: 10.1007/s13760-023-02327-6] [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: 03/25/2023] [Accepted: 06/27/2023] [Indexed: 08/14/2023]
Abstract
INTRODUCTION Reading disorders caused by homonymous visual field defects (HVFDs) have a significant impact on a patient's quality of life. However, no review has been conducted to evaluate the available evidence on the effects of rehabilitative interventions on reading disorders caused by HVFDs. Thus, the aim of this study was to systematically evaluate the effects of rehabilitative interventions on reading disorders caused by HVFDs. METHODS We searched the MEDLINE/PubMed, Cochrane Library, ClinicalTrials.gov, CINAHL, and ScienceDirect databases for relevant articles. Relevant search terms were used to identify reports of randomized controlled trials or randomized crossover trials published between January 1990 and December 2021. Only studies that included reading-speed-related outcomes were analyzed. Risk of bias was assessed using the PEDro scale. Meta-analysis was conducted using a random-effects model, and standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using the Ι2 statistic. RESULTS Nine studies were included in the meta-analysis. The results showed that rehabilitative interventions significantly improved reading disorders caused by HVFDs (SMD = 0.30; 95% CI 0.08-0.51; P < 0.01; Ι2 = 0.0%). Subgroup analysis showed that reading training significantly improved reading disorders (SMD = 0.35; 95% CI 0.05-0.66; P = 0.02; Ι2 = 0.0%). CONCLUSION Reading disorders caused by HVFDs can be improved through rehabilitation. In addition, reading training for the improvement of eye movement and fixation to compensate for foveal and parafoveal visual field defects may improve reading speed.
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Affiliation(s)
- Takaya Maeyama
- Graduate School of Health Sciences, Hokkaido University, Kita 12-Jo Nishi 5-Chome, Kitaku, Sapporo, Hokkaido, Japan
| | - Hiroki Okada
- Department of Rehabilitation Sciences, Hokkaido University, Kita 12-Jo Nishi 5-Chome, Kita-Ku, Sapporo, Hokkaido, Japan.
| | - Shinya Sakai
- Department of Rehabilitation Sciences, Hokkaido University, Kita 12-Jo Nishi 5-Chome, Kita-Ku, Sapporo, Hokkaido, Japan
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2
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He Q, Zhu X, Fang F. Enhancing visual perceptual learning using transcranial electrical stimulation: Transcranial alternating current stimulation outperforms both transcranial direct current and random noise stimulation. J Vis 2023; 23:2. [PMID: 38054934 DOI: 10.1167/jov.23.14.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023] Open
Abstract
Diverse strategies can be employed to enhance visual skills, including visual perceptual learning (VPL) and transcranial electrical stimulation (tES). Combining VPL and tES is a popular method that holds promise for producing significant improvements in visual acuity within a short time frame. However, there is still a lack of comprehensive evaluation regarding the effects of combining different types of tES and VPL on enhancing visual function, especially with a larger sample size. In the present study, we recruited four groups of subjects (26 subjects each) to learn an orientation discrimination task with five daily training sessions. During training, the occipital region of each subject was stimulated by one type of tES-anodal transcranial direct current stimulation (tDCS), alternating current stimulation (tACS) at 10 Hz, high-frequency random noise stimulation (tRNS), and sham tACS-while the subject performed the training task. We found that, compared with the sham stimulation, both the high-frequency tRNS and the 10-Hz tACS facilitated VPL efficiently in terms of learning rate and performance improvement, but there was little modulatory effect in the anodal tDCS condition. Remarkably, the 10-Hz tACS condition exhibited superior modulatory effects compared with the tRNS condition, demonstrating the strongest modulation among the most commonly used tES types for further enhancing vision when combined with VPL. Our results suggest that alpha oscillations play a vital role in VPL. Our study provides a practical guide for vision rehabilitation.
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Affiliation(s)
- Qing He
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing, China
- IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Xinyi Zhu
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing, China
- IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Fang Fang
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing, China
- IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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Wu D, Zhang P, Wang Y, Liu N, Sun K, Wang P, Xiao W. Anodal online transcranial direct current stimulation facilitates visual motion perceptual learning. Eur J Neurosci 2023; 57:479-489. [PMID: 36511948 DOI: 10.1111/ejn.15895] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022]
Abstract
Visual perceptual learning (VPL) has great potential implications for clinical populations, but adequate improvement often takes weeks to months to obtain; therefore, practical applications of VPL are limited. Strategies that enhance visual performance acquisition make great practical sense. Transcranial direct current stimulation (tDCS) could be beneficial to VPL, but thus far, the results are inconsistent. The current study had two objectives: (1) to investigate the effect of anodal tDCS on VPL and (2) to determine whether the timing sequence of anodal tDCS and training influences VPL. Anodal tDCS was applied on the left human middle temporal (hMT+) during training on a coherent motion discrimination task (online), anodal tDCS was also applied before training (offline) and sham tDCS was applied during training (sham). The coherent thresholds were measured without stimulation before, 2 days after and 1 month after training. All participants trained for five consecutive days. Anodal tDCS resulted in more performance improvement when applied during daily training but not when applied before training. Additionally, neither within-session improvement nor between-session improvement differed among the online, offline and sham tDCS conditions. These findings contribute to the development of efficient stimulation protocols and a deep understanding of the mechanisms underlying the effect of tDCS on VPL.
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Affiliation(s)
- Di Wu
- Department of Medical Psychology, Air Force Medical University, Xi'an, China
- Department of Neurobiology, Basic Medical School, Air Force Medical University, Xi'an, China
| | - Pan Zhang
- Department of Psychology, Hebei Normal University, Shijiazhuang, China
| | - Yifan Wang
- Department of Medical Psychology, Air Force Medical University, Xi'an, China
| | - Na Liu
- Department of Nursing, Air Force Medical University, Xi'an, China
| | - Kewei Sun
- Department of Medical Psychology, Air Force Medical University, Xi'an, China
| | - Panhui Wang
- Department of Medical Psychology, Air Force Medical University, Xi'an, China
| | - Wei Xiao
- Department of Medical Psychology, Air Force Medical University, Xi'an, China
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Moghadas Tabrizi Y, Yavari Kateb M, Shahrbanian S. Enhancement of Visuospatial Working Memory by Transcranial Direct Current Stimulation on Prefrontal and Parietal Cortices. Basic Clin Neurosci 2023; 14:129-136. [PMID: 37346865 PMCID: PMC10279990 DOI: 10.32598/bcn.2021.3275.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 08/14/2021] [Accepted: 09/11/2021] [Indexed: 11/02/2023] Open
Abstract
Introduction Previous studies have reported dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex (PPC) activation during the performance of spatial working memory (SWM), therefore this study aims to compare the effect of transcranial direct current stimulation (tDCS) between these two areas. Methods Fifty-four healthy right-handed students (27 women, 27 men; age=24.3±0.2 years) were randomly assigned to an anodal group (n=27) and a sham group (n=27), each of these groups was divided into F4 (representing right DLPFC) or P4 (representing right PPC) subgroups, respectively. A computerized Corsi block tapping (CBT) task was used to measure SWM. The tDCS intervention consisted of five daily sessions with a direct current of 1.5 mA for 15 minutes on the F4 or P4 area of the brain at 24-hour intervals. Results Significant enhancement of the SWM span as well as a faster response was observed after anodal tDCS in both the anterior and posterior direction. Moreover, stimulation of the left DLPFC induced a faster reaction time compared to the right PPC. Conclusion Stimulation DLPFC and PPC, as an element of the frontoparietal network, showed SWM enhancement, with the DLPFC being more affected. Our finding provides new evidence to compare the effect of stimulation on the two main activated cortical areas during visual SWM.
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Affiliation(s)
- Yousef Moghadas Tabrizi
- Department of Sport Pathology and Corrective Exercises, Faculty of Sports and Health Sciences, University of Tehran, Tehran, Iran
| | - Meysam Yavari Kateb
- Department of Behavioral and Cognitive Sports Sciences, Faculty of Sports and Health Sciences, University of Tehran, Tehran, Iran
| | - Shahnaz Shahrbanian
- Department of Sports Science, Faculty of Humanities, Tarbiat Modares University, Tehran, Iran
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Bello UM, Wang J, Park ASY, Tan KWS, Cheung BWS, Thompson B, Cheong AMY. Can visual cortex non-invasive brain stimulation improve normal visual function? A systematic review and meta-analysis. Front Neurosci 2023; 17:1119200. [PMID: 36937668 PMCID: PMC10017867 DOI: 10.3389/fnins.2023.1119200] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Objective Multiple studies have explored the use of visual cortex non-invasive brain stimulation (NIBS) to enhance visual function. These studies vary in sample size, outcome measures, and methodology. We conducted a systematic review and meta-analyses to assess the effects of NIBS on visual functions in human participants with normal vision. Methods We followed the PRISMA guidelines, and a review protocol was registered with PROSPERO before study commencement (CRD42021255882). We searched Embase, Medline, PsychInfo, PubMed, OpenGrey and Web of Science using relevant keywords. The search covered the period from 1st January 2000 until 1st September 2021. Comprehensive meta-analysis (CMA) software was used for quantitative analysis. Results Fifty studies were included in the systematic review. Only five studies utilized transcranial magnetic stimulation (TMS) and no TMS studies met our pre-specified criteria for meta-analysis. Nineteen transcranial electrical stimulation studies (tES, 38%) met the criteria for meta-analysis and were the focus of our review. Meta-analysis indicated acute effects (Hedges's g = 0.232, 95% CI: 0.023-0.442, p = 0.029) and aftereffects (0.590, 95% CI: 0.182-0.998, p = 0.005) of tES on contrast sensitivity. Visual evoked potential (VEP) amplitudes were significantly enhanced immediately after tES (0.383, 95% CI: 0.110-0.665, p = 0.006). Both tES (0.563, 95% CI: 0.230-0.896, p = 0.001) and anodal-transcranial direct current stimulation (a-tDCS) alone (0.655, 95% CI: 0.273-1.038, p = 0.001) reduced crowding in peripheral vision. The effects of tES on visual acuity, motion perception and reaction time were not statistically significant. Conclusion There are significant effects of visual cortex tES on contrast sensitivity, VEP amplitude, an index of cortical excitability, and crowding among normally sighted individuals. Additional studies are required to enable a comparable meta-analysis of TMS effects. Future studies with robust experimental designs are needed to extend these findings to populations with vision loss. Clinical trial registration ClinicalTrials.gov/, identifier CRD42021255882.
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Affiliation(s)
- Umar M. Bello
- Centre for Eye and Vision Research, Hong Kong Science Park, Hong Kong, Hong Kong SAR, China
- Department of Physiotherapy and Paramedicine, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Jingying Wang
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Adela S. Y. Park
- Centre for Eye and Vision Research, Hong Kong Science Park, Hong Kong, Hong Kong SAR, China
| | - Ken W. S. Tan
- Centre for Eye and Vision Research, Hong Kong Science Park, Hong Kong, Hong Kong SAR, China
| | - Blossom W. S. Cheung
- Centre for Eye and Vision Research, Hong Kong Science Park, Hong Kong, Hong Kong SAR, China
| | - Benjamin Thompson
- Centre for Eye and Vision Research, Hong Kong Science Park, Hong Kong, Hong Kong SAR, China
- School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Allen M. Y. Cheong
- Centre for Eye and Vision Research, Hong Kong Science Park, Hong Kong, Hong Kong SAR, China
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
- *Correspondence: Allen M. Y. Cheong,
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Qi S, Liang Z, Wei Z, Liu Y, Wang X. Effects of transcranial direct current stimulation on motor skills learning in healthy adults through the activation of different brain regions: A systematic review. Front Hum Neurosci 2022; 16:1021375. [PMID: 36277051 PMCID: PMC9582610 DOI: 10.3389/fnhum.2022.1021375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Objective This systematic review aims to analyze existing literature of the effects of transcranial direct current stimulation (tDCS) on motor skills learning of healthy adults and discuss the underlying neurophysiological mechanism that influences motor skills learning. Methods This systematic review has followed the recommendations of the Preferred Reporting Items for Systematic reviews and Meta-Analyses. The PubMed, EBSCO, and Web of Science databases were systematically searched for relevant studies that were published from database inception to May 2022. Studies were included based on the Participants, Intervention, Comparison, Outcomes, and Setting inclusion strategy. The risk of bias was evaluated by using the Review manager 5.4 tool. The quality of each study was assessed with the Physiotherapy Evidence Database (PEDro) scale. Results The electronic search produced 142 studies. Only 11 studies were included after filtering. These studies performed well in terms of distribution, blinding availability and selective reporting. They reported that tDCS significantly improved motor skills learning. The main outcomes measure were the improvement of the motor sequence tasks and specific motor skills. Nine studies showed that tDCS interventions reduced reaction time to complete motor sequence tasks in healthy adults and two studies showed that tDCS interventions improved golf putting task performance. Conclusion The included studies showed that tDCS can help healthy adults to improve the motor skills learning by activating different brain regions, such as the primary motor cortex, left dorsolateral prefrontal cortex and right cerebellum. However, the number of included studies was limited, and the sample sizes were small. Therefore, more studies are urgently needed to validate the results of current studies and further explore the underlying neurophysiological mechanisms of tDCS in the future.
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Wu D, Wang Y, Liu N, Wang P, Sun K, Xiao W. High-definition transcranial direct current stimulation of the left middle temporal complex does not affect visual motion perception learning. Front Neurosci 2022; 16:988590. [PMID: 36117616 PMCID: PMC9474993 DOI: 10.3389/fnins.2022.988590] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/15/2022] [Indexed: 11/13/2022] Open
Abstract
Visual perceptual learning (VPL) refers to the improvement in visual perceptual abilities through training and has potential implications for clinical populations. However, improvements in perceptual learning often require hundreds or thousands of trials over weeks to months to attain, limiting its practical application. Transcranial direct current stimulation (tDCS) could potentially facilitate perceptual learning, but the results are inconsistent thus far. Thus, this research investigated the effect of tDCS over the left human middle temporal complex (hMT+) on learning to discriminate visual motion direction. Twenty-seven participants were randomly assigned to the anodal, cathodal and sham tDCS groups. Before and after training, the thresholds of motion direction discrimination were assessed in one trained condition and three untrained conditions. Participants were trained over 5 consecutive days while receiving 4 × 1 ring high-definition tDCS (HD-tDCS) over the left hMT+. The results showed that the threshold of motion direction discrimination significantly decreased after training. However, no obvious differences in the indicators of perceptual learning, such as the magnitude of improvement, transfer indexes, and learning curves, were noted among the three groups. The current study did not provide evidence of a beneficial effect of tDCS on VPL. Further research should explore the impact of the learning task characteristics, number of training sessions and the sequence of stimulation.
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Affiliation(s)
- Di Wu
- Department of Medical Psychology, Air Force Medical University, Xi’an, China
| | - Yifan Wang
- Department of Medical Psychology, Air Force Medical University, Xi’an, China
| | - Na Liu
- Department of Nursing, Air Force Medical University, Xi’an, China
| | - Panhui Wang
- Department of Medical Psychology, Air Force Medical University, Xi’an, China
| | - Kewei Sun
- Department of Medical Psychology, Air Force Medical University, Xi’an, China
| | - Wei Xiao
- Department of Medical Psychology, Air Force Medical University, Xi’an, China
- *Correspondence: Wei Xiao,
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8
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Battaglini L, Di Ponzio M, Ghiani A, Mena F, Santacesaria P, Casco C. Vision recovery with perceptual learning and non-invasive brain stimulation: Experimental set-ups and recent results, a review of the literature. Restor Neurol Neurosci 2022; 40:137-168. [PMID: 35964213 DOI: 10.3233/rnn-221261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Vision is the sense which we rely on the most to interact with the environment and its integrity is fundamental for the quality of our life. However, around the globe, more than 1 billion people are affected by debilitating vision deficits. Therefore, finding a way to treat (or mitigate) them successfully is necessary. OBJECTIVE This narrative review aims to examine options for innovative treatment of visual disorders (retinitis pigmentosa, macular degeneration, optic neuropathy, refractory disorders, hemianopia, amblyopia), especially with Perceptual Learning (PL) and Electrical Stimulation (ES). METHODS ES and PL can enhance visual abilities in clinical populations, inducing plastic changes. We describe the experimental set-ups and discuss the results of studies using ES or PL or their combination in order to suggest, based on literature, which treatment is the best option for each clinical condition. RESULTS Positive results were obtained using ES and PL to enhance visual functions. For example, repetitive transorbital Alternating Current Stimulation (rtACS) appeared as the most effective treatment for pre-chiasmatic disorders such as optic neuropathy. A combination of transcranial Direct Current Stimulation (tDCS) and visual training seems helpful for people with hemianopia, while transcranial Random Noise Stimulation (tRNS) makes visual training more efficient in people with amblyopia and mild myopia. CONCLUSIONS This narrative review highlights the effect of different ES montages and PL in the treatment of visual disorders. Furthermore, new options for treatment are suggested. It is noteworthy to mention that, in some cases, unclear results emerged and others need to be more deeply investigated.
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Affiliation(s)
- Luca Battaglini
- Department of General Psychology, University of Padova, Italy.,Centro di Ateneo dei Servizi Clinici Universitari Psicologici (SCUP), University of Padova, Padova, Italy.,Neuro.Vis.U.S, University of Padova, Padova, Italy
| | - Michele Di Ponzio
- Department of General Psychology, University of Padova, Italy.,Istituto di Neuroscienze, Florence, Italy
| | - Andrea Ghiani
- Department of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, the Netherlands
| | - Federica Mena
- Department of General Psychology, University of Padova, Italy
| | | | - Clara Casco
- Department of General Psychology, University of Padova, Italy.,Centro di Ateneo dei Servizi Clinici Universitari Psicologici (SCUP), University of Padova, Padova, Italy.,Neuro.Vis.U.S, University of Padova, Padova, Italy
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Park JG. Update on Stroke Rehabilitation for Non-Motor Impairment. BRAIN & NEUROREHABILITATION 2022; 15:e13. [PMID: 36743206 PMCID: PMC9833475 DOI: 10.12786/bn.2022.15.e13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/13/2022] [Accepted: 07/18/2022] [Indexed: 11/08/2022] Open
Abstract
Various interventions exist to treat non-motor impairments caused by stroke. Adjuvant treatments such as non-invasive brain stimulation, virtual reality, computer-assisted training, neurostimulation, and biofeedback are being investigated and applied in the areas of cognitive dysfunction, language problems, visual disorders, dysphagia, mood disorders, and post-stroke pain. Most of these treatments have shown efficacy and symptom improvement, but further investigation is required to fully clarify their effects.
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Affiliation(s)
- Jin Gee Park
- Department of Physical Medicine and Rehabilitation, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
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10
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Evidence of Neuroplastic Changes after Transcranial Magnetic, Electric, and Deep Brain Stimulation. Brain Sci 2022; 12:brainsci12070929. [PMID: 35884734 PMCID: PMC9313265 DOI: 10.3390/brainsci12070929] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 07/06/2022] [Accepted: 07/08/2022] [Indexed: 02/04/2023] Open
Abstract
Electric and magnetic stimulation of the human brain can be used to excite or inhibit neurons. Numerous methods have been designed over the years for this purpose with various advantages and disadvantages that are the topic of this review. Deep brain stimulation (DBS) is the most direct and focal application of electric impulses to brain tissue. Electrodes are placed in the brain in order to modulate neural activity and to correct parameters of pathological oscillation in brain circuits such as their amplitude or frequency. Transcranial magnetic stimulation (TMS) is a non-invasive alternative with the stimulator generating a magnetic field in a coil over the scalp that induces an electric field in the brain which, in turn, interacts with ongoing brain activity. Depending upon stimulation parameters, excitation and inhibition can be achieved. Transcranial electric stimulation (tES) applies electric fields to the scalp that spread along the skull in order to reach the brain, thus, limiting current strength to avoid skin sensations and cranial muscle pain. Therefore, tES can only modulate brain activity and is considered subthreshold, i.e., it does not directly elicit neuronal action potentials. In this review, we collect hints for neuroplastic changes such as modulation of behavior, the electric activity of the brain, or the evolution of clinical signs and symptoms in response to stimulation. Possible mechanisms are discussed, and future paradigms are suggested.
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11
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Perspectives on the Combined Use of Electric Brain Stimulation and Perceptual Learning in Vision. Vision (Basel) 2022; 6:vision6020033. [PMID: 35737420 PMCID: PMC9227313 DOI: 10.3390/vision6020033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 11/29/2022] Open
Abstract
A growing body of literature offers exciting perspectives on the use of brain stimulation to boost training-related perceptual improvements in humans. Recent studies suggest that combining visual perceptual learning (VPL) training with concomitant transcranial electric stimulation (tES) leads to learning rate and generalization effects larger than each technique used individually. Both VPL and tES have been used to induce neural plasticity in brain regions involved in visual perception, leading to long-lasting visual function improvements. Despite being more than a century old, only recently have these techniques been combined in the same paradigm to further improve visual performance in humans. Nonetheless, promising evidence in healthy participants and in clinical population suggests that the best could still be yet to come for the combined use of VPL and tES. In the first part of this perspective piece, we briefly discuss the history, the characteristics, the results and the possible mechanisms behind each technique and their combined effect. In the second part, we discuss relevant aspects concerning the use of these techniques and propose a perspective concerning the combined use of electric brain stimulation and perceptual learning in the visual system, closing with some open questions on the topic.
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12
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He Q, Yang XY, Zhao D, Fang F. Enhancement of visual perception by combining transcranial electrical stimulation and visual perceptual training. MEDICAL REVIEW (BERLIN, GERMANY) 2022; 2:271-284. [PMID: 37724187 PMCID: PMC10388778 DOI: 10.1515/mr-2022-0010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/16/2022] [Indexed: 09/20/2023]
Abstract
The visual system remains highly malleable even after its maturity or impairment. Our visual function can be enhanced through many ways, such as transcranial electrical stimulation (tES) and visual perceptual learning (VPL). TES can change visual function rapidly, but its modulation effect is short-lived and unstable. By contrast, VPL can lead to a substantial and long-lasting improvement in visual function, but extensive training is typically required. Theoretically, visual function could be further improved in a shorter time frame by combining tES and VPL than by solely using tES or VPL. Vision enhancement by combining these two methods concurrently is both theoretically and practically significant. In this review, we firstly introduced the basic concept and possible mechanisms of VPL and tES; then we reviewed the current research progress of visual enhancement using the combination of two methods in both general and clinical population; finally, we discussed the limitations and future directions in this field. Our review provides a guide for future research and application of vision enhancement and restoration by combining VPL and tES.
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Affiliation(s)
- Qing He
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing, China
- IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Xin-Yue Yang
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing, China
- IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Daiqing Zhao
- Department of Psychology, The Pennsylvania State University, University Park, State College, PA, USA
| | - Fang Fang
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing, China
- IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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13
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Saionz EL, Busza A, Huxlin KR. Rehabilitation of visual perception in cortical blindness. HANDBOOK OF CLINICAL NEUROLOGY 2022; 184:357-373. [PMID: 35034749 PMCID: PMC9682408 DOI: 10.1016/b978-0-12-819410-2.00030-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Blindness is a common sequela after stroke affecting the primary visual cortex, presenting as a contralesional, homonymous, visual field cut. This can occur unilaterally or, less commonly, bilaterally. While it has been widely assumed that after a brief period of spontaneous improvement, vision loss becomes stable and permanent, accumulating data show that visual training can recover some of the vision loss, even long after the stroke. Here, we review the different approaches to rehabilitation employed in adult-onset cortical blindness (CB), focusing on visual restoration methods. Most of this work was conducted in chronic stroke patients, partially restoring visual discrimination and luminance detection. However, to achieve this, patients had to train for extended periods (usually many months), and the vision restored was not entirely normal. Several adjuvants to training such as noninvasive, transcranial brain stimulation, and pharmacology are starting to be investigated for their potential to increase the efficacy of training in CB patients. However, these approaches are still exploratory and require considerably more research before being adopted. Nonetheless, having established that the adult visual system retains the capacity for restorative plasticity, attention recently turned toward the subacute poststroke period. Drawing inspiration from sensorimotor stroke rehabilitation, visual training was recently attempted for the first time in subacute poststroke patients. It improved vision faster, over larger portions of the blind field, and for a larger number of visual discrimination abilities than identical training initiated more than 6 months poststroke (i.e., in the chronic period). In conclusion, evidence now suggests that visual neuroplasticity after occipital stroke can be reliably recruited by a range of visual training approaches. In addition, it appears that poststroke visual plasticity is dynamic, with a critical window of opportunity in the early postdamage period to attain more rapid, more extensive recovery of a larger set of visual perceptual abilities.
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Affiliation(s)
- Elizabeth L Saionz
- Medical Scientist Training Program, University of Rochester, Rochester, NY, United States
| | - Ania Busza
- Department of Neurology, University of Rochester, Rochester, NY, United States
| | - Krystel R Huxlin
- Flaum Eye Institute, University of Rochester, Rochester, NY, United States.
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14
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Abstract
PURPOSE OF REVIEW Homonymous visual field defects are a common sequela of stroke, and are assumed to be permanent within a few weeks of the event. Because consensus about the efficacy of rehabilitation is lacking, visual therapy is rarely prescribed. Here, we review current rehabilitation options and strategies in the translational pipeline that could change these perspectives. RECENT FINDINGS The mainstays of available therapy for homonymous visual defects are compensation training and substitution, which allow patients to better use their spared vision. However, early clinical studies suggest that vision can partially recover following intensive training inside the blind field. Research into the relative efficacy of different restorative approaches continues, providing insights into neurophysiologic substrates of recovery and its limitations. This, in turn, has led to new work examining the possible benefits of earlier intervention, advanced training procedures, noninvasive brain stimulation, and pharmacological adjuvants, all of which remain to be vetted through properly powered, randomized, clinical trials. SUMMARY Research has uncovered substantial visual plasticity after occipital strokes, suggesting that rehabilitative strategies for this condition should be more aggressive. For maximal benefit, poststroke vision-restorative interventions should begin early, and in parallel with strategies that optimize everyday use of an expanding field of view.
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Affiliation(s)
| | - Steven E Feldon
- Flaum Eye Institute
- Center for Visual Science, University of Rochester, Rochester, NY, USA
| | - Krystel R Huxlin
- Flaum Eye Institute
- Center for Visual Science, University of Rochester, Rochester, NY, USA
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15
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Wu D, Li C, Liu N, Xu P, Xiao W. Visual motion perception improvements following direct current stimulation over V5 are dependent on initial performance. Exp Brain Res 2020; 238:2409-2416. [PMID: 32776173 DOI: 10.1007/s00221-020-05842-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 05/25/2020] [Indexed: 11/26/2022]
Abstract
Transcranial direct current stimulation (tDCS) can improve visual perception. However, the effect of tDCS on visual perception is largely variable, possibly due to individual differences in initial performance. The goal of the present study was to evaluate the dependency of visual motion perception improvements on initial performance. Twenty-eight observers were randomly divided into two groups. Anodal tDCS and sham stimulation were separately applied to V5 (1.5 mA, 20 min), while observers performed a coherent motion direction identification task. The results showed that compared to sham stimulation, anodal tDCS induced a significant improvement in motion perception that lasted at least 20 min. In addition, the degree of improvement was dependent on initial performance, with a greater improvement magnitude observed for those with poorer initial performance. These results may have implications for understanding the nature of the stimulation rule and for the use of a customised stimulation protocol to enhance tDCS efficiency in practical applications.
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Affiliation(s)
- Di Wu
- Department of Medical Psychology, Air Force Medical University, Xi'an, China
| | - Chenxi Li
- Scholl of Nursing, Yueyang Vocational Technical College, Yueyang, China
| | - Na Liu
- Department of Nursing, Air Force Medical University, Xi'an, China
| | - Pengbo Xu
- Department of Medical Psychology, Air Force Medical University, Xi'an, China
| | - Wei Xiao
- Department of Medical Psychology, Air Force Medical University, Xi'an, China.
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16
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Perin C, Viganò B, Piscitelli D, Matteo BM, Meroni R, Cerri CG. Non-invasive current stimulation in vision recovery: a review of the literature. Restor Neurol Neurosci 2020; 38:239-250. [PMID: 31884495 PMCID: PMC7504999 DOI: 10.3233/rnn-190948] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Background: Around 253 million people worldwide suffer from irreversible visual damage. Numerous studies have been carried out in order to unveil the effects of electrical stimulation (ES) as a useful tool for rehabilitation for different visual conditions and pathologies. Objective: This systematic review aimed to 1) examine the current evidence of ES efficacy for the treatment of visual pathologies and 2) define the corresponding degree of the recommendation of different ES techniques. Methods: A systematic review was conducted in MEDLINE and Cochrane Library database to collect documents published between 2000 and 2018. For each study, Level of Evidence of Effectiveness of ES as well as the Class of Quality for the treatment of different visual pathologies were determined. Results: Thirty-eight articles were included. Studies were grouped according to the pathology treated and the type of stimulation administered. The first group included studies treating pre-chiasmatic pathologies (age-related macular degeneration, macular dystrophy, retinal artery occlusion, retinitis pigmentosa, glaucoma, optic nerve damage, and optic neuropathy) using pre-chiasmatic stimulation; the second group included studies treating both pre-chiasmatic pathologies (amblyopia, myopia) and post-chiasmatic pathologies or brain conditions (hemianopsia, brain trauma) by means of post-chiasmatic stimulation. In the first group, repetitive transorbital alternating current stimulation (rtACS) reached level A recommendation, and transcorneal electrical stimulation (tcES) reached level B. In the second group, both high-frequency random noise stimulation (hf-RNS) and transcranial direct current stimulation (tDCS) reached level C recommendation. Conclusions: Study’s findings suggest conclusive evidence for rtACS treatment. For other protocols results are promising but not conclusive since the examined studies assessed different stimulation parameters and endpoints. A comparison of the effects of different combinations of these variables still lacks in the literature. Further studies are needed to optimize existing protocols and determine if different protocols are needed for different diseases.
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Affiliation(s)
- Cecilia Perin
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy.,Milan Center for Neuroscience (NeuroMI), University of Milan-Bicocca, Milan, Italy
| | | | - Daniele Piscitelli
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy.,School of Physical and Occupational Therapy, McGill University, Montreal, QC, Canada
| | - Barbara Maria Matteo
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy
| | - Roberto Meroni
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy.,Milan Center for Neuroscience (NeuroMI), University of Milan-Bicocca, Milan, Italy.,Current Affilation: Department of Physiotherapy, LUNEX International University of Health, Exercise and Sports. Differdange, Luxembourg
| | - Cesare Giuseppe Cerri
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy.,Milan Center for Neuroscience (NeuroMI), University of Milan-Bicocca, Milan, Italy
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Sabel BA, Thut G, Haueisen J, Henrich-Noack P, Herrmann CS, Hunold A, Kammer T, Matteo B, Sergeeva EG, Waleszczyk W, Antal A. Vision modulation, plasticity and restoration using non-invasive brain stimulation – An IFCN-sponsored review. Clin Neurophysiol 2020; 131:887-911. [DOI: 10.1016/j.clinph.2020.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 12/18/2019] [Accepted: 01/02/2020] [Indexed: 12/11/2022]
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Pollock A, Hazelton C, Rowe FJ, Jonuscheit S, Kernohan A, Angilley J, Henderson CA, Langhorne P, Campbell P. Interventions for visual field defects in people with stroke. Cochrane Database Syst Rev 2019; 5:CD008388. [PMID: 31120142 PMCID: PMC6532331 DOI: 10.1002/14651858.cd008388.pub3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Visual field defects are estimated to affect 20% to 57% of people who have had a stroke. Visual field defects can affect functional ability in activities of daily living (commonly affecting mobility, reading and driving), quality of life, ability to participate in rehabilitation, and depression and anxiety following stroke. There are many interventions for visual field defects, which are proposed to work by restoring the visual field (restitution); compensating for the visual field defect by changing behaviour or activity (compensation); substituting for the visual field defect by using a device or extraneous modification (substitution); or ensuring appropriate diagnosis, referral and treatment prescription through standardised assessment or screening, or both. OBJECTIVES To determine the effects of interventions for people with visual field defects after stroke. SEARCH METHODS We searched the Cochrane Stroke Group Trials Register, the Cochrane Eyes and Vision Group Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, AMED, PsycINFO, and PDQT Databse, and clinical trials databases, including ClinicalTrials.gov and WHO Clinical Trials Registry, to May 2018. We also searched reference lists and trials registers, handsearched journals and conference proceedings, and contacted experts. SELECTION CRITERIA Randomised trials in adults after stroke, where the intervention was specifically targeted at improving the visual field defect or improving the ability of the participant to cope with the visual field loss. The primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, reading ability, visual field measures, balance, falls, depression and anxiety, discharge destination or residence after stroke, quality of life and social isolation, visual scanning, adverse events, and death. DATA COLLECTION AND ANALYSIS Two review authors independently screened abstracts, extracted data and appraised trials. We undertook an assessment of methodological quality for allocation concealment, blinding of outcome assessors, method of dealing with missing data, and other potential sources of bias. We assessed the quality of evidence for each outcome using the GRADE approach. MAIN RESULTS Twenty studies (732 randomised participants, with data for 547 participants with stroke) met the inclusion criteria for this review. However, only 10 of these studies compared the effect of an intervention with a placebo, control, or no treatment group, and eight had data which could be included in meta-analyses. Only two of these eight studies presented data relating to our primary outcome of functional abilities in activities of daily living. One study reported evidence relating to adverse events.Three studies (88 participants) compared a restitutive intervention with a control, but data were only available for one study (19 participants). There was very low-quality evidence that visual restitution therapy had no effect on visual field outcomes, and a statistically significant effect on quality of life, but limitations with these data mean that there is insufficient evidence to draw any conclusions about the effectiveness of restitutive interventions as compared to control.Four studies (193 participants) compared the effect of scanning (compensatory) training with a control or placebo intervention. There was low-quality evidence that scanning training was more beneficial than control or placebo on quality of life, measured using the Visual Function Questionnaire (VFQ-25) (two studies, 96 participants, mean difference (MD) 9.36, 95% confidence interval (CI) 3.10 to 15.62). However, there was low or very-low quality evidence of no effect on measures of visual field, extended activities of daily living, reading, and scanning ability. There was low-quality evidence of no significant increase in adverse events in people doing scanning training, as compared to no treatment.Three studies (166 participants) compared a substitutive intervention (a type of prism) with a control. There was low or very-low quality evidence that prisms did not have an effect on measures of activities of daily living, extended activities of daily living, reading, falls, or quality of life, and very low-quality evidence that they may have an effect on scanning ability (one study, 39 participants, MD 9.80, 95% CI 1.91 to 17.69). There was low-quality evidence of an increased odds of an adverse event (primarily headache) in people wearing prisms, as compared to no treatment.One study (39 participants) compared the effect of assessment by an orthoptist to standard care (no assessment) and found very low-quality evidence that there was no effect on measures of activities of daily living.Due to the quality and quantity of evidence, we remain uncertain about the benefits of assessment interventions. AUTHORS' CONCLUSIONS There is a lack of evidence relating to the effect of interventions on our primary outcome of functional ability in activities of daily living. There is limited low-quality evidence that compensatory scanning training may be more beneficial than placebo or control at improving quality of life, but not other outcomes. There is insufficient evidence to reach any generalised conclusions about the effect of restitutive interventions or substitutive interventions (prisms) as compared to placebo, control, or no treatment. There is low-quality evidence that prisms may cause minor adverse events.
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Affiliation(s)
- Alex Pollock
- Nursing, Midwifery and Allied Health Professions Research Unit, Glasgow Caledonian University, 6th Floor, Govan Mbeki Building, Cowcaddens Road, Glasgow, UK, G4 0BA
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19
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After-effects of repetitive anodal transcranial direct current stimulation on learning and memory in a rat model of Alzheimer’s disease. Neurobiol Learn Mem 2019; 161:37-45. [DOI: 10.1016/j.nlm.2019.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 01/21/2019] [Accepted: 02/03/2019] [Indexed: 11/16/2022]
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Magis D, D’Ostilio K, Lisicki M, Lee C, Schoenen J. Anodal frontal tDCS for chronic cluster headache treatment: a proof-of-concept trial targeting the anterior cingulate cortex and searching for nociceptive correlates. J Headache Pain 2018; 19:72. [PMID: 30128947 PMCID: PMC6102161 DOI: 10.1186/s10194-018-0904-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/06/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Percutaneous occipital nerve stimulation (ONS) is effective in refractory chronic cluster headache (rCCH) patients. Responders to ONS differ from non-responders by greater glucose metabolism in subgenual anterior cingulate cortex (sgACC). We reasoned that transcranial direct current stimulation (tDCS), a non-invasive approach, might be able to activate this area and thus improve rCCH patients. Our objective was to explore in a pilot trial the therapeutic potential of tDCS (anode at Fz, cathode over C7) and its possible effects on pain perception, frontal executive functions and mood in rCCH patients. METHODS Thirty-one patients were asked to apply daily 20-min sessions of 2 mA tDCS for 4 or 8 weeks after a 1-month baseline. CH attacks were monitored with paper diaries. The primary outcome measure was change in weekly attacks between baseline and the last week of tDCS. Twenty-three patients were available for a modified ITT analysis, 21 for per-protocol analysis. We also explored treatment-related changes in thermal pain thresholds and nociceptive blink reflexes (nBR), frontal lobe function and mood scales. RESULTS In the per-protocol analysis there was a mean 35% decrease of attack frequency (p = 0.0001) with 41% of patients having a ≥ 50% decrease. Attack duration and intensity were also significantly reduced. After 8 weeks (n = 10), the 50% responder rate was 45%, but at follow-up 2 weeks after tDCS (n = 16) mean attack frequency had returned to baseline levels. The treatment effect was significant in patients with high baseline thermal pain thresholds in the forehead (n = 12), but not in those with low thresholds (n = 9). The Frontal Assessment Battery score increased after tDCS (p = 0.01), while there was no change in depression scores or nBR. CONCLUSION tDCS with a Fz-C7 montage may have a preventive effect in rCCH patients, especially those with low pain sensitivity, suggesting that a sham-controlled trial in cluster headache is worthwhile. Whether the therapeutic effect is due to activation of the sgACC that can in theory be reached by the electrical field, or of other prefrontal cortical areas remains to be determined.
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Affiliation(s)
- Delphine Magis
- Headache Research Unit, University Department of Neurology CHR, CHU de Liège, Boulevard du 12ème de Ligne 1, 4000 Liège, Belgium
| | - Kevin D’Ostilio
- Headache Research Unit, University Department of Neurology CHR, CHU de Liège, Boulevard du 12ème de Ligne 1, 4000 Liège, Belgium
| | - Marco Lisicki
- Headache Research Unit, University Department of Neurology CHR, CHU de Liège, Boulevard du 12ème de Ligne 1, 4000 Liège, Belgium
| | - Chany Lee
- Department of Biomedical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763 South Korea
| | - Jean Schoenen
- Headache Research Unit, University Department of Neurology CHR, CHU de Liège, Boulevard du 12ème de Ligne 1, 4000 Liège, Belgium
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21
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Bocci T, Nasini F, Caleo M, Restani L, Barloscio D, Ardolino G, Priori A, Maffei L, Nardi M, Sartucci F. Unilateral Application of Cathodal tDCS Reduces Transcallosal Inhibition and Improves Visual Acuity in Amblyopic Patients. Front Behav Neurosci 2018; 12:109. [PMID: 29896093 PMCID: PMC5986963 DOI: 10.3389/fnbeh.2018.00109] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/09/2018] [Indexed: 12/12/2022] Open
Abstract
Objective: Amblyopia is a neurodevelopmental disorder characterized by visual acuity and contrast sensitivity loss, refractory to pharmacological and optical treatments in adulthood. In animals, the corpus callosum (CC) contributes to suppression of visual responses of the amblyopic eye. To investigate the role of interhemispheric pathways in amblyopic patients, we studied the response of the visual cortex to transcranial Direct Current Stimulation (tDCS) applied over the primary visual area (V1) contralateral to the “lazy eye.” Methods: Visual acuity (logMAR) was assessed before (T0), immediately after (T1) and 60’ following the application of cathodal tDCS (2.0 mA, 20’) in 12 amblyopic patients. At each time point, Visual Evoked Potentials (VEPs) triggered by grating stimuli of different contrasts (K90%, K20%) were recorded in both hemispheres and compared to those obtained in healthy volunteers. Results: Cathodal tDCS improved visual acuity respect to baseline (p < 0.0001), whereas sham polarization had no significant effect. At T1, tDCS induced an inhibitory effect on VEPs amplitudes at all contrasts in the targeted side and a facilitation of responses in the hemisphere ipsilateral to the amblyopic eye; compared with controls, the facilitation persisted at T2 for high contrasts (K90%; Holm–Sidak post hoc method, p < 0.001), while the stimulated hemisphere recovered more quickly from inhibition (Holm–Sidak post hoc method, p < 0.001). Conclusions: tDCS is a promising treatment for amblyopia in adults. The rapid recovery of excitability and the concurrent transcallosal disinhibition following perturbation of cortical activity may support a critical role of interhemispheric balance in the pathophysiology of amblyopia.
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Affiliation(s)
- Tommaso Bocci
- Section of Neurophysiopathology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.,Clinical Center for Neurotechnologies, Neuromodulation, and Movement Disorders, Fondazione IRCCS Ca'Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesco Nasini
- Department of Surgical, Medical, and Molecular Pathology and Critical Care, University of Pisa, Pisa, Italy
| | - Matteo Caleo
- CNR Institute of Neuroscience, University of Pisa, Pisa, Italy
| | - Laura Restani
- CNR Institute of Neuroscience, University of Pisa, Pisa, Italy
| | - Davide Barloscio
- Section of Neurophysiopathology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Gianluca Ardolino
- Clinical Center for Neurotechnologies, Neuromodulation, and Movement Disorders, Fondazione IRCCS Ca'Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Alberto Priori
- Clinical Center for Neurotechnologies, Neuromodulation, and Movement Disorders, Fondazione IRCCS Ca'Granda Ospedale Maggiore Policlinico, Milan, Italy.,Department of Health Sciences, University of Milan and Ospedale San Paolo, Milan, Italy
| | - Lamberto Maffei
- CNR Institute of Neuroscience, University of Pisa, Pisa, Italy
| | - Marco Nardi
- Department of Surgical, Medical, and Molecular Pathology and Critical Care, University of Pisa, Pisa, Italy
| | - Ferdinando Sartucci
- Section of Neurophysiopathology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.,CNR Institute of Neuroscience, University of Pisa, Pisa, Italy
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23
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Matteo BM, Viganò B, Cerri CG, Meroni R, Cornaggia CM, Perin C. Transcranial direct current stimulation (tDCS) combined with blindsight rehabilitation for the treatment of homonymous hemianopia: a report of two-cases. J Phys Ther Sci 2017; 29:1700-1705. [PMID: 28932016 PMCID: PMC5599849 DOI: 10.1589/jpts.29.1700] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/08/2017] [Indexed: 11/24/2022] Open
Abstract
[Purpose] Homonymous hemianopia is one of the most common symptoms following neurologic damage leading to impairments of functional abilities and activities of daily living. There are two main types of restorative rehabilitation in hemianopia: "border training" which involves exercising vision at the edge of the damaged visual field, and "blindsight training," which is based on exercising the unconscious perceptual functions deep inside the blind hemifield. Only border effects have been shown to be facilitated by transcranial direct current stimulation (tDCS). This pilot study represents the first attempt to associate the modulatory effects of tDCS over the parieto-occipital cortex to blindsight treatment in the rehabilitation of the homonymous hemianopia. [Subjects and Methods] Patients TA and MR both had chronic hemianopia. TA underwent blindsight treatment which was combined with tDCS followed by blindsight training alone. MR underwent the two training rounds in reverse order. [Results] The patients showed better scores in clinical-instrumental, functional, and ecological assessments after tDCS combined with blindsight rehabilitation rather than rehabilitation alone. [Conclusion] In this two-case report parietal-occipital tDCS modulate the effects induced by blindsight treatment on hemianopia.
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Affiliation(s)
- Barbara Maria Matteo
- School of Medicine and Surgery, University of
Milan-Bicocca: Piazza dell’Ateneo Nuovo, 1, 20126, Milan, Italy
| | - Barbara Viganò
- School of Psychology, University of Milan-Bicocca,
Italy
| | - Cesare Giuseppe Cerri
- School of Medicine and Surgery, University of
Milan-Bicocca: Piazza dell’Ateneo Nuovo, 1, 20126, Milan, Italy
| | - Roberto Meroni
- School of Medicine and Surgery, University of
Milan-Bicocca: Piazza dell’Ateneo Nuovo, 1, 20126, Milan, Italy
| | - Cesare Maria Cornaggia
- School of Medicine and Surgery, University of
Milan-Bicocca: Piazza dell’Ateneo Nuovo, 1, 20126, Milan, Italy
| | - Cecilia Perin
- School of Medicine and Surgery, University of
Milan-Bicocca: Piazza dell’Ateneo Nuovo, 1, 20126, Milan, Italy
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Behrens JR, Kraft A, Irlbacher K, Gerhardt H, Olma MC, Brandt SA. Long-Lasting Enhancement of Visual Perception with Repetitive Noninvasive Transcranial Direct Current Stimulation. Front Cell Neurosci 2017; 11:238. [PMID: 28860969 PMCID: PMC5559806 DOI: 10.3389/fncel.2017.00238] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 07/26/2017] [Indexed: 12/23/2022] Open
Abstract
Understanding processes performed by an intact visual cortex as the basis for developing methods that enhance or restore visual perception is of great interest to both researchers and medical practitioners. Here, we explore whether contrast sensitivity, a main function of the primary visual cortex (V1), can be improved in healthy subjects by repetitive, noninvasive anodal transcranial direct current stimulation (tDCS). Contrast perception was measured via threshold perimetry directly before and after intervention (tDCS or sham stimulation) on each day over 5 consecutive days (24 subjects, double-blind study). tDCS improved contrast sensitivity from the second day onwards, with significant effects lasting 24 h. After the last stimulation on day 5, the anodal group showed a significantly greater improvement in contrast perception than the sham group (23 vs. 5%). We found significant long-term effects in only the central 2–4° of the visual field 4 weeks after the last stimulation. We suspect a combination of two factors contributes to these lasting effects. First, the V1 area that represents the central retina was located closer to the polarization electrode, resulting in higher current density. Second, the central visual field is represented by a larger cortical area relative to the peripheral visual field (cortical magnification). This is the first study showing that tDCS over V1 enhances contrast perception in healthy subjects for several weeks. This study contributes to the investigation of the causal relationship between the external modulation of neuronal membrane potential and behavior (in our case, visual perception). Because the vast majority of human studies only show temporary effects after single tDCS sessions targeting the visual system, our study underpins the potential for lasting effects of repetitive tDCS-induced modulation of neuronal excitability.
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Affiliation(s)
- Janina R Behrens
- Charité Universitätsmedizin BerlinBerlin, Germany.,NeuroCare Clinical Research Center, Charité Universitätsmedizin BerlinBerlin, Germany
| | - Antje Kraft
- Department of Psychiatry, Psychiatric University Hospital St. Hedwig, Charité Universitätsmedizin BerlinBerlin, Germany
| | | | - Holger Gerhardt
- Center for Economics and Neuroscience, Rheinische Friedrich-Wilhelms-Universität BonnBonn, Germany
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Maniglia M, Cottereau BR, Soler V, Trotter Y. Rehabilitation Approaches in Macular Degeneration Patients. Front Syst Neurosci 2016; 10:107. [PMID: 28082876 PMCID: PMC5187382 DOI: 10.3389/fnsys.2016.00107] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 12/12/2016] [Indexed: 11/13/2022] Open
Abstract
Age related macular degeneration (AMD) is a visual disease that affects elderly population. It entails a progressive loss of central vision whose consequences are dramatic for the patient's quality of life. Current rehabilitation programs are restricted to technical aids based on visual devices. They only temporarily improve specific visual functions such as reading skills. Considering the rapid increase of the aging population worldwide, it is crucial to intensify clinical research on AMD in order to develop simple and efficient methods that improve the patient's visual performances in many different contexts. One very promising approach to face this challenge is based on perceptual learning (PL). Through intensive practice, PL can induce neural plasticity in sensory cortices and result in long-lasting enhancements for various perceptual tasks in both normal and visually impaired populations. A growing number of studies showed how appropriate PL protocols improve visual functions in visual disorders, namely amblyopia, presbyopia or myopia. In order to successfully apply these approaches to more severe conditions such as AMD, numerous challenges have to be overcome. Indeed, the overall elderly age of patients and the reduced cortical surface that is devoted to peripheral vision potentially limit neural plasticity in this population. In addition, ocular fixation becomes much less stable because patients have to rely on peripheral fixation spots outside the scotoma whose size keeps on evolving. The aim of this review article is to discuss the recent literature on this topic and to offer a unified approach for developing new rehabilitation programs of AMD using PL. We argue that with an appropriate experimental and training protocol that is adapted to each patient needs, PL can offer fascinating opportunities for the development of simple, non-expensive rehabilitation approaches a large spectrum of visual functions in AMD patients.
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Affiliation(s)
- Marcello Maniglia
- Centre de Recherche Cerveau et Cognition, Université de Toulouse-UPSToulouse, France; Centre National de la Recherche ScientifiqueToulouse, France; Department of Psychology, University of CaliforniaRiverside, CA, USA
| | - Benoit R Cottereau
- Centre de Recherche Cerveau et Cognition, Université de Toulouse-UPSToulouse, France; Centre National de la Recherche ScientifiqueToulouse, France
| | - Vincent Soler
- Department of Ophthalmology, Hopital CHU Purpan Toulouse, France
| | - Yves Trotter
- Centre de Recherche Cerveau et Cognition, Université de Toulouse-UPSToulouse, France; Centre National de la Recherche ScientifiqueToulouse, France
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Ljubisavljevic M, Maxood K, Bjekic J, Oommen J, Nagelkerke N. Long-Term Effects of Repeated Prefrontal Cortex Transcranial Direct Current Stimulation (tDCS) on Food Craving in Normal and Overweight Young Adults. Brain Stimul 2016; 9:826-833. [PMID: 27498606 DOI: 10.1016/j.brs.2016.07.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 06/28/2016] [Accepted: 07/09/2016] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The dorsolateral prefrontal cortex (DLPFC) plays an important role in the regulation of food intake. Several previous studies demonstrated that a single session of transcranial direct current stimulation (tDCS) of the DLPFC reduces food craving and caloric intake. OBJECTIVES We hypothesized that repeated tDCS of the right DLPFC cortex may exert long-term changes in food craving in young, healthy adults and that these changes may differ between normal and overweight subjects. METHODS Thirty healthy individuals who reported frequent food cravings without a prior history of eating disorders were initially recruited. Subjects were randomized into an ACTIVE group who received 5 days of real tDCS (20 minutes, anode right-cathode left montage, 2 mA with current density kept at 0.06 mA/cm2, 1 min ramp-up/ramp-down), and a SHAM group, who received one day of real tDCS, on the first day (same parameters), followed by 4 days of sham tDCS. Food craving intensity was examined by Food Craving Questionnaires State and Trait and Food Craving Inventory before, during, (5-days) and one month (30-days) after tDCS. RESULTS Single session of tDCS significantly reduced the intensity of current food craving (FCQ-S). Five days of active tDCS significantly reduced habitual experiences of food craving (FCQ-T), when compared to baseline pre-stimulation levels. Furthermore, both current (FCQ-S) and habitual craving (FCQ-T) were significantly reduced 30 days after active tDCS, while sham tDCS, i.e. a single tDCS session did not have significant effects. Also, active tDCS significantly decreased craving for fast food and sweets, and to a lesser degree for fat, while it did not have significant effects on craving for carbohydrates (FCI). There were no significant differences between individual FCQ-T subscales (craving dimensions) after 5 or 30 days of either sham or active tDCS. Changes in craving were not significantly associated with the initial weight, or with weight changes 30 days after the stimulation in the subjects. CONCLUSIONS The results confirm earlier findings that single session of tDCS has immediate effects in reducing food craving. They also show that repeated tDCS over the right DLPFC may increase the duration of its effects, which may be present 30 days after the stimulation. These results support further investigation of the use of tDCS in obesity.
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Affiliation(s)
- M Ljubisavljevic
- Department of Physiology, College of Medicine and Health Sciences, UAE University, PO Box 17666, Al Ain, United Arab Emirates.
| | - K Maxood
- Department of Physiology, College of Medicine and Health Sciences, UAE University, PO Box 17666, Al Ain, United Arab Emirates
| | - J Bjekic
- Department of Neurophysiology, Institute for Medical Research, University of Belgrade, PO Box 124, Belgrade, Serbia
| | - J Oommen
- Department of Physiology, College of Medicine and Health Sciences, UAE University, PO Box 17666, Al Ain, United Arab Emirates
| | - N Nagelkerke
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Queen Elizabeth Central Hospital, Malawi; Institute of Public Health, College of Medicine and Health Sciences, PO Box 17666, UAE University, Al Ain, United Arab Emirates
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Transcranial direct current stimulation as a tool in the study of sensory-perceptual processing. Atten Percept Psychophys 2016; 77:1813-40. [PMID: 26139152 DOI: 10.3758/s13414-015-0932-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulatory technique with increasing popularity in the fields of basic research and rehabilitation. It is an affordable and safe procedure that is beginning to be used in the clinic, and is a tool with potential to contribute to the understanding of neural mechanisms in the fields of psychology, neuroscience, and medical research. This review presents examples of investigations in the fields of perception, basic sensory processes, and sensory rehabilitation that employed tDCS. We highlight some of the most relevant efforts in this area and discuss possible limitations and gaps in contemporary tDCS research. Topics include the five senses, pain, and multimodal integration. The present work aims to present the state of the art of this field of research and to inspire future investigations of perception using tDCS.
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28
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Andrade SM, Santos NA, Fernández-Calvo B, Boggio PS, Oliveira EA, Ferreira JJ, Sobreira A, Morgan F, Medeiros G, Cavalcanti GS, Gadelha ID, Duarte J, Marrocos J, Silva MA, Rufino T, Nóbrega SR. Stroke Treatment Associated with Rehabilitation Therapy and Transcranial DC Stimulation (START-tDCS): a study protocol for a randomized controlled trial. Trials 2016; 17:56. [PMID: 26822418 PMCID: PMC4731905 DOI: 10.1186/s13063-016-1186-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 01/19/2016] [Indexed: 11/16/2022] Open
Abstract
Background Traditional treatment for motor impairment after stroke includes medication and physical rehabilitation. The transcranial direct current stimulation associated with a standard physical therapy program may be an effective therapeutic alternative for these patients. Methods This study is a sham-controlled, double-blind, randomized clinical trial aiming to evaluate the efficacy of transcranial direct current stimulation in activities of daily living and motor function post subacute stroke. In total there will be 40 patients enrolled, diagnosed with subacute, ischemic, unilateral, non-recurring stroke. Participants will be randomized to two groups, one with active stimulation and the other with a placebo current. Patients and investigators will be blinded. Everyone will receive systematic physical therapy, based on constraint-induced movement therapy. The intervention will be applied for 10 consecutive days. Patients will undergo three functional assessments: at baseline, week 2, and week 4. Neuropsychological tests will be performed at baseline and week 4. Adverse effects will be computed at each session. On completion of the baseline measures, randomization will be conducted using random permuted blocks. The randomization will be concealed until group allocation. Discussion This study will investigate the combined effects of transcranial direct current stimulation and physical therapy on functional improvement after stroke. We tested whether the combination of these treatments is more effective than physical therapy alone when administered in the early stages after stroke. Trial registration NCT02156635 - May 30, 2014. Randomization is ongoing (40 participants randomized as of the end of December 2015).
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Affiliation(s)
- Suellen M Andrade
- Cognitive Neuroscience and Behavior Program, Federal University of Paraíba, João Pessoa, Brazil.
| | - Natanael A Santos
- Perception, Neurosciences and Behavior Laboratory, Federal University of Paraíba, João Pessoa, Brazil.
| | | | - Paulo S Boggio
- Cognitive Neuroscience Laboratory and Developmental Disorders Program, Mackenzie Presbyterian University, São Paulo, Brazil.
| | - Eliane A Oliveira
- Center for Research in Human Movement Sciences, Federal University of Paraíba, João Pessoa, Brazil.
| | - José J Ferreira
- Study Group of Human Movement, Federal University of Paraíba, João Pessoa, Brazil.
| | - Amanda Sobreira
- Center for Research in Human Movement Sciences, Federal University of Paraíba, João Pessoa, Brazil.
| | - Felipe Morgan
- Center for Research in Human Movement Sciences, Federal University of Paraíba, João Pessoa, Brazil.
| | - Germana Medeiros
- Study Group of Human Movement, Federal University of Paraíba, João Pessoa, Brazil.
| | - Gyovanna S Cavalcanti
- Center for Research in Human Movement Sciences, Federal University of Paraíba, João Pessoa, Brazil.
| | - Ingrid D Gadelha
- Center for Research in Human Movement Sciences, Federal University of Paraíba, João Pessoa, Brazil.
| | - Jader Duarte
- Study Group of Human Movement, Federal University of Paraíba, João Pessoa, Brazil.
| | - Joercia Marrocos
- Center for Research in Human Movement Sciences, Federal University of Paraíba, João Pessoa, Brazil.
| | - Michele A Silva
- Center for Research in Human Movement Sciences, Federal University of Paraíba, João Pessoa, Brazil.
| | - Thatiana Rufino
- Study Group of Human Movement, Federal University of Paraíba, João Pessoa, Brazil.
| | - Sanmy R Nóbrega
- Neuromuscular Adaptations Laboratory, Federal University of São Carlos, São Carlos, Brazil.
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Convento S, Russo C, Zigiotto L, Bolognini N. Transcranial Electrical Stimulation in Post-Stroke Cognitive Rehabilitation. EUROPEAN PSYCHOLOGIST 2016. [DOI: 10.1027/1016-9040/a000238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Abstract. Cognitive rehabilitation is an important area of neurological rehabilitation, which aims at the treatment of cognitive disorders due to acquired brain damage of different etiology, including stroke. Although the importance of cognitive rehabilitation for stroke survivors is well recognized, available cognitive treatments for neuropsychological disorders, such as spatial neglect, hemianopia, apraxia, and working memory, are overall still unsatisfactory. The growing body of evidence supporting the potential of the transcranial Electrical Stimulation (tES) as tool for interacting with neuroplasticity in the human brain, in turn for enhancing perceptual and cognitive functions, has obvious implications for the translation of this noninvasive brain stimulation technique into clinical settings, in particular for the development of tES as adjuvant tool for cognitive rehabilitation. The present review aims at presenting the current state of art concerning the use of tES for the improvement of post-stroke visual and cognitive deficits (except for aphasia and memory disorders), showing the therapeutic promises of this technique and offering some suggestions for the design of future clinical trials. Although this line of research is still in infancy, as compared to the progresses made in the last years in other neurorehabilitation domains, current findings appear very encouraging, supporting the development of tES for the treatment of post-stroke cognitive impairments.
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Affiliation(s)
- Silvia Convento
- Department of Psychology, University of Milano Bicocca, Milan, Italy
| | - Cristina Russo
- Department of Psychology, University of Milano Bicocca, Milan, Italy
| | - Luca Zigiotto
- Department of Psychology, University of Milano Bicocca, Milan, Italy
- Laboratory of Neuropsychology, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Nadia Bolognini
- Department of Psychology, University of Milano Bicocca, Milan, Italy
- Laboratory of Neuropsychology, IRCCS Istituto Auxologico Italiano, Milan, Italy
- NeuroMi – Milan Center for Neuroscience, Milan, Italy
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Biundo R, Weis L, Fiorenzato E, Gentile G, Giglio M, Schifano R, Campo MC, Marcon V, Martinez-Martin P, Bisiacchi P, Antonini A. Double-blind Randomized Trial of t-DCS Versus Sham in Parkinson Patients With Mild Cognitive Impairment Receiving Cognitive Training. Brain Stimul 2015; 8:1223-5. [DOI: 10.1016/j.brs.2015.07.043] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 07/29/2015] [Indexed: 11/27/2022] Open
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Zhao S, Dou Z, Wei X, Li J, Dai M, Wang Y, Yang Q, He H. Task-concurrent anodal tDCS modulates bilateral plasticity in the human suprahyoid motor cortex. Front Hum Neurosci 2015; 9:370. [PMID: 26157383 PMCID: PMC4478379 DOI: 10.3389/fnhum.2015.00370] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 06/11/2015] [Indexed: 12/11/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive method to modulate cortical excitability in humans. Here, we examined the effects of anodal tDCS on suprahyoid motor evoked potentials (MEP) when applied over the hemisphere with stronger and weaker suprahyoid/submental projections, respectively, while study participants performed a swallowing task. Thirty healthy volunteers were invited to two experimental sessions and randomly assigned to one of two different groups. While in the first group stimulation was targeted over the hemisphere with stronger suprahyoid projections, the second group received stimulation over the weaker suprahyoid projections. tDCS was applied either as anodal or sham stimulation in a random cross-over design. Suprahyoid MEPs were assessed immediately before intervention, as well as 5, 30, 60, and 90 min after discontinuation of stimulation from both the stimulated and non-stimulated contralateral hemisphere. We found that anodal tDCS (a-tDCS) had long-lasting effects on suprahyoid MEPs on the stimulated side in both groups (tDCS targeting the stronger projections: F(1,14) = 96.2, p < 0.001; tDCS targeting the weaker projections: F(1,14) = 37.45, p < 0.001). While MEPs did not increase when elicited from the non-targeted hemisphere after stimulation of the stronger projections (F(1,14) = 0.69, p = 0.42), we found increased MEPs elicited from the non-targeted hemisphere after stimulating the weaker projections (at time points 30–90 min) (F(1,14) = 18.26, p = 0.001). We conclude that anodal tDCS has differential effects on suprahyoid MEPs elicited from the targeted and non-targeted hemisphere depending on the site of stimulation. This finding may be important for the application of a-tDCS in patients with dysphagia, for example after stroke.
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Affiliation(s)
- Shaofeng Zhao
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University Guangzhou, China ; Department of Rehabilitation Medicine, The First Affiliated Hospital of Soochow University Suzhou, China
| | - Zulin Dou
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University Guangzhou, China
| | - Xiaomei Wei
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University Guangzhou, China
| | - Jin Li
- Department of Neurology, The Third Affiliated Hospital, Sun Yat-sen University Guangzhou, China
| | - Meng Dai
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University Guangzhou, China
| | - Yujue Wang
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University Guangzhou, China
| | - Qinglu Yang
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University Guangzhou, China
| | - Huai He
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Soochow University Suzhou, China
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Cohen Kadosh R. Modulating and enhancing cognition using brain stimulation: Science and fiction. JOURNAL OF COGNITIVE PSYCHOLOGY 2015. [DOI: 10.1080/20445911.2014.996569] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Understanding the behavioural consequences of noninvasive brain stimulation. Trends Cogn Sci 2015; 19:13-20. [DOI: 10.1016/j.tics.2014.10.003] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/19/2014] [Accepted: 10/29/2014] [Indexed: 01/05/2023]
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Bikson M, Name A, Rahman A. Origins of specificity during tDCS: anatomical, activity-selective, and input-bias mechanisms. Front Hum Neurosci 2013; 7:688. [PMID: 24155708 PMCID: PMC3800813 DOI: 10.3389/fnhum.2013.00688] [Citation(s) in RCA: 242] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/30/2013] [Indexed: 01/14/2023] Open
Abstract
Transcranial Direct Current Stimulation (tDCS) is investigated for a broad range of neuropsychiatric indications, various rehabilitation applications, and to modulate cognitive performance in diverse tasks. Specificity of tDCS refers broadly to the ability of tDCS to produce precise, as opposed to diffuse, changes in brain function. Practically, specificity of tDCS implies application-specific customization of protocols to maximize desired outcomes and minimize undesired effects. Especially given the simplicity of tDCS and the complexity of brain function, understanding the mechanisms leading to specificity is fundamental to the rational advancement of tDCS. We define the origins of specificity based on anatomical and functional factors. Anatomical specificity derives from guiding current to targeted brain structures. Functional specificity may derive from either activity-selectivity, where active neuronal networks are preferentially modulated by tDCS, or input-selectivity, where bias is applied to different synaptic inputs. Rational advancement of tDCS may require leveraging all forms of specificity.
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Affiliation(s)
- Marom Bikson
- Department of Biomedical Engineering, The City College of the City University of New York New York, NY, USA
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