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Unger N, Stahl B, Darkow R, Scholz V, Weinmar I, Schmidt J, Breitenstein C, Meinzer M, Grewe T, Flöel A. [Transcranial direct current stimulation to enhance training effectiveness in chronic poststroke aphasia-A challenge for recruiting participants]. Nervenarzt 2024; 95:368-375. [PMID: 38175228 PMCID: PMC11014807 DOI: 10.1007/s00115-023-01572-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/26/2023] [Indexed: 01/05/2024]
Abstract
INTRODUCTION/BACKGROUND DC_TRAIN_APHASIA is an ongoing multicenter, randomized controlled trial, conducted since November 2019 under the lead of the University Medicine Greifswald (ClinicalTrials.gov Identifier: NCT03930121). The study seeks to determine whether adjuvant transcranial direct current stimulation (tDCS) can increase the effectiveness of a 3‑week treatment with intensive speech-language therapy in chronic post-stroke aphasia. MATERIAL AND METHOD Until the end of 2024, a total of 130 patients are to be included in Germany. Recruitment has been a challenge throughout the study and substantial efforts went into devising innovative recruiting approaches. Standard recruitment strategies were used, such as directly approaching people with aphasia in clinical settings, inpatient and outpatient language rehabilitation facilities, and patient support and advocacy groups, alongside more innovative techniques including radio commercials, dissemination of study information via national television and social media platforms. PROVISIONAL RESULTS Up until now, 110 patients have been included into the study. The largest short-term response was achieved via television and radio. The largest long-term response was obtained through recruitment via logopaedic and neurological facilities, patient support groups, and social media. Participants served as "testimonials", expressing that they were satisfied with the therapy and the tDCS application. DISCUSSION The multicenter study DC_TRAIN_APHASIA aims to provide evidence on tDCS as an adjuvant application to increase the effect size of intensive speech-language therapy in chronic post-stroke aphasia. The present review may guide future studies in recruiting samples that involve people with impaired communicative abilities.
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Affiliation(s)
- Nina Unger
- Klinik und Poliklinik für Neurologie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475, Greifswald, Deutschland.
| | - Benjamin Stahl
- Klinik und Poliklinik für Neurologie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475, Greifswald, Deutschland
- Fakultät Naturwissenschaften, Medical School Berlin, Berlin, Deutschland
- Max-Planck-Institut für Kognitions- und Neurowissenschaften, Leipzig, Deutschland
| | | | - Veronika Scholz
- Klinik und Poliklinik für Neurologie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475, Greifswald, Deutschland
| | - Isabel Weinmar
- Klinik und Poliklinik für Neurologie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475, Greifswald, Deutschland
| | - Johanna Schmidt
- Klinik und Poliklinik für Neurologie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475, Greifswald, Deutschland
| | - Caterina Breitenstein
- Klinik für Neurologie mit Institut für Translationale Neurologie, Universität Münster, Münster, Deutschland
| | - Marcus Meinzer
- Klinik und Poliklinik für Neurologie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475, Greifswald, Deutschland
| | - Tanja Grewe
- Abt. Technik & Gesundheit für Menschen, Studiengang Logopädie, Jade Hochschule, Oldenburg, Deutschland
| | - Agnes Flöel
- Klinik und Poliklinik für Neurologie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475, Greifswald, Deutschland
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Ransmayr L, Fuchs A, Ransmayr-Tepser S, Kommenda R, Kögl M, Schwingenschuh P, Fellner F, Guger M, Eggers C, Darkow R, Mangesius S, Ransmayr G. Differences in aphasia syndromes between progressive supranuclear palsy-Richardson's syndrome, behavioral variant frontotemporal dementia and Alzheimer's dementia. J Neural Transm (Vienna) 2022; 129:1039-1048. [PMID: 35821453 DOI: 10.1007/s00702-022-02524-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/12/2022] [Indexed: 11/30/2022]
Abstract
Language impairments, hallmarks of speech/language variant progressive supranuclear palsy, also occur in Richardson's syndrome (PSP-RS). Impaired communication may interfere with daily activities. Therefore, assessment of language functions is crucial. It is uncertain whether the Aachen Aphasia Test (AAT) is practicable in PSP-RS, behavioral variant frontotemporal dementia (bvFTD) and Alzheimer's dementia (AD) and language deficits differ in these disorders. 28 PSP-RS, 24 AD, and 24 bvFTD patients were investigated using the AAT and the CERAD-Plus battery. 16-25% of all patients failed in AAT subtests for various reasons. The AAT syndrome algorithm diagnosed amnestic aphasia in 5 (23%) PSP-RS, 7 (36%) bvFTD and 6 (30%) AD patients, Broca aphasia in 1 PSP-RS and 1 bvFTD patient, Wernicke aphasia in 1 bvFTD and 3 (15%) AD patients. However, aphasic symptoms resembled non-fluent primary progressive aphasia in 14 PSP-RS patients. In up to 46% of PSP-RS patients, 61% of bvFTD and 64% of AD patients significant impairments were found in the AAT subtests spontaneous speech, written language, naming, language repetition, language comprehension and the Token subtest. The CERAD-Plus subtest semantic fluency revealed significant impairment in 81% of PSP-RS, 61% of bvFTD, 44% of AD patients, the phonemic fluency subtest in 31, 40 and 31%, respectively. In contrast to bvFTD and AD, severity of language impairment did not correlate with cognitive decline in PSP-RS. In summary, the patterns of aphasia differ between the diagnoses. Local frontal language networks might be impaired in PSP-RS, whereas in AD and bvFTD, more widespread neuropathology might underly language impairment.
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Affiliation(s)
- Lucia Ransmayr
- Institute for Logopedics, FH Joanneum, University of Applied Sciences, Graz, Austria.,Department of Neurology 2, Kepler University Hospital, Johannes Kepler University, Krankenhausstr. 9, 4021, Linz, Austria
| | - Alexandra Fuchs
- Department of Clinical and Health Psychology, Kepler University Hospital, Linz, Austria.,Faculty of Medicine, Johannes Kepler University, Linz, Austria
| | - Sibylle Ransmayr-Tepser
- Department of Neurology 2, Kepler University Hospital, Johannes Kepler University, Krankenhausstr. 9, 4021, Linz, Austria
| | - Romana Kommenda
- Department of Clinical and Health Psychology, Kepler University Hospital, Linz, Austria.,Faculty of Medicine, Johannes Kepler University, Linz, Austria
| | - Mariella Kögl
- Department of Neurology, Medical University of Graz, Graz, Austria
| | | | - Franz Fellner
- Central Institute of Radiology, Kepler University Hospital, Linz, Austria.,Faculty of Medicine, Johannes Kepler University, Linz, Austria
| | - Michael Guger
- Department of Neurology, Pyhrn-Eisenwurzen Hospital Steyr, Steyr, Austria.,Faculty of Medicine, Johannes Kepler University, Linz, Austria
| | - Christian Eggers
- Department of Neurology 2, Kepler University Hospital, Johannes Kepler University, Krankenhausstr. 9, 4021, Linz, Austria.,Faculty of Medicine, Johannes Kepler University, Linz, Austria
| | - Robert Darkow
- Institute for Logopedics, FH Joanneum, University of Applied Sciences, Graz, Austria
| | - Stephanie Mangesius
- Department of Neuroradiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Gerhard Ransmayr
- Department of Neurology 2, Kepler University Hospital, Johannes Kepler University, Krankenhausstr. 9, 4021, Linz, Austria. .,Faculty of Medicine, Johannes Kepler University, Linz, Austria.
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Christova M, Strohmaier R, Fuchs-Neuhold B, Guggenberger B, Loder-Fink B, Draxler T, Palli C, Simi H, Schadenbauer S, Nischelwitzer A, Sprung G, Pilz R, Darkow R, Staubmann W. Mixed Reality Prototype of Multimodal Screening for Early Detection of Cognitive Impairments in Elderly Individuals: Protocol Development and Usability Study (Preprint). JMIR Res Protoc 2022; 11:e39513. [PMID: 36239994 PMCID: PMC9617182 DOI: 10.2196/39513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/28/2022] [Accepted: 09/12/2022] [Indexed: 11/30/2022] Open
Abstract
Background The early diagnosis of cognitive impairments is an important step in the adequate management of dementia. The project “Smart Cognition & Behaviour Screening powered by Augmented Reality” (SCOBES-AR) aims to develop a multimodal screening tool (MST) for the early detection of cognitive impairments using augmented and virtual reality. The first project phase selected validated assessments for combination with the MST and tested it in 300 healthy older adults. Objective This study established a protocol for the implementation and usability of a mixed reality (MR)–enhanced multidisciplinary screening tool for the early detection of cognitive impairments in older adults. The developed MST will be partially enhanced by MR, which is a combination of augmented reality (AR) and virtual reality (VR). This MR-enhanced prototype of the screening tool (MR-MST) will be tested and compared to the previously developed MST. The usability of the prototype will also be examined. Methods This single-center observational crossover design study screens 100 healthy participants (aged 60-75 years) for cognitive decline using a specially developed MST (assessment of cognitive functions, olfactory sensitivity, nutritional preferences, gait parameters, reaction times, and activities of daily living) and an MR-enhanced MST in which the assessments of cognitive functions, reaction time, activities of daily living, and gait will be performed using tailor-made software and AR and VR hardware. The results of the MR-enhanced MST will be compared to those without MR. The usability of the developed MR-enhanced MST will be tested on 10 investigators and 10 test participants using observed summative evaluation and the codiscovery method, and on 2 usability experts using the codiscovery and cognitive walkthrough methods. Results This study was funded by the Austrian Research Promotion Agency (grant 866873) and received approval from the ethics committee of the Medical University of Graz. The MR-MST and the experimental protocol for this study were developed. All participants gave written informed consent. As of July 15, 2022, a total of 70 participants have been screened. Data analysis and dissemination are scheduled for completion by September 2023. Conclusions The development and testing of the MR-MST is an important step toward the establishment of the best practice procedure for the implementation of AR and VR in the screening of cognitive declines in older adults. It will help improve our knowledge of the usability and applicability of the developed prototype and promote further advancement in AR and VR technologies to be used in therapeutic settings. International Registered Report Identifier (IRRID) DERR1-10.2196/39513
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Affiliation(s)
- Monica Christova
- Institute of Physiotherapy, University of Applied Sciences FH JOANNEUM, Graz, Austria
- Section of Physiology, Otto Loewi Research Center, Medical University of Graz, Graz, Austria
| | - Robert Strohmaier
- Institute of Business Informatics and Data Science, University of Applied Sciences FH JOANNEUM, Graz, Austria
| | - Bianca Fuchs-Neuhold
- Institute of Dietetics and Nutrition, University of Applied Sciences FH JOANNEUM, Graz, Austria
- Institute of Health and Tourism Management, University of Applied Sciences FH JOANNEUM, Bad Gleichenberg, Austria
| | - Bernhard Guggenberger
- Institute of Physiotherapy, University of Applied Sciences FH JOANNEUM, Graz, Austria
- Department of Orthopaedics and Trauma, Medical University of Graz, Graz, Austria
| | - Brigitte Loder-Fink
- Institute of Occupational Therapy, University of Applied Sciences FH JOANNEUM, Graz, Austria
| | - Theresa Draxler
- Institute of Dietetics and Nutrition, University of Applied Sciences FH JOANNEUM, Graz, Austria
| | - Christoph Palli
- Institute of Health Care and Nursing, University of Applied Sciences FH JOANNEUM, Graz, Austria
| | - Helmut Simi
- Institute of Health and Tourism Management, University of Applied Sciences FH JOANNEUM, Bad Gleichenberg, Austria
| | - Sandra Schadenbauer
- Institute of Business Informatics and Data Science, University of Applied Sciences FH JOANNEUM, Graz, Austria
| | - Alexander Nischelwitzer
- Institute of Business Informatics and Data Science, University of Applied Sciences FH JOANNEUM, Graz, Austria
| | - Gerhard Sprung
- Institute of Business Informatics and Data Science, University of Applied Sciences FH JOANNEUM, Graz, Austria
| | - René Pilz
- Department of Psychiatry and Psychotherapeutic Medicine, Medical University of Graz, Graz, Austria
| | - Robert Darkow
- Institute of Logopedics, University of Applied Sciences FH JOANNEUM, Graz, Austria
| | - Wolfgang Staubmann
- Institute of Dietetics and Nutrition, University of Applied Sciences FH JOANNEUM, Graz, Austria
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Taud B, Lindenberg R, Darkow R, Wevers J, Höfflin D, Grittner U, Meinzer M, Flöel A. Limited Add-On Effects of Unilateral and Bilateral Transcranial Direct Current Stimulation on Visuo-Motor Grip Force Tracking Task Training Outcome in Chronic Stroke. A Randomized Controlled Trial. Front Neurol 2021; 12:736075. [PMID: 34858310 PMCID: PMC8631774 DOI: 10.3389/fneur.2021.736075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/01/2021] [Indexed: 11/13/2022] Open
Abstract
Background: This randomized controlled trial investigated if uni- and bihemispheric transcranial direct current stimulation (tDCS) of the motor cortex can enhance the effects of visuo-motor grip force tracking task training and transfer to clinical assessments of upper extremity motor function. Methods: In a randomized, double-blind, sham-controlled trial, 40 chronic stroke patients underwent 5 days of visuo-motor grip force tracking task training of the paretic hand with either unilateral or bilateral (N = 15/group) or placebo tDCS (N = 10). Immediate and long-term (3 months) effects on training outcome and motor recovery (Upper Extremity Fugl-Meyer, UE-FM, Wolf Motor Function Test, and WMFT) were investigated. Results: Trained task performance significantly improved independently of tDCS in a curvilinear fashion. In the anodal stimulation group UE-FM scores were higher than in the sham group at day 5 (adjusted mean difference: 2.6, 95%CI: 0.6–4.5, p = 0.010) and at 3 months follow up (adjusted mean difference: 2.8, 95%CI: 0.8–4.7, p = 0.006). Neither training alone, nor the combination of training and tDCS improved WMFT performance. Conclusions: Visuo-motor grip force tracking task training can facilitate recovery of upper extremity function. Only minimal add-on effects of anodal but not dual tDCS were observed. Clinical Trial Registration:https://clinicaltrials.gov/ct2/results?recrs=&cond=&term=NCT01969097&cntry=&state=&city=&dist=, identifier: NCT01969097, retrospectively registered on 25/10/2013.
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Affiliation(s)
- Benedikt Taud
- Neurocure Cluster of Excellence, Charité University Medicine, Berlin, Germany
| | - Robert Lindenberg
- Neurocure Cluster of Excellence, Charité University Medicine, Berlin, Germany.,Department of History, Philosophy and Ethics of Medicine, Heinrich Heine University, Düsseldorf, Germany
| | - Robert Darkow
- Neurocure Cluster of Excellence, Charité University Medicine, Berlin, Germany
| | - Jasmin Wevers
- Neurocure Cluster of Excellence, Charité University Medicine, Berlin, Germany
| | - Dorothee Höfflin
- Neurocure Cluster of Excellence, Charité University Medicine, Berlin, Germany
| | - Ulrike Grittner
- Berlin Institute of Health at Charité, Charité University Medicine, Berlin, Germany.,Institute of Biometry and Clinical Epidemiology, Charité University Medicine, Berlin, Germany
| | - Marcus Meinzer
- Neurocure Cluster of Excellence, Charité University Medicine, Berlin, Germany.,Department of Neurology, University Medicine Greifswald, Greifswald, Germany
| | - Agnes Flöel
- Neurocure Cluster of Excellence, Charité University Medicine, Berlin, Germany.,Department of Neurology, University Medicine Greifswald, Greifswald, Germany.,German Centre for Neurodegenerative Diseases, Site Greifswald/Rostock, Greifswald, Germany.,Center for Stroke Research, Charité University Medicine, Berlin, Germany
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Stahl B, Darkow R, von Podewils V, Meinzer M, Grittner U, Reinhold T, Grewe T, Breitenstein C, Flöel A. Transcranial Direct Current Stimulation to Enhance Training Effectiveness in Chronic Post-Stroke Aphasia: A Randomized Controlled Trial Protocol. Front Neurol 2019; 10:1089. [PMID: 31695667 PMCID: PMC6817733 DOI: 10.3389/fneur.2019.01089] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/27/2019] [Indexed: 11/30/2022] Open
Abstract
Background: Intensive speech-language therapy (SLT) can promote recovery from chronic post-stroke aphasia, a major consequence of stroke. However, effect sizes of intensive SLT are moderate, potentially reflecting a physiological limit of training-induced progress. Transcranial direct current stimulation (tDCS) is an easy-to-use, well-tolerated and low-cost approach that may enhance effectiveness of intensive SLT. In a recent phase-II randomized controlled trial, 26 individuals with chronic post-stroke aphasia received intensive SLT combined with anodal-tDCS of the left primary motor cortex (M1), resulting in improved naming and proxy-rated communication ability, with medium-to-large effect sizes. Aims: The proposed protocol seeks to establish the incremental benefit from anodal-tDCS of M1 in a phase-III randomized controlled trial with adequate power, ecologically valid outcomes, and evidence-based SLT. Methods: The planned study is a prospective randomized placebo-controlled (using sham-tDCS), parallel-group, double-blind, multi-center, phase-III superiority trial. A sample of 130 individuals with aphasia at least 6 months post-stroke will be recruited in more than 18 in- and outpatient rehabilitation centers. Outcomes: The primary outcome focuses on communication ability in chronic post-stroke aphasia, as revealed by changes on the Amsterdam-Nijmegen Everyday Language Test (A-scale; primary endpoint: 6-month follow-up; secondary endpoints: immediately after treatment, and 12-month follow-up). Secondary outcomes include measures assessing linguistic-executive skills, attention, memory, emotional well-being, quality of life, health economic costs, and adverse events (endpoints: 6-month follow-up, immediately after treatment, and 12-month follow-up). Discussion: Positive results will increase the quality of life for persons with aphasia and their families while reducing societal costs. After trial completion, a workshop with relevant stakeholders will ensure transfer into best-practice guidelines and successful integration within clinical routine. Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT03930121.
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Affiliation(s)
- Benjamin Stahl
- Department of Neurology, University Medicine Greifswald, Greifswald, Germany.,Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany.,Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,Psychologische Hochschule Berlin, Berlin, Germany
| | - Robert Darkow
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute of Logopedics, FH Johanneum University of Applied Sciences, Graz, Austria
| | - Viola von Podewils
- Department of Neurology, University Medicine Greifswald, Greifswald, Germany
| | - Marcus Meinzer
- Department of Neurology, University Medicine Greifswald, Greifswald, Germany.,Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
| | - Ulrike Grittner
- Institute of Biometry and Clinical Epidemiology, Charité Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany
| | - Thomas Reinhold
- Institute of Social Medicine, Epidemiology and Health Economics, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Tanja Grewe
- Faculty of Health and Social Sciences, Fresenius University of Applied Sciences, Idstein, Germany
| | - Caterina Breitenstein
- Department of Neurology with Institute of Translational Neurology, University of Münster, Münster, Germany
| | - Agnes Flöel
- Department of Neurology, University Medicine Greifswald, Greifswald, Germany.,German Center for Neurodegenerative Diseases, Rostock/Greifswald, Germany
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Flöel A, Darkow R, Meinzer M. Brain stimulation in aphasia rehabilitation: Current state and future projects. Brain Stimul 2017. [DOI: 10.1016/j.brs.2017.01.102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Meinzer M, Lindenberg R, Darkow R, Ulm L, Copland D, Flöel A. Transcranial direct current stimulation and simultaneous functional magnetic resonance imaging. J Vis Exp 2014. [PMID: 24796646 DOI: 10.3791/51730] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses weak electrical currents administered to the scalp to manipulate cortical excitability and, consequently, behavior and brain function. In the last decade, numerous studies have addressed short-term and long-term effects of tDCS on different measures of behavioral performance during motor and cognitive tasks, both in healthy individuals and in a number of different patient populations. So far, however, little is known about the neural underpinnings of tDCS-action in humans with regard to large-scale brain networks. This issue can be addressed by combining tDCS with functional brain imaging techniques like functional magnetic resonance imaging (fMRI) or electroencephalography (EEG). In particular, fMRI is the most widely used brain imaging technique to investigate the neural mechanisms underlying cognition and motor functions. Application of tDCS during fMRI allows analysis of the neural mechanisms underlying behavioral tDCS effects with high spatial resolution across the entire brain. Recent studies using this technique identified stimulation induced changes in task-related functional brain activity at the stimulation site and also in more distant brain regions, which were associated with behavioral improvement. In addition, tDCS administered during resting-state fMRI allowed identification of widespread changes in whole brain functional connectivity. Future studies using this combined protocol should yield new insights into the mechanisms of tDCS action in health and disease and new options for more targeted application of tDCS in research and clinical settings. The present manuscript describes this novel technique in a step-by-step fashion, with a focus on technical aspects of tDCS administered during fMRI.
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Affiliation(s)
- Marcus Meinzer
- Centre for Clinical Research, University of Queensland; Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin;
| | - Robert Lindenberg
- Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin
| | - Robert Darkow
- Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin
| | - Lena Ulm
- Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin
| | - David Copland
- Centre for Clinical Research, University of Queensland
| | - Agnes Flöel
- Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin
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Meinzer M, Jähnigen S, Copland DA, Darkow R, Grittner U, Avirame K, Rodriguez AD, Lindenberg R, Flöel A. Transcranial direct current stimulation over multiple days improves learning and maintenance of a novel vocabulary. Cortex 2014; 50:137-47. [PMID: 23988131 DOI: 10.1016/j.cortex.2013.07.013] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 07/23/2013] [Accepted: 07/23/2013] [Indexed: 11/18/2022]
Affiliation(s)
- Marcus Meinzer
- Department of Neurology, Charité University Medicine, Berlin, Germany; Center for Stroke Research, Charité University Medicine, Berlin, Germany; Center for Clinical Research, University of Queensland, Brisbane, Australia.
| | - Sophia Jähnigen
- Department of Neurology, Charité University Medicine, Berlin, Germany
| | - David A Copland
- Center for Clinical Research, University of Queensland, Brisbane, Australia; CCRE in Aphasia Rehabilitation, University of Queensland, Brisbane, Australia
| | - Robert Darkow
- Department of Neurology, Charité University Medicine, Berlin, Germany
| | - Ulrike Grittner
- Center for Stroke Research, Charité University Medicine, Berlin, Germany; Department for Biostatistics and Clinical Epidemiology, Charité University Medicine, Berlin, Germany
| | - Keren Avirame
- Department of Neurology, Charité University Medicine, Berlin, Germany
| | - Amy D Rodriguez
- Center for Clinical Research, University of Queensland, Brisbane, Australia; CCRE in Aphasia Rehabilitation, University of Queensland, Brisbane, Australia
| | - Robert Lindenberg
- Department of Neurology, Charité University Medicine, Berlin, Germany
| | - Agnes Flöel
- Department of Neurology, Charité University Medicine, Berlin, Germany; Center for Stroke Research, Charité University Medicine, Berlin, Germany; NeuroCure Cluster of Excellence, Charité University Medicine, Berlin, Germany.
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Darkow R, Hußmann K, Huber W. Supervidierte computergestützte Benenntherapie mit randomisierten Items: Zwei Einzelfallstudien bei Aphasie. Sprache Stimme Gehör 2009. [DOI: 10.1055/s-0029-1242743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
Nanoparticles consisting of a polystyrene core and a polyglycidyl methacrylate shell were prepared by a two-step emulsion polymerization. The size and surface properties of the particles were characterized by scanning electron microscopy, dynamic light scattering and polyelectrolyte titration techniques. Particles were found to be monodisperse with a mean diameter of about 85 nm. Parent particles were modified with a number of different ligands including diamines of increasing chain length, amino acids and corresponding amines and higher molecular weight ligands like polymyxin B. The modified particles were tested for their endotoxin (ET) binding capacity in water and physiological sodium chloride solution with the Limulus amebocyte lysate (LAL) assay. It was found that the ET binding properties of the different ligands depend both on the ability of the ligand to form Coulomb- and van der Waals-interactions with the ET molecule influenced by the nature of the suspension medium. Therefore, the choice of ligands for particle modification has to consider minutely the conditions under which ET has to be removed, e.g. removal from pure water, dialysis fluids, plasma or blood.
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Affiliation(s)
- R Darkow
- GKSS Research Center, Institute of Chemistry, Teltow, Germany
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Mullaney M, Groth T, Darkow R, Hesse R, Albrecht W, Paul D, von Sengbusch G. Investigation of plasma protein adsorption on functionalized nanoparticles for application in apheresis. Artif Organs 1999; 23:87-97. [PMID: 9950185 DOI: 10.1046/j.1525-1594.1999.06280.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Particles with specific ligands for the adsorption of plasma proteins can be used in therapeutic or preparative apheresis. The development of these particles may benefit from an improved knowledge of the relationship between protein adsorption and the structure of ligands. Nanoparticles were functionalized with aliphatic diamines of increasing chain length; with the amino acids lysine, tryptophan, histidine, and their corresponding amines; and with tryptophan and histidine spaced with diamines of different length. Suitable protocols were developed for the washing of particles and the subsequent desorption of proteins adsorbed from human plasma. The adsorption pattern, as well as the quantification of the overall adsorption of proteins on these modified particles, was investigated with gel electrophoresis. This was followed by immunoblotting which yielded specific assessments of bound human serum albumin and fibrinogen. The comparison of protein adsorption with surface charge density and measured hydrophobicities yielded no simple correlations although in general more hydrophobic ligands bound higher quantities of protein. The detection of human serum albumin yielded similar results because it was observed for overall protein adsorption while the adsorption of fibrinogen expressed a different pattern. In this case, particular nanoparticles functionalized with aliphatic diamines bound significantly higher amounts of fibrinogen than all other ligands.
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