The effect of tDCS on functional connectivity in primary progressive aphasia
Transcranial direct current stimulation (tDCS) is an innovative technique recently shown to improve language outcomes even in neurodegenerative conditions such as primary progressive aphasia (PPA), but the underlying brain mechanisms are not known. The present study tested whether the additional lan...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2018-01-01
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| Series: | NeuroImage: Clinical |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2213158218301682 |
| _version_ | 1818417455101378560 |
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| author | Bronte N. Ficek Zeyi Wang Yi Zhao Kimberly T. Webster John E. Desmond Argye E. Hillis Constantine Frangakis Andreia Vasconcellos Faria Brian Caffo Kyrana Tsapkini |
| author_facet | Bronte N. Ficek Zeyi Wang Yi Zhao Kimberly T. Webster John E. Desmond Argye E. Hillis Constantine Frangakis Andreia Vasconcellos Faria Brian Caffo Kyrana Tsapkini |
| author_sort | Bronte N. Ficek |
| collection | DOAJ |
| description | Transcranial direct current stimulation (tDCS) is an innovative technique recently shown to improve language outcomes even in neurodegenerative conditions such as primary progressive aphasia (PPA), but the underlying brain mechanisms are not known. The present study tested whether the additional language gains with repetitive tDCS (over sham) in PPA are caused by changes in functional connectivity between the stimulated area (the left inferior frontal gyrus (IFG)) and the rest of the language network.We scanned 24 PPA participants (11 female) before and after language intervention (written naming/spelling) with a resting-state fMRI sequence and compared changes before and after three weeks of tDCS or sham coupled with language therapy. We correlated changes in the language network as well as in the default mode network (DMN) with language therapy outcome measures (letter accuracy in written naming).Significant tDCS effects in functional connectivity were observed between the stimulated area and other language network areas and between the language network and the DMN. TDCS over the left IFG lowered the connectivity between the above pairs. Changes in functional connectivity correlated with improvement in language scores (letter accuracy as a proxy for written naming) evaluated before and after therapy.These results suggest that one mechanism for anodal tDCS over the left IFG in PPA is a decrease in functional connectivity (compared to sham) between the stimulated site and other posterior areas of the language network. These results are in line with similar decreases in connectivity observed after tDCS over the left IFG in aging and other neurodegenerative conditions. Keywords: Primary progressive aphasia (PPA), Transcranial direct current stimulation (tDCS), Resting-state fMRI (rsfMRI), Functional connectivity, Neurodegenerative diseases |
| first_indexed | 2024-12-14T12:07:03Z |
| format | Article |
| id | doaj.art-b7127dbdcb3d49ad9238d2fde7ef671e |
| institution | Directory Open Access Journal |
| issn | 2213-1582 |
| language | English |
| last_indexed | 2024-12-14T12:07:03Z |
| publishDate | 2018-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | NeuroImage: Clinical |
| spelling | doaj.art-b7127dbdcb3d49ad9238d2fde7ef671e2022-12-21T23:01:50ZengElsevierNeuroImage: Clinical2213-15822018-01-0119703715The effect of tDCS on functional connectivity in primary progressive aphasiaBronte N. Ficek0Zeyi Wang1Yi Zhao2Kimberly T. Webster3John E. Desmond4Argye E. Hillis5Constantine Frangakis6Andreia Vasconcellos Faria7Brian Caffo8Kyrana Tsapkini9Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USADepartment of Biostatistics, Johns Hopkins School of Public Health, Baltimore, MD 21287, USADepartment of Biostatistics, Johns Hopkins School of Public Health, Baltimore, MD 21287, USADepartment of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA; Department of Otolaryngology - Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD 21287, USADepartment of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USADepartment of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA; Department of Cognitive Science, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, Baltimore, MD 21287, USADepartment of Biostatistics, Johns Hopkins School of Public Health, Baltimore, MD 21287, USA; Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21287, USADepartment of Radiology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USADepartment of Biostatistics, Johns Hopkins School of Public Health, Baltimore, MD 21287, USADepartment of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA; Department of Cognitive Science, Johns Hopkins University, Baltimore, MD 21218, USA; Corresponding author at: Department of Neurology, Cerebrovascular Division, 600 N. Wolfe Street, Phipps 488, Baltimore, MD 21287, USA.Transcranial direct current stimulation (tDCS) is an innovative technique recently shown to improve language outcomes even in neurodegenerative conditions such as primary progressive aphasia (PPA), but the underlying brain mechanisms are not known. The present study tested whether the additional language gains with repetitive tDCS (over sham) in PPA are caused by changes in functional connectivity between the stimulated area (the left inferior frontal gyrus (IFG)) and the rest of the language network.We scanned 24 PPA participants (11 female) before and after language intervention (written naming/spelling) with a resting-state fMRI sequence and compared changes before and after three weeks of tDCS or sham coupled with language therapy. We correlated changes in the language network as well as in the default mode network (DMN) with language therapy outcome measures (letter accuracy in written naming).Significant tDCS effects in functional connectivity were observed between the stimulated area and other language network areas and between the language network and the DMN. TDCS over the left IFG lowered the connectivity between the above pairs. Changes in functional connectivity correlated with improvement in language scores (letter accuracy as a proxy for written naming) evaluated before and after therapy.These results suggest that one mechanism for anodal tDCS over the left IFG in PPA is a decrease in functional connectivity (compared to sham) between the stimulated site and other posterior areas of the language network. These results are in line with similar decreases in connectivity observed after tDCS over the left IFG in aging and other neurodegenerative conditions. Keywords: Primary progressive aphasia (PPA), Transcranial direct current stimulation (tDCS), Resting-state fMRI (rsfMRI), Functional connectivity, Neurodegenerative diseaseshttp://www.sciencedirect.com/science/article/pii/S2213158218301682 |
| spellingShingle | Bronte N. Ficek Zeyi Wang Yi Zhao Kimberly T. Webster John E. Desmond Argye E. Hillis Constantine Frangakis Andreia Vasconcellos Faria Brian Caffo Kyrana Tsapkini The effect of tDCS on functional connectivity in primary progressive aphasia NeuroImage: Clinical |
| title | The effect of tDCS on functional connectivity in primary progressive aphasia |
| title_full | The effect of tDCS on functional connectivity in primary progressive aphasia |
| title_fullStr | The effect of tDCS on functional connectivity in primary progressive aphasia |
| title_full_unstemmed | The effect of tDCS on functional connectivity in primary progressive aphasia |
| title_short | The effect of tDCS on functional connectivity in primary progressive aphasia |
| title_sort | effect of tdcs on functional connectivity in primary progressive aphasia |
| url | http://www.sciencedirect.com/science/article/pii/S2213158218301682 |
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