Evidence map›Paper›PMID 31029018›Full record

ArticleNeurobiology of aging2019

Reductions in GABA following a tDCS-language intervention for primary progressive aphasia.

Ashley D Harris, Zeyi Wang, Bronte Ficek, Kim Webster, Richard Ae Edden, Kyrana Tsapkini

Open access · greenAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Neurobiology of aging, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 28 papers, 7 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
28citing papers in PubMed, 7 pooled it
2.2field-weighted citation impact, top 12% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

28 citing papers in PubMed, 7 syntheses or guidelines pooled it, 53 citations in OpenAlex.

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  4. Efficacy of Transcranial Direct Current Stimulation in Patients with Primary Progressive Aphasia: A Systematic Review and Updated Meta-analysis.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2025
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  19. Frontotemporal lobar degeneration.Nature reviews. Disease primers · 2023
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 3 institutions in 2 countries.

Ashley D HarrisDepartment of Radiology, University of Calgary, Calgary, Alberta, Canada; Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada. Electronic address: ashley.harris2@ucalgary.ca.
Zeyi WangDepartment of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Bronte FicekDepartment of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA.
Kim WebsterDepartment of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA; Department of Otolaryngology Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA.
Richard Ae EddenRussell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
Kyrana TsapkiniDepartment of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA; Department of Cognitive Science, Johns Hopkins University, Baltimore, MD, USA.
Johns Hopkins University · USKennedy Krieger Institute · USUniversity of Calgary · CA

Funding

TR&D 4: Algorithms for functional and anatomical brain analysisP41EB015909 · NIBIB · HUGO W. MOSER RES INST KENNEDY KRIEGER · PI VAN ZIJL, PETER CM · 2012 to 2020
$13.1M
Universal GABA-edited MRS at 3TR01EB016089 · NIBIB · JOHNS HOPKINS UNIVERSITY · PI Richard Anthony Edward Edden · 2013 to 2026
$5.4M
Effects of transcranial direct current stimulation in spoken and written production in primary progressive aphasiaR01DC014475 · NIDCD · JOHNS HOPKINS UNIVERSITY · PI TSAPKINI, KYRANA · 2015 to 2019
$4.1M
NIBIB NIH HHS P41 EB015909NIBIB NIH HHS R01 EB016089NIDCD NIH HHS R01 DC014475
6 · The paper itself

Abstract

Transcranial direct current stimulation (tDCS) has shown efficacy in augmenting the effects of language therapy in primary progressive aphasia (PPA). The mechanism of action of tDCS is not understood, but preliminary work in healthy adults suggests it modulates γ-aminobutyric acid (GABA) levels to create an environment optimal for learning. It is unknown if this proposed mechanism translates to aging or neurodegenerative conditions. This study tested the hypothesis that tDCS reduces GABA at the stimulated tissue in PPA. We applied GABA-edited magnetic resonance spectroscopy to quantify GABA levels before and after a sham-controlled tDCS intervention with language therapy in PPA. All participants showed improvements but those receiving active tDCS showed significantly greater language improvements compared to sham both immediately after the intervention and at 2-month follow-up. GABA levels in the targeted tissue decreased from baseline after the intervention and remained decreased 2 months after the intervention. This work supports the hypothesis that tDCS modulates GABAergic inhibition to augment learning and is clinically useful for PPA combined with language therapy.

Indexed as

Language TherapyTranscranial Direct Current StimulationAgedAphasia, Primary ProgressiveFemaleFollow-Up Studiesgamma-Aminobutyric AcidHumansLearningMagnetic Resonance SpectroscopyMaleMiddle AgedNeuronal PlasticityTime Factorsgamma-Aminobutyric AcidAnodal tDCSGABA-edited MRSLanguage therapyLearningNeural plasticityNeurodegenerative disorder

Identifiers

PMID31029018
PMCPMC6591063
OpenAlexW2925328820

What OpenQuestion holds

Textmetadata
LicenceTDM
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.