Evidence map›Paper›PMID 34602464›Full record

Trial reportJournal of Alzheimer's disease : JAD2021

Effects of High Definition-Transcranial Direct Current Stimulation on Local GABA and Glutamate Levels Among Older Adults with and without Mild Cognitive Impairment: An Exploratory Study.

Ketrin Lengu, Shannon Ryan, Scott J Peltier, Troy Tyszkowski, Anson Kairys, Bruno Giordani, Benjamin M Hampstead

Registry-linked trialOpen access · greenAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in Journal of Alzheimer's disease : JAD, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT01958437 (Enhancing Spatial Navigation Using Non-Invasive Brain Stimulation), which is not on this map. Cited by 11 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
11citing papers in PubMed, 1 pooled it
1.0field-weighted citation impact, top 24% 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.

NCT01958437 nacompletednot on this map

Enhancing Spatial Navigation Using Non-Invasive Brain Stimulation

TypeinterventionalSponsorVA Office of Research and DevelopmentRan2013 to 2017Enrolled44ConditionsMild Cognitive Impairment, Alzheimer's DiseaseArmsTranscranial direct current stimulation (tDCS)
3 · Its place in the literature

Who cites it

11 citing papers in PubMed, 1 synthesis or guideline pooled it, 17 citations in OpenAlex.

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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

7 authors at 2 institutions in 1 country.

Ketrin LenguNeuropsychology Section, Mental Health Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA.
Shannon RyanResearch Program on Cognition and Neuromodulation-Based Interventions (RP-CNBI), Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
Scott J PeltierFunctional MRI Laboratory, University of Michigan, Ann Arbor, MI, USA.
Troy TyszkowskiResearch Program on Cognition and Neuromodulation-Based Interventions (RP-CNBI), Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
Anson KairysResearch Program on Cognition and Neuromodulation-Based Interventions (RP-CNBI), Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
Bruno GiordaniResearch Program on Cognition and Neuromodulation-Based Interventions (RP-CNBI), Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
Benjamin M HampsteadNeuropsychology Section, Mental Health Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA.
University of Michigan–Ann Arbor · USVA Ann Arbor Healthcare System · US

Funding

Research Education ComponentP30AG072931 · NIA · UNIVERSITY OF MICHIGAN AT ANN ARBOR · PI Henry L Paulson · 2021 to 2026
$26.5M
Michigan Alzheimer's Disease Core CenterP30AG053760 · NIA · UNIVERSITY OF MICHIGAN AT ANN ARBOR · PI LIEBERMAN, ANDREW P · 2016 to 2020
$10.1M
Research Program on Cognition and Neuromodulation Based Interventions (RP-CNBI)R35AG072262 · NIA · UNIVERSITY OF MICHIGAN AT ANN ARBOR · PI HAMPSTEAD, BENJAMIN MICHAEL · 2021 to 2025
$4.2M
NIA NIH HHS P30 AG053760NIA NIH HHS P30 AG072931NIA NIH HHS R35 AG072262RRD VA I21 RX001381
6 · The paper itself

Abstract

backgroundPrior research, primarily with young adults, suggests transcranial direct current stimulation (tDCS) effects are driven by the primary excitatory and/or inhibitory neurotransmitters, glutamate, and gamma-aminobutyric acid (GABA), respectively.

objectiveWe examined the neurometabolic mechanisms of tDCS in older adults with and without mild cognitive impairment (MCI).

methodsWe used data from a double-blind, cross-over, randomized controlled trial (NCT01958437) in 32 older adults to evaluate high definition (HD)-tDCS-induced changes in glutamate and GABA via magnetic resonance spectroscopy (MRS). Participants underwent MRS following two counterbalanced HD-tDCS sessions (one active, one sham) that targeted the right superior parietal cortex (center anode at P2) and delivered 2mA for 20 minutes.

resultsRelative to sham, and when co-varying for MRS voxel overlap and right superior parietal volume, active HD-tDCS significantly increased GABA and decreased the ratio of glutamate to GABA. No changes were observed in a left prefrontal control MRS voxel. Although we did not find a significant correlation between strength of delivered current (measured via MRI-based computational modeling) and neurometabolite change, there was a robust positive relationship between the volume of right superior parietal cortex and neurometabolite change.

conclusionOur preliminary findings of increased GABA and reduced glutamate/GABA ratio raise the possibility that (HD-)tDCS effects differ by age. Moreover, age- and disease-related regional brain volume loss may be especially important to consider when planning future studies. Replication would emphasize the importance of developing population-specific tDCS parameters that consider structural and physiologic changes associated with "normal" and pathological aging.

Indexed as

Transcranial Direct Current StimulationAgedCognitive DysfunctionDouble-Blind MethodFemalegamma-Aminobutyric AcidGlutamic AcidHumansMagnetic Resonance SpectroscopyMalePrefrontal Cortexgamma-Aminobutyric AcidGlutamic AcidAgingmagnetic resonance spectroscopymild cognitive impairmentneuromodulationneurotransmitterstranscranial electrical stimulation

Identifiers

PMID34602464
PMCPMC8925725
OpenAlexW3204860582

What OpenQuestion holds

Textmetadata
LicenceTDM
Read underepoch 390

Registered trials

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.