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Randomized Controlled Trial
. 2019 Oct;6(10):1938-1948.
doi: 10.1002/acn3.50823. Epub 2019 Sep 17.

Randomized controlled trial of TDCS on cognition in 201 seniors with mild neurocognitive disorder

Hanna Lu  1   2 , Sandra Sau Man Chan  1 , Wai Chi Chan  3 , Cuichan Lin  1 , Calvin Pak Wing Cheng  3 , Lam Linda Chiu Wa  1
Affiliations
Randomized Controlled Trial

Randomized controlled trial of TDCS on cognition in 201 seniors with mild neurocognitive disorder

Hanna Lu et al. Ann Clin Transl Neurol. 2019 Oct.

Abstract

Objective: To examine the efficacy and safety of combined transcranial direct current stimulation (tDCS) and working memory training (WMT) in enhancing the cognitive functions for individuals with mild neurocognitive disorder due to AD (NCD-AD).

Methods: In this double-blind, sham-controlled randomized clinical trial (RCT), 201 patients with NCD-AD were randomly assigned for a 4-week intervention of either a combination of tDCS and WMT, sham tDCS and WMT, or tDCS and control cognitive training (CCT). Global cognition and domain-specific cognitive function were assessed before and after the intervention with Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog), category verbal fluency test, logical memory, digit, and visual span tests.

Results: Study participants did not show intervention group differences in baseline demographics, or cognitive characteristics (ANOVA). Cognitive enhancement was found across three groups after 4 weeks intervention. Combined tDCS-WMT group showed significantly greater improvement compared with single-modality groups in delayed recall (P = 0.043, η2 = 0.036) and working memory capacity (P = 0.04, η2 = 0.038) at 4th week, and logical memory at 12th week (P = 0.042, η2 = 0.037). Adverse events, including skin lesions (2.2%), were similar between groups.

Interpretation: tDCS or WMT could be a safe, feasible, and effective intervention for individuals with NCD-AD. A combination of tDCS and WMT presents greater cognitive enhancement, which may highlight the potential synergistic effects of combined modality intervention on cognition.

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Conflict of interest statement

The authors declare that they have no conflict of interest.

Figures

Figure 1
Figure 1
Consolidated Standards of Reporting Trials (CONSORT) flow diagram for the transcranial direct current stimulation (tDCS) and working memory training (WMT) trial
Figure 2
Figure 2
Primary outcome of the Alzheimer’s Disease Assessment Scale‐Cognitive subscale (ADAS‐Cog) and delayed recall. Panel A shows the results for the change from baseline in the score on ADAS‐Cog (Higher score indicating greater enhancement). Panel B shows the results for the change from baseline in the score on mean reaction time (Higher score indicating great enhancement). Error bars represent the standard error (SEM)
Figure 3
Figure 3
Secondary outcomes of other memory performance. Panel A shows the results for the change from baseline in the score on delayed recall performance (Higher score indicating greater enhancement). Panel B shows the results for the change from baseline in the score on working memory capacity (WMC) (Higher score indicating greater enhancement). Panel C shows the results for the change from baseline in the score on logical memory (Higher score indicating greater enhancement). Panel D shows the results for the change from baseline in the score on category verbal fluency test (CVFT) (Higher score indicating greater enhancement). Error bars represent the standard error (SEM). *Indicates significant between‐group difference (P < 0.05)
See this image and copyright information in PMC

References

    1. Jia J, Wei C, Chen S, et al. The cost of Alzheimer's disease in China and re‐estimation of costs worldwide. Alzheimers Dement 2018;14:483–491. - PubMed
    1. Nichols E, Szoeke CE, Vollset SE, et al. Global, regional, and national burden of Alzheimer's disease and other dementias, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol 2019;18:88–106. - PMC - PubMed
    1. Salloway S, Sperling R, Fox NC, et al. Two phase 3 trials of bapineuzumab in mild‐to‐moderate Alzheimer's disease. N Engl J Med 2014;370:322–333. - PMC - PubMed
    1. Honig LS, Vellas B, Woodward M, et al. Trial of solanezumab for mild dementia due to Alzheimer’s disease. N Engl J Med 2018;378:321–330. - PubMed
    1. Egan MF, Kost J, Tariot PN, et al. Randomized trial of verubecestat for mild‐to‐moderate Alzheimer’s disease. N Engl J Med 2018;378:1691–1703. - PMC - PubMed

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