Preliminary Evidence That Excitatory Transcranial Direct Current Stimulation Extends Time to Task Failure of a Sustained, Submaximal Muscular Contraction in Older Adults

Transcranial direct current stimulation (tDCS) has demonstrated effectiveness in reducing clinical and experimental measures of pain in patients with chronic pain; however, research examining the mechanisms of action for the effects of tDCS has been lacking. The present study investigated the effect of active tDCS on measures of inflammation and stress. Older adults (aged 50–70 years) with knee osteoarthritis (OA) were randomly assigned to receive daily 20-min sessions of either tDCS ( n = 20) or sham tDCS ( n = 20) for 5 consecutive days. Participants provided blood samples at baseline and the end of treatment. The following measures of immune function and stress were collected: interleukin (IL)-6 and 10, tumor necrosis factor-α (TNF-α), C-reactive protein, cortisol, and β-endorphin. Generalized linear modeling evaluated each posttreatment measure as a function of tDCS group, controlling for baseline (measuring residual change, analogous to analysis of covariance). Bayesian statistical inference was used to directly quantify the probability of the effect of active tDCS. IL-6, IL-10, TNF-α, and β-endorphin demonstrated lower levels of stress and inflammation in the active tDCS group. These findings provide preliminary evidence that active (relative to sham) tDCS is associated with reduced levels of inflammation.

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Selective directed forgetting is mediated by the lateral prefrontal cortex: Preliminary evidence with transcranial direct current stimulation

Cognitive Neuroscience ◽

10.1080/17588928.2021.1953973 ◽

2021 ◽

pp. 1-10

Author(s):

Juan J. Imbernón ◽

Carmen Aguirre ◽

Carlos J. Gómez-Ariza

Keyword(s):

Prefrontal Cortex ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Preliminary Evidence ◽

Directed Forgetting ◽

Lateral Prefrontal Cortex ◽

Direct Current Stimulation

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Can Transcranial Direct Current Stimulation Enhance Functionality in Older Adults? A Systematic Review

Journal of Clinical Medicine ◽

10.3390/jcm10132981 ◽

2021 ◽

Vol 10 (13) ◽

pp. 2981

Author(s):

Andrés Pino-Esteban ◽

Álvaro Megía-García ◽

David Martín-Caro Álvarez ◽

Hector Beltran-Alacreu ◽

Juan Avendaño-Coy ◽

...

Keyword(s):

Systematic Review ◽

Older Adults ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Randomized Clinical Trials ◽

Scientific Evidence ◽

Healthy Older Adults ◽

Sham Stimulation ◽

Direct Current Stimulation ◽

Potential Benefits

Transcranial direct current stimulation (tDCS) is a non-invasive, easy to administer, well-tolerated, and safe technique capable of affecting brain excitability, both at the cortical and cerebellum levels. However, its effectiveness has not been sufficiently assessed in all population segments or clinical applications. This systematic review aimed at compiling and summarizing the currently available scientific evidence about the effect of tDCS on functionality in older adults over 60 years of age. A search of databases was conducted to find randomized clinical trials that applied tDCS versus sham stimulation in the above-mentioned population. No limits were established in terms of date of publication. A total of 237 trials were found, of which 24 met the inclusion criteria. Finally, nine studies were analyzed, including 260 healthy subjects with average age between 61.0 and 85.8 years. Seven of the nine included studies reported superior improvements in functionality variables following the application of tDCS compared to sham stimulation. Anodal tDCS applied over the motor cortex may be an effective technique for improving balance and posture control in healthy older adults. However, further high-quality randomized controlled trials are required to determine the most effective protocols and to clarify potential benefits for older adults.

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Effects of transcranial direct current stimulation combined with listening to preferred music on memory in older adults

Scientific Reports ◽

10.1038/s41598-021-91977-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ricky Chow ◽

Alix Noly-Gandon ◽

Aline Moussard ◽

Jennifer D. Ryan ◽

Claude Alain

Keyword(s):

Older Adults ◽

Working Memory ◽

Recognition Memory ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Digit Span ◽

Recognition Task ◽

Music Listening ◽

Subsequent Performance ◽

Direct Current Stimulation

AbstractListening to autobiographically-salient music (i.e., music evoking personal memories from the past), and transcranial direct current stimulation (tDCS) have each been suggested to temporarily improve older adults’ subsequent performance on memory tasks. Limited research has investigated the effects of combining both tDCS and music listening together on cognition. The present study examined whether anodal tDCS stimulation over the left dorsolateral prefrontal cortex (2 mA, 20 min) with concurrent listening to autobiographically-salient music amplified subsequent changes in working memory and recognition memory in older adults than either tDCS or music listening alone. In a randomized sham-controlled crossover study, 14 healthy older adults (64–81 years) participated in three neurostimulation conditions: tDCS with music listening (tDCS + Music), tDCS in silence (tDCS-only), or sham-tDCS with music listening (Sham + Music), each separated by at least a week. Working memory was assessed pre- and post-stimulation using a digit span task, and recognition memory was assessed post-stimulation using an auditory word recognition task (WRT) during which electroencephalography (EEG) was recorded. Performance on the backwards digit span showed improvement in tDCS + Music, but not in tDCS-only or Sham + Music conditions. Although no differences in behavioural performance were observed in the auditory WRT, changes in neural correlates underlying recognition memory were observed following tDCS + Music compared to Sham + Music. Findings suggest listening to autobiographically-salient music may amplify the effects of tDCS for working memory, and highlight the potential utility of neurostimulation combined with personalized music to improve cognitive performance in the aging population.

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