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

Abstract

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.

Discrete Ricci curvatures capture age-related changes in human brain functional connectivity networks

“…Previous studies on neurocognitive aging have provided ample evidence for age-related impairments in motor performance, which may include difficulties in planning, execution and control of movement and deficits in coordination (Krampe et al, 2002 ; Sawaki et al, 2003 ; Zimerman and Hummel, 2010 ). Non-invasive brain stimulation technologies such as tDCS, tACS, and TMS provide an attractive option to modulate brain function and help preserve motor performance in older adults (Summers et al, 2016 ; Patel et al, 2019 ; Lee et al, 2021 ; Pino-Esteban et al, 2021 ). The Neurosynth meta-analysis decoding performed in the present work demonstrated the ability of both FRC and ORC to identify brain regions that are associated with movement.…”

“…We followed a three-stage procedure to identify relevant articles from the list of 1,659 articles returned by the PubMed search (see Supplementary Figure 1 ). First, we checked all the meta-analysis papers studying the effects of tDCS, tACS, or TMS on motor performance in elderly individuals (Summers et al, 2016 ; Patel et al, 2019 ; Lee et al, 2021 ; Pino-Esteban et al, 2021 ) to identify articles that were missing from the list of 1,659 articles. Second, we filtered the relevant articles from the list of 1,659 articles based on title and abstract.…”

Discrete Ricci curvatures capture age-related changes in human brain functional connectivity networks

“…Previous studies on neurocognitive aging have provided ample evidence for age-related impairments in motor performance, which may include difficulties in planning, execution and control of movement and deficits in coordination [13,93,94]. Non-invasive brain stimulation technologies such as tDCS, tACS and TMS provide an attractive option to modulate brain function and help preserve motor performance in older adults [76][77][78][79]. The Neurosynth meta-analysis decoding performed in the present work demonstrated the ability of both FRC and ORC to identify brain regions that are associated with movement.…”

“…We followed a three-stage procedure to identify relevant articles from the list of 1659 articles returned by the PubMed search (see Figure 1). First, we checked all the meta-analysis papers studying the effects of tDCS, tACS or TMS on motor performance in elderly individuals [76][77][78][79] to identify articles that were missing from the list of 1659 articles. Second, we filtered the relevant articles from the list of 1659 articles based on title and abstract.…”