Effects of transcranial direct current stimulation on motor learning in healthy elderly individuals: a systematic review and meta-analysis

Abstract

Background

Transcranial direct current stimulation (tDCS) is widely used in motor recovery. Nevertheless, whether tDCS improves motor learning in healthy older adults is still controversial. This review aims to investigate the effectiveness of tDCS on motor learning in healthy elderly individuals.

Methods

The PubMed, Cochrane Library, Web of Science and Embase databases were initially searched from inception to December 5, 2022. The standard mean difference (SMD) with the corresponding 95% confidence intervals (CIs) were analysed via random-effect models.

Results

Compared with the sham group, no significant effects were found regarding improvement in motor learning based on the speed or accuracy of the task and reaction time for the tDCS intervention group. After subgroup analysis, a significant effect was found for improved motor learning based on reaction time in the primary motor cortex (M1)-cerebellar group.

Conclusions

This review revealed that tDCS had no significant effect on improving the speed or accuracy of motor learning in healthy elderly adults. However, it has a significant effect on improving the motor learning ability based on the reaction time of the task (mainly referring to the tDCS stimulation position of M1 and cerebellar), although the results have obvious heterogeneity and uncertainty.

Keywords:

• Transcranial direct current stimulation (tDCS)
• healthy elderly
• motor learning
• M1
• cerebellar

Authors’ contributions

FSZ and YBH conceived and designed this study. FSZ and HLW performed the data extraction and wrote the main draft. YL and DYT analysed qualitative data. YBH polished the language. All authors contributed to manuscript revision, read, and approved the submitted version.

Disclosure statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Additional information

Funding

This work was supported by the National Social Science Foundation of China (Grant 21XTY018).