Comparing Transcranial Direct Current Stimulation (tDCS) with Other Non-Invasive Brain Stimulation (NIBS) in the Treatment of Alzheimer’s Disease: A Literature Review

Abstract Purpose Identifying the effective treatments for diseases has been a critical issue in daily clinical practice, especially for Alzheimer’s dementia (AD). Abundant evidence showed that non-invasive brain stimulation (NIBS) has the potential to slow or reverse cognitive function decline. Among them, the transcranial Direct Current Stimulation (tDCS) would be relatively safe for patients with AD. The purpose of this study was to review the relevant articles to explore the mechanism and effect of tDCS and other NIBS in AD treatment. Methods All the reported works were retrieved from two databases (i.e., PubMed and Google Scholar) by using the keywords “NIBS” and “AD”. The mechanisms and effects of different NIBS applied in AD, including transcranial ultrasound stimulation (TUS), transcranial near-infrared (tNIR) light therapy, transcranial magnetic stimulation (TMS), and transcranial electric stimulation (TES) were reviewed. Results The positive effects of TUS and tNIR on AD were supported by a few small samples and uncontrolled pilot studies. tDCS and repetitive TMS have been often used in an attempt to improve the cognition in people with brain disorders. Both the tDCS and TMS have benefits in AD by introducing long-term potentiation like change in synaptic strength. The reports showed that tDCS could be more safe, convenient, affordable, and well-tolerated method among all applications for AD treatment. Conclusion In this review, it was shown that all the NIBS have positive effects on AD treatment. But, however, tDCS showed the great potential in improving the cognition of AD.