Transcranial electrical stimulation as a therapeutic strategy for Alzheimer's disease: Current uses and challenges

Alzheimer's disease (AD) is an age-related neurodegenerative disorder for which there are currently rarely effective drug treatments available to halt or slow down its progression. With the aging of the world population, AD as the primary cause of dementia, is rapidly becoming one of the most expensive, lethal, and burdening diseases of this century. In recent years, the new method used to treat nervous system diseases including AD is transcranial electrical stimulation (tES) with non-invasive and for regulating the flexibility of neural circuits operation and behaviors. The rationale of tES for AD neuromodulation is derived from research on animal and clinical trials. In the present paper, we review the current uses of the tES including transcranial direct current stimulation, transcranial alternating current stimulation, and transcranial pulsed electrical stimulation in rehabilitation for AD's core clinical symptom with cognitive dysfunctions, as well as the relevant data from AD animal models have also been discussed. Finally, the regarding applied challenges of tES in AD therapy have been referred for further improvement.