Would transcranial direct current stimulation (tDCS) enhance the effects of working memory training in older adults with mild neurocognitive disorder due to Alzheimer's disease: study protocol for a randomized controlled trial

• Published in: Current controlled trials in cardiovascular medicine Vol. 16; no. 1; p. 479
• Main Authors: Cheng, Calvin P W, Chan, Sandra S M, Mak, Arthur D P, Chan, Wai Chi, Cheng, Sheung Tak, Shi, Lin, Wang, Defeng, Lam, Linda Chiu-Wa
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 24.10.2015; BioMed Central
• Subjects: Aged; Aged, 80 and over; Alzheimer Disease - diagnosis; Alzheimer Disease - physiopathology; Alzheimer Disease - psychology; Alzheimer Disease - therapy; Alzheimer's disease; Analysis; Brain - physiopathology; Brain research; Care and treatment; Clinical Protocols; Clinical trials; Cognition; Cognition & reasoning; Cognitive ability; Cognitive Behavioral Therapy; Combined Modality Therapy; Dementia; Development and progression; Diagnosis; Double-Blind Method; Female; Health aspects; Hong Kong; Humans; Intention to Treat Analysis; Intervention; Male; Medical research; Medicine, Experimental; Memory; Memory, Short-Term; Middle Aged; Neuronal Plasticity; Neurons; Neuropsychological Tests; Older people; Paradigms; Patient Compliance; Research Design; Severity of Illness Index; Short-term memory; Study Protocol; Time Factors; Training; Transcranial Direct Current Stimulation - adverse effects; Treatment Outcome
• ISSN: 1745-6215; 1745-6215
• DOI: 10.1186/s13063-015-0999-0

There has been longstanding interesting in cognitive training for older adults with cognitive impairment. In this study, we will investigate the effects of working memory training, and explore augmentation strategies that could possibly consolidate the effects in older adults with mild neurocognitive disorder. Transcranial direct current stimulation (tDCS) has been demonstrated to affect the neuronal excitability and reported to enhance memory performance. As tDCS may also modulate cognitive function through changes in neuroplastic response, it would be adopted as an augmentation strategy for working memory training in the present study. This is a 4-week intervention double-blind randomized controlled trial (RCT) of tDCS. Chinese older adults (aged 60 to 90 years) with mild neurocognitive disorder due to Alzheimer's disease (DSM-5 criteria) would be randomized into a 4-week intervention of either tDCS-working memory (DCS-WM), tDCS-control cognitive training (DCS-CC), and sham tDCS-working memory (WM-CD) groups. The primary outcome would be working memory test - the n-back task performance and the Chinese version of the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog). Secondary outcomes would be test performance of specific cognitive domains and mood. Intention-to-treat analysis would be carried out. Changes of efficacy indicators with time and intervention would be tested with mixed effect models. This study adopts the theory of neuroplasticity to evaluate the potential cognitive benefits of non-invasive electrical brain stimulation, working memory training and dual stimulation in older adults at risk of cognitive decline. It would also examine the tolerability, program adherence and adverse effects of this novel intervention. Information would be helpful for further research of dementia prevention studies. ChiCTR-TRC- 14005036 Date of registration: 31 July 2014.