The Efficacy of HD-tDCS-Augmented Step Training in Older Adults With Mild Dementia

Falls and mobility decline are major health concerns among older adults with dementia, often linked to deterioration in executive function and cognitive-motor control. Step training interventions that challenge both cognitive and motor faculties have shown promise in enhancing balance and motor reaction to reduce fall risk. However, long-term retention of training gains remains limited, largely constrained by reduced neuroplasticity and underlying neurodegeneration in this population. The primary objective of this study is to investigate the efficacy of high-definition transcranial direct current stimulation (HD-tDCS), a form of wearable non-invasive brain stimulation, combined with step training in community-dwelling older adults with mild dementia. Participants will be randomly allocated to either an active HD-tDCS plus step training group or a sham stimulation plus step training control group. Assessments will be conducted at baseline, immediately post-intervention, and at a 3-month follow-up to evaluate changes in cognitive and physical function (including choice stepping reaction time (CSRT), executive function, and dual-task ability) as well as cortical activity during stepping. In addition, a mid-point assessment will be conducted for the primary outcome (i.e., CSRT). An embedded qualitative evaluation will be conducted with participant-caregiver dyads and healthcare professionals/staff to evaluate implementation outcomes and feasibility (including perceived acceptability, user experience, and practical facilitators and barriers to adoption). Findings from this trial will help optimize neuromodulation-augmented rehabilitation strategies and inform community-based fall prevention programs.