NCT07433738

Personalized Assessment of High-definition Slow-oscillatory Transcranial Direct Current Stimulation (So-tDCS) in Older Adults With Subjective Cognitive and Sleep Complaints

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 80 (estimated)
• Sponsor: Chinese University of Hong Kong · Academic / Other
• Sex: All
• Age: 60 Years – 80 Years
• Healthy volunteers: Not accepted

Summary

Background: Subjective cognitive decline (SCD) is considered to be the early risk stage of dementia. Untreated SCD comorbid with sleep disturbances may accelerate the progression of neurodegeneration (β-amyloid and tau) and lead to cognitive deficits. At present, non-pharmacological interventions for managing SCD and sleep disturbances are very limited. High-definition slow-oscillatory transcranial direct current stimulation (so-tDCS) is a newly developed frequency-specific modality of brain stimulation for promoting brain health and cognition. Notably, neurophysiological feature (impedance) during tDCS was found to be related to treatment outcomes and adverse effects (skin injury). Objectives: We propose to 1) develop a high-performing neurophysiological signal detector for tDCS and test its feasibility and flexibility in a randomized clinical trial; 2) investigate the short-term and long-term effects of high-definition so-tDCS on SCD, sleep quality and plasma Aβ and p-tau levels; 3) examine the values of neurophysiological signals in predicting the treatment outcomes at individual level. Design: A randomized, double-blind, sham-controlled trial. Methods: Chinese right-handed older adults with SCD and sleep disturbances will be randomly assigned to a 4-week intervention of either high-definition 0.75 Hz so-tDCS or sham tDCS, with 40 participants per arm. Pre-treatment magnetic resonance imaging (MRI) scans will be collected to exclude the cases with major neurological disease and quantify individual's brain features. Galvanic skin response, subjective cognitive complaints, sleep quality, plasma p-tau and β-amyloid levels and domain-specific cognition will be assessed at baseline, 4th week, 8th week and 12th week. Program adherence and adverse effects will be monitored throughout the whole intervention.

Detailed description

This study aims to investigate the efficacy and sustainability of high-definition so-tDCS for managing SCD and sleep disturbances in older adults. The neurophysiological signal detector will be featured with a compact and high-performing GSR assessor with the state-of-the-art personalized measurement during so-tDCS. The successful implement of this signal detector will provide researchers assess to an "add-on" setting that allows them easily, quickly and quantitatively evaluate real-time neurophysiological signals and further incorporate transcranial brain stimulation in clinical practice.

Conditions

• Subjective Cognitive Complaints (SCCs)
• Sleep

Interventions

Type	Name	Description
DEVICE	so-tDCS	The so-tDCS is delivered by a battery driven direct current stimulator (DC-Stimulator Plus, NeuroConn, Ilmenau, Germany). The high-definition setting is applied by placing an anodal electrode over the center of the treatment target and placing four cathodal electrodes surrounded the anodal electrod. Each electrode in the "4 × 1" montages had a diameter of 1.2 cm. We place the anodal electrode over the center of left dorsolateral prefrontal cortex (DLPFC) (i.e., F3 according to the international 10-20 EEG system).
DEVICE	Sham so-tDCS	Sham so-tDCS: With a same setting of high-definition as active so-tDCS, the stimulation of sham so-tDCS only lasts for 30 seconds. The electrodes will be left in place for a further 20 minutes.

Timeline

• Start date: 2026-05-01
• Primary completion: 2028-05-01
• Completion: 2028-11-01
• First posted: 2026-02-25
• Last updated: 2026-02-25

Locations

1 site across 1 country: Hong Kong