Background: Sleep disturbances, as a common symptom, can jeopardize the brain health and cognitive function and even lead to cognitive impairments in older adults. The co-occurring sleep disturbances cognitive complaints can significantly affect brain functions, and even be implicated as a key contributing factor in the development of prodromal Alzheimer's disease (AD). At present, very few non-pharmacological therapies are developed for managing these comorbidities in older adults. Focused low-intensity transcranial ultrasound stimulation (TUS) enables to stimulation the deep brain structures, such as hippocampus, with optimized focality and specific frequency.
Objectives: 1) To investigate the safety, feasibility and efficacy of a 2-week focused low-intensity hippocampal TUS on the severity of sleep disturbances and cognitive impairments in elderly patients; 2) to determine the sample size of a full-scale randomized clinical trial of low-intensity TUS in patients with preclinical AD; 3) to evaluate the effects of low-intensity TUS on the severity of sleep quality and cognitive functions at 2, 6 and 10 weeks after the treatments.
Design: A 2-week randomized, double-blind, controlled clinical trial. Methods: Chinese right-handed preclinical AD patients with sleep disturbances (aged from 60 to 90 years) will be randomly assigned to a 2-week intervention of either low intensity TUS or sham TUS, with 10 participants per arm. Before intervention, T1-weighted magnetic resonance imaging (MRI) data is used to construct individual realistic head model. Comprehensive assessments, including sleep quality, cognitive performance and plasma p-tau217, Aß42 and Aß40 will be conducted at baseline, 2nd week, 6th week and 10th week. Program adherence and adverse effects will be monitored throughout intervention.