The goal of this clinical trial is to learn if using deep repetitive transcranial magnetic stimulation (rTMS) targeting the precuneus is feasible, tolerable, and potentially efficacious for memory in Probable Alzheimer's Dementia. Previous work studying rTMS in Alzheimer's is mixed, but recent work studying rTMS of the precuneus is encouraging for both its short-term and long-term effects. The main questions this study aims to answer are: * Is deep rTMS of the precuneus feasible and tolerable in Alzheimer's? * Are there signs of positive brain changes in response to deep rTMS? * Is deep rTMS potentially efficacious for memory in Alzheimer's? Researchers will compare active stimulation to placebo stimulation while obtaining memory testing and measurements of the brain (imaging, scalp electrode measurements, bloodwork) to see if active treatment works to treat mild-to-moderate probable Alzheimer's Dementia. Participants will: * Engage with memory testing, brain scans, and bloodwork during a comprehensive assessment * Visit the clinic 3 times for 12 consolidated rTMS sessions, followed by 4 once weekly maintenance sessions * Be offered a full open-label active treatment course after completing their treatment course if they are initially in the placebo group
This study is designed to examine whether non-invasive electromagnetic stimulation of a specific brain region can help improve memory in the short-term in Alzheimer's Disease (AD). AD is a progressive neurodegenerative disease that affects multiple domains, including cognitive (e.g. memory, executive function), behavioral (e.g. wandering, difficulty controlling impulses, irritability), emotional (e.g. anxiety, depression), and functional (e.g. ability to live independently and complete activities of daily living) domains. It is also associated with increased caregiver burden, which can adversely affect caregivers' health. One increasingly apparent contributor to disease progression in AD is brain network dysregulation, particularly within the default mode network. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive therapeutic modality that can be used to stimulate the precuneus, a key node in the default mode network, and maintain signaling function within the default mode network. Previous studies have shown that targeting the precuneus with rTMS may enhance memory in the short term and delay disease progression and functional decline in AD over longer periods. rTMS protocols that have demonstrated promise for treatment delay have first shown short-term impacts on memory, particularly memory of recent and past events. We will conduct a two-phase trial of rTMS targeting the precuneus in patients with mild to moderate probable AD focused primarily on determining safety and feasibility and secondarily focused on determining short-term efficacy for memory. Participants will be recruited through fliers, social media, print, and web advertising, as well as referrals from other UCLA studies, UCLA clinics, and known community clinics. The first phase will be a handful of subjects (5-10) receiving active treatment only to refine the protocol. After refinement, the second phase will consist of a randomized, double-blind, sham controlled clinical trial with post-blinding crossover examining both safety and short-term efficacy for memory. Participants will be randomized on a 1:1 ratio to either receive precuneus or sham rTMS. Participants will undergo 16 total rTMS brain stimulation sessions (each session being about 20 minutes) over the course of 5 weeks. The initial induction 3-day intensive course in which rTMS (or sham) will be applied four times daily with 1-hour breaks between treatments will be followed by a 4-week maintenance course in which stimulation will be applied once weekly. Participants will undergo a range of assessments including brain imaging and oxygenation, genotyping, eye reactivity to light testing, and brain electrical activity measurements to identify changes that occur in the precuneus and its connected regions over time. Participants will also undergo comprehensive neuropsychological (memory and behavioral) testing at baseline and during follow up. Additionally, participants and their caregivers will complete brief weekly check-ins at each treatment during the study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
QUADRUPLE
Enrollment
54
rTMS Stimulation Parameters Pulse count: 1600 pulses Frequency: 20Hz Pules per train: 40 pulses Inter-train interval: 28 seconds Intensity: 100% Motor Threshold (depth-corrected from MRI) Target: Precuneus using structural MRI navigation with MNI coordinates
Sham coil placed in same location and set with same parameters as active treatment coil. However, this device will not output active treatment and scalp electrodes will mimic the sensation of rTMS for the participant.
UCLA TMS Clinical and Research Service
Los Angeles, California, United States
RECRUITINGCompletion Rate
The percentage/fraction of participants who complete the full course of study treatment
Time frame: From enrollment to the end of treatment after 5 weeks
Adverse Events
The incidence of adverse events/side effects during the course of study treatment. Known common side effects of rTMS for other indications include discomfort/pain at the site of stimulation and mild transient headaches. Known rare though serious side effects include seizure (generally 1 in 30,000)
Time frame: From enrollment until the end of treatment at 5 weeks
Gray Matter Volume
There are indications rTMS may preserve gray matter volume in neurodegenerative disease near the site of stimulation and connected areas. Volume of the precuneus, stimulated areas, and connected areas will be studied before and after treatment.
Time frame: From pre-treatment baseline structural MRI to post-treatment structural MRI
EEG
Beta and Gamma Oscillatory power, as well as Beta/Theta periodic power ratios will be examined.
Time frame: From pre-treatment EEG to post-treatment EEG after 5 weeks
NIH Cognitive Toolbox
The NIH Cognitive Toolbox consists of a battery of tests well-validated for memory testing. Participants will undergo testing with this tool before and after completing treatment.
Time frame: Enrollment to end of 5 weeks of treatment
resting-state functional MRI connectivity
Participants will undergo resting-state functional blood-oxygen-level dependent (BOLD) MRI (rs-fMRI) to examine functional connectivity between the precuneus and other areas of the brain, particularly within the default mode network
Time frame: from enrollment to the end of treatment at 5 weeks
Repeatable Battery for the Assessment of Neuropsychological Status Update (RBANS Update)
The RBANS Update is a well-established neuropsychological test for memory. Participants will undergo testing with the RBANS before treatment, between induction and maintenance treatment, and after completing treatment. Scores range from 40 to 160, with higher scores indicating better performance and lower scores indicating worse performance.
Time frame: From pre-treatment to post-induction pre-maintenance to end-of-treatment after 5 weeks.
Clinical Dementia Rating Scale (CDR)
CDR score and CDR-SB (sum of boxes score) are gathered from the CDR, an interview-based measure of global dementia severity. Participants and caregivers engage in interview. Global scores range from 0 to 3 with higher scores indicating greater severity of dementia. Sum of boxes scores range from 0 to 18 with higher scores indicating greater severity of dementia.
Time frame: From enrollment to the end of treatment at 5 weeks
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