Advancing Alzheimer's Care: Home-based tDCS for Affective Symptoms

Participants will be asked to participate in this research study of a device that creates transcranial direct current stimulation (tDCS).

The researchers hope to learn if 30 minute sessions of transcranial direct current stimulation (tDCS) improve such a mood or feelings in people with Alzheimer's Disease.

This study involves the use of an investigational device called a tDC stimulator. "Investigational" means that the device has not yet been approved by the U.S. Food \& Drug Administration (FDA) for treating Alzheimer's Disease.

This study will help find out what effects, good and/or bad, this has. The safety of this device in humans has been tested in prior research studies; however, some side effects may not yet be known.

Three in-person visits will occur: (1) on the week prior to the first day of stimulation visit patients will undergo brain MRI scan to collect T1, T2, DWI and resting state functional MRI (rs-fMRI), and functional Near-Infrared Spectroscopy/Electroencephalography (fNIRS/EEG) imaging. In this visit, patients and caregivers will be taught how to operate the tDCS device and will receive a unit to take home; (2) on the day after completing the first treatment period, patients will undergo a second MRI scan with the same sequences and fNIRS/EEG imaging; (3) on the day after completing the second treatment period, at the end of week 5, patients will return the tDCS device to the study team and perform a last fNIRS/EEG imaging.

At in-person visits and during treatment periods patients will be asked questions regarding tolerability and acceptability, including monitoring for side effects, as well as completing questionnaires that assess cognition and NPS. All sessions will be remotely supervised via video conference platform.

Eligibility Criteria:
Inclusion Criteria:

1. individuals aged 18-85 years with confirmed HD mutation and/or established family history alongside typical symptoms (i.e., chorea) of HD;
2. early (stages 1 and 2) or moderate (stage 3) stages according to Shoulson-Fahn criteria, also known as the UHDRS total functional capacity (TFC) scale (Bates, Tabrizi, and Jones 2014);
3. exhibit mild to moderate behavioral symptoms defined by severity scores in the PBA-S between 1 and 3 for any of the evaluated symptoms and no symptoms with a severity score of 4;
4. stable doses of medications for at least one month.
5. Ability of subject to understand and the willingness to sign a written informed consent document.
6. Have a caregiver willing to be present during tDCS sessions and answer questionnaires.

Caregiver

1. An adult who serves as an unpaid caregiver for an individual enrolled in the study as interpreted by the PI or delegate physician.
2. Adequate cognitive capacity to provide verbal consent to participate in the caregiver arm of the study.
3. Adequate reading, writing, hearing, and verbal capacity to provide collateral information about the study participant as well as answer questions related to their health and care.

Exclusion Criteria:

1. Unstable medical conditions (e.g. unstable angina, uncontrolled diabetes and hypertension, advanced cancer, etc.);
2. History of epilepsy;
3. Clinical diagnosis of major cognitive disorder (i.e., dementia);
4. Have risk of suicidal behavior, defined as any suicidal behavior or suicidal ideation of type 4 (active suicidal ideation with some intent to act, without specific plan) or type 5 (active suicidal ideation with specific plan and intent) based on the Columbia-Suicide Severity Rating Scale (C-SSRS) in the 3 months prior to screening (Posner et al. 2011);
5. Being an active participant in other therapeutic clinical trial;
6. Determined to be incapable of consent per PMH or via assessment by the study staff at time of consent.
7. Participant has a pacemaker or any other implanted device/material contraindicated in the use of tDCS per current labeling requirements.

Caregiver

1. Any individual who does not meet all the inclusion criteria