Non-invasive Brain Stimulation for Cognitive and Motor Dysfunction in Dementia

This project aims to examine the efficacy of remote, caregiver-led tES/brain stimulation intervention targeted to improve memory, mobility, and executive functioning among older adults with mild cognitive impairment or mild dementia.

This is a randomized controlled trial to test the efficacy of a home-based brain stimulation intervention of tACS (for angular gyrus) and tDCS (for the prefrontal cortex) to improve memory, mobility, and executive function. It will include 144 older adults with mild dementia or mild cognitive impairment and their caregiver/administrator who will be trained to lead the remote, home-based brain stimulation. Participants will be randomized into one of four conditions, a) active combination of tACS + tDCS, b) combination of active tACS + sham tDCS, c) combination of sham tACS + active tDCS, and d) combination of sham tACS + sham tDCS. Participants will engage in a set of pre-intervention assessments, the brain stimulation intervention--consisting of 20, once-daily 30-min stimulation sessions administered over a 4-week period, and a set of post-intervention assessments (immediately following brain stimulation, 3 months post-brain stimulation, and 6 months post-brain stimulation). This project is expected to demonstrate that tACS and tDCS can be combined to optimize the functional impact of a home-based tES intervention for older adults with mild dementia.

Eligibility Criteria:
Inclusion Criteria:

Participants (Ps)

* willing and capable to give informed consent for the participation in the study after it has been thoroughly explained
* able and willing to comply with all study requirements
* an informed consent form was signed
* able to read, write, and communicate in English
* able to identify an eligible administrator to participate with them in the study

Caregiver/Administrators (As)

* at least 21 years of age
* able to read, write, and communicate in English
* self-reported computer proficiency and willingness to learn how to use tES as defined by "yes" answers to the questions "Do you feel comfortable using a computer?" and "Are you willing to be the primary caregiver for a participant and learn how to administer tES?"
* stated availability during weekdays throughout the study period to administer tES to the Ps

Exclusion Criteria:

Participants (Ps)

* major psychiatric co-morbidity including major depressive disorder, schizophrenia or psychosis
* blindness or other disabilities that prevent task performance
* contraindications to tES, as recorded on a standardized screening questionnaire, which include a reported seizure within the past two years, use of neuroactive drugs, self-reported presence of specific implanted medical devices (e.g., deep brain stimulator, medication infusion pump, cochlear implant, etc.)
* the presence of any active dermatological condition, such as eczema, on the scalp a score of 18 or less on the Montreal Cognitive Assessment (MoCA) during the in-person screen
* an inability to understand study procedures following review of the Informed Consent form
* Understanding will be assessed by asking the participant to answer the following three questions: 1) What is the purpose of this study? 2) What are the risks of study involvement? 3) If you decide to participate, are you allowed to withdraw from the study at any time? Answers will be recorded by study personnel on the "Assessment of Protocol Understanding" form. Insufficient understanding will be defined by one or more incorrect answers, as determined at the discretion of the investigator

Caregiver/Administrators (As)

* mild cognitive impairment defined by a MoCA score ≤26 during the in-person screen
* insufficient understanding of study procedures following review of the Informed Consent form
* Understanding will be assessed by asking the participant to answer the following three questions: 1) What is the purpose of this study? 2) What are the risks of study involvement? 3) If you decide to participate, are you allowed to withdraw from the study at any time? Answers will be recorded by study personnel on the "Assessment of Protocol Understanding" form. Insufficient understanding will be defined by one or more incorrect answers, as determined at the discretion of the investigator.
* poor eyesight, severe arthritis in the hands, pain, deformity or other condition that interferes with successful administration of tES