tDCS and Cognitive Training for Mild Cognitive Impairment and Alzheimer's Dementia

Overview

There are currently no disease-modifying treatments for cognitive and behavioral symptoms associated with early clinical Alzheimer's disease (AD), and only minimally effective symptomatic treatments are available. In this application, we propose a transcranial direct current stimulation (tDCS) augmented executive functioning training intervention. This intervention will target cognition and brain circuits that are impaired in patients with mild cognitive impairment (MCI) and early AD. The goal is to improve cognitive performance and functional outcomes in patients with MCI and early AD.

Objectives There are currently no disease-modifying treatments for cognitive and behavioral symptoms associated with early clinical Alzheimer's disease (AD), and only minimally effective symptomatic treatments are available. In this application, we propose a transcranial direct current stimulation (tDCS) augmented executive functioning training intervention. This intervention will target cognition and brain circuits that are impaired in patients with mild cognitive impairment (MCI) and early AD. The goal is to improve cognitive performance and functional outcomes in patients with MCI and early AD. Research Plan and Methods This study will recruit 50 Veterans with MCI or very early AD who are receiving outpatient services at the Minneapolis VA Health Care System (MVAHCS) Geriatric Research, Education, and Clinical Center (GRECC) Memory Loss Clinic. This study will be a double-blind, randomized, placebo (sham) controlled study. Participants will be randomly assigned to receive either active or sham tDCS, both paired with cognitive training tasks. Ten sessions of training/tDCS sessions (20 minutes of 2mA current stimulation with 45 minutes of cognitive training tasks) will occur over 2-3 weeks, performed at the participant's home. Participants will attend an in-person enrollment and training session prior to study intervention. Follow-up sessions will occur via phone or video conference at 3 and 6 months after study initiation. Clinical Relevance Executive cognitive impairments in patients with MCI or early AD have been associated with poor decision-making ability and lack of insight, potentially leading to compromised job performance, financial mismanagement, increased personal safety risk, relationship stress, and poor medical treatment adherence. While disproportionate memory impairment is a hallmark of both conditions, there are compensatory strategies available to reduce disability associated with very early stage memory impairment in those who are otherwise cognitively intact. Compensatory strategies are much less effective for executive dysfunction, as the disability itself impairs one's ability to recognize when such strategies are needed and successfully employ them. Novel, well-tolerated, neuroplasticity-based interventions that can reduce executive impairment by targeting both cognitive control (an executive ability) and its underlying neural dysfunction are needed to improve cognitive outcomes, safety, and quality of life for patients with MCI or early AD. Knowledge gained from this study can inform the future development of clinical treatment approaches aimed at reducing risk and delaying out-of-home placement in Veterans with cognitive impairment.