Noninvasive Brain Stimulation in Mild Cognitive Impairment and Dementia

The research objective of this study is to examine the efficacy of HD-tDCS to the preSMA/DACC region and its influence on verbal episodic memory in patients with MCI or dementia after 10 sessions of HD-tDCS. There will be three treatment arms: two active HD-tDCS (1 mA or 2 mA) and a sham group. A verbal episodic memory task will be completed at baseline, immediately following the last HD-tDCS session, and a 2-month follow-up.

This is a pilot study being done to attempt to improve verbal episodic memory in persons with mild cognitive impairment (MCI) and dementia. Although the hippocampus is a brain structure most often associated with early deficits in MCI and dementia, the pre-supplemental motor area (preSMA) and dorsal anterior cingulate cortex (DACC) have been shown to play a role in verbal episodic memory for such patients. The purpose of this study is to examine the efficacy of high-definition transcranial direct current stimulation (HD-tDCS) to the preSMA/DACC region and its influence on verbal episodic memory in patients with MCI and dementia. Entraining the preSMA/DACC circuit with 10 sessions at one of two levels of HD-tDCS will allow the researchers to investigate whether neuromodulation may be used to improve verbal episodic memory. Participants will receive 10 sessions at one of two levels of active stimulation (1 mA or 2 mA anodal HD-tDCS targeting preSMA/DACC for 20 min) or sham across 2 weeks. The device is used to deliver high definition transcranial direct current stimulation to targeted regions. A verbal episodic memory task will be completed at baseline, immediately following the last HD-tDCS session, and a 2-month follow-up. The investigators plan to recruit English-speaking participants aged 50 years and older with MCI and dementia. Participants will be randomized into HD-tDCS conditions.

Transcranial direct current stimulation, Alzheimer Disease, Mild Cognitive Impairment, Dementia, MCI, Mild neurocognitive disorder, Amnestic, Pre- alzheimer

Participants wear a neoprene cap on their head and electrodes filled with gel are attached and will deliver 1mA to the scalp.

Participants wear a neoprene cap on their head and electrodes filled with gel are attached and will deliver 2mA to the scalp.

Participants wear a neoprene cap on their head and electrodes filled with gel are attached and will deliver no current to the scalp.

The RAVLT is a verbal episodic memory task where a list of 15 words is read aloud for 5 consecutive trials followed by a 20 minute delayed recall trial. The number of items recalled immediately after each trial are summed to create a total learning score, ranging from 0-75. Also, the number of items recalled for the delayed trial are recorded as a delayed recall score, ranging from 0-15. Higher scores reflect better episodic memory performance. Changes from baseline for the total learning and delayed recall scores at the last HD-tDCS session and the 2-month follow-up will be measured as the primary outcomes.

Inclusion Criteria: Age 50 and older Fluent in English Active diagnosis of MCI or dementia Exclusion Criteria: Substance use disorder Has metal fragments in head Taking medications that may interact with the HD-tDCS effect (i.e., amphetamines, L-dopa, carbamazepine, sulpiride, pergolide, lorazepam, dextromethorphan, D-cycloserine, flunarizine, or ropinirole)