Clinical Trial Through Combined tACS Therapy in Patients With Mild Cognitive Impairment

Summary

The aging of the population has led to an increase in the prevalence of disabling and high-cost diseases, such as dementia and Mild Cognitive Impairment (MCI). The latter can be considered a prodromal phase of some dementias and a critical stage for interventions to postpone the impairment of functionality and thus maintain a better quality of life. A cognitive function to intervene in working memory (WM) since it represents the fundamental component of executive functions and is the gateway to maintaining long-term memory. This project proposes an intervention to enhance WM in these users, combining cognitive training with non-invasive brain stimulation, specifically transcranial electrical stimulation of alternating current (tACS). This proposal arises from recent evidence showing that it is possible to increase the capacity of WM in users with MCI through cognitive training. Along with this, tACS has been proposed as a specific neuronal plasticity inducer for the oscillatory pattern required for each mental process. WM is a process particularly susceptible to being enhanced by this technique, as the underlying electrophysiological oscillatory patterns of this process are well described. Thus, tACS would act as a potentiator of the residual capacity of WM in patients with neurodegenerative diseases.

This study is a phase II randomized, double-blind clinical trial with a 3-month follow-up. The study will be of 62 participants diagnosed with MCI over 60 years from Valparaíso, Chile. Participants will receive intervention that will combine 12 cognitive training sessions with non-invasive brain stimulation, specifically tACS. Depending on the intervention group to which they will be assigned, in 8 of these sessions, participants will receive either tACS or sham stimulation. Sessions will last approximately 1 hour and take place twice a week, over six weeks. The primary outcomes will be the electroencephalographic measurements, and the secondary effects will be cognitive assessments of WM. The outcomes will be performed before, immediately after, and three months after the end of the intervention.

The outcomes of this trial will add evidence about the benefits and feasibility of an intervention that combines cognitive training with non-invasive brain stimulation. The objective is to contribute tools for optimal cognitive treatment in patients with MCI. To enhance WM capacity, postpone the impairment of functionality, and obtain a better quality of life.

Conditions

• Mild Cognitive Impairment

Interventions

COMBINATION_PRODUCT

Combined tACS and Cognitive Training Program

The program contemplates 12 WM training sessions based on tasks of storage and manipulation of verbal and visuospatial information, with a frequency of twice a week during six weeks (total of 12 sessions). Patients will receive real electrical stimulation for 10 minutes during verbal working memory task. This includes 10s periods of phase-in and 10 s of phase-out and will be done in parallel with the cognitive intervention program in sessions 3, 4, 5, 6, 7, 8, 9, and 11. The electrical stimulation will be applied with two 3x1 arrays of electrodes. The central stimulation electrodes will be positioned in F3 and CP3 (10-20 system). The AC stimulation will be one mA from the baseline to the stimulation peak. The stimulation will have a gamma sine waveform (80Hz) over the positive phase of the theta oscillation (between 4 and 8 Hz, adjusted by each subject, Reinhart et al, 2019) phase-locked between arrays with impedances always under 10 kOhm.

BEHAVIORAL

Traditional Cognitive Training Program

Participants will start a cognitive intervention program identical to the intervention group. Still, unlike the intervention group, they will receive placebo electrical stimulation, i.e., an electrical current will be applied for a short period at the beginning of the session (30 seconds), and then the stimulation will be stopped. This procedure induces a sensation in the skin similar to the real stimulation without generating a detectable impact on the brain state. They will be performed in parallel to the cognitive intervention program in sessions 1, 2, 3, 4, 5, 7, 9, and 10.

Sponsors & Collaborators

• Universidad del Desarrollo

  lead OTHER

Principal Investigators

• Pablo Billeke, PhD · Social Neuroscience and Neuromodulation Laboratory Director

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

60 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-01-26

Primary Completion

2023-09-21

Completion

2024-09-21

Countries

• Chile

Study Locations