tDCS and Cognitive Efficiency in Ageing (FRtDCS)

December 17, 2024 updated by: Juan Carlos Melendez, University of Valencia

Non-invasive Transcranial Direct Current Stimulation to Improve Cognitive Efficiency

Normal aging is associated with a progressive decline in cognitive functions, especially memory. This decline in cognitive function can negatively impact the quality of life of older adults. Although there are currently few possibilities to prevent and/or slow the signs of cognitive decline, both those associated with age and neurodegenerative pathologies, one of the non-invasive brain stimulation techniques that has gained attention in recent years is Transcranial Direct Current Stimulation (tDCS). tDCS is a technique based on the application of a low-intensity (< 2 mA) direct electrical current between two large-area electrodes placed on various surface areas of the head. Moreover, according to safety-related meta-analyses it is a very safe technique, without any major side effects, provided that internationally established safety protocols are taken into account in its application. This technique has recently been investigated as a potential treatment for both healthy elderly people and people with mild cognitive impairment and Alzheimer's disease in several cognitive variables, having shown encouraging results in working memory learning curves, modulation of plasticity and recognition tasks. This project aims to implement an intervention using transcranial direct current stimulation in healthy older adults, MCI and AD. The main objective is to test if there is an improvement in cognitive efficiency and if the changes are maintained over time (1 month). For this purpose, the effect of the technique will be studied on participants assigned to treatment and control groups, analyzing the possible modifications in the following cognitive variables: cognitive plasticity and learning potential, recognition and familiarity and false alarms.

Study Overview

Detailed Description

The clinical trial protocol involves the recruitment of participants from three different groups: healthy older adults, individuals with mild cognitive impairment (MCI), and patients with Alzheimer's disease (AD). Participants will be randomly assigned to either a treatment group or a control group.

For the treatment group, transcranial direct current stimulation (tDCS) will be administered over a specified period using a standard protocol involving the application of low-intensity electrical current (< 2 mA) through electrodes placed on specific scalp areas. The duration and frequency of stimulation will be predetermined based on scientific literature and established safety recommendations.

The control group will receive a sham procedure where a low-intensity current, having no effect on neuronal activity, will be applied to maintain treatment masking.

Prior to commencing the intervention, a baseline assessment of participants' cognitive functions will be conducted using a battery of standardized tests, including measures of cognitive plasticity, memory, attention, executive functions, and other relevant cognitive abilities.

During the intervention period, regular tDCS or placebo sessions will be conducted according to participants' assigned groups. Additionally, data on potential side effects and tolerability of the technique will be collected.

At the end of the intervention period, a post-treatment assessment will be conducted to determine any changes in participants' cognitive functions. These data will be compared to baseline assessments to ascertain the intervention's efficacy.

Furthermore, participants will be followed up for a period of at least one month after the intervention to evaluate the persistence of effects and any potential long-term effects.

It is important to emphasize that this protocol will adhere to all ethical and safety regulations established by relevant regulatory authorities and ethics committees. Participants will be fully informed about the procedures and risks involved, and their informed consent will be obtained before their participation in the study.

Study Type

Interventional

Enrollment (Actual)

38

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Valencia, Spain, 46010
        • Faculty of Psychology

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

65 years and older (Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

For the group of healthy older adults:

  • MEC score greater than 26 points.
  • GDS between 1 and 3.

For the MCI group:

  • MEC score between 21 and 26 points.
  • GDS between 1 and 3.

For the mild EA group:

  • MEC score between 18 and 23 points.
  • GDS between 3 and 4.

Exclusion Criteria:

  • Presentation of contraindications to tDCS (presence of intracranial metal implants, intracranial hypertension, comitial risk).
  • Significant asymptomatic neurovascular disease
  • History of previous symptomatic stroke
  • Alcohol or drug abuse/dependence
  • Severe psychiatric symptoms
  • Depressive symptoms higher than mild

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: tDCS. Transcranial direct current stimulation
The stimulation time was 20 minutes, with an initial and final ramp of 30 seconds so that the participant could adapt to the sensation of the current. 10 sessions. Constant current intensity of 2 mA The anode was placed on position F3, coinciding with the dorsolateral prefrontal cortex, and the cathode was placed on Fp2, coinciding with the right supraorbital area (rSO).
10 sessions of tDCS stimulation on dorsolateral prefrontal cortex with the apparatus HDC stimulator (Newronika TM)
Other Names:
  • Transcranial direct current stimulation
Sham Comparator: Sham stimulation
The sham group received direct current only on the ramps to generate a sensation of the effect.
The sham group received direct current only on the ramps to generate a sensation of the effect.10 sessions
Other Names:
  • Transcranial direct current stimulation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Complutense Verbal Learning Test (TAVEC) - Memory
Time Frame: Baseline to approximately 4 weeks
This test presents a list of 16 words that, after being read by the evaluator, have to be repeated by the participant. The list is repeated five times (trials); the participant is again asked to remember the 16 words. The test was administered to evaluate the participant's immediate memory (Trial 1), learning ability (Trial 5 ). Post-intervention minus baseline. Scale is scored 0-16. Difference score range is (-16 to 16) with positive scores reflecting improvement.
Baseline to approximately 4 weeks
Digits Wechsler Intelligence Scale for Adults-III (WAIS-III)
Time Frame: Baseline to approximately 4 weeks
Direct and inverse digits of the Wechsler Intelligence Scale for Adults-III (Wechsler, 2001). These tests assess attentional capacity by exposing the participant to increasing amounts of information. On the direct digits task, which is used to assess immediate recall, the subject must repeat the sequence of numbers in the same order in which they are read by the examiner. On the inverse digit task, which assesses working memory and mental flexibility, the subject must say the digits backwards from the way they were presented by the examiner. Both tests are evaluated in the same way, assigning one point for each correct item, with a maximum score of 16 for both tests. Post-intervention minus baseline. Difference score range is (-16 to 16) with positive scores reflecting improvement.
Baseline to approximately 4 weeks
Mini Mental State Examination
Time Frame: Baseline to approximately 4 weeks
This is a screening test for general cognitive status. This test is evaluated on a maximum of 30 points. Participants with scores equal to or below 23 would be considered cognitively deficient. Post-intervention minus baseline. Scale is scored 0-30. Difference score range is (-30 to 30) with positive scores reflecting improvement.
Baseline to approximately 4 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Barcelona Test (BT) - Ability to Access and Recall Elements From the Lexical and Semantic Store
Time Frame: Baseline to approximately 4 weeks
Barcelona Test assesses the ability to access and recall lexical and semantic items by means of two subtests: a. Semantic fluency: recall the highest number of words from the category 'animals' in one minute; b. Phonological fluency: recall the highest number of words beginning with the letter 'p' in three minutes. Minimum and maximum range for Semantic fluency and Phonological fluency: 0 to n (no upper limit). Method of calculation: Scores for each subtest are reported separately. No combined scores or averages between subtests are calculated. Interpretation: Good categorical recall is considered good when evoking more than 16 animals in 1 minute and good verbal fluency when evoking more than 19 words beginning with 'p' in 3 minutes. This test assesses the ability to access and recall items from the lexical and semantic store. Processes involved: processing speed, cognitive flexibility and working memory. Post-intervention less baseline with positive scores reflecting improvement.
Baseline to approximately 4 weeks

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Global Deterioration Scale (GDS)
Time Frame: Baseline to approximately 4 weeks
This test is evaluated on a maximum of 30 points. Participants with scores equal to or below 23 would be considered cognitively deficient.
Baseline to approximately 4 weeks
Memory Alteration Test (M@T) - Cognitive Impairment
Time Frame: Baseline to approximately 4 weeks
This test offers a rapid and effective screening with excellent discriminative properties for amnestic Mild Cognitive Impairment (MCI-A) and early AD in the general primary care population. The test assesses a variety of abilities such as encoding, orientation, semantic memory and free recall. It consists of oral questions with only one possible answer, and the maximum achievable score is 50 points. The optimal cut-off point for distinguishing amnestic-like mild cognitive impairment from subjective memory complaints is 37 points. The optimal cut-off point for Alzheimer's disease is 31 points. Post-intervention minus baseline. Scale is scored 0-50. Difference score range is (-50 to 50) with positive scores reflecting improvement.
Baseline to approximately 4 weeks
Experimental Task - Recognition Familiarity and False Alarms
Time Frame: Baseline to approximately 4 weeks

This experimental task is composed by three lists of words with two conditions: half and entire.

The half condition included two lists of 50 words each, formed entirely from the following letters of the Spanish alphabet: a, e, u, b, d, g, j, n, r, and z (list A) or i, o, c, f, h, l, m, p, s, t, v, and y (list B).

List C (entire condition) contained 50 words formed from the entire alphabet, with the only criterion being that each word had to contain at least one letter from list A and at least one letter from list B.

In the half condition, the recognition estimates for each participant were derived by subtracting the proportion of false alarms on words with the same letters, as in the study list, from the proportion of hits, whereas in the entire condition, the recognition estimates were derived by subtracting the proportion of false alarms on words with all the letters in the alphabet from the proportion of hits as a way to control the response bias of the participants.

Baseline to approximately 4 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Juan C Melendez, University of Valencia

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 30, 2020

Primary Completion (Actual)

December 30, 2021

Study Completion (Actual)

May 30, 2023

Study Registration Dates

First Submitted

January 19, 2022

First Submitted That Met QC Criteria

January 19, 2022

First Posted (Actual)

January 31, 2022

Study Record Updates

Last Update Posted (Actual)

March 25, 2025

Last Update Submitted That Met QC Criteria

December 17, 2024

Last Verified

December 1, 2024

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

All the information of the study, as well as its results, will be shared in scientific publications and conferences related to the research area.

The information that is intended to be published in scientific journals includes:

1) Study Protocol, 2) Statistical Analysis, 3) Informed Consent Form, 4) Clinical Study Results.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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