Effects of tDCS on Cognition in MCI: A RCT

NCT05584748 | Not Yet Recruiting FDA Device

• 1 other identifier: UGC/FDS17/M06/22
• Study Type: interventional
• Target: 48
• Locations: 0 countries
• Sites: N/A

Brief Summary

MCI is considered an intermediate stage between normal cognitive aging and dementia. As such, improving cognitive functions of people with MCI may delay dementia onset. In recent years, tDCS, which regulates brain activity by increasing or decreasing brain tissue excitability, has become a commonly used brain stimulation method. Accumulating evidence indicates the promising effects of cognitive enhancement after tDCS over the frontal scalp regions in people with MCI (PwMCI). However, previous studies were limited by including only a self-report measure, focused on memory performance, not assessing long-term effect, and not reporting their results in follow-up. In addition, knowledge of the precise physiological consequences of tDCS on the brain tissue and related neural mechanisms in PwMCI remains rudimentary. The objectives of the proposed study, which will target PwMCI, are to investigate the effects of tDCS at the left dorsolateral prefrontal cortex on the cognitive performance and to explore the modulation of neural mechanisms associated with the use of tDCS. Forty-eight MCI participants aged over 60 years will be recruited. All participants will be assessed by Hong Kong version of Montreal Cognitive Test. Participants that meet selection criteria will be invited to the experiment. Participants will be assigned to experimental or control groups randomly. The experiment will consist of pre- and post-assessments and a 1-month follow-up assessment. Between pre- and post-assessments, participants will receive 8 sessions (2x/week for 4 weeks) of tDCS treatment (either real or sham, 20 min per session). Outcome measures include digit span test, colour trail test, verbal fluency test, Chinese version of the Verbal Learning Test , and Hong Kong version of Montreal Cognitive Assessment. Participants will also complete a computer memory task at each assessment point (performance in this task is also used as an outcome measure) and will have their brain wave recorded while completing the task. The task will require them to study and memorise Chinese characters, followed by a recognition memory test. In the study phase, participants will be required to view Chinese characters and judge whether the characters are of the animal category. In the recognition phase, participants will decide whether the characters have been seen before.

Conditions

Mild Cognitive Impairment

Keywords

tDCS; ERP/EEG; Cognition; Dorsolateral prefrontal cortex

Outcome Measures

Primary Outcomes (7)

• Digit span test (Wechsler & De Lemos, 1981)

  Participants are presented with a random series of digits, and are asked to repeat them in the order presented.

  2 minutes

• Colour Trail Test (CTT) (D' Elia et al., 1996)

  CTT1: Must be administered first and requires the respondent to connect circles in an ascending numbered sequence (1-25). CTT2: Must follow the CTT1 and requires the respondent to connect numbers in an ascending sequence while alternating between pink and yellow colors.

  8 minutes

• verbal fluency test (Lezak et al., 2004)

  Participants produce as many words as possible from a category in 60 seconds.

  3 minutes

• Chinese version of the Verbal Learning Test (Chang et al., 2010)

  Participants repeat 9 Chinese words after they are presented.

  10 minutes

• Hong Kong version of Montreal Cognitive Assessment (Yeung et al., 2014)

  A screening tool for MCI

  15 minutes

• Computerized memory task

  During the study phase of the memory task, the participants will view the Chinese words on a computer screen and decide whether they are from the animal category. After finishing the study/encoding phase, the participants will perform the recognition/test task. During this task, the participants will view characters and judge whether they had seen them previously in the study phase.

  40 minutes

• Event-related potential

  Electroencephalograms are recorded while completing the computerized memory task

  40 minutes

Secondary Outcomes (1)

• Geriatric Depression Scale (Chiu et al., 1994)

  5 minutes

Study Arms (2)

Simulation group

EXPERIMENTAL

During anodal stimulation, the participants will receive 1.5 mA of constant current over the site for 20 min, with a 15-second ramp up and scale down at the beginning and the end of the procedure.

Device: transcranial direct current stimulation

Sham group

SHAM COMPARATOR

In the sham stimulation condition, the current will only be administered during the first 30 seconds and last 30 seconds of the 20-minute window.

Device: transcranial direct current stimulation

Interventions

transcranial direct current stimulation DEVICE

tDCS is planned to be administered via electrodes positioned over the left dlPFC (anodal/sham electrode) and the left supraorbital area (reference electrode).

Sham group; Simulation group

Eligibility Criteria

• Age: 60 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• inexperienced with tDCS
• normal or corrected-to-normal vision
• right-handed
• independent in activities of daily living
• no history of seizures, head injuries, migraine, epilepsy or other psychiatric or neurological conditions

You may not qualify if:

• taking medication or supplements known to affect cognition (such as Ginkgo)
• exhibiting symptoms of emotional disorders
• having a history of cerebrovascular surgery
• with a metal plate in their skull

Sponsors & Collaborators

• Tung Wah College: lead

Related Publications (7)

• Kuo MC, Liu KP, Ting KH, Chan CC. Differentiation of perceptual and semantic subsequent memory effects using an orthographic paradigm. Brain Res. 2012 Nov 27;1486:82-91. doi: 10.1016/j.brainres.2012.10.005. Epub 2012 Oct 10.

  PMID: 23063888 BACKGROUND

• Kuo MC, Liu KP, Ting KH, Chan CC. Age-related effects on perceptual and semantic encoding in memory. Neuroscience. 2014 Mar 7;261:95-106. doi: 10.1016/j.neuroscience.2013.12.036. Epub 2013 Dec 25.

  PMID: 24374080 BACKGROUND

• Meinzer M, Lindenberg R, Antonenko D, Flaisch T, Floel A. Anodal transcranial direct current stimulation temporarily reverses age-associated cognitive decline and functional brain activity changes. J Neurosci. 2013 Jul 24;33(30):12470-8. doi: 10.1523/JNEUROSCI.5743-12.2013.

  PMID: 23884951 BACKGROUND

• Meinzer M, Lindenberg R, Phan MT, Ulm L, Volk C, Floel A. Transcranial direct current stimulation in mild cognitive impairment: Behavioral effects and neural mechanisms. Alzheimers Dement. 2015 Sep;11(9):1032-40. doi: 10.1016/j.jalz.2014.07.159. Epub 2014 Nov 20.

  PMID: 25449530 BACKGROUND

• Ownby RL, Acevedo A. A pilot study of cognitive training with and without transcranial direct current stimulation to improve cognition in older persons with HIV-related cognitive impairment. Neuropsychiatr Dis Treat. 2016 Oct 25;12:2745-2754. doi: 10.2147/NDT.S120282. eCollection 2016.

  PMID: 27822047 BACKGROUND

• Fileccia E, Di Stasi V, Poda R, Rizzo G, Stanzani-Maserati M, Oppi F, Avoni P, Capellari S, Liguori R. Effects on cognition of 20-day anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex in patients affected by mild cognitive impairment: a case-control study. Neurol Sci. 2019 Sep;40(9):1865-1872. doi: 10.1007/s10072-019-03903-6. Epub 2019 May 7.

  PMID: 31062189 BACKGROUND

• Gomes MA, Akiba HT, Gomes JS, Trevizol AP, de Lacerda ALT, Dias AM. Transcranial direct current stimulation (tDCS) in elderly with mild cognitive impairment: A pilot study. Dement Neuropsychol. 2019 Apr-Jun;13(2):187-195. doi: 10.1590/1980-57642018dn13-020007.

  PMID: 31285793 BACKGROUND

MeSH Terms

Conditions

Cognitive Dysfunction

Interventions

Transcranial Direct Current Stimulation

Condition Hierarchy (Ancestors)

Cognition Disorders; Neurocognitive Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Central Study Contacts

Michael Kuo, PhD

CONTACT

+85234686656; michaelkuo@twc.edu.hk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: October 10, 2022
• First Posted: October 18, 2022
• Study Start: June 1, 2023
• Primary Completion: May 1, 2025
• Study Completion: May 1, 2026
• Last Updated: October 18, 2022

Record last verified: 2022-10

Data Sharing

• IPD Sharing: Will not share