Effects of Gamma-tACS on Memory and Sleep

NCT ID: NCT05907707

Last Updated: 2025-04-02

Study Results

Results available

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Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

11 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-06-28

Study Completion Date

2023-12-28

Brief Summary

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The purpose of this clinical trial is to investigate the feasibility and efficacy of non-invasive transcranial alternating current stimulation (tACS) at gamma frequency in enhancing memory recall and modulating sleep network dynamics measured by at-home electroencephalography (EEG) in healthy elderly people. Eligible participants will first collect sleep EEG at home for one night to acclimate to the data collection during sleep. Participants are then randomized into first undergoing either tACS at gamma band frequencies (i.e. 40Hz) or tACS at a control frequency (i.e. 21Hz). Stimulation is administered in the lab during a cognitive testing battery that includes memorizing items. After a night of sleep with EEG at home, participants return to the lab the following day to measure memory recall. Recall is performed again after five days. This sequence of encoding during stimulation in the lab, sleep EEG at home for one night, and recall is then repeated for the other stimulation condition about a week later. Participants are wearing an actigraphy wristband throughout the study period.

Detailed Description

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Conditions

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Transcranial Alternating Current Stimulation Aging Cognitive Decline Memory Sleep

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

Primary Study Purpose

OTHER

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors

Study Groups

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First gamma (40Hz) stimulation, then active control (21Hz) stimulation

After collecting sleep EEG at home for one night to acclimate to the data collection during sleep, participants first receive gamma (40Hz) tACS on Day 1 followed by a 5-9 day washout. Participants then receive active control (21Hz) stimulation.

Group Type EXPERIMENTAL

Gamma transcranial alternating current stimulation

Intervention Type DEVICE

tACS (gamma frequency, 40Hz) during cognitive testing (about 40 minutes duration).

Control transcranial alternating current stimulation

Intervention Type DEVICE

tACS (control frequency, 21Hz) during cognitive testing (about 40 minutes duration).

EEG headband

Intervention Type DEVICE

At-home, ambulatory, single-channel EEG headband which records brain activity during sleep

Actigraphy wristband

Intervention Type DEVICE

At-home, ambulatory, wrist-worn accelerometer which records levels of motor activity during the whole day

First active control (21 Hz) stimulation, then gamma (40 Hz) stimulation

After collecting sleep EEG at home for one night to acclimate to the data collection during sleep, participants first receive active control (21Hz) tACS on Day 1 followed by a 5-9 day washout. Participants then receive gamma (40Hz) stimulation.

Group Type EXPERIMENTAL

Gamma transcranial alternating current stimulation

Intervention Type DEVICE

tACS (gamma frequency, 40Hz) during cognitive testing (about 40 minutes duration).

Control transcranial alternating current stimulation

Intervention Type DEVICE

tACS (control frequency, 21Hz) during cognitive testing (about 40 minutes duration).

EEG headband

Intervention Type DEVICE

At-home, ambulatory, single-channel EEG headband which records brain activity during sleep

Actigraphy wristband

Intervention Type DEVICE

At-home, ambulatory, wrist-worn accelerometer which records levels of motor activity during the whole day

Interventions

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Gamma transcranial alternating current stimulation

tACS (gamma frequency, 40Hz) during cognitive testing (about 40 minutes duration).

Intervention Type DEVICE

Control transcranial alternating current stimulation

tACS (control frequency, 21Hz) during cognitive testing (about 40 minutes duration).

Intervention Type DEVICE

EEG headband

At-home, ambulatory, single-channel EEG headband which records brain activity during sleep

Intervention Type DEVICE

Actigraphy wristband

At-home, ambulatory, wrist-worn accelerometer which records levels of motor activity during the whole day

Intervention Type DEVICE

Other Intervention Names

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DC-STIMULATOR MC Stimulator Plus DC-STIMULATOR MC Stimulator Plus ULTEEMNite

Eligibility Criteria

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Inclusion Criteria

* \>50 years old

Exclusion Criteria

* Implanted device or metal in head (including cochlear implant or other hearing aid), cardiac pacemaker or any other powered medical device
* Known neurological disease from history (epilepsy, sleep disorder (insomnia, sleep apnea, restless legs syndrome, parasomnia), stroke or transitory ischemic attack, cognitive impairment, neurodegenerative disease (for example Alzheimer's disease, Parkinson's disease or amyotrophic lateral sclerosis), immune-mediated disease of the central nervous system, chronic infectious brain disease, brain tumor, traumatic brain injury with loss of consciousness and/or intracranial bleeding, chronic pain with the need for daily analgesic use)
* Positive screening for epilepsy (questionnaire)
* Pathological Montreal Cognitive Assessment (MoCA \<26/30 points)
* Brain surgery in the past (lifetime)
* Known psychiatric disorder from history (schizophrenia (lifetime), obsessive compulsive disorder (OCD; lifetime), borderline personality disorder (lifetime), anxiety disorder (lifetime), bipolar disorder (lifetime), psychosis (lifetime), eating disorder (lifetime), depression (within the last three months)
* Positive screening for anxiety disorder (GAD-7 ≥10/21 points) or positive screening for depression (PHQ-9 ≥5/27 points)
* Known other relevant medical condition from history (moderate to severe chronic obstructive pulmonary disease (COPD), abnormal kidney function (defined as estimated Glomerular Filtration Rate \<60ml/min), current liver disease (defined as hepatitis and/or liver cirrhosis), cancer, diabetes mellitus, cardiac disease (heart failure, myocardial infarct, atrial fibrillation and revascularization - all within the last three months)
* Working in night shifts or going to bed after midnight on 3 or more nights per week
* Positive screening for sleep disorder (PSQI \>5/21 points)
* Psychotropic treatment or illegal drugs (including cannabis) within the last three months
* Indication for alcohol use disorder: AUDIT score (Alcohol Use Disorders Identification Test; screening for unhealthy alcohol use) ≥7 for females and for males ≥ 65 years or ≥8 for males \<65 years
* Not willing to abstain alcohol at least 24 hours before each study visit
* Pregnancy, planned pregnancy, fertility treatment planned or ongoing
* Having experienced an adverse event in the past after receiving Transcranial Magnetic Stimulation (TMS)
* If, after filling out a questionnaire on the participant's medical history that informs researchers of relevant events that marginally increase the risk of an adverse event occurring during TMS, researchers will exercise their expert judgement to determine whether that participant should be excluded
Minimum Eligible Age

50 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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University of North Carolina, Chapel Hill

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Flavio Frohlich, PhD

Role: PRINCIPAL_INVESTIGATOR

University of North Carolina, Chapel Hill

Locations

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Carolina Center for Neurostimulation

Chapel Hill, North Carolina, United States

Site Status

Countries

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United States

Provided Documents

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Document Type: Study Protocol and Statistical Analysis Plan

View Document

Other Identifiers

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23-0597

Identifier Type: -

Identifier Source: org_study_id

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