N/A
N=11
Effects of Gamma-tACS on Memory and Sleep
Transcranial Alternating Current Stimulation · Aging · Cognitive Decline · Memory · Sleep
Bottom Line
View on ClinicalTrials.gov: NCT05907707 ↗Enrolled (actual)
11
Serious AEs
0.0%
Results posted
Dec 2024
Primary outcome: Primary: Percent of Participants Tolerating Cognitive Testing During tACS — 100; 100 percentage of participants
Study Design & Population
- Study type
- Interventional
- Phase
- N/A
- Interventions
- Gamma transcranial alternating current stimulation (Device); Control transcranial alternating current stimulation (Device); EEG headband (Device); Actigraphy wristband (Device)
- Age
- Adult, Older Adult · 50+ yrs
- Sex
- All
- Sponsor
- University of North Carolina, Chapel Hill
- Primary completion
- Dec 2023
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Percent of Participants Tolerating Cognitive Testing During tACS |
100; 100 | — |
| PRIMARY Verbal Memory at Day 1 |
7.7; 6.9 | — |
| PRIMARY Verbal Memory at Day 2 |
5.7; 5.5 | — |
| PRIMARY Verbal Memory at Day 5 |
4.1; 3.9 | — |
| PRIMARY Associative Verbal Memory at Day 1 |
6.1; 5.7 | — |
| PRIMARY Associative Verbal Memory at Day 2 |
5.9; 4.7 | — |
| PRIMARY Associative Verbal Memory at Day 5 |
5.9; 5.0 | — |
| PRIMARY Percentage of Participants in Which it is Possible to Obtain at Least 4 Hours EEG Recording |
60; 60 | — |
| PRIMARY Percentage of Participants Who Wear the EEG Device During All Three Nights for at Least 4 Hours |
10; 10 | — |
| PRIMARY Amount of Sleep Spindles in Sleep-EEG |
57.6; 35.8 | — |
| PRIMARY Amount of Slow Wave Sleep in Sleep-EEG |
25.2; 23.2 | — |
| SECONDARY Performance in Phonematic Fluency-Correct Words |
46.0; 45.5; 46.9; 47.8 | — |
| SECONDARY Performance in Phonematic Fluency-Perseverations |
1.5; 1.1; 1.3; 1.1 | — |
| SECONDARY Performance in Phonematic Fluency-Rule Breaks |
0.9; 0.7; 2.0; 1.0 | — |
| SECONDARY Executive Functioning (Time to Complete Stroop Test) |
54.5; 58.6; 48.5; 53.2 | — |
| SECONDARY Executive Functioning (Trail Making Test) |
1.7; 1.9; 2.3; 1.9 | — |
| SECONDARY Attentional Performance (TAP) |
31.4; 32.3; 42.8; 56.1; 26.2; 13.8 | — |
Summary
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.
Eligibility Criteria
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 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
Data sourced from ClinicalTrials.gov (NCT05907707). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.