Mild Cognitive Impairment
Conditions
Brief summary
The overall goal of this project is to improve cognitive control abilities in adults with mild cognitive impairment (MCI) through a form of non-invasive brain stimulation, transcranial alternating current stimulation (tACS).
Detailed description
30 older adults aged 60-80 years with md-aMCI were randomized to 8 sessions of transcranial alternating current stimulation (tACS) with simultaneous cognitive control training (CCT). The intervention took place within the participant's home without direct researcher assistance. Half of the participants received prefrontal theta tACS during CCT and the other half received control tACS. Outcomes were assessed pre and post intervention.
Interventions
DEVICETranscranial alternating current stimulation
Transcranial alternating current stimulation (tACS) will be applied across the prefrontal cortex near electrodes coordinates AF3/AF4
Sponsors
National Institute on Aging (NIA)
University of California, San Francisco
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
60 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
* English speaking * Grade 12 or more education * Normal or corrected to normal vision and hearing * Ability to complete cognitive tasks * Ability to cooperate and comply with all study procedures * Ability to tolerate tACS * Montreal Cognitive Assessment score: 17-28 * -1 z-score on immediate memory, delayed memory, fluency, processing speed, or task switch * Self-reported memory complaint
Exclusion criteria
* Neurological or psychiatric disorders other than mild cognitive impairment * Receiving investigational medications or have participated in a trial with investigational medications within last 30 days * Family history of epilepsy * Implanted electronic devices (e.g., pacemaker) * Prior head trauma * Pregnant * IQ \< 80 * Taking cholinesterase inhibitory, memantine, or psychotropic medication * Taking anti-depressants or anti-anxiety medication * Color blind * Substance abuse * Glaucoma * Macular degeneration * Amblyopia (lazy eye) * Strabismus (crossed eyes)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Divided Attention Performance | Post-tACS (1-day follow-up), approximately 1 week after baseline | Divided attention was assessed as the difficulty level achieved during perceptual discrimination performance while participants were engaged in the Akili AKL-T01 task. Higher is better. |
| Sustained Attention Performance | Post-tACS (1-day follow-up), approximately 1 week after baseline | Sustained attention was assessed via response times to visual targets during the continuous performance task. Lower is better. |
| Working Memory Performance | Post-tACS (1-day follow-up), approximately 1 week after baseline | Working memory was assessed as the average maximum number correct from the ACE-X span tasks - memory for order of illuminated squares. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Instrumental Activities of Daily Living (IADL) | Post-tACS (1-day follow-up), approximately 1 week after baseline | Scores on the IADL will be assessed pre and post intervention. Higher scores are better (minimum = 0, maximum = 4). |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Theta Stimulation Group This group will receive 6 Hz (theta) stimulation
Transcranial alternating current stimulation: Transcranial alternating current stimulation (tACS) will be applied across the prefrontal cortex near electrodes coordinates AF3/AF4 | 15 |
| Delta Stimulation Group This group will receive 1 Hz (delta) stimulation
Transcranial alternating current stimulation: Transcranial alternating current stimulation (tACS) will be applied across the prefrontal cortex near electrodes coordinates AF3/AF4 | 15 |
| Total | 30 |
Baseline characteristics
| Characteristic | Theta Stimulation Group | Delta Stimulation Group | Total |
|---|---|---|---|
| Age, Continuous | 70 years STANDARD_DEVIATION 6 | 70 years STANDARD_DEVIATION 4 | 70 years STANDARD_DEVIATION 5 |
| Divided Attention | 8.01 difficulty level achieved STANDARD_DEVIATION 1.56 | 8.51 difficulty level achieved STANDARD_DEVIATION 1.65 | 8.27 difficulty level achieved STANDARD_DEVIATION 1.61 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants | 0 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 14 Participants | 15 Participants | 29 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Instrumental Activities of Daily Living | 3.92 score on a scale STANDARD_DEVIATION 0.29 | 4 score on a scale STANDARD_DEVIATION 0 | 3.96 score on a scale STANDARD_DEVIATION 0.14 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 2 Participants | 1 Participants | 3 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants | 1 Participants | 2 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 12 Participants | 13 Participants | 25 Participants |
| Region of Enrollment United States | 15 Participants | 15 Participants | 30 Participants |
| Sex: Female, Male Female | 10 Participants | 5 Participants | 15 Participants |
| Sex: Female, Male Male | 5 Participants | 10 Participants | 15 Participants |
| Sustained Attention | 527 milliseconds STANDARD_DEVIATION 108 | 432 milliseconds STANDARD_DEVIATION 56 | 481 milliseconds STANDARD_DEVIATION 82 |
| Working Memory | 6.13 number correct STANDARD_DEVIATION 0.96 | 6.56 number correct STANDARD_DEVIATION 0.81 | 6.34 number correct STANDARD_DEVIATION 0.89 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 15 | 0 / 15 |
| other Total, other adverse events | 0 / 15 | 0 / 15 |
| serious Total, serious adverse events | 0 / 15 | 0 / 15 |
Outcome results
Primary
Divided Attention Performance
Divided attention was assessed as the difficulty level achieved during perceptual discrimination performance while participants were engaged in the Akili AKL-T01 task. Higher is better.
Time frame: Post-tACS (1-day follow-up), approximately 1 week after baseline
Population: Only data from participants who completed the full protocol were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Theta Stimulation Group | Divided Attention Performance | 9.29 difficulty level acheived | Standard Deviation 2.83 |
| Delta Stimulation Group | Divided Attention Performance | 9.31 difficulty level acheived | Standard Deviation 2.4 |
Primary
Divided Attention Performance
Divided attention was assessed as the difficulty level achieved during perceptual discrimination performance while participants were engaged in the Akili AKL-T01 task. Higher is better.
Time frame: Post-tACS (1-month follow-up), approximately 1 month after baseline
Population: Only data from participants who completed the full protocol were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Theta Stimulation Group | Divided Attention Performance | 10.10 difficulty level acheived | Standard Deviation 1.4 |
| Delta Stimulation Group | Divided Attention Performance | 10.67 difficulty level acheived | Standard Deviation 1.18 |
Primary
Sustained Attention Performance
Sustained attention was assessed via response times to visual targets during the continuous performance task. Lower is better.
Time frame: Post-tACS (1-day follow-up), approximately 1 week after baseline
Population: Only data from participants who completed the full protocol were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Theta Stimulation Group | Sustained Attention Performance | 436 milliseconds | Standard Deviation 73 |
| Delta Stimulation Group | Sustained Attention Performance | 416 milliseconds | Standard Deviation 60 |
Primary
Sustained Attention Performance
Sustained attention was assessed via response times to visual targets during the continuous performance task. Lower is better.
Time frame: Post-tACS (1-month follow-up), approximately 1 month after baseline
Population: Only data from participants who completed the full protocol were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Theta Stimulation Group | Sustained Attention Performance | 428 milliseconds | Standard Deviation 64 |
| Delta Stimulation Group | Sustained Attention Performance | 395 milliseconds | Standard Deviation 49 |
Primary
Working Memory Performance
Working memory was assessed as the average maximum number correct from the ACE-X span tasks - memory for order of illuminated squares.
Time frame: Post-tACS (1-day follow-up), approximately 1 week after baseline
Population: Only data from participants who completed the full protocol were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Theta Stimulation Group | Working Memory Performance | 6.09 number correct | Standard Deviation 1.29 |
| Delta Stimulation Group | Working Memory Performance | 6.89 number correct | Standard Deviation 0.78 |
Primary
Working Memory Performance
Working memory was assessed as the average maximum number correct from the ACE-X span tasks - memory for order of illuminated squares
Time frame: Post-tACS (1-month follow-up), approximately 1 month after baseline
Population: Only data from participants who completed the full protocol were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Theta Stimulation Group | Working Memory Performance | 6.13 number correct | Standard Deviation 1.15 |
| Delta Stimulation Group | Working Memory Performance | 6.50 number correct | Standard Deviation 0.75 |
Secondary
Instrumental Activities of Daily Living (IADL)
Scores on the IADL will be assessed pre and post intervention. Higher scores are better (minimum = 0, maximum = 4).
Time frame: Post-tACS (1-day follow-up), approximately 1 week after baseline
Population: Only data from participants who completed the full protocol were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Theta Stimulation Group | Instrumental Activities of Daily Living (IADL) | 3.92 score on a scale | Standard Deviation 0.29 |
| Delta Stimulation Group | Instrumental Activities of Daily Living (IADL) | 4 score on a scale | Standard Deviation 0 |
Secondary
Instrumental Activities of Daily Living (IADL)
Scores on the IADL will be assessed pre and post intervention. Higher scores are better (minimum = 0, maximum = 4).
Time frame: Post-tACS (1-month follow-up), approximately 1 month after baseline
Population: Only data from participants who completed the full protocol were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Theta Stimulation Group | Instrumental Activities of Daily Living (IADL) | 4 score on a scale | Standard Deviation 0 |
| Delta Stimulation Group | Instrumental Activities of Daily Living (IADL) | 4 score on a scale | Standard Deviation 0 |