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Feasibility of Gamma Transcranial Alternating Current Stimulation to Reduce Beta-amyloid Load and Improve Memory

Not Applicable
Completed
Conditions
Mild Cognitive Impairment
Interventions
Device: Transcranial alternating current stimulation
Registration Number
NCT04646499
Lead Sponsor
University of California, San Francisco
Brief Summary

This project assessed the feasibility of transcranial alternating current stimulation in the gamma band to lower beta-amyloid load and improve memory performance.

Detailed Description

Thirteen individuals with aMCI received eight 60-minute sessions of 40-Hz (gamma) transcranial alternating current stimulation (tACS) in a single-arm design. Outcome measures were assessed pre- and post-intervention.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
14
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
  • Self-reported memory complaint
  • Diagnosed with mild cognitive impairment
  • Amyloid positive
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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)
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Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Gamma Stimulation GroupTranscranial alternating current stimulationThis group will receive gamma stimulation
Primary Outcome Measures
NameTimeMethod
Drop Outpost-tACS, up to 1 month

Drop out rate will be assessed as the number of participants who withdraw or are withdrawn from the study.

Side EffectsAverage of all post-tACS sessions, up to 1 month

Side effects were measured on a scale from 0 (not noticable) to 10 (not tolerable): headache, neck pain, scalp pain, tingling, itching, burning sensation, increased sleepiness, trouble concentrating, acute mood change, and phosphenes. Average rating across all measures reported as indicator of side effects.

Secondary Outcome Measures
NameTimeMethod
Change in Taupre-tACS (baseline), post-tACS (after one month of treatment)

Plasma tau levels was assessed pre and post intervention. Change was calculated as post minus pre. Greater decrease is better.

Beta Amyloid Load Changepre-tACS (baseline) and post-tACS (1 month)

Change in plasma-based beta amyloid (AB) load was assessed as the AB42/40 ratio, calculated as post minus pre AB42/40 ratio. Greater increase is better.

Memory: Recall Changepre-tACS (baseline), post-tACS (after one month of treatment)

Episodic memory was assessed pre and post intervention as the number of words correct during the short delay free recall portion of the California Verbal Learning Test. Change was assessed as post minus pre. Greater increase is better.

Memory: Fluency Changepre-tACS (baseline), post-tACS (after one month of treatment)

Episodic memory fluency was assessed pre and post intervention from performance on the FAS task. Unit of measurement is the number of words names starting with the letter f, a, or s. Change was calculated as post minus pre. Greater increase is better.

Memory: Paired Associates Changepre-tACS (baseline), post-tACS (after one month of treatment)

Episodic memory was assessed pre and post intervention from memory accuracy for a paired associates task for visual objects. Change was assessed post minus pre. Greater increase is better.

Trial Locations

Locations (1)

University of California, San Francisco

🇺🇸

San Francisco, California, United States

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