tACS Improves Memory in Elders With Subjective Memory Complaints

Remember NIBS? tACS Improves Memory Performance in Elders With Subjective Memory Complaints

Subjective memory complaints (SMC), the main cognitive component of which is event memory, is a predictor of Alzheimer's disease in elderly people. The purpose of this study was to investigate the effect of transcranial alternating current stimulation (tACS) with theta frequency (6 Hz) on the medial prefrontal cortex in the improvement of episodic memory in individuals with SMC in a double blind, randomized, and sham-controlled parallel study. Sixteen participants with SMC received either active or sham theta tACS on the medial prefrontal cortex (mPFC). EEG was recorded and Rey Auditory Verbal Learning Test (RAVLT) was administered. The aim of the current study was to see if theta tACS over the mPFC can improve event memory in individuals with SMC and thus can be considered a potential therapeutic intervention for this population or not.

Study Overview

• Status: Completed
• Conditions: tACS; Memory Deficits
• Intervention / Treatment: Device: active tACS; Device: sham tACS

• Study Type: Interventional
• Enrollment (Actual): 16
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Iran, Islamic Republic of
  • Tehran, Iran, Islamic Republic of, 1439957131
    • National Brain Mapping Lab

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 46 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Being 50 or older,
• Mini Mental State Examination (MMSE) grade from 27 to 30
• Total score of 58 or more on the Everyday Memory Questionnaire (EMQ)
• no indications of depression and anxiety measured by Geriatric Depression Scale (GDS) and State-Trait Anxiety Inventory (STAI)
• No sign of dementia based on Diagnostic and statistical manual of mental disorder, 5th edition (DSM-V) criteria

Exclusion Criteria:

• History of a major psychological or neurological condition
• History of head trauma leading to unconsciousness,
• Presence of metal in the head
• History of seizures
• Serious cardiovascular disease
• Use of medications with an impact on cognitive functions
• Recent use of alcohol or substance abuse

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active tACS; Participants in this group received 20 minutes of active 6 Hz stimulation over the medial prefrontal cortex.	Device: active tACS; transcranial alternating current stimulation is a non-invasive method of entraining specific frequency bands in the brain by applying weak intensities of electric current in a desired shape and phase to the desired brain regions.
Sham Comparator: Sham tACS; Participants in this group received 20 minutes of sham stimulation over the medial prefrontal cortex.	Device: sham tACS; transcranial alternating current stimulation is a non-invasive method of entraining specific frequency bands in the brain by applying weak intensities of electric current in a desired shape and phase to the desired brain regions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in performance	Rey auditory-verbal learning test (RAVLT)	25 minutes i.e., before versus after the stimulation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in EEG power in theta frequency band	Spectral analysis measuring power in different frequency bands	30 minutes, i.e., before versus after stimulation
Change in phase synchronization connectivity in theta frequency band	Phase relations between neural signals realized by means of phase-locking values (PLV)	30 minutes, i.e., before versus after stimulation

Collaborators and Investigators

• Sponsor: University of Tehran
• Investigators: Study Director: Reza Rostami, M.D., University of Tehran; Principal Investigator: Sahereh Varastegan, MSc, University of Tehran

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2021
• Primary Completion (Actual): June 1, 2022
• Study Completion (Actual): August 1, 2022

Study Registration Dates

• First Submitted: September 24, 2022
• First Submitted That Met QC Criteria: October 3, 2022
• First Posted (Actual): October 6, 2022

Study Record Updates

• Last Update Posted (Actual): October 10, 2022
• Last Update Submitted That Met QC Criteria: October 5, 2022
• Last Verified: October 1, 2022

More Information

Terms related to this study

• Keywords: tACS; SMC; Episodic memory; medial Prefrontal Cortex
• Additional Relevant MeSH Terms: Nervous System Diseases; Neurologic Manifestations; Neurobehavioral Manifestations; Memory Disorders
• Other Study ID Numbers: tACS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No