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Mild Cognitive ImpairmentNCT05710549

Understanding Brain Mechanisms Involved in Autobiographical Memory

A study testing high-density electroencephalography (hdEEG) and Transcranial alternating current stimulation (tACS) in people with Mild Cognitive Impairment and Alzheimer Disease, run by Lucie Bréchet at 1 site in Switzerland.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The overall objective of this project is to characterize the spatiotemporal dynamics of brain oscillations underpinning autobiographical memory (ABM) and the modulation of the memory network using non-invasive brain stimulation. Read more about this study

Who is it for?
Ages 18 to 85 yearsHealthy volunteers can take part
What is being tested?
high-density electroencephalography (hdEEG) and Transcranial alternating current stimulation (tACS)
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
120 participants
Where
1 siteSwitzerland
Study dates
25 Apr 2022to 1 Aug 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 85 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Cognitively-Unimpaired Younger and Older Adults
  • Age 18 to 35 years old (younger adults)
  • Age 55+ years old (older adults)
  • without any cognitive impairment (based on the Montreal Cognitive Assessment: MoCA)
  • willing and capable to give informed consent for participation in the study after it has been thoroughly explained able
  • willing to comply with all study requirements informed consent form was signed
Show all 17Show fewer
  • Mild Cognitive Impairment (MCI) patients
  • Age 55+ years old
  • Clinical Diagnosis of MCI
  • Confirmation of diagnosis will be made by the study MD based on a holistic consideration of the participant's cognitive evaluation and history
  • Mini-Mental State Examination (MMSE) ≥ 18 (Mild AD ≥ 21)
  • CDR ≥ .5
  • Demonstration or history of autobiographical memory impairments
  • On a stable dose of medications for memory loss including cholinesterase inhibitors (e.g. donepezil, rivastigmine) or memantine as defined as 6 consecutive weeks of treatment at an unchanging dose
  • Minimum of completed 8th-grade education
  • willing and capable to give informed consent for participation in the study after it has been thoroughly explained - note that to ensure this in the case of the MCI participants, a cut-off of MOCA score >18 will be applied
  • able and willing to comply with all study requirements informed consent form was signed

Who cannot join

  • Cognitively-Unimpaired Younger and Older Adults
  • any cognitive impairment captured by the Montreal Cognitive Assessment (MoCA) - score < 26
  • major psychiatric co-morbidity including major depressive disorder, schizophrenia, or psychosis
  • blindness or other disabilities that prevent task performance
  • Contraindication for undergoing MRI
  • Any metal in the brain or skull (excluding dental fillings) or elsewhere in the body unless cleared by the responsible covering MD (e.g. MRI compatible joint replacement)
Show all 19Show fewer
  • Mild Cognitive Impairment (MCI) patients
  • Age < 55 years old
  • Any current diagnosis of a major psychiatric disorder (e.g., schizophrenia, bipolar disorder, major depressive disorder)
  • Other than MCI, any history of other progressive or genetic neurologic disorder (e.g. Parkinson's disease, multiple sclerosis, tubular sclerosis) or acquired neurological disease (e.g. stroke, traumatic brain injury, tumor), including intracranial lesions
  • History of head trauma resulting in prolonged loss of consciousness
  • Current history of poorly controlled headaches including chronic medication for migraine prevention
  • History of fainting spells of unknown or undetermined etiology that might constitute seizures
  • History of seizures, diagnosis of epilepsy, or immediate (1st-degree relative) family history of epilepsy with the exception of a single seizure of benign etiology (e.g. febrile seizures) in the judgment of a board-certified neurologist
  • Any unstable medical condition or chronic (particularly) uncontrolled medical conditions that may cause a medical emergency in case of a provoked seizure (cardiac malformation, cardiac dysrhythmia, asthma, etc.) or study complication
  • contraindications to tACS, as recorded on a standardized screening questionnaire, which include a reported seizure within the past two years, use of neuroactive drugs, self-reported presence of specific implanted medical devices (e.g., deep brain stimulator, medication infusion pump, cochlear implant, pacemaker, etc.), or the presence of any active dermatological condition, such as eczema, on the scalp
  • Contraindication for undergoing MRI or receiving tACS
  • Any metal in the brain or skull (excluding dental fillings) or elsewhere in the body unless cleared by the responsible covering MD (e.g. MRI compatible joint replacement)
  • Any devices such as a pacemaker, medication pump, nerve stimulator, TENS unit, ventriculoperitoneal shunt unless cleared by the responsible covering MD

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Lucie Bréchet, PhD contact

+41 22 379 08 52

lucie.brechet@unige.ch

Switzerland1 site, 1 recruiting

  • University of Geneva, Campus Biotech

    Geneva, Canton of Geneva, 1202

    Lucie Bréchet, PhD

    Lucie Bréchet, PhD

    Recruiting

Other trials in Switzerland

About this study

Official title: Understanding Brain Mechanisms Involved in Autobiographical Memory Using High-density Electroencephalography and Transcranial Alternating Current Stimulation

The overall objective of this project is to characterize the spatiotemporal dynamics of brain oscillations underpinning autobiographical memory (ABM) and the modulation of the memory network using non-invasive brain stimulation.

Read the detailed description

Accumulating evidence suggests that activity in distributed networks supporting ABM is altered even decades before the expected onset of clinical symptoms in Alzheimer's disease (AD). Robust network alterations associated with age-related memory and cognitive decline have been linked to abnormal oscillatory brain rhythmic activity and functional dysconnectivity. However, the detailed neural mechanisms are still poorly understood. The investigators propose to precisely characterize the underlying neurophysiological mechanisms that lead to behavioral and cognitive disturbances in ABM of MCI patients. Specifically, hdEEG will be used to characterize the sources and spatiotemporal dynamics of the neuronal activity involved in the ABM network of 40 mild cognitive impairment (MCI) patients and compare it to 40 age-matched, older healthy participants and 40 healthy young participants. The investigators will then apply non-invasive brain stimulation in the form of transcranial alternating current stimulation (tACS) to gain novel insights into the causal role of brain oscillations in the ABM network of MCI patients.

Being tested
high-density electroencephalography (hdEEG), Transcranial alternating current stimulation (tACS)
Keywords
autobiographical memory (ABM), high-density electroencephalography (EEG), magnetic resonance imaging (MRI), non-invasive brain stimulation (NIBS), transcranial alternating current stimulation (tACS)
Medical subject headings
Cognitive Dysfunction, Alzheimer Disease, Memory Disorders

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • high-density electroencephalography (hdEEG)Device

    EEG will be recorded with a 257-channel EEG system (Geodesic Sensor Net, MegStim). An EEG net is applied at once on the head with evenly spaced sensors that provide full scalp coverage, including the cheek, Ag/Ag-Cl electrodes that are interconnected by thin rubber bands and contain small sponges soaked with saline water that touches the participant's scalp surface directly. Net application takes about 10 min to derive impedances to <30 kOhms. EEG is recorded with 1 kHz and band-pass filtered between 0.1-200 Hz. Vertex electrode Cz is used as an acquisition reference.

  • Transcranial alternating current stimulation (tACS)Device

    tACS will be delivered by a battery-driven current stimulator Starstim SS32 (Neuroelectrics) through surface Ag/AgCl electrodes placed into holes of a neoprene cap corresponding to the international 10/20 EEG system. Gel (Parker Lab, Inc.) will be applied to optimize signal conductivity and lower impedance.

Study groups in NCT05710549
Study groupRoleWhat they receive
neurophysiological measurementsExperimental40 cognitively-unimpaired healthy young adults (age 18-35 years old), 40 cognitively-unimpaired healthy older adults (age 55+ years old), and 40 age-matched patients with mild cognitive impairment (MCI) (age 55+ years old) will be assessed using high-density electroencephalography (hdEEG) to characterize the spatiotemporal dynamics of brain oscillations during personalized, autobiographical memory (ABM) tasks.
Receives: Device: high-density electroencephalography (hdEEG)
neuropsychological examinationExperimental40 MCI patients (age 55+ years old) will undergo 20min multi-channel protocols of transcranial alternating current stimulation; tACS (either gamma, beta, or ActiSham stimulation randomized across the three laboratory sessions) to modify cognitive functioning (MoCA score), and oscillatory brain activity during performing personalized, autobiographical memory (ABM) tasks and resting-state EEG.
Receives: Device: Transcranial alternating current stimulation (tACS)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Spatiotemporal dynamic changes measured with electroencephalography (hdEEG)

    Changes in spatiotemporal dynamics in different frequency bands (theta, alpha, beta, gamma) will be assessed with hdEEG

    Measured: up to 30 minutes

  2. Cognitive Assessment

    The Montreal Cognitive Assessment (MOCA) will be administered to characterize the cognitive status

    Measured: baseline

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Feb 2023
  2. Study start25 Apr 2022
  3. Primary completion1 May 2027 (estimated)
  4. Study completion1 Aug 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Participant
Enrolment
120 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05710549
Sponsor's protocol ID
2021-01388
Status last verified
Jul 2025
First submitted
12 Jan 2023
Last updated
15 Jul 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Brechet L, Brunet D, Birot G, Gruetter R, Michel CM, Jorge J. Capturing the spatiotemporal dynamics of self-generated, task-initiated thoughts with EEG and fMRI. Neuroimage. 2019 Jul 1;194:82-92. doi: 10.1016/j.neuroimage.2019.03.029. Epub 2019 Mar 19.

    PubMed 30902640

  • Roehri N, Brechet L, Seeber M, Pascual-Leone A, Michel CM. Phase-Amplitude Coupling and Phase Synchronization Between Medial Temporal, Frontal and Posterior Brain Regions Support Episodic Autobiographical Memory Recall. Brain Topogr. 2022 Mar;35(2):191-206. doi: 10.1007/s10548-022-00890-4. Epub 2022 Jan 26.

    PubMed 35080692

  • Michel CM, He B. EEG source localization. Handb Clin Neurol. 2019;160:85-101. doi: 10.1016/B978-0-444-64032-1.00006-0.

    PubMed 31277878

Questions about this trial

What is this clinical trial studying?

A study testing high-density electroencephalography (hdEEG) and Transcranial alternating current stimulation (tACS) in people with Mild Cognitive Impairment and Alzheimer Disease, run by Lucie Bréchet at 1 site in Switzerland.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 17 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 15 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Lucie Bréchet, PhD (+41 22 379 08 52, lucie.brechet@unige.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Spatiotemporal dynamic changes measured with electroencephalography (hdEEG) (time frame: up to 30 minutes). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05710549, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Jul 2025.

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