EpilepsyTIEFSNCT07663578
Cognitive and Electrophysiological Assessment of Non-Invasive Temporally-Interfering Electric Fields Stimulation (TIEFS)
A study testing Temporal Interference Electrical Stimulation in people with Epilepsy, run by University of California, Davis at 1 site in United States.
Trial summary
The goal of this clinical trial is to learn how a non-invasive brain stimulation method called Temporally Interfering Electric Fields Stimulation (TIEFS) affects brain activity and thinking in adults. TIEFS uses electrical currents applied to the scalp to influence brain activity without surgery. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Epilepsy
- What is being tested?
- Temporal Interference Electrical Stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteUnited States
- Study dates
- 16 Apr 2025to 15 Apr 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 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adult patients (age 18-65 years of age) undergoing an intracerebral electrophysiology study for epilepsy pre-surgical evaluation are eligible for inclusion.
- For healthy control subjects are also eligible for inclusion (Scalp EEG measurements).
- Participants must be able to sufficiently speak and understand English or Spanish for consent and be able to understand and complete cognitive tasks.
- All subjects must have the ability to give valid informed consent.
Who cannot join
- No pregnant women will be recruited.
- People with implanted electrical devices such as Deep Brain Stimulation devices or Pacemakers.
- No prisoners will be recruited.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of California Davis Medical Center
Sacramento, California, 95817
Nigel P Pedersen, MBBS, 617-462-8120, nppedersen@health.ucdavis.edu
Nigel P Pedersen, MBBS
About this study
The goal of this clinical trial is to learn how a non-invasive brain stimulation method called Temporally Interfering Electric Fields Stimulation (TIEFS) affects brain activity and thinking in adults. TIEFS uses electrical currents applied to the scalp to influence brain activity without surgery.
The main questions this study aims to answer are:
Read more
- How does TIEFS change brain signals measured with brain recordings?
- Does TIEFS affect thinking abilities such as memory, language, movement, or perception?
- Is TIEFS safe and well tolerated when used in people?
This study includes two groups of participants. One group includes adults with epilepsy who are already undergoing specialized brain monitoring as part of their medical care. The other group includes healthy adults with no history of seizures.
Participants will:
- Receive brief sessions of TIEFS using electrodes placed on the scalp
- Complete computer-based tasks that test memory, attention, language, or movement. Answer questions about how the stimulation feels
- Have brain activity recorded during the study
Each study visit lasts up to three hours and may occur in one or two sessions. Information from this study may help researchers better understand the human brain and support the development of future non-invasive brain stimulation treatments.
- Conditions
- Epilepsy
- Being tested
- Temporal Interference Electrical Stimulation
- Keywords
- Brain Stimulation
- Medical subject headings
- Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Temporal Interference Electrical StimulationDevice
Temporal Interference Electrical Stimulation (TIEFS) is a non-invasive brain stimulation technique that uses two high-frequency electrical fields (>1 kHz) to generate an interference pattern at a specific brain region, creating a low-frequency envelope (Δf = f2 - f1) at the target depth. Unlike traditional stimulation methods, which affect only superficial brain regions, TIEFS can reach deeper structures without the need for implanted electrodes. The stimulation is applied through scalp electrodes. It has the potential for targeted brain interventions in both functional studies and clinical applications for neurological conditions.
| Study group | Role | What they receive |
|---|---|---|
| Comparison of Active vs Sham TIEFS Stimulation in SEEG patients | Experimental | This arm involves a within-subject comparison of different frequencies of active TIEFS stimulation and sham stimulation, all within the same session. Patients will already have been admitted to SEEG surgery, and will be approached while still having the electrodes implanted. Each participant will receive multiple types of stimulation at different envelope frequencies (ranging from 1-130 Hz). During the session, electrodes will be placed on the scalp to administer TIEFS at varying frequencies. Each frequency will be tested in separate trials within the session, with multiple trials per frequency. The results from these trials will be averaged to determine the overall impact of each frequency on brain activity (measured through SEEG) and/or cognitive functions (evaluated using tasks related to memory, language, motor function, and perception). Sham stimulation will also be delivered within the same session, and participants will be blinded to the type of stimulation (active vs sham). Receives: Device: Temporal Interference Electrical Stimulation |
| Comparison of Active vs Sham TIEFS Stimulation in Healthy Subjects | Experimental | This arm involves a within-subject comparison of active and sham TIEFS stimulation in healthy control subjects. Participants will receive both active and sham stimulation in a single session, with different frequencies of TIEFS applied during active stimulation. The goal is to measure the changes in brain activity using EEG and assess the impact of TIEFS on cognitive functions such as memory, motor function, language, and perception. Participants will be blinded to the type of stimulation they are receiving during the session. Receives: Device: Temporal Interference Electrical Stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Brain activity changes during Stimulation
This outcome measures the changes in brain activity, either measured through scalp EEG electrodes (in Healthy Participant controls), or intracranial stereotaxic EEG electrodes (for SEEG pre-surgical evaluation epilepsy patients). Local field potential (LFP) power and EEG power in response to active TIEFS stimulation will be compared to sham stimulation. Electrical signals recorded from the brain reflect neural activity. Intracranial signals will be measured across different locations in the brain using implanted SEEG electrodes. Additionally, SEEG electrodes may have tetrodes tips to capture single neuron activity. We will compare how the brain's electrical activity changes during active TIEFS at various frequencies and during the sham stimulation to assess the impact on brain and neural function.
Measured: Measurements will be recorded throughout the stimulation session (lasting up to 90 minutes), with data collected before, during, and immediately after each stimulation.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jun 2026
- Study start16 Apr 2025
- Primary completion15 Apr 2027 (estimated)
- Study completion15 Apr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for EpilepsyStudies of the same condition, open and under way.
- More trials run by University of California, DavisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Non-randomised
- Intervention model
- Sequential
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Davis
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Nigel P Pedersen, MBBS, Principal investigator, University of California Davis, School of Medicine, Neurology Department
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07663578
- Sponsor's protocol ID
- 2226959
- Acronym
- TIEFS
- Status last verified
- Jun 2026
- First submitted
- 16 Jun 2026
- Last updated
- 23 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: Upon publication, anonymized individual participant data (IPD) will be shared as part of the supplementary materials. The shared data will include EEG recordings, cognitive task results (memory, language, motor, perception), and stimulation parameters (active vs sham, frequencies). All IPD will be de-identified, with personal identifiers removed to ensure confidentiality and compliance with HIPAA. The de-identified data will be made available through a repository or data-sharing platform, accessible to qualified researchers for scientific and educational use only.
Study at a glance
From the registry record, last updated by the sponsor on 23 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cognitive and Electrophysiological Assessment of Non-Invasive Temporally-Interfering Electric Fields Stimulation (TIEFS)
- ClinicalTrials.gov ID
- NCT07663578
- Acronym / sponsor ID
- TIEFS / 2226959
- Conditions
- Epilepsy
- Keywords
- Brain Stimulation
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- University of California, DavisUniversity, hospital or other
- Study start
- 16 Apr 2025 (actual)
- Primary completion
- 15 Apr 2027 (estimated)
- Study completion
- 15 Apr 2027 (estimated)
- First posted
- 23 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to learn how a non-invasive brain stimulation method called Temporally Interfering Electric Fields Stimulation (TIEFS) affects brain activity and thinking in adults. TIEFS uses electrical currents applied to the scalp to influence brain activity without surgery.
The main questions this study aims to answer are:
- How does TIEFS change brain signals measured with brain recordings?
- Does TIEFS affect thinking abilities such as memory, language, movement, or perception?
- Is TIEFS safe and well tolerated when used in people?
This study includes two groups of participants. One group includes adults with epilepsy who are already undergoing specialized brain monitoring as part of their medical care. The other group includes healthy adults with no history of seizures.
Participants will:
- Receive brief sessions of TIEFS using electrodes placed on the scalp
- Complete computer-based tasks that test memory, attention, language, or movement. Answer questions about how the stimulation feels
- Have brain activity recorded during the study
Each study visit lasts up to three hours and may occur in one or two sessions. Information from this study may help researchers better understand the human brain and support the development of future non-invasive brain stimulation treatments.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Comparison of Active vs Sham TIEFS Stimulation in SEEG patients | Experimental | Device: Temporal Interference Electrical StimulationThis arm involves a within-subject comparison of different frequencies of active TIEFS stimulation and sham stimulation, all within the same session. Patients will already have been admitted to SEEG surgery, and will be approached while still having the electrodes implanted. Each participant will receive multiple types of stimulation at different envelope frequencies (ranging from 1-130 Hz). During the session, electrodes will be placed on the scalp to administer TIEFS at varying frequencies. Each frequency will be tested in separate trials within the session, with multiple trials per frequency. The results from these trials will be averaged to determine the overall impact of each frequency on brain activity (measured through SEEG) and/or cognitive functions (evaluated using tasks related to memory, language, motor function, and perception). Sham stimulation will also be delivered within the same session, and participants will be blinded to the type of stimulation (active vs sham). |
| Comparison of Active vs Sham TIEFS Stimulation in Healthy Subjects | Experimental | Device: Temporal Interference Electrical StimulationThis arm involves a within-subject comparison of active and sham TIEFS stimulation in healthy control subjects. Participants will receive both active and sham stimulation in a single session, with different frequencies of TIEFS applied during active stimulation. The goal is to measure the changes in brain activity using EEG and assess the impact of TIEFS on cognitive functions such as memory, motor function, language, and perception. Participants will be blinded to the type of stimulation they are receiving during the session. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adult patients (age 18-65 years of age) undergoing an intracerebral electrophysiology study for epilepsy pre-surgical evaluation are eligible for inclusion.
- For healthy control subjects are also eligible for inclusion (Scalp EEG measurements).
- Participants must be able to sufficiently speak and understand English or Spanish for consent and be able to understand and complete cognitive tasks.
- All subjects must have the ability to give valid informed consent.
Key exclusion criteria (3 listed)
- No pregnant women will be recruited.
- People with implanted electrical devices such as Deep Brain Stimulation devices or Pacemakers.
- No prisoners will be recruited.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Temporal Interference Electrical StimulationTemporal Interference Electrical Stimulation (TIEFS) is a non-invasive brain stimulation technique that uses two high-frequency electrical fields (>1 kHz) to generate an interference pattern at a specific brain region, creating a low-frequency envelope (Δf = f2 - f1) at the target depth. Unlike traditional stimulation methods, which affect only superficial brain regions, TIEFS can reach deeper structures without the need for implanted electrodes. The stimulation is applied through scalp electrodes. It has the potential for targeted brain interventions in both functional studies and clinical applications for neurological conditions. | Device | Comparison of Active vs Sham TIEFS Stimulation in Healthy Subjects, Comparison of Active vs Sham TIEFS Stimulation in SEEG patients |
Primary outcome
Brain activity changes during Stimulation
Time frame: Measurements will be recorded throughout the stimulation session (lasting up to 90 minutes), with data collected before, during, and immediately after each stimulation.
This outcome measures the changes in brain activity, either measured through scalp EEG electrodes (in Healthy Participant controls), or intracranial stereotaxic EEG electrodes (for SEEG pre-surgical evaluation epilepsy patients). Local field potential (LFP) power and EEG power in response to active TIEFS stimulation will be compared to sham stimulation. Electrical signals recorded from the brain reflect neural activity. Intracranial signals will be measured across different locations in the brain using implanted SEEG electrodes. Additionally, SEEG electrodes may have tetrodes tips to capture single neuron activity. We will compare how the brain's electrical activity changes during active TIEFS at various frequencies and during the sham stimulation to assess the impact on brain and neural function.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jun 2026.
- Individual participant dataSharing planned: Yes. Upon publication, anonymized individual participant data (IPD) will be shared as part of the supplementary materials. The shared data will include EEG recordings, cognitive task results (memory, language, motor, perception), and stimulation parameters (active vs sham, frequencies). All IPD will be de-identified, with personal identifiers removed to ensure confidentiality and compliance with HIPAA. The de-identified data will be made available through a repository or data-sharing platform, accessible to qualified researchers for scientific and educational use only.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Nigel P Pedersen, MBBS principal investigator
University of California Davis, School of Medicine, Neurology Department
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Temporal Interference Electrical Stimulation in people with Epilepsy, run by University of California, Davis at 1 site in United States.
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 4 inclusion and 3 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 23 Jun 2026. 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 United States. 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 Nigel P Pedersen, MBBS (617-462-8120, nppedersen@health.ucdavis.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Brain activity changes during Stimulation (time frame: Measurements will be recorded throughout the stimulation session (lasting up to 90 minutes), with data collected before, during, and immediately after each stimulation.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 23 Jun 2026.