Spinocerebellar Ataxia Type 3NCT07743866
Optimizing Parameters of Transcranial Temporal Interference Stimulation for Spinocerebellar Ataxia Type 3
A study testing Transcranial Temporal Interference Stimulation (tTIS) in people with Spinocerebellar Ataxia Type 3, run by First Affiliated Hospital of Fujian Medical University at 1 site in China.
Trial summary
The purpose of this research study is to identify the optimal biological dose for tTIS that targets DN in SCA3 while achieving the best possible balance between therapeutic efficacy and safety. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Spinocerebellar Ataxia Type 3
- What is being tested?
- Transcranial Temporal Interference Stimulation (tTIS)
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteChina
- Study dates
- 7 Aug 2026to 28 Feb 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 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- A physician-diagnosed SCA3 according to diagnostic criteria, with definite clinical symptoms and confirmed genetic testing;
- Age 18-75 years;
- Baseline total score of SARA: 8-30 points (inclusive); SARA gait function subscore: 2-6 points (inclusive);
- Willing to participate and provide informed consent;
- Have a reliable caregiver available;
- No severe cognitive impairment that would preclude reliable reporting of adverse events or efficacy during treatment.
Who cannot join
- History of seizures or convulsions, or a seizure within 6 months prior to enrolment;
- History of severe traumatic brain injury or intracranial neurosurgery;
- Presence of cardiac pacemakers, cochlear implants, intracranial implanted electronic devices, or other MRI-contraindicated ferromagnetic implants;
- Severe cognitive impairment (Mini-Mental State Examination [MMSE] score ≤ 9) or severe visual, auditory, or speech dysfunction preventing cooperation with scale assessments and study procedures;
- Pregnant or lactating women, or women of childbearing age not using reliable contraception;
- Previous neuromodulation treatment (e.g., rTMS or tDCS) within the past year;
- Skin breakdown or inflammation at the electrode placement site, or known allergy to conductive gel or electrode patch adhesives;
- Currently participating in other interventional clinical trials, or planning to participate in other trials that might affect the outcome assessment of this study during the study period.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site
Department of Rehabilitation Medicine, The First Affiliated Hospital of Fujian Medical University
Fuzhou, Fujian
Xin-Yuan Chen, +86 15005065282, fychenxinyuan@fjmu.edu.cn
About this study
Official title: Efficacy and Safety of Transcranial Temporal Interference Stimulation of the Cerebellar Dentate Nucleus Using Individualized Head Modeling in Patients With Spinocerebellar Ataxia Type 3
The purpose of this research study is to identify the optimal biological dose for tTIS that targets DN in SCA3 while achieving the best possible balance between therapeutic efficacy and safety.
Read the detailed description
Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease, is an autosomal dominant neurodegenerative disorder caused by CAG repeat expansion in the ATXN3 gene. Selective degeneration of neurons in the cerebellar dentate nucleus (DN) leads to abnormal cerebellar outflow circuitry and impaired motor control, resulting in progressive gait ataxia, dysarthria and other motor symptoms. Current treatments are symptomatic only, with no disease-modifying therapies available. Deep brain stimulation targeting the dentate nucleus has shown efficacy but is invasive and associated with significant adverse events.
Transcranial temporal interference stimulation (tTIS) enables non-invasive, deep and spatially precise neuromodulation. It has been applied in various neurological and psychiatric disorders with favorable safety and efficacy, demonstrating potential for neuromodulation of deep cerebellar circuits.
This phase I/II adaptive dose-finding prospective interventional study evaluates the safety and efficacy of tTIS targeting the cerebellar dentate nucleus in patients with spinocerebellar ataxia type 3. Using MRI-derived individualized head models and real-time neuronavigation, the study employs a utility-based Bayesian optimal interval (U-BOIN) design with three difference frequencies: 30 Hz, 40 Hz, and 70 Hz. Patients are enrolled in sequential cohorts of three, with dose escalation guided by a utility-based approach integrating safety and efficacy data. Each patient receives ten tTIS sessions over two consecutive weeks, with one session daily. Motor function, balance function, activities of daily living, and multimodal magnetic resonance imaging are evaluated before the first treatment session and after the final treatment session.
- Conditions
- Spinocerebellar Ataxia Type 3
- Being tested
- Transcranial Temporal Interference Stimulation (tTIS)
- Keywords
- Transcranial Temporal Interference stimulation, Spinocerebellar ataxia type 3, Cerebellar dentate nucleus, Stimulation difference frequency, Individualized head modeling
- Medical subject headings
- Machado-Joseph Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Transcranial Temporal Interference Stimulation (tTIS)Device
Participants assigned to this intervention arm receive transcranial temporal interference stimulation (tTIS) with a difference frequency (Δf) of 30Hz/40Hz/70 Hz.
Before treatment, individualized electric field modeling is performed based on each participant's 3D-T1 MRI data to optimize electrode placement and stimulation parameters. The stimulation target is the bilateral cerebellar dentate nuclei. A personalized finite element head model is generated, and electrode positions are determined through simulation-based optimization to achieve focused interference electric fields at the target region.
During each treatment session, tTIS is delivered using two carrier frequencies of 2000 Hz and 2030Hz/2040Hz/2070 Hz, with a current intensity of 2.0 mA (zero-to-peak). Each session lasts 20 minutes. Treatment is administered twice daily, 5 days per week, for a total of 10 sessions.
| Study group | Role | What they receive |
|---|---|---|
| 30 Hz Difference Frequency tTIS | Experimental | Transcranial Temporal Interference Stimulation (tTIS) uses a difference frequency (Δf) of 30 Hz. Receives: Device: Transcranial Temporal Interference Stimulation (tTIS) |
| 40 Hz Difference Frequency tTIS | Experimental | Transcranial Temporal Interference Stimulation (tTIS) uses a difference frequency (Δf) of 40 Hz. Receives: Device: Transcranial Temporal Interference Stimulation (tTIS) |
| 70 Hz Difference Frequency tTIS | Experimental | Transcranial Temporal Interference Stimulation (tTIS) uses a difference frequency (Δf) of 70 Hz. Receives: Device: Transcranial Temporal Interference Stimulation (tTIS) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety: Incidence of Dose-Limiting Toxicity (DLT)
DLT event is defined as any one of the following 5 categories:
- Grade Ⅱ (moderate) or higher adverse events per the NCI-CTCAE grading criteria[1] that require topical or non-invasive intervention, such as skin burns (skin breakdown, blister formation);
- Clinically observable seizures during stimulation;
- Severe headache with vomiting, confusion, or severe dizziness leading to syncope;
- Severe sleep disturbance with psychiatric abnormalities (anxiety, depression, hallucinations, etc.);
- New brain lesions on imaging, or decreased apparent diffusion coefficient (ADC) values in the subcortex beneath the stimulation site.
References [1] Antal A, et al. Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines (2017-2025: An update) - endorsed by the European Society for Brain Stimulation (ESBS) and by the International Federation for Clinical Neurophysiology (IFCN). Clin Neurophysiol. 2026. 184: 2111436
Measured: At any point during or immediately following intervention on day of tTIS application
Efficacy: To assess the proportion of patients with SARA improvement (decrease) of at least 1.5 from baseline after 5 days
The Scale for the Assessment and Rating of Ataxia (SARA) evaluates the severity of ataxia symptoms, including gait, posture, speech, and limb kinetic functions.
Score range: 0-40 Higher scores indicate more severe ataxia. Response is defined as a reduction of ≥1.5 points from baseline.
Measured: Baseline and within 24 hours after completing the 5-day tTIS treatment
Comprehensive Benefit-Risk: Utility
Utility is a composite measure integrating dose-limiting toxicity (DLT) and efficacy response to quantify the overall benefit-risk balance for each dose group.
During the trial, the Utility value for each dose group is dynamically calculated using the U-BOIN design platform. In Stage II, the Utility value determines dose allocation for subsequent cohorts. At study completion, the dose group with the highest Utility value is identified as the optimal biological dose.
Measured: Within 24 hours after completing the 5-day tTIS treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Aug 2026
- Study start7 Aug 2026 (estimated)
- Primary completion30 Nov 2026 (estimated)
- Study completion28 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Spinocerebellar Ataxia Type 3Studies of the same condition, open and under way.
- 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
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- First Affiliated Hospital of Fujian Medical University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Xinyuan Chen, First Affiliated Hospital of Fujian Medical University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07743866
- Sponsor's protocol ID
- MRCTA,ECFAH of FMU[2026]803
- Status last verified
- Aug 2026
- First submitted
- 29 Jul 2026
- Last updated
- 1 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy and Safety of Transcranial Temporal Interference Stimulation of the Cerebellar Dentate Nucleus Using Individualized Head Modeling in Patients With Spinocerebellar Ataxia Type 3
- ClinicalTrials.gov ID
- NCT07743866
- Acronym / sponsor ID
- MRCTA,ECFAH of FMU[2026]803
- Conditions
- Spinocerebellar Ataxia Type 3
- Keywords
- Transcranial Temporal Interference stimulation, Spinocerebellar ataxia type 3, Cerebellar dentate nucleus, Stimulation difference frequency, Individualized head modeling
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- First Affiliated Hospital of Fujian Medical UniversityUniversity, hospital or other
- Study start
- 7 Aug 2026 (estimated)
- Primary completion
- 30 Nov 2026 (estimated)
- Study completion
- 28 Feb 2027 (estimated)
- First posted
- 4 Aug 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 purpose of this research study is to identify the optimal biological dose for tTIS that targets DN in SCA3 while achieving the best possible balance between therapeutic efficacy and safety.
Detailed description
Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease, is an autosomal dominant neurodegenerative disorder caused by CAG repeat expansion in the ATXN3 gene. Selective degeneration of neurons in the cerebellar dentate nucleus (DN) leads to abnormal cerebellar outflow circuitry and impaired motor control, resulting in progressive gait ataxia, dysarthria and other motor symptoms. Current treatments are symptomatic only, with no disease-modifying therapies available. Deep brain stimulation targeting the dentate nucleus has shown efficacy but is invasive and associated with significant adverse events.
Transcranial temporal interference stimulation (tTIS) enables non-invasive, deep and spatially precise neuromodulation. It has been applied in various neurological and psychiatric disorders with favorable safety and efficacy, demonstrating potential for neuromodulation of deep cerebellar circuits.
This phase I/II adaptive dose-finding prospective interventional study evaluates the safety and efficacy of tTIS targeting the cerebellar dentate nucleus in patients with spinocerebellar ataxia type 3. Using MRI-derived individualized head models and real-time neuronavigation, the study employs a utility-based Bayesian optimal interval (U-BOIN) design with three difference frequencies: 30 Hz, 40 Hz, and 70 Hz. Patients are enrolled in sequential cohorts of three, with dose escalation guided by a utility-based approach integrating safety and efficacy data. Each patient receives ten tTIS sessions over two consecutive weeks, with one session daily. Motor function, balance function, activities of daily living, and multimodal magnetic resonance imaging are evaluated before the first treatment session and after the final treatment session.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| 30 Hz Difference Frequency tTIS | Experimental | Device: Transcranial Temporal Interference Stimulation (tTIS)Transcranial Temporal Interference Stimulation (tTIS) uses a difference frequency (Δf) of 30 Hz. |
| 40 Hz Difference Frequency tTIS | Experimental | Device: Transcranial Temporal Interference Stimulation (tTIS)Transcranial Temporal Interference Stimulation (tTIS) uses a difference frequency (Δf) of 40 Hz. |
| 70 Hz Difference Frequency tTIS | Experimental | Device: Transcranial Temporal Interference Stimulation (tTIS)Transcranial Temporal Interference Stimulation (tTIS) uses a difference frequency (Δf) of 70 Hz. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- A physician-diagnosed SCA3 according to diagnostic criteria, with definite clinical symptoms and confirmed genetic testing;
- Age 18-75 years;
- Baseline total score of SARA: 8-30 points (inclusive); SARA gait function subscore: 2-6 points (inclusive);
- Willing to participate and provide informed consent;
- Have a reliable caregiver available;
Key exclusion criteria (8 listed)
- History of seizures or convulsions, or a seizure within 6 months prior to enrolment;
- History of severe traumatic brain injury or intracranial neurosurgery;
- Presence of cardiac pacemakers, cochlear implants, intracranial implanted electronic devices, or other MRI-contraindicated ferromagnetic implants;
- Severe cognitive impairment (Mini-Mental State Examination [MMSE] score ≤ 9) or severe visual, auditory, or speech dysfunction preventing cooperation with scale assessments and study procedures;
- Pregnant or lactating women, or women of childbearing age not using reliable contraception;
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 |
|---|---|---|
| Transcranial Temporal Interference Stimulation (tTIS)Participants assigned to this intervention arm receive transcranial temporal interference stimulation (tTIS) with a difference frequency (Δf) of 30Hz/40Hz/70 Hz. Before treatment, individualized electric field modeling is performed based on each participant's 3D-T1 MRI data to optimize electrode placement and stimulation parameters. The stimulation target is the bilateral cerebellar dentate nuclei. A personalized finite element head model is generated, and electrode positions are determined through simulation-based optimization to achieve focused interference electric fields at the target region. During each treatment session, tTIS is delivered using two carrier frequencies of 2000 Hz and 2030Hz/2040Hz/2070 Hz, with a current intensity of 2.0 mA (zero-to-peak). Each session lasts 20 minutes. Treatment is administered twice daily, 5 days per week, for a total of 10 sessions. | Device | 30 Hz Difference Frequency tTIS, 40 Hz Difference Frequency tTIS, 70 Hz Difference Frequency tTIS |
Primary outcome
Safety: Incidence of Dose-Limiting Toxicity (DLT)
Time frame: At any point during or immediately following intervention on day of tTIS application
DLT event is defined as any one of the following 5 categories: 1. Grade Ⅱ (moderate) or higher adverse events per the NCI-CTCAE grading criteria[1] that require topical or non-invasive intervention, such as skin burns (skin breakdown, blister formation); 2. Clinically observable seizures during stimulation; 3. Severe headache with vomiting, confusion, or severe dizziness leading to syncope; 4. Severe sleep disturbance with psychiatric abnormalities (anxiety, depression, hallucinations, etc.); 5. New brain lesions on imaging, or decreased apparent diffusion coefficient (ADC) values in the subcortex beneath the stimulation site. References [1] Antal A, et al. Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines (2017-2025: An update) - endorsed by the European Society for Brain Stimulation (ESBS) and by the International Federation for Clinical Neurophysiology (IFCN). Clin Neurophysiol. 2026. 184: 2111436
Efficacy: To assess the proportion of patients with SARA improvement (decrease) of at least 1.5 from baseline after 5 days
Time frame: Baseline and within 24 hours after completing the 5-day tTIS treatment
The Scale for the Assessment and Rating of Ataxia (SARA) evaluates the severity of ataxia symptoms, including gait, posture, speech, and limb kinetic functions. Score range: 0-40 Higher scores indicate more severe ataxia. Response is defined as a reduction of ≥1.5 points from baseline.
Comprehensive Benefit-Risk: Utility
Time frame: Within 24 hours after completing the 5-day tTIS treatment
Utility is a composite measure integrating dose-limiting toxicity (DLT) and efficacy response to quantify the overall benefit-risk balance for each dose group. During the trial, the Utility value for each dose group is dynamically calculated using the U-BOIN design platform. In Stage II, the Utility value determines dose allocation for subsequent cohorts. At study completion, the dose group with the highest Utility value is identified as the optimal biological dose.
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 1 Sep 2026.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Transcranial Temporal Interference Stimulation (tTIS) in people with Spinocerebellar Ataxia Type 3, run by First Affiliated Hospital of Fujian Medical University at 1 site in China.
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 6 inclusion and 8 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: opening soon, as of the sponsor's last update on 1 Sep 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 China. 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 Xin-Yuan Chen (+86 15005065282, fychenxinyuan@fjmu.edu.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety: Incidence of Dose-Limiting Toxicity (DLT) (time frame: At any point during or immediately following intervention on day of tTIS application). The study lists 3 primary outcomes in all. 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 1 Sep 2026; AzTrials last refreshed its copy on 26 Oct 2026.