Essential TremorNCT06331052
3-D Tractography FUS Ablation for Essential Tremor
A study testing MR-guided Focused Ultrasound Ablation in people with Essential Tremor, run by University of North Carolina, Chapel Hill at 1 site in United States.
Trial summary
The investigators propose to advance Vim-FUSA (Ventral Intermediate Nucleus - Focused Ultrasound Ablation) with the support of 3-D tractography, a neuroimaging technique to visually represent nerve tracts within the brain. Read more about this study
- Who is it for?
- Ages 22 years and older
- Conditions the study is for
- Essential Tremor
- What is being tested?
- MR-guided Focused Ultrasound Ablation
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Feb 2024to 28 Feb 2028
- 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 22 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Diagnosis of moderate to severe ET agreed upon by at least two movement disorder trained physicians
- Symptoms refractory to at least two medications
- Stable essential tremor medication regimen for at least 4 weeks prior to screening
- Willing and able to participate in all follow-up visits
- Willing and able to undergo MR imaging.
Who cannot join
- Uncontrolled hypertension
- Medically unstable coronary artery disease
- Coagulopathy with inability to temporarily stop any antithrombotic medication
- Tremor disorders other than ET (e.g., Parkinson disease, traumatic tremor, alcohol or drug dependent tremor that remains after at least 2 weeks of abstinence etc.)
- Unwilling or unable to undergo tremor surgery while awake
- Significant and non-correctible motion artifact in imaging
Show all 14Show fewer
- Pregnant at the time of enrollment or preoperative evaluation
- Dementia
- History of psychosis
- Prior brain surgery that could influence the focused ultrasound procedure outcomes, including deep brain stimulation
- Botulinum toxin injection in the tremor-impacted areas three months prior to the baseline assessment and until 3-months after Vim-FUSA
- does not qualify for FDA-approved clinical use based on current FDA labeling except that skull density ratio ≤ 0.4 will be allowed for this study
- Any significant issue raised by the neurologist or neurosurgeon that may compromise participant safety or potentially interfere with study interpretation.
- non-English speaking
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 North Carolina at Chapel Hill
Chapel Hill, North Carolina, 27599
Victoria Scott, 919-966-0864, Victoria_Scott@med.unc.edu
Vibhor Krishna, MD, SM, 919-445-2410, vibhor_krishna@med.unc.edu
About this study
Official title: 3-D Tractography Focused Ultrasound Ablation for Essential Tremor
The investigators propose to advance Vim-FUSA (Ventral Intermediate Nucleus - Focused Ultrasound Ablation) with the support of 3-D tractography, a neuroimaging technique to visually represent nerve tracts within the brain. The investigators hypothesize that 3-D tractography Vim-FUSA will improve the Vim ablation compared to standard Vim-FUSA and prove safe and feasible in the clinical setting. The investigators also hypothesize that intraoperative magnetic resonance (i-MR) monitoring will differentiate ablated tissue from immediate perilesional edema and accurately predict the Vim-FUSA clinical outcomes.
Read the detailed description
Essential tremor (ET) is a common neurological disorder and a leading cause of functional and psychological disabilities that can be difficult to suppress with oral medications, many of which have considerable side effects limiting adequate dosing. As a result, up to 20% of ET patients cannot achieve satisfactory control of their symptoms and must consider interventional options. Focused ultrasound ablation (FUSA) of the ventral intermediate nucleus (Vim) is an FDA-approved and Medicare-reimbursed procedure for ET resistant to medications that can selectively ablate the brain area associated with tremor without the need for surgical incisions or anesthesia. The success of Vim-FUSA depends on the ability to accurately ablate 70% of the Vim volume without lesioning neighboring structures, a goal that is complicated by technical challenges in three critical phases of the procedure: planning (identifying the Vim location and extension); delivery (ablating the Vim volume with adequate accuracy); and monitoring (confirming Vim ablation with reliable intraoperative imaging). The investigators propose to advance Vim-FUSA with the support of 3-D tractography, a neuroimaging technique to visually represent nerve tracts within the brain. The investigators hypothesize that 3-D tractography Vim-FUSA will improve the Vim ablation compared to standard Vim-FUSA and prove safe and feasible in the clinical setting. The investigators also hypothesize that intraoperative magnetic resonance (i-MR) monitoring will differentiate ablated tissue from immediate perilesional edema and accurately predict the Vim-FUSA clinical outcomes. Aim 1. Estimate and characterize the improvement in Vim ablation achieved with 3-D tractography Vim-FUSA vs. standard Vim-FUSA in an experimental controlled animal study. Through an experimental animal study, the investigators will characterize the Vim ablation delivered with 3-D tractography Vim-FUSA in one hemisphere (experimental group) vs. standard Vim-FUSA in the opposite hemisphere (control group). Aim 2. Test safety, feasibility, and preliminary efficacy, and estimate effect size of 3-D tractography Vim-FUSA in a phase-II, two-groups, pre-post interventional human study. In a human study, the investigators will test the safety and feasibility of ablating 70% of the Vim volume while checking for side effects with intraoperative clinical testing. Tremor assessments will be videotaped at baseline and 12 weeks and compared, in a blinded fashion, with age-sex matched controls randomly selected from the video repository of the two FDA-regulated studies of standard Vim-FUSA at baseline and 12 weeks. Aim 3 (Exploratory). Assess the accuracy of i-MR in differentiating tissue ablation from immediate perilesional edema and its utility in predicting Vim-FUSA clinical outcomes. In the experimental animal study, the investigators will estimate and compare the accuracy of conventional and non-conventional i-MR in differentiating tissue necrosis from perilesional edema. In the interventional human study, the investigators will evaluate the utility of i-MR in predicting Vim-FUSA clinical outcomes
- Conditions
- Essential Tremor
- Being tested
- MR-guided Focused Ultrasound Ablation
- Medical subject headings
- Essential Tremor
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MR-guided Focused Ultrasound AblationDevice
Also called 3-D Tractography
3-D tractography Vim-FUSA -D tractography Vim-FUSA will be carried out as follows: (a) head shaving and placement of the stereotactic frame (Integra radionics frame, Integra Lifesciences, NJ, USA) secured to the skull with transcutaneous screws; (b) positioning on the procedure table and placement of the ultrasound transducer; (c) acquisition of conventional magnetic resonance (MR) imaging and co-registration with the CT head and 3-D tractography imaging acquired pre-surgically; (d) exploration of the target area with subtherapeutic sonications; (e) intraoperative monitoring with clinical testing of tremor and side effects with a standardized protocol. (f) Therapeutic sonications in the target area to deliver definitive ablation followed by clinical testing of tremor and side effects with a standardized protocol as described in section (e).
| Study group | Role | What they receive |
|---|---|---|
| 3-D Tractography Vim FUSA | Experimental | Twenty-four consecutive essential tremor (ET) participants undergoing Vim FUSA using 3-D tractography will be assessed at baseline and Month 3. Receives: Device: MR-guided Focused Ultrasound Ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants without Side Effects
Feasibility is defined as the ability to complete the procedure without side effects.
Measured: during the surgical procedure
Absolute Change in Tremor
The absolute change from baseline to Month 3 follow-up in upper extremity Tremor-Motor scores for the treated side is a sub-scale of Clinical Rating Scale for Tremor (CRST) Part A and Part B sum used to measure treated-side upper extremity tremor changes over time. Tremor-motor scores range from 0-32 points. Individual subject's scores at Baseline and 3 Months used to calculate absolute change from baseline and averaged across subjects. High absolute change from baseline is better (shows improvement).
Measured: Baseline, Month 3
Relative Change in Tremor
The relative change from baseline to Month 3 follow-up in upper extremity Tremor-Motor scores for the treated side is a sub-scale of Clinical Rating Scale for Tremor (CRST) Part A and Part B sum used to measure treated-side upper extremity tremor changes over time. Tremor-motor scores range from 0-32 points. Individual subject's scores at Baseline and 3 Months used to calculate relative change from baseline and averaged across subjects. High relative change from baseline is better (shows improvement).
Measured: Baseline, Month 3
Secondary outcomes (3)
Number of Participants with Procedure-Related Side Effects
Prevalence and severity of procedure-related side effects measured by the following: ataxia (SARA), speech disturbance (VHI), sensory loss (SWME), muscle weakness (MRC)
Measured: 3 months after the surgical procedure
Relative Change in Tremor-Related Quality of Life
The Quality of Life Essential Tremor Questionnaire (QUEST) will be used to assess tremor-related quality of life. QUEST has scores ranging from 0 to 100 with higher scores indicating worse disability.
Measured: 3 months after the surgical procedure
Number of Participants Who Are Satisfied with Treatment
Measured using a single question asking about patient satisfaction ranging from 1 to 5 with higher scores indicating higher satisfaction.
Measured: 3 months after the surgical procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Mar 2024
- Study start28 Feb 2024
- Primary completion28 Feb 2028 (estimated)
- Study completion28 Feb 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Essential TremorStudies 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of North Carolina, Chapel Hill
- Sponsor type
- University, hospital or other
- Collaborators
- University of Pittsburgh, National Institute of Neurological Disorders and Stroke (NINDS), University of Missouri-Columbia
- Responsible party
- Sponsor
- Investigators
- Vibhor Krishna, MD, Principal investigator, University of North Carolina at Chapel Hll
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06331052
- Sponsor's protocol ID
- 23-2431
- Other IDs
- 1R01NS125386-01
- Status last verified
- Aug 2026
- First submitted
- 19 Mar 2024
- Last updated
- 8 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: De-identified individual data that supports the results will be shared beginning 9 to 36 months following publication provided the investigator who proposes to use the data has approval from an Institutional Review Board (IRB), Independent Ethics Committee (IEC), or Research Ethics Board (REB), as applicable, and executes a data use/sharing agreement with UNC.
Study at a glance
From the registry record, last updated by the sponsor on 8 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 3-D Tractography Focused Ultrasound Ablation for Essential Tremor
- ClinicalTrials.gov ID
- NCT06331052
- Acronym / sponsor ID
- 23-2431
- Conditions
- Essential Tremor
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- University of North Carolina, Chapel HillUniversity, hospital or other
- Collaborators
- University of Pittsburgh, National Institute of Neurological Disorders and Stroke (NINDS), University of Missouri-Columbia
- Study start
- 28 Feb 2024 (actual)
- Primary completion
- 28 Feb 2028 (estimated)
- Study completion
- 28 Feb 2028 (estimated)
- First posted
- 26 Mar 2024 (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 investigators propose to advance Vim-FUSA (Ventral Intermediate Nucleus - Focused Ultrasound Ablation) with the support of 3-D tractography, a neuroimaging technique to visually represent nerve tracts within the brain. The investigators hypothesize that 3-D tractography Vim-FUSA will improve the Vim ablation compared to standard Vim-FUSA and prove safe and feasible in the clinical setting. The investigators also hypothesize that intraoperative magnetic resonance (i-MR) monitoring will differentiate ablated tissue from immediate perilesional edema and accurately predict the Vim-FUSA clinical outcomes.
Detailed description
Essential tremor (ET) is a common neurological disorder and a leading cause of functional and psychological disabilities that can be difficult to suppress with oral medications, many of which have considerable side effects limiting adequate dosing. As a result, up to 20% of ET patients cannot achieve satisfactory control of their symptoms and must consider interventional options. Focused ultrasound ablation (FUSA) of the ventral intermediate nucleus (Vim) is an FDA-approved and Medicare-reimbursed procedure for ET resistant to medications that can selectively ablate the brain area associated with tremor without the need for surgical incisions or anesthesia. The success of Vim-FUSA depends on the ability to accurately ablate 70% of the Vim volume without lesioning neighboring structures, a goal that is complicated by technical challenges in three critical phases of the procedure: planning (identifying the Vim location and extension); delivery (ablating the Vim volume with adequate accuracy); and monitoring (confirming Vim ablation with reliable intraoperative imaging). The investigators propose to advance Vim-FUSA with the support of 3-D tractography, a neuroimaging technique to visually represent nerve tracts within the brain. The investigators hypothesize that 3-D tractography Vim-FUSA will improve the Vim ablation compared to standard Vim-FUSA and prove safe and feasible in the clinical setting. The investigators also hypothesize that intraoperative magnetic resonance (i-MR) monitoring will differentiate ablated tissue from immediate perilesional edema and accurately predict the Vim-FUSA clinical outcomes. Aim 1. Estimate and characterize the improvement in Vim ablation achieved with 3-D tractography Vim-FUSA vs. standard Vim-FUSA in an experimental controlled animal study. Through an experimental animal study, the investigators will characterize the Vim ablation delivered with 3-D tractography Vim-FUSA in one hemisphere (experimental group) vs. standard Vim-FUSA in the opposite hemisphere (control group). Aim 2. Test safety, feasibility, and preliminary efficacy, and estimate effect size of 3-D tractography Vim-FUSA in a phase-II, two-groups, pre-post interventional human study. In a human study, the investigators will test the safety and feasibility of ablating 70% of the Vim volume while checking for side effects with intraoperative clinical testing. Tremor assessments will be videotaped at baseline and 12 weeks and compared, in a blinded fashion, with age-sex matched controls randomly selected from the video repository of the two FDA-regulated studies of standard Vim-FUSA at baseline and 12 weeks. Aim 3 (Exploratory). Assess the accuracy of i-MR in differentiating tissue ablation from immediate perilesional edema and its utility in predicting Vim-FUSA clinical outcomes. In the experimental animal study, the investigators will estimate and compare the accuracy of conventional and non-conventional i-MR in differentiating tissue necrosis from perilesional edema. In the interventional human study, the investigators will evaluate the utility of i-MR in predicting Vim-FUSA clinical outcomes
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| 3-D Tractography Vim FUSA | Experimental | Device: MR-guided Focused Ultrasound AblationTwenty-four consecutive essential tremor (ET) participants undergoing Vim FUSA using 3-D tractography will be assessed at baseline and Month 3. |
Who may qualify
- Ages
- 22 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Diagnosis of moderate to severe ET agreed upon by at least two movement disorder trained physicians
- Symptoms refractory to at least two medications
- Stable essential tremor medication regimen for at least 4 weeks prior to screening
- Willing and able to participate in all follow-up visits
- Willing and able to undergo MR imaging.
Key exclusion criteria (14 listed)
- Uncontrolled hypertension
- Medically unstable coronary artery disease
- Coagulopathy with inability to temporarily stop any antithrombotic medication
- Tremor disorders other than ET (e.g., Parkinson disease, traumatic tremor, alcohol or drug dependent tremor that remains after at least 2 weeks of abstinence etc.)
- Unwilling or unable to undergo tremor surgery while awake
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 |
|---|---|---|
| MR-guided Focused Ultrasound AblationAlso: 3-D Tractography3-D tractography Vim-FUSA -D tractography Vim-FUSA will be carried out as follows: (a) head shaving and placement of the stereotactic frame (Integra radionics frame, Integra Lifesciences, NJ, USA) secured to the skull with transcutaneous screws; (b) positioning on the procedure table and placement of the ultrasound transducer; (c) acquisition of conventional magnetic resonance (MR) imaging and co-registration with the CT head and 3-D tractography imaging acquired pre-surgically; (d) exploration of the target area with subtherapeutic sonications; (e) intraoperative monitoring with clinical testing of tremor and side effects with a standardized protocol. (f) Therapeutic sonications in the target area to deliver definitive ablation followed by clinical testing of tremor and side effects with a standardized protocol as described in section (e). | Device | 3-D Tractography Vim FUSA |
Primary outcome
Number of Participants without Side Effects
Time frame: during the surgical procedure
Feasibility is defined as the ability to complete the procedure without side effects.
Absolute Change in Tremor
Time frame: Baseline, Month 3
The absolute change from baseline to Month 3 follow-up in upper extremity Tremor-Motor scores for the treated side is a sub-scale of Clinical Rating Scale for Tremor (CRST) Part A and Part B sum used to measure treated-side upper extremity tremor changes over time. Tremor-motor scores range from 0-32 points. Individual subject's scores at Baseline and 3 Months used to calculate absolute change from baseline and averaged across subjects. High absolute change from baseline is better (shows improvement).
Relative Change in Tremor
Time frame: Baseline, Month 3
The relative change from baseline to Month 3 follow-up in upper extremity Tremor-Motor scores for the treated side is a sub-scale of Clinical Rating Scale for Tremor (CRST) Part A and Part B sum used to measure treated-side upper extremity tremor changes over time. Tremor-motor scores range from 0-32 points. Individual subject's scores at Baseline and 3 Months used to calculate relative change from baseline and averaged across subjects. High relative change from baseline is better (shows improvement).
3 secondary outcomes
Number of Participants with Procedure-Related Side Effects
Time frame: 3 months after the surgical procedure
Relative Change in Tremor-Related Quality of Life
Time frame: 3 months after the surgical procedure
Number of Participants Who Are Satisfied with Treatment
Time frame: 3 months after the surgical procedure
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 8 Sep 2026.
- Individual participant dataSharing planned: Yes. De-identified individual data that supports the results will be shared beginning 9 to 36 months following publication provided the investigator who proposes to use the data has approval from an Institutional Review Board (IRB), Independent Ethics Committee (IEC), or Research Ethics Board (REB), as applicable, and executes a data use/sharing agreement with UNC.
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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.
Vibhor Krishna, MD principal investigator
University of North Carolina at Chapel Hll
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing MR-guided Focused Ultrasound Ablation in people with Essential Tremor, run by University of North Carolina, Chapel Hill 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 5 inclusion and 14 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 8 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 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 Vibhor Krishna, MD (+1(919)-445-2410, vibhor_krishna@med.unc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants without Side Effects (time frame: during the surgical procedure). 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 8 Sep 2026.