Responsive Deep Brain Stimulator for Essential Tremor

January 7, 2026 updated by: University of Florida

Closing the Loop on Tremor: A Responsive Deep Brain Stimulator for the Treatment of Essential Tremor

Essential tremor is an incurable, degenerative brain disorder that results in increasingly debilitating tremor, and afflicts an estimated 7 million people in the US. In one study, 25% of essential tremor patients were forced to change jobs or take early retirement because of tremor. Essential tremor is directly linked to progressive functional impairment, social embarrassment, and even depression. The tremor associated with essential tremor is typically slow, involves the hands (and sometimes the head and voice), worsens with intentional movements, and is insidiously progressive over many years. Deep brain stimulation has emerged as a highly effective treatment for intractable, debilitating essential tremor. However, since the intention tremor of essential tremor is typically intermittent, and commonly absent at rest, the currently available continuous deep brain stimulation may be delivering unnecessary current to the brain that increases undesirable side effects such as slurred speech and walking difficulty, and hastens the depletion of device batteries, necessitating more frequent surgical procedures to replace spent pulse generators. The overall objective of this early feasibility study is to provide preliminary data on the safety and efficacy of "closed-loop" deep brain stimulation for intention tremor using novel deep brain stimulation devices capable of continuously sensing brain activity and delivering therapeutic stimulation only when necessary to suppress tremor.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The purpose of this study is to investigate brain signals related to intention tremor in essential tremor in order to deliver deep brain stimulation only when the patient is showing symptoms. By delivering stimulation only when needed, the investigators hypothesize that the treatment will be more effective, will cause fewer adverse side effects and will increase battery time of the device (reducing the number of battery replacement surgeries).

Participation in this study will require extensive pre-surgical screening to determine eligibility for deep brain stimulation surgery, a deep brain stimulation surgical procedure, and regular follow-ups. Subjects will be seen monthly post surgery for 6 months. After 6 months, data will be assessed and closed-loop deep brain stimulation may be offered as a stimulation setting. If so, the stimulator settings will be changed from chronic to responsive. If not, the subject will continue to receive chronic deep brain stimulation stimulation. Subsequent visits will be scheduled every 6 months until a total of 24 months of study participation (also at month 9).

At the end of the initial 24-month study period, subjects will have the choice of 1) continuing active stimulation at the current setting, 2) continuing stimulation but searching for a new setting, 3) discontinuing stimulation (turning the device off), 4) having the device removed. If the subject continues to receive active stimulation, they will be followed by the investigators and seen at yearly intervals.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Aysegul Gunduz, Ph.D
  • Phone Number: 3522736877
  • Email: agunduz@ufl.edu

Study Contact Backup

Study Locations

  • United States
    • Florida
      • Gainesville, Florida, United States, 32611
        • University of Florida

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

21 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. You provide informed consent.
  2. You are over 21 years of age.
  3. You are diagnosed with a postural-intention (essential) tremor for at least 3 years and meet strict diagnostic criteria and have been seen and examined by a movement disorders fellowship trained neurologist.
  4. You have had a significant disabling medical-refractory upper extremity tremor with no evidence of supraspinal central nervous system disease or injury (tremor not adequately controlled by medications for at least three (3) months before implant).
  5. You have had a postural or kinetic tremor severity score of at least 2 out of 4 in the extremity intended for treatment on the Fahn-Tolosa-Marin Clinical Rating Scale for Tremor (CRST).
  6. You have had a CRST score of 2 or above in any one of the items 16-23 from the Disability subsection of the CRST: speaking, feeding other than liquids, bringing liquids to mouth, hygiene, dressing, writing, working and social activities.
  7. Your tremor is refractory adequate trials of at least two medications, one of which should be either propranolol or primidone. An adequate medication trial is defined as a therapeutic dose of each medication or the development of side effects as the medication dose is titrated.
  8. You are available for appropriate follow-up times for the length of the study.

Exclusion Criteria:

  1. Any previous neurosurgical intervention including deep brain stimulation or ablative brain lesions.
  2. Medication related movement disorders.
  3. Any suspicion of Parkinsonian tremor, including presence of Parkinsonian features such as bradykinesia, rigidity, or postural instability.
  4. Any behaviors consistent with ethanol or substance abuse as defined by the criteria outlined in DSM-V.
  5. Severe medical co-morbidity including cardiovascular disorder, lung disorder, kidney disease, continuous neurological disease, hematological disease, or frailty that impact tolerability of the surgery as judged by the screening physicians.
  6. Abnormal brain MRI including hydrocephalus, stroke, structural lesions, demyelinating lesions, or infectious lesions. Also excluded will be subjects with severe atrophy.
  7. Any uncontrolled symptoms or signs of increased intracranial pressure (e.g., headache, nausea, vomiting, lethargy, papilledema).
  8. A history of seizures within the past year.
  9. A dementia rating scale score (DRS) <130 signifying significant cognitive dysfunction and a potential for inability to cooperate with tasks involved in the study.
  10. Any attempt or intent of suicide in the last six months.
  11. Presence or history of psychosis.

  12. Significant or active mood disorders including depression. For the purpose of this study, we consider a significant mood disorder to include any subject who has:

    1. Scores ≥ 20 on the Patient Health Questionnaire - 9 (PHQ-9).
    2. Currently under the care of a psychiatrist
    3. Currently participating in cognitive-behavioral therapy
    4. Been hospitalized for the treatment of a psychiatric illness within 12 months
    5. Ever received transcranial magnetic stimulation
    6. Ever received electroconvulsive therapy

n. In addition, patients who are pregnant or plan to become pregnant will be excluded from this study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Deep brain stimulation
All participants will undergo unilateral deep brain stimulation (DBS) implantation for essential tremor. Medtronic Summit RC+S devices will be used because these are capable of recording brain signals, as well as delivering DBS. Participants will receive continuous (open-loop) and closed-loop deep brain stimulation interventions, which will be compared for efficacy.
Device: Deep brain stimulation
The deep brain stimulation system includes an implantable neurostimulator, thalamic leads to be implanted in the ventral intermediate nucleus (Vim), and subdural cortical strips. The deep brain stimulation system will be set to provide continuous stimulation for the 6 months following surgery. Subjects will be seen monthly for evaluation as a part of normal clinical care for deep brain stimulation. At 6 months, the investigators will determine whether or not the subject is a candidate for closed-loop deep brain stimulation. Qualifying subjects will have the option to have their settings changed in order to participate in the RBS stimulation intervention. These subjects will been seen every 6 months for evaluation as part of normal clinical care for deep brain stimulation.
Other Names:
  • Medtronic Summit RC+S
Device: Closed-loop deep brain stimulation
The deep brain stimulation system includes an implantable neurostimulator, Vim thalamic leads, and subdural strips. Six months post-surgery, the deep brain stimulation system will be set to provide responsive stimulation for the duration of the study. Subjects will be seen every 6 months for evaluation as a part of normal clinical care for deep brain stimulation. Data gathered from the subject during the first 6 months will be used to determine if this intervention is applicable for each individual subject. Subjects who do not qualify will continue to receive the other study intervention.
Other Names:
  • Medtronic Nexus-E

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Clinical Rating Scale for Tremor (CRST) for continuous deep brain stimulation
Time Frame: 6 months post-surgery

- Reduction in Clinical Rating Scale for Tremor after 6 months as an effect of continuous Vim deep brain stimulation

The Fahn-Tolosa-Marin Tremor Rating Scale is a clinical rating scale assessing severity of tremor by body part from 0 (none) to 4 (severe). The scale is divided into three parts, where Part A assesses tremor severity at rest, during posture, and kinetic maneuvers for nine body parts; Part B assesses ability to perform specific motor tasks/functions (writing, drawing, and pouring with dominant and nondominant hands); and Part C assesses patient-reported functional disability resulting from the tremor. Score ranges from 0 to 80 for Part A, from 0 to 36 for Part B, and from 0 to 28 for Part C. The total score obtained by adding the three parts is 144. A higher score indicates a higher severity of the tremor. Finally, the scale includes one separate item dealing with global assessment of tremor-related disability, rated by both patient and examiner on a 5-point scale.
6 months post-surgery
Clinical Rating Scale for Tremor (CRST) for closed-loop deep brain stimulation
Time Frame: Baseline until 24 months post-surgery

- Closed-loop deep brain stimulation as an effective alternative to continuous deep brain stimulation

Clinical scores during continuous stimulation will be compared to scores on the during closed-loop stimulation.
Baseline until 24 months post-surgery
Clinical Rating Scale for Tremor (CRST) for continuous deep brain stimulation
Time Frame: 24 months post-surgery
- Reduction in Clinical Rating Scale for Tremor after 24 months as an effect of continuous Vim deep brain stimulation
24 months post-surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Florida

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Neurological Disorders and Stroke (NINDS)
Medtronic

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Aysegul Gunduz, Ph.D, University of Florida

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 1, 2017

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 6, 2016

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 6, 2016

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 7, 2016

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 7, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB201501021 -N-A
  • 5UH3NS095553-04 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Once 24 month follow-up is completed for all subjects, the investigators will consider data sharing requests for de-identified data.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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