Essential TremorNCT02649166
Responsive Deep Brain Stimulator for Essential Tremor
A study testing Deep brain stimulation and Closed-loop deep brain stimulation in people with Essential Tremor, run by University of Florida at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 21 years and older
- Conditions the study is for
- Essential Tremor
- What is being tested?
- Deep brain stimulation and Closed-loop deep brain stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Feb 2017to 30 Jun 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 21 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- You provide informed consent.
- You are over 21 years of age.
- 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.
- 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).
- 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).
- 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.
- 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.
- You are available for appropriate follow-up times for the length of the study.
Who cannot join
- Any previous neurosurgical intervention including deep brain stimulation or ablative brain lesions.
- Medication related movement disorders.
- Any suspicion of Parkinsonian tremor, including presence of Parkinsonian features such as bradykinesia, rigidity, or postural instability.
- Any behaviors consistent with ethanol or substance abuse as defined by the criteria outlined in DSM-V.
- 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.
- Abnormal brain MRI including hydrocephalus, stroke, structural lesions, demyelinating lesions, or infectious lesions. Also excluded will be subjects with severe atrophy.
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- Any uncontrolled symptoms or signs of increased intracranial pressure (e.g., headache, nausea, vomiting, lethargy, papilledema).
- A history of seizures within the past year.
- A dementia rating scale score (DRS) <130 signifying significant cognitive dysfunction and a potential for inability to cooperate with tasks involved in the study.
- Any attempt or intent of suicide in the last six months.
- Presence or history of psychosis.
- 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:
- Scores ≥ 20 on the Patient Health Questionnaire - 9 (PHQ-9).
- Currently under the care of a psychiatrist
- Currently participating in cognitive-behavioral therapy
- Been hospitalized for the treatment of a psychiatric illness within 12 months
- Ever received transcranial magnetic stimulation
- Ever received electroconvulsive therapy
- In addition, patients who are pregnant or plan to become pregnant will be excluded from this study.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: 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.
Read the 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.
- Conditions
- Essential Tremor
- Being tested
- Deep brain stimulation, Closed-loop deep brain stimulation
- Keywords
- Essential tremor, Kinetic tremor, Intention tremor
- Medical subject headings
- Essential Tremor, Tremor
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Deep brain stimulationDevice
Also called Medtronic Summit RC+S
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.
Closed-loop deep brain stimulationDevice
Also called Medtronic Nexus-E
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.
| Study group | Role | What they receive |
|---|---|---|
| Deep brain stimulation | Experimental | 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. Receives: Device: Deep brain stimulation; Device: Closed-loop deep brain stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Clinical Rating Scale for Tremor (CRST) for continuous deep brain stimulation
- 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.
Measured: 6 months post-surgery
Clinical Rating Scale for Tremor (CRST) for closed-loop deep brain stimulation
- 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.
Measured: Baseline until 24 months post-surgery
Clinical Rating Scale for Tremor (CRST) for continuous deep brain stimulation
- Reduction in Clinical Rating Scale for Tremor after 24 months as an effect of continuous Vim deep brain stimulation
Measured: 24 months post-surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jan 2016 (estimated)
- Study start1 Feb 2017
- Primary completion30 Jun 2027 (estimated)
- Study completion30 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Essential TremorStudies of the same condition, open and under way.
- More trials run by University of FloridaThe 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
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Florida
- Sponsor type
- University, hospital or other
- Collaborators
- Medtronic, National Institute of Neurological Disorders and Stroke (NINDS)
- Responsible party
- Sponsor
- Investigators
- Aysegul Gunduz, Ph.D, Principal investigator, University of Florida
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02649166
- Sponsor's protocol ID
- IRB201501021 -N-A
- Other IDs
- 5UH3NS095553-04
- Status last verified
- Jan 2026
- First submitted
- 6 Jan 2016
- Last updated
- 9 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: Once 24 month follow-up is completed for all subjects, the investigators will consider data sharing requests for de-identified data.
Publications
Parks B, Almeida L, Okun MS, Hilliard JD, Foote KD, Gunduz A. Cortical vs Subcortical Recordings to Drive Closed-Loop Deep Brain Stimulation in Essential Tremor. Neuromodulation. 2026 Jul;29(5):787-794. doi: 10.1016/j.neurom.2026.02.011. Epub 2026 Apr 22.
PubMed 42017861
Study at a glance
From the registry record, last updated by the sponsor on 9 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Closing the Loop on Tremor: A Responsive Deep Brain Stimulator for the Treatment of Essential Tremor
- ClinicalTrials.gov ID
- NCT02649166
- Acronym / sponsor ID
- IRB201501021 -N-A
- Conditions
- Essential Tremor
- Keywords
- Essential tremor, Kinetic tremor, Intention tremor
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of FloridaUniversity, hospital or other
- Collaborators
- Medtronic, National Institute of Neurological Disorders and Stroke (NINDS)
- Study start
- 1 Feb 2017 (actual)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 30 Jun 2027 (estimated)
- First posted
- 7 Jan 2016 (estimated)
- 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.
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.
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 design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Deep brain stimulation | Experimental | Device: Deep brain stimulation, Device: Closed-loop deep brain stimulationAll 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. |
Who may qualify
- Ages
- 21 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- You provide informed consent.
- You are over 21 years of age.
- 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.
- 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).
- 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).
Key exclusion criteria (19 listed)
- Any previous neurosurgical intervention including deep brain stimulation or ablative brain lesions.
- Medication related movement disorders.
- Any suspicion of Parkinsonian tremor, including presence of Parkinsonian features such as bradykinesia, rigidity, or postural instability.
- Any behaviors consistent with ethanol or substance abuse as defined by the criteria outlined in DSM-V.
- 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.
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 |
|---|---|---|
| Deep brain stimulationAlso: Medtronic Summit RC+SThe 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. | Device | Deep brain stimulation |
| Closed-loop deep brain stimulationAlso: Medtronic Nexus-EThe 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. | Device | Deep brain stimulation |
Primary outcome
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.
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.
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
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 9 Jan 2026.
- Derived from this study: PubMed 42017861Parks B, Almeida L, Okun MS, Hilliard JD, Foote KD, Gunduz A. Cortical vs Subcortical Recordings to Drive Closed-Loop Deep Brain Stimulation in Essential Tremor. Neuromodulation. 2026 Jul;29(5):787-794. doi: 10.1016/j.neurom.2026.02.011. Epub 2026 Apr 22.
- Individual participant dataSharing planned: Yes. Once 24 month follow-up is completed for all subjects, the investigators will consider data sharing requests for de-identified data.
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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. This study is not recruiting at the moment.
Aysegul Gunduz, Ph.D principal investigator
University of Florida
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Deep brain stimulation and Closed-loop deep brain stimulation in people with Essential Tremor, run by University of Florida 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 8 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: under way, not looking for participants, as of the sponsor's last update on 9 Jan 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Clinical Rating Scale for Tremor (CRST) for continuous deep brain stimulation (time frame: 6 months post-surgery). 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?
On the ClinicalTrials.gov record for NCT02649166, which also lists 1 linked publication.
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 9 Jan 2026.