The Motor Network in Essential Tremor: Mechanisms of Therapy

January 12, 2026 updated by: University of Florida
Essential tremor (ET) is among the most common movement disorders, and is the most prevalent tremor disorder. It is a progressive, degenerative brain disorder that results in increasingly debilitating tremor, and afflicts an estimated 7 million people in the US (2.2% of the population) and estimates from population studies worldwide range from 0.4% to 6.3%. ET is directly linked to progressive functional impairment, social embarrassment, and even depression. Intention (kinetic) tremor of the arms occurs in approximately half of ET patients, and is typically a slow tremor (~5-10Hz) that occurs at the end of a purposeful movement, and is insidiously progressive over many years. Based on direct and indirect neurophysiological studies, it has been suggested that a pathological synchronous oscillation in a neuronal network involving the ventral intermediate nucleus (Vim) of the thalamus, the premotor (PM), primary motor (M1) cortices, and the cerebellum, may result in the production of ET. In spite of the numerous therapeutic modalities available, 65% of those suffering from upper limb tremor report serious difficulties during their daily lives. Deep brain stimulation (DBS) has emerged as an effective treatment option for those suffering from medically refractory ET. The accepted target for ET DBS therapy is the Vim thalamus. Vim projects to PM, M1, and supplementary motor areas (SMA) and receives afferents from the ipsilateral cerebellum. Moreover, electrophysiological recordings from Vim during stereotactic surgery have identified "tremor cells" that synchronously discharge with oscillatory muscle activity during tremor. Clinical and computational findings indicate that DBS suppresses tremor by masking these "burst driver" inputs to the thalamus. The overall goal is to investigate the neural signatures of tremor generation in the thalamocortical network by recording data during DBS implantation surgery. Investigators will record data from the macroelectrode implanted in the Vim for DBS therapy, and through an additional 6-contact subdural cortical strip that will be placed on the hand motor cortical area temporarily through the same burr hole opened for the implantation of the DBS electrode.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The research study goal is to advance the understanding of the mechanisms for essential tremor through brain recordings. The investigators will collect brain signals in persons with essential tremor undergoing neurosurgical treatment (deep brain stimulation implantation). By recording from the implanted electrodes for deep brain stimulation along with two other non-invasive intraoperative monitoring electrodes, the origins of tremor will be studied in the human motor network. Moreover, by performing recordings during deep brain stimulation delivery, the mechanisms in which deep brain stimulation modulates this network to suppress tremor will be investigated.

During the standard of care DBS procedure neural recordings are performed as the participant is in a reclined position on the operating table. In addition to neural recordings it is standard to ask the patient to move their arms and legs during the procedure. An additional intraoperative monitoring subdural electrode strip, used in epilepsy and tumor surgeries to perform functional mapping, will be placed by the neurosurgeon after the DBS electrode is placed per the clinical need of the patient. In addition, the Ad-Tech Medical Instrumentation Corp. device will be used to test responses with wireless sensors placed on the participant's arms, which can record electromyogram (EMG) activity. Brain signals will be recorded using the clinical NeuroOmega system Medtronic RC+S, which are devices capable of recording during stimulation. This additional testing will add approximately 30-45 minutes to the surgical time. The Medtronic RC+S stimulator will not be implanted in these subjects, and will not used as a therapy. No interventions are compared against any controls for this study.

Study Type

Observational

Enrollment (Actual)

21

Contacts and Locations

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

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

Ages Eligible for Study

17 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

Neurosurgical patient populations with essential tremor (main cohort) and Parkinson's disease (control cohort)

Description

Inclusion Criteria:

  • Neurosurgical patient populations with essential tremor (main cohort) and Parkinson's disease (control cohort)

Exclusion Criteria:

  • Non surgical candidates

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

  • Observational Models: Cohort
  • Time Perspectives: Cross-Sectional

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Essential tremor
Participants in this group will be undergoing deep brain stimulation implantation surgery as part of the standard of care. In addition, the Ad-Tech Medical Instrumentation Corp. device will be used to test responses with wireless sensors placed on the participant's arms, which can record EMG activity. Brain signals will be recorded using the clinical FHC Guideline 4000+ system and/or Medtronic RC+S devices, which are capable of recording during stimulation.
Procedure: Deep brain stimulation implantation surgery
Deep brain stimulation is a neuromodulatory therapy in which electrodes are implanted in deep brain structures. Electrical pulses are delivered through these electrodes to suppress pathological activity that are causing the symptoms of essential tremor or Parkinson's disease.
Device: Ad-Tech Medical Instrumentation Corp. electrodes/subdural strips
Ad-Tech Medical Instrumentation Corp. electrodes are intraoperative monitoring subdural strips will be placed on the surface of the cortex (non-penetrating).
Other Names:
  • Ad-tech intraoperative monitoring subdural strips
Device: FHC Guideline 4000+ system and/or Medtronic RC+S
Brain signals will be recorded using the clinical Participants in this group with Parkinson's disease will be undergoing deep brain stimulation implantation surgery as part of the standard of care. In addition, the Ad-Tech Medical Instrumentation Corp. device will be used to test responses with wireless sensors placed on the participant's arms, which can record EMG activity. Brain signals will be recorded using the clinical FHC Guideline 4000+ system and/or Medtronic RC+S devices, which are capable of recording during stimulation.
Parkinson's disease and dystonia
Participants in this group with Parkinson's disease and/or dystonia will be undergoing deep brain stimulation implantation surgery as part of the standard of care. In addition, the Ad-Tech Medical Instrumentation Corp. device will be used to test responses with wireless sensors placed on the participant's arms, which can record EMG activity. Brain signals will be recorded using the clinical FHC Guideline 4000+ system and/or Medtronic RC+S devices, which are capable of recording during stimulation.
Procedure: Deep brain stimulation implantation surgery
Deep brain stimulation is a neuromodulatory therapy in which electrodes are implanted in deep brain structures. Electrical pulses are delivered through these electrodes to suppress pathological activity that are causing the symptoms of essential tremor or Parkinson's disease.
Device: Ad-Tech Medical Instrumentation Corp. electrodes/subdural strips
Ad-Tech Medical Instrumentation Corp. electrodes are intraoperative monitoring subdural strips will be placed on the surface of the cortex (non-penetrating).
Other Names:
  • Ad-tech intraoperative monitoring subdural strips
Device: FHC Guideline 4000+ system and/or Medtronic RC+S
Brain signals will be recorded using the clinical Participants in this group with Parkinson's disease will be undergoing deep brain stimulation implantation surgery as part of the standard of care. In addition, the Ad-Tech Medical Instrumentation Corp. device will be used to test responses with wireless sensors placed on the participant's arms, which can record EMG activity. Brain signals will be recorded using the clinical FHC Guideline 4000+ system and/or Medtronic RC+S devices, which are capable of recording during stimulation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Brain signals between the groups
Time Frame: intraoperative
FHC Guideline 4000+ system or Medtronic devices will be connected to Ad-Tech Medical Instrumentation Corp. electrodes and deep brain electrodes to measure brain signals between the groups
intraoperative

Collaborators and Investigators

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

Sponsor

University of Florida

Collaborators

National Institute of Neurological Disorders and Stroke (NINDS)
Medtronic

Investigators

  • Principal Investigator: Aysegul Gunduz, PhD, 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)

March 15, 2016

Primary Completion (Actual)

October 13, 2025

Study Completion (Actual)

October 13, 2025

Study Registration Dates

First Submitted

March 15, 2016

First Submitted That Met QC Criteria

March 17, 2016

First Posted (Estimated)

March 18, 2016

Study Record Updates

Last Update Posted (Estimated)

January 13, 2026

Last Update Submitted That Met QC Criteria

January 12, 2026

Last Verified

August 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB201600172-N
  • 03UH3NS095553 (Other Grant/Funding Number: National Institute of Neurological Disorders and Stroke)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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