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DBS Severe ET Closed Loop

  • Status
    Accepting Candidates
  • Age
    21 Years - 99 Years
  • Sexes
  • Healthy Volunteers
    Accepts Healthy Volunteers


This is a feasibility study based on physician-initiated Investigational Device Exemption (IDE) including intraoperative experiments and chronic testing of implanted dual thalamic DBS lead systems. This study will inform protocols for optimal use of implanted next-gen DBS systems for primarily tremor control in refractory essential tremor.If the approach appears to be successful, the pilot data generated will be used to base a future pivotal trial for FDA approval for enhanced tremor control and adaptive DBS (aDBS) functionality of DBS systems.


Ventralis intermedius nucleus of the thalamus (VIM) Deep Brain Stimulation (DBS) has emerged as a highly effective treatment for essential tremor, which is an incurable, degenerative brain disorder that results in progressively debilitating tremor, afflicting an estimated 7 million people in the US (2.2% of the population). Clinical observation shows, however, that disease progression results in eventual recurrence of debilitating tremor in 10 to 20% of VIM DBS patients. DBS revision surgery, with replacement of sub-optimally positioned VIM DBS leads and addition of an ipsilateral ventralis oralis (VO) DBS lead, has emerged as an effective rescue strategy for many such patients with delayed failure of VIM DBS therapy.

Since essential tremors are typically not continuous, tremor suppressing DBS therapy need not necessarily be delivered continuously and could theoretically be effective if delivered only when movement intent or tremor is present.

Our central hypothesis is that a VIM+VO DBS system capable of detecting the neurophysiologic markers of essential tremor (ET) associated with goal directed movements, and providing responsive dual lead thalamic stimulation in a targeted and personalized manner, would provide improved suppression of severe tremor, reduce adverse effects associated with continuous stimulation, and prolong the battery life of the implantable neurostimulator (INS), decreasing the frequency of surgical procedures necessary to replace devices with depleted batteries.


Full study title Dual Lead Thalamic DBR-DBS Interface for Closed Loop Control of Severe Essential Tremor
Protocol number OCR29622 ID NCT04212780
Phase N/A


Inclusion Criteria:

  • Patient gives an informed consent.

  • Patient is over 21 years of age.

  • Patient is diagnosed with a postural-intention (essential) tremor for at least 3 years, meets diagnostic criteria for ET, has been evaluated and examined by a movement disorders fellowship trained neurologist, and is being treated with traditional VIM DBS therapy.

  • Patient has no evidence of non-ET central nervous system disease or injury and has had a significantly disabling, upper extremity tremor despite ongoing VIM DBS therapy for at least three (3) months prior to DBS revision surgery.

  • Patient has 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 (TRS) despite ongoing VIM DBS therapy.

  • Patient has a TRS score of 2 or above in any one of the items 16-23 from the

Disability subsection of the Trs: speaking, feeding other than liquids, bringing

liquids to mouth, hygiene, dressing, writing, working and social activities despite

ongoing VIM DBS therapy.

  • Patient's tremor is refractory to adequate trials of at least two medications, one of which should be either propranolol or primidone. Proof of this is not required for patients with a current device that is being removed and replaced with a new device. 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.

  • Patient is available for appropriate follow-up times for the length of the study.

Exclusion Criteria:

  • Any previous neurosurgical intervention other than VIM DBS, including ablative brain lesions for tremor suppression.

  • Medication related movement disorders.

  • Any suspicion of Parkinson's disease, including presence of Parkinsonian features such as bradykinesia, rigidity, or postural instability.

  • Any behaviors consistent with alcohol or substance abuse as defined by the criteria outlined in Diagnostic and Statistical Manual of Mental Disorders (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 brain atrophy.

  • 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)

Participate in a study

Here are some general steps to consider when participating in a research study:

  1. Step

    Contact the research team

    Call or email the research team listed within the specific clinical trial or study to let them know that you're interested. A member of the research team, such as the researcher or study coordinator, will be available to tell you more about the study and to answer any questions or concerns you may have.

    Primary contact

    Karim Oweiss
  2. Step

    Get screened to confirm eligibility

    You may be asked to take part in prescreening to make sure you are eligible for a study. The prescreening process ensures it is safe for you to participate. During the prescreening process, you will be asked some questions and you may also be asked to schedule tests or procedures to confirm your eligibility.

  3. Step

    Provide your consent to participate

    If you are eligible and want to join the clinical trial or study, a member of the research team will ask for your consent to participate. To give consent, you will be asked to read and sign a consent form for the study. This consent form explains the study's purpose, procedures, risks, benefits and provides other important information, such as the study team's contact information.

  4. Step


    If you decide to participate in a clinical trial or study, the research team will keep you informed of the study requirements and what you will need to do to throughout the study. For some trials or studies, your health care provider may work with the research team to ensure there are no conflicts with other medications or treatments.