Long-Term Transcutaneous Stimulation and Essential Tremor: A PET Study

NCT03778060 | Active Not Recruiting FDA Device

• 1 other identifier: 18-006984
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

Essential tremor (ET) is the most common movement disorder in the United States and affects up to 5% of the population. ET patients experience involuntary shaking of the hands, head and/or voice that can range from mildly limiting to severely disabling. Treatment options are limited and there are currently no medications specifically designed to treat it, and medications that are prescribed to relieve tremors are often limited by either inadequate efficacy or intolerable side effects. A subset of essential tremor patients whose tremors are inadequately treated by medication choose to undergo deep brain stimulation (DBS) of the ventral intermediate thalamic nucleus. DBS has been shown to be highly effective for tremor suppression. However, DBS carries significant risks. As a result, a very small (less than 3%) percentage of essential tremor patients undergo DBS therapy. The medical technology company Cala Health has developed a wristband device (the Cala TWO) that offers individuals with essential tremor a novel non-pharmacological, non-invasive alternative, in the form of stimulation of peripheral nerves, to aid in hand tremor relief. This innovative form of therapy has the potential to have important health, quality of life, and economic benefits for essential tremor patients. The present pilot study (Aim 1) will assess the effectiveness of 3-month twice daily treatment with the Cala TWO device to aid in the relief of hand tremors in adult essential tremor subjects that have been approved to undergo deep brain stimulation surgery at Mayo Clinic - Rochester. This study is a prospective, within subject, non-significant risk study at Mayo Clinic - Rochester, enrolling approximately 20 subjects. A completely optional component of this study (Aim 2) is seeking to perform three standard PET/CT sessions on a subset of these subjects (n=10) at Mayo Clinic - Rochester to evaluate changes in brain metabolic activity as a result of 3 months treatment with the device. The first session would take place upon a subjects entry into the study (start of month 1) and prior to any treatment with the Cala device, a second the following day after a 40 minute treatment period with the Cala device, and a third session at the end of the third month. This study is a prospective, within subject, greater than minimum risk study.

Conditions

Essential Tremor

Keywords

Transcutaneous Nerve Stimulation; Positron-Emission Tomography

Outcome Measures

Primary Outcomes (3)

• Essential Tremor Assessment Following Transcutaneous Stimulation

  • The Essential Tremor Rating Assessment Scale (TETRAS) - dominant hand subset mean change (pre-stimulation rating - post-stimulation rating) across visits. Upper limb tremor will be assessed during three maneuvers: forward horizontal reach posture, lateral "wing beating" posture and finger-nose-finger testing. Each upper limb will be assessed and scored individually according to the following scale: 0 = no tremor ; 1 = tremor is barely visible ; 1.5 = tremor is visible, but less than 1 cm ; 2 = tremor is 1- less than 3 cm amplitude ; 2.5 = tremor is 3- less than 5 cm amplitude ; 3 = tremor is 5- less than 10 cm amplitude ; 3.5 = tremor is 10- less than 20 cm amplitude ; 4 = tremor is less than 20 cm amplitude

  Patient assessed at entry to study and at exit of study (3 months).

• Assessment of Daily Activities Following Transcutaneous Stimulation

  • Bain \& Findley Activities of Daily Living (ADL) Scale (pre-stimulation rating - poststimulation rating) across visits. ADL tasks are: Use a spoon to drink soup ; Hold a cup of tea ; Pour milk from a bottle or carton ; Dial a telephone ; Pick up your change in a shop ; Insert an electric plug into a socket ; Unlock your front door with a key. Each task will be rated on a 4-point scale (1-4): 1 = Able to do the activity without difficulty ; 2 = Able to do the activity with a little effort ; 3 = Able to do the activity with a lot of effort ; 4 = Cannot do the activity by yourself

  Patient assessed at entry to study and at exit of study (3 months).

• Assessment of Tremor Severity Following Transcutaneous Stimulation

  • The Patient Global Impression - Severity scale (PGI-S) on tremor mean improvement change across pre- and post-stimulation sessions. The PGI-S will be a 7-point scale that the participant will use to assess their overall tremor severity of the stimulated hand and consists of: 1 = Normal ; 2 = Hardly perceptible ; 3 = Mild ; 4 = Moderate ; 5 = Marked ; 6 = Severe ; 7 = Extreme

  Patient assessed at entry to study and at exit of study (3 months).

Secondary Outcomes (1)

• Daily Changes in Tremor over 3 Months of Transcutaneous Stimulation

  Patient assessed at entry to study, twice daily over the course of 3 months, and at exit of study (3 months).

Study Arms (1)

Transcutaneous stimulation

EXPERIMENTAL

Participants in the clinical study will consist of subjects with essential tremor who are scheduled more than 3 months in advance to undergo deep brain stimulation surgery for treatment of essential tremor at Mayo Clinic. Subjects will wear a Cala TWO stimulator to reduce hand tremors.

Device: Cala TWO stimulator

Interventions

Cala TWO stimulator DEVICE

Treatment intervention will consist of subjects undergoing 40 minute sessions of transcutaneous stimulation with the Cala TWO stimulator twice daily for 3 months to reduce hand tremors prior to their undergoing deep brain stimulation 'surgery for treatment of essential tremor at Mayo Clinic.

Transcutaneous stimulation

Eligibility Criteria

• Age: 21 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Prospective subjects must meet all of the following criteria to be eligible for study participation:
• Must be greater than or equal to 21 years of age. Must be approved for DBS surgery at Mayo Clinic for treatment of essential tremor.
• Competent and willing to provide signed, informed consent to participate in the study.
• Stable dose of tremor medications, if applicable, for 30 days prior to study entry.
• Stable dose of antidepressant medications, if applicable, for 90 days prior to study entry.
• Willing to comply with study protocol requirements including: remaining on a stable dosage of tremor and antidepressant medications, if applicable, during the duration of the study; no significant alcohol or caffeine consumption within 8 hours of study visits; no usage of the Cala TWO device within 8 hours of study visits.

You may not qualify if:

• Prospective subjects that meet any of the following criteria are not eligible for enrollment in this study:
• Moderate to severe ethanol dependence as defined by the criteria outlined in the DSM-5 (score of 4 or higher).
• Implanted electrical medical device, such as a pacemaker, defibrillator, or deep brain stimulator.
• Previous thalamotomy procedure, including stereotactic thalamotomy, gamma knife radiosurgical thalamotomy, and focused ultrasound for the treatment of tremor.
• Suspected or diagnosed epilepsy or other seizure disorder. Swollen, infected, inflamed areas, or skin eruptions, open wounds, or cancerous lesions of skin at stimulation site (wrist).
• Peripheral neuropathy affecting the tested upper extremity. Presence of any other neurodegenerative disease like Parkinson plus syndromes suspected on neurological examination. These include: multisystem atrophy, progressive supranuclear palsy, dementia with Lewy bodies, and Alzheimer's disease.
• Anyone suspected to have the diagnosis of idiopathic Parkinson's disease (PD). This includes excluding anyone with the presence of parkinsonian features including bradykinesia rigidity, or postural instability. Subjects that exhibit only mild resting tremor but no other symptoms or signs of PD may be included.
• Botulinum toxin injection for hand tremor within 6 months prior to study enrollment.
• Are participating or have participated in another interventional clinical trial in the last 30 days which may confound the results of this study, unless approved by the Principal Investigator.
• Significant alcohol or caffeine consumption within 8 hours of study enrollment, which may confound the results of the study, where significant caffeine is considered more than 95 mg (equivalent to a cup of coffee), and significant alcohol is considered more than 14 g (equivalent to 5 oz of wine, 12 oz of beer, or 1.5 oz of distilled spirits).
• Subjects unable to communicate with the investigator and staff. Any health condition that in the investigator's opinion should preclude participation in this study.
• Pregnancy or anticipated pregnancy during the course of the study.

Sponsors & Collaborators

• Mayo Clinic: lead
• Cala Health, Inc.: collaborator

Study Sites (1)

Mayo Clinic in Rochester

Rochester, Minnesota, 55905, United States

Location

Related Links

• Mayo Clinic Clinical Trials

MeSH Terms

Conditions

Essential Tremor

Condition Hierarchy (Ancestors)

Movement Disorders; Central Nervous System Diseases; Nervous System Diseases

Study Officials

• Kendall H Lee

  Mayo Clinic

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Masking Details: No other parties will be masked
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Professor

Study Record Dates

• First Submitted: December 7, 2018
• First Posted: December 19, 2018
• Study Start: February 11, 2019
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: January 30, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)