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

Study 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

Primary Outcome

• 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 =

Conditions Studied

Interventions

• DEVICE Cala TWO stimulator

Study Locations (1)