Prospective Study for Symptomatic Relief of ET With Cala Therapy
Prospective Study for Symptomatic Relief of ET With Cala Therapy
Prospective, multi-center, single-arm, non-significant risk study designed to evaluate the
 Cala TWO device. Subjects will be screened for eligibility and fitted with a Cala TWO device.
 Subjects will wear the device at home for a period of 3 months, during which they will be
 asked to stimulate their dominant hand twice a day. The stimulation amplitude will be based
 on each subject's stimulation threshold. Subjects will have in clinic assessments at
 enrollment, month 1 and 3.
Inclusion Criteria:

 -  Must be ≥22 years of age

 -  Competent and willing to provide written, informed consent to participate in the study

 -  A diagnosis of essential tremor as confirmed from clinical history and examination by
 a movement disorder neurologist

 -  A tremor severity score of 2 or above in the dominant hand/arm as measured by any one
 of the TETRAS upper limb items and a minimum subset score of 6 across all upper limb
 items

 -  Significant disability due to essential tremor (Bain & Findley score of 3 or above in
 any one of the upper limb items and a minimum subset score of 8 across all upper limb
 items)

 -  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 prior to study
 visits

 -  no usage of the Cala TWO device within 8 hours prior to study visits

 Exclusion Criteria:

 -  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, or implanted metal in the wrist to be stimulated

 -  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

 -  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 who 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
 Sponsor

 -  Significant alcohol or caffeine consumption within 8 hours prior to 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