Patient case (clinical description): A 60-year-old man comes to the clinic complaining of hand tremor that started few months ago.  It is most bothering when he wants to drink from a glass or pour from a bottle. He does not smoke, but drinks occasionally. He recently started consuming more alcohol as his tremor subsides somewhat when he drinks small amounts of alcohol.  Family history is significant for similar problems in his mother.  Vital signs are normal and the patient has no other medical conditions.  Neurologic examination shows bilateral tremor in the upper extremities. The diagnosis of essential tremor is confirmed.

Patient's own account: I'm only a 60 years old man but I already suffer from shaky hands. It started a few months ago, and it really bothers me when I want to pour myself a glass or even while drinking. I don't smoke, but I drink alcohol from time to time. To be honest, I've been drinking a little more lately since it helps me with the shaking. My mom had the same issue when she was my age. The doctor took my vitals, and they were normal. I don't have any other medical issues. I underwent neurological exams and it showed that I’m shaky from both sides. The doctor diagnosed me with essential tremor.

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

Eligibility criteria:
Subject population (children, adults, groups): Adults approved for DBS surgery at Mayo
        Clinic for treatment of essential tremor

        Inclusion Criteria:

          -  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.

        Exclusion Criteria:

          -  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.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 21 Years old.
Subject must be at most 70 Years

Eligibility (NLI label): Entailment