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: Neurophysiologic Study of Patient With Essential Tremor and Dystonic Tremor

Eligibility criteria:
-  INCLUSION CRITERIA

        Tremor Subjects:

          -  Must be 18 years or older

          -  Fulfill the diagnostic criteria of essential tremor, pure dystonic tremor and tremor
             associated dystonia, as defined by the Consensus Statement of the Movement Disorder
             Society on Tremor, 1998. We will recruit patients displaying hand tremors in each
             group as the follows:

               -  Hand tremor patients in ET group.

               -  Dystonic hand tremor patients in pDT group.

               -  Cervical dystonia (CD) patients or spasmodic dysphonia and hand tremor without
                  clinical evidence of hand dystonia in TAWD group.

          -  Ability to give informed consent.

          -  Ability to comply with all study procedures, based on the judgment by the
             investigator(s).

          -  Agree to not drink caffeine or alcohol for 48 hours before participating in the
             protocol.

        Healthy Volunteers:

          -  Must be 18 years or older

          -  Absence of dystonia or other neurological disorder with any effect on the motor or
             sensory systems.

          -  Ability to give informed consent.

          -  Ability to comply with all study procedures, based on the judgment by the
             investigator(s).

          -  Agree to not drink caffeine or alcohol for 48 hours before participating in the
             protocol.

        EXCLUSION CRITERIA:

        Patients:

          -  Botulinum toxin treatment < 3 months prior to visit.

          -  Employees and/or staff of NINDS

          -  Has used illegal drugs within the past 6 months based on history. The intent is to
             exclude those with drug use that may affect study results. Participants who appear to
             be intoxicated at the time of testing will be rescheduled.

          -  Has more than 7 alcoholic drinks a week in the case of a woman and 14 alcoholic drinks
             a week in the case of a man.

          -  Abnormal findings on neurologic exam (other than tremor and dystonia in patient group)

          -  Has had a brain tumor, a stroke, head trauma, epilepsy or a history of seizures.

          -  Has major depression or any major mental disorders (axis I disorders)

          -  Has a neurologic disorder other than tremor or dystonia

          -  Has had a head injury where there was a loss of consciousness for more than a few
             seconds.

          -  Currently taking primidone, anticholinergics or benzodiazepines.

        Healthy Volunteers:

          -  Employees and/or staff of NINDS

          -  Has used illegal drugs within the past 6 months based on history. The intent is to
             exclude those with drug use that may affect study results. Participants who appear to
             be intoxicated at the time of testing will be rescheduled.

          -  Has more than 7 alcoholic drinks a week in the case of a woman and 14 alcoholic drinks
             a week in the case of a man.

          -  Abnormal findings on neurologic exam.

          -  Has had a brain tumor, a stroke, head trauma, epilepsy or a history of seizures.

          -  Has a neurologic disorder other than tremor or dystonia

          -  Has major depression or any major mental disorders (axis I disorders)

          -  Has had a head injury where there was a loss of consciousness for more than a few
             seconds.

        Additional Exclusion Criteria for MRI:

          -  Has metal in the body, such as a cardiac pacemaker, brain stimulator, shrapnel,
             surgical metal, clips in the brain, cochlear implants, or metal fragments in the eye

          -  Pregnancy

          -  Unable to lie flat on the back for the expect length of the study up to 3 hours.

          -  Feeling uncomfortable being in a small space for up to 3 hours.

        <TAB>

        Additional Exclusion Criteria for TMS:

          -  Has metal in the body, such as a cardiac pacemaker, brain stimulator, shrapnel,
             surgical metal, clips in the brain, cochlear implants, or metal fragments in the eye

          -  Pregnancy
No condition on gender to be admitted to the trial.
Accepts Healthy Volunteers
Subject must be at least 18 Years old.
Subject must be at most 85 Years

Eligibility (NLI label): Entailment