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: Clinical and Physiological Studies of Tremor Syndromes

Eligibility criteria:
-  INCLUSION CRITERIA FOR TREMOR PATIENTS:

          -  Patients diagnosed with a tremor syndrome, including, but not limited to

               -  Essential tremor (per definition of the Tremor Research Group)

               -  Parkinson disease (per UK Brain Bank criteria)

               -  Focal tremor such as isolated head tremor, voice tremor

               -  Task-specific tremor such as primary writing tremor

               -  Orthostatic tremor

               -  Patients with other tremor syndromes such as dystonic tremor, intention tremor,
                  etc.

          -  Age 18 or older

          -  Able to give informed consent

          -  Agree to not drink caffeine or alcohol for 12 hours before phenotyping and selected
             sub-study visits because both agents can modify brain activity and may confound
             outcome measures.

        INCLUSION CRITERIA FOR HEALTHY VOLUNTEERS:

          -  Age 18 or older.

          -  Able to give informed consent.

          -  Agree to not consume caffeine or alcohol for 12 hours before selected sub-study visits
             because both agents may modify the activity of the brain during the study.

        EXCLUSION CRITERIA FOR TREMOR PATIENTS:

          -  Problematic alcohol use, as defined by a score of 8 or higher on the WHO Alcohol Use
             Disorders Identification Test (AUDIT).

          -  History of a brain tumor, a stroke, traumatic brain injury, epilepsy or a history of
             seizures.

          -  History of psychotic disorder, Bipolar Disorder or a current depressive episode.

          -  History or clinical evidence of another neurologic disorder than a tremor syndrome as
             defined above, which may interfere with the ability to comply with protocol
             requirements or interpret the obtained results.

        EXCLUSION CRITERIA FOR HEALTHY VOLUNTEERS:

          -  Have abnormal findings of clinical significance on the neurological examination that
             may affect the scientific integrity of the study

          -  Problematic alcohol use, as defined by a score of 8 or higher on the WHO Alcohol Use
             Disorders Identification Test (AUDIT)

          -  History of a brain tumor, a stroke, traumatic brain injury, epilepsy or a history of
             seizures.

          -  History of psychotic disorder, Bipolar Disorder or a current depressive episode.

        ADDITIONAL EXCLUSION CRITERIA FOR MOVEMENT DISORDER PATIENTS AND HEALTHY VOLUNTEERS
        SPECIFICALLY FOR MRI:

        We will follow the NMR Center guidelines for MR safety.

        Some of the exclusions are:

          -  Have non-MRI compatible metal in the body, such as a cardiac pacemaker, brain
             stimulator, shrapnel, surgical metal, clips in the brain or on blood vessels, cochlear
             implants, artificial heart valves or ferromagnetic fragments in the eye or oral cavity
             as these make having an MRI unsafe.

          -  Unable to lie flat on the back for the expected length of the experiment.

          -  Have uncontrolled movements of the head.

          -  Have an abnormality on the brain imaging or neurologic examination not related to the
             diagnosis.

          -  Uncomfortable being in a small space for the expected length of the experiment.

          -  Non-removable body piercing or tattoo posing MRI risk

          -  Pregnancy.

        ADDITIONAL EXCLUSION CRITERIA FOR TREMOR PATIENTS AND HEALTHY VOLUNTEERS FOR TMS AND MRI:

          -  Ferromagnetic metal in the cranial cavity or eye, e.g. aneurysm clip or ocular foreign
             body.

          -  Implanted electronic device including deep brain stimulation systems.
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 99 Years

Eligibility (NLI label): Entailment