Neurophysiologic Study of Patient With Essential Tremor and Dystonic Tremor

Study Summary

Background: Essential tremor is when a person has tremor, but no other neurological symptoms. Dystonic tremor is when a person also has dystonia. Dystonia is a condition in which muscle contraction causes changes in posture. Researchers do not fully know what areas of the brain cause these tremors, or how the types differ. They also do not know what tests can identify the differences. Objective: To look at differences between essential tremor and dystonic tremor. Eligibility: People ages 18 and older with or without tremor Design: Participants will be screened with medical history, physical exam, and urine tests. Those with tremor will complete questionnaires about how tremor affects them. The screening and study visits can be done on the same day or on separate days. Participants will have 1 or 2 study visits. These include magnetic resonance imaging (MRI) and tremor testing. For MRI, participants will lie on a table that slides in and out of a cylinder that takes pictures. Sensors on the skin measure breathing, heart rate, and muscle activity. This takes about 2 hours. Tremor testing will include transcranial magnetic stimulation (TMS), electrical stimulation of the fingers, doing a movement task, and recording of tremor movements. For TMS, two wire coils will be held on the scalp and a brief magnetic field will be produced. A brief electrical current will pass through the coils. For the other tests, small sticky pad electrodes will be put on the skin. Participants will move their hand when they hear a sound. They will get weak electrical shocks to their fingers. These tests will take 3-4 hours. Participants can take part in either or both parts of the study.