Clinical and Physiological Studies of Tremor Syndromes

Background: Researchers have some data on how the brain controls movement and why some people have tremor. But the causes of tremor are not fully known. Researchers want to study people with tremor to learn about changes in the brain and possible causes of tremor. Objective: To better understand how the brain controls movement, learn more about tremor, and train movement disorder specialists. Eligibility: People ages 18 and older with a diagnosed tremor syndrome Healthy volunteers ages 18 and older Design: Participants will be screened with: - Medical history - Physical exam - Urine tests - Clinical rating scales - Health questions - They may have electromyography (EMG) or accelerometry. Sensors or electrodes taped to the skin measure movement. Participation lasts up to 1 year. Some participants will have a visit to examine their tremor more. They may have rating scales, EMG, and drawing and writing tests. Participants will be in 1 or more substudies. These will require up to 7 visits. Visits could include the following: - EMG with accelerometry - Small electrodes taped on the body give small electric shocks that stimulate nerves. - MRI: Participants lie on a table that slides into a cylinder that takes pictures of the body while they do simple tasks. - Small electrodes on the scalp record brain waves. - A cone with detectors on the head measures brain activity while participants do tasks. - A wire coil held on the scalp gives an electrical current that affects brain activity. - Tests for thinking, memory, smell, hearing, or vision - Electrodes on the head give a weak electrical current that affects brain activity. - Photographs or videos of movement Participant data may be shared with other researchers.