Background: * The brain has natural electrical rhythms of brain activities. These rhythms may be different in people with movement disorders, such as dystonia (involuntary muscle movement, cramps, or tremors). Understanding these rhythms may provide more information about movement disorders. * Focal hand dystonia, also known as "writer's cramp" or "musician's cramp," is a painful condition that affects the hand and arm muscles. Researchers want to use transcranial magnetic stimulation (TMS) to study brain rhythms in people with and without focal hand dystonia. Objectives: \- To better understand brain rhythms involved in focal hand dystonia. Eligibility: * Individuals between 18 and 70 years of age who are right-handed and have focal hand dystonia. * Healthy right-handed volunteers between 18 and 60 years of age. Design: * Participants will be screened with a physical exam and medical history. * This study includes two tests: a pilot test and a main test. The pilot test will determine the frequency of TMS that will be used in the main test. Participants may be in one or both tests. Each test requires a single outpatient visit that will last up to 5 hours. * Participants will have a base test to see how their muscles respond to TMS. This will look at the electrical activity of the muscles. Participants will have a wire coil held on their scalp. A brief electrical current will pass through the coil. It creates a magnetic pulse that stimulates the brain. Researchers will test the TMS on the right and left sides of the head. This will help find the spot that activates the finger muscles, and see how much TMS is needed. * In the main test, participants will have repetitive TMS (rTMS). rTMS involves repeated magnetic pulses delivered in short bursts. There will be four pulses in each burst. Participants will have multiple bursts during the test. This test will look at how the muscles of the hand and fingers respond to brain stimulation. * Treatment for focal hand dystonia will not be provided as part of this study.
Age range
18 Years – 70 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Motor evoked potential following TMS conditioning versus the baseline MEP amplitude in dystonia patients and healthy subjects.
Timeframe: 6 months