fMRI Studies of Task Specificity in Focal Hand Dystonia

This study will examine how the brain makes involuntary spasms and contractions in patients with focal hand dystonia (FHD). Patients with dystonia have muscle spasms that cause uncontrolled twisting and repetitive movement or abnormal postures. In FHD, only the hand is involved. The study will use functional magnetic resonance imaging (fMRI, see below) to study which areas of the brain are primarily affected in FHD and better understand how brain changes produce dystonia symptoms. Normal right-handed volunteers and patients with FHD who are 18-65 years of age may be eligible for this study. Candidates are screened with a medical history and physical and neurological examinations. Women who can become pregnant have a urine pregnancy test. All participants undergo fMRI. This test uses a strong magnetic field and radio waves to obtain images of body organs and tissues. The subject lies on a table that is moved into the scanner (a metal cylinder), wearing earplugs to muffle loud knocking and thumping sounds that occur during the scanning process. The procedure lasts about 90 minutes, during which time the patient is asked to lie still for 10-15 minutes at a time. During the procedure, subjects are asked to perform some tasks, including writing, tapping with their hand, and drawing in a zigzag motion. Each task is performed using the right hand, left hand and right foot.