EEG and EMG Studies of Hand Dystonia

INCLUSION CRITERIA: The study population will consist of (a) healthy volunteers; and (b) patients with focal hand dystonia. Healthy subjects: Healthy volunteers who consented to participate in the study. Patients diagnosed with focal hand dystonia: unilateral focal hand dystonia from our dystonia patient database who consented to participate in the study. EXCLUSION CRITERIA: Healthy subjects: abnormal neurological exam or history of past neurological disease. Dystonia patients: the presence of a second neurological disease or condition; abnormal neurological findings on exam that are not related to their focal hand dystonia. For MRI studies, patients with metallic implants will be excluded to remove potential risks from this procedure. For MRI purposes, women who are pregnant are excluded from this part of the protocol. Therefore, all women of childbearing potential will have a pregnancy test performed prior to prospective MRI studies, which must be negative, before proceeding. For TMS studies, healthy volunteers or focal hand dystonia patients who have a pacemaker, an implanted medical pump, a metal plate or metal object in the skull or eye (for example, after brain surgery), or who have a history of seizure disorder will be excluded from the trial.