Deep Brain Stimulation in Treating Patients With Dystonia

RATIONALE: Dystonia is a disorder in which the muscles that control voluntary movements are persistently or intermittently contracted (not relaxed). Deep brain stimulation is provided by a small, battery operated implant placed under the skin of the chest that delivers low voltage electrical pulses through a wire under the skin that is connected to a specific area of the brain. Deep brain stimulation may help lessen the symptoms of dystonia. PURPOSE: Phase II/III trial to study the effectiveness of deep brain stimulation in treating patients who have dystonia.