--Disease Characteristics-- Idiopathic or secondary cervical, segmental, or generalized dystonia not adequately controlled with traditional pharmacotherapy and/or botulinum toxin --Prior/Concurrent Therapy-- All medical therapy must be stable within the past month Biologic therapy: Not specified Chemotherapy: Not specified Endocrine therapy: Not specified Radiotherapy: Not specified Surgery: No prior destructive neurosurgical procedure Other: At least 3 months since prior botulinum toxin injections --Patient Characteristics-- Age: 18 to 75 Performance status: Not specified Hematopoietic: Not specified Hepatic: Not specified Renal: Not specified Cardiovascular: No demand cardiac pacemaker Other: No history of substance abuse