Clinical Outcomes for Deep Brain Stimulation

This study tracks long-term outcomes for patients who receive deep brain stimulation (DBS) — a surgical treatment where a small device is implanted in the brain to regulate abnormal electrical signals — for Parkinson's disease, essential tremor, or dystonia. **You may be eligible if...** - You have Parkinson's disease that responds to levodopa medication, OR - You have essential tremor that no longer responds well to medication, OR - You have dystonia (involuntary muscle contractions) that no longer responds well to medication **You may NOT be eligible if...** - You have dementia (a score below 130 on the Mattis Dementia Rating Scale) - You have structural brain abnormalities that make brain surgery unsafe Talk to your doctor to see if this trial is right for you.