Subjects will undergo surgical transplantation of the dopamine-producing cells under general anesthesia into a part of the brain called the putamen. Subjects then take medicines to partially suppress their immune system (aimed to prevent the body from rejecting the cells) for 1 year. Safety, tolerability, evidence of cell survival (using MRI and PET scans of the brain), and effect on Parkinson's disease symptoms are assessed for 2 years post-transplant.
This clinical trial is designed to test whether surgically injecting nerve cells that make dopamine into the brain of Parkinson's disease patients is safe, and to monitor for potential side effects.