In the first successful randomized, double-blind clinical trial of a gene therapy for Parkinson's or any neurologic disorder, Dr. Michael Kaplitt, from Weill Cornell Medical College (New York, USA), and colleagues introduced a gene into the brain to normalize chemical signaling.  Forty-five patients with moderate to advanced Parkinson's disease who were not adequately controlled with current therapies were enrolled in a  double-blind trial, with half randomized to receive the gene therapy and the other half to a "sham surgery" -- a mock procedure designed to make patients think they could have received the experimental approach. Half of patients receiving gene therapy achieved dramatic symptom improvements, compared with just 14% in the control group. Overall, patients receiving gene therapy had a 23.1% improvement in motor score, compared to a 12.7% improvement in the control group.  The researchers observe that: “The efficacy and safety of bilateral infusion of AAV2-GAD in the subthalamic nucleus supports its further development for Parkinson's disease and shows the promise for gene therapy for neurological disorders.”