During the last decade, Dr Anthony Lang and the Movement Disorder Group of Toronto Western Hospital have gifted the medical community with several outstanding scientific studies and reviews, especially in the field of surgery for Parkinson disease (PD); their recent article1 was no exception.
The author's main critique of publications on surgery of PD, especially pallidotomy and deep brain stimulation (DBS), concentrates on the lack of large-scale studies that meet the requirements that are applied for medical drug trials (ie, controlled, prospective, double-blind studies with independent assessment using established scales). Dr Lang acknowledges the fact that it is practically and ethically difficult to conduct surgical trials with sham surgery. Furthermore, he reviews eloquently the great disparities in imaging and surgical methods, intraoperative physiological techniques, patient selection, etc, as well as the fact that the great majority of published studies on surgery for PD report a small number of patients with a very short follow-up. He concludes that "despite numerous claims, the evidence for benefit from surgical therapies in patients with PD is relatively weak by today's scientific standards."