This is a study done in the UK. Fortunately, you can read the entire study for free (there is a fee for the full article).

Title:
Deep brain stimulation plus best medical therapy versus best medical therapy alone for advanced Parkinson's disease (PD SURG trial): a randomised, open-label trial

http://www.thelancet.com/journals/la...093-4/fulltext
Excerpts: The PD SURG trial is an ongoing randomised, open-label trial. At 13 neurosurgical centres in the UK, between November, 2000, and December, 2006, patients with Parkinson's disease that was not adequately controlled by medical therapy were randomly assigned by use of a computerised minimisation procedure to immediate surgery (lesioning or deep brain stimulation at the discretion of the local clinician) and best medical therapy or to best medical therapy alone. Patients were analysed in the treatment group to which they were randomised, irrespective of whether they received their allocated treatment. The primary endpoint was patient self-reported quality of life on the 39-item Parkinson's disease questionnaire (PDQ-39).

Conclusion: (My words) DBS plus your best medication regime makes for a better quality of life than medicine alone.
(I hope they didn't pay too much for this study; I could have told them that!)

My point I would like to discuss is this: What about placebo effect? Could it be that those that had the surgery (open-label means they knew they had the surgery) did better due to placebo effect??
This just doesn't seem like a really good study. Comments?