Again, I'm no expert but it may certainly be the case that the portfolio of considerations for each trial will differ, and hence lead to different design elements. But, it would seem that the role of the sham surgery in helping determine efficacy (or lack thereof) in the Ceregene trial was vital.

Peggy raises a different question...one of how well does any patient understand all the implications of participating in trials. Informed consent is a challenging and ongoing area with focus for improvement, no doubt.

Re the trial design differences for DBS ... I don't know but would offer that DBS is a symptomatic treatment where the surgery implants a device in the brain but the "treatment" comes from turning on the device not located in the brain...maybe that changes the confidence/nuance about ability to blind--the flind would come from turning on/off but the implant would have to take place regardless?

Just guesses.