Does the sham surgery really make the trial blind? Did the patients who got the sham in the CERE trial have the exact physical reaction(s) (severe facial & eye swelling, etc) as those whose brains were invaded by the treatment?

If theํr physical reactions were milder, then wouldn't the treating doctors & nurses see that and come to the obvious conclusion that they didn't get the real treatment?

Just wondering... how can we find out?