I too have been on the higest doses of about 35 pain meds, muscle relaxants, anti dep. None ever worked. I also was on 600 lyrica - didn't even know I was taking it. I have no reactions to high doses. My body metabolizes them very quickly so they are ineffective. I believe we would be considered "polymorphic". I read that somewhere.
I am back on lyrica again and going to go up to 900mg. or more. I know it is scarey but I am desperate and my Dr. is willing to try it as my metabolism is so unusual. Of course I have gained weight in the past 2 weeks and eat almost nothing.
Re: an EMG. I refused one at the Mayo Clinic and also at the local (supposedly expert) pain mang. Dr. They stick needles in you and then they give you elecric shocks. It is something like that. Goggle it and see more about it. With RSD you must be so careful not to allow invasive type procedures like that to be done.
Best wishes. I wish I could be more helpful but unfortunately I am "in the same boat" with pain meds. Nothing ever helps. I just take sleeping pill and go to bed to get away from the pain.
Good luck,
Sydney