I had a dorsal column stimuklator for phantom facial pain, and trigeminal neuralgia. It helped about 85% of the pain gone.
Unfortunately I lost it to an infection unrelated to the implant. had a second placed in same place with no benefit. I also lost that to an infection, again unrelated to the implant (had friend with staph and think caught it from him) and because other surgeons had been in same area could not have a third.
I now have a totally experimental implant (they are not doing it anymore, I am 13th in country to have it sensory cortical) that failed a few months back.
I have had it since 1991 and untyil it failed I was unaware of how much benefit I was getting from it.
I am not a medical person but because I had good benefit from it, and because it is relatively benign (my understanding of it) I recommend considering them.