I had my first SCS in 1986. for trigeminal neuralgia, atypical TN, atypical acial pain and anaesthesia dolorosa.
It worked for about 85% of the pain. Unfortunately I lost it due to an unrelated infection. The next did not work at all and I also lost that to an unrelated infection.
Having no other options I had a sensory cortical stimulator implant placed in 1991. It was 100% experimental, only the 13th in world to have it.
All of the were covered by my insurance, medicare and blue cross and blue shield.
The last one helped more then I realized. It failed about a year ago and that allowed me to see how much better I had been doing with it working.
The are not sure why it failed. I apparently have had it on and working longer then anyone else on whom they have records.
I have been told that insurance companies are not willing any longer to pay motor cortical and brain implants because the studies do not back up the benefit.