I get tingling and light burning that runs up my buttocks and continues up my back, when I sit. This is fairly new for me so I have been questioning if I was imagining it. When I mentioned it to my neurologist she just looked confused by my symptoms. She just referred me to the Johns Hopkins Pain Treatment Center. I have diffused large fiber neuropathic pain. They only know that because the skin biopsy was negative for SFN. I'll post any information I get there although the first available is not until the end of Sept.