I have had loads of blood work done, mri’s, nerve conduction study -all came back negative. My pain started with cold feet for many years, which got worse and worse and then moved into my hands. The next symptoms were electric like currents that shot up all the way up my arms and legs. The “electric shocks are now in my face, head and trunk. It’s it constant. My neurologist though hesitant to diagnose before getting all the data was pretty sure it was small fiber Neuropathy but then the biopsy came back negative.