It is believed to be caused from a Vitamine B6 defeciency. We are trying to get a balance of this Vitamine, but my body seems to be very sensitive. We went from being defecient to Toxic by only taking 50 mg. a day. I am taking 25mg now and will re-test in a few weeks. In the past year and 1/2 My nueropathy has progressed from my toes all the way up my legs and in my hands with pain in my arms at times. Today was the first time I felt burning in my thighs. And all I can do today is cry.