I'm curious about what the difference is between Idiopathic SFN and saying that it could be caused by Lyme. Have you tested positive for Lyme? Over 40% of SFN cases are deemed to be idiopathic. What were the results of the biopsy? Mine were 1.79 with abnormal being anything below 2.9 and normal being 2.9-4.3. In terms of progression, I have read that there is a reasonable chance of progression, staying the same, or even improving.