--is educate the endo that one does not have to have a diagnosis of frank diabetes to have neuropathy caused by sugar dysregulation; thre has been mounting evidence for some time that impaired glucose tolerance can result in nerve damage, especially the small-fiber kind, well before the hemoglobin A1c levels or fasting blood sugar is highly elevated:

See the following thread:

http://neurotalk.psychcentral.com/sh...nce+neuropathy

And, of course, many autoimmune conditions can cause neuropathy, either through direct antibody attack on nerve or secondary to ischemic/vascular damage that starves nerves of nutrients and allows toxins to accumulate.

It is true that a good quarter to third of all people with neuropathy remain stubbornly "idiopathic"--no cause is ever found. Still, you're entitled to all the testing you can get, and often doctors are not well-versed in possible neuropathy causes or tests for them, which is why I recommend the Liza Jane spreadsheets, which were designed to list tests for investigate neuropathic symptoms (central or peripheral):

www.lizajane.org

Very good for tracking results over time and looking for patterns, as well as suggesting avenues to physicians who don't tend to think outside the box.