--though many of us have multiple conditons that contribute to possible neuropathy, and sometimes it's a major puzzle to figure out just what resulted in what.

Vasculitis is a much more common cause of PN that many doctors think, and it is one of the causes that can be revealed by a muscle/nerve biopsy. Any condition in which blood vessels are damaged can result in nerves not getting enough nutrients and in waste prducts toxic to nerve function building up--in fact, the mechanism of diabetic neuropathy is thought to be primarily vasculitic in nature.

Take a look at this info--particularly the chart at the bottom, that divides the effects into size of blood vessel involved:

http://www.neuro.wustl.edu/neuromusc...html#vascassoc

Vasculitis can be toxic, metabolic dysregulated, or autoimmune, but is not a nice thing in any case; blood vessel damage is one of those things that have effects so many other places in the body.