Rapidly progressing PNs can be treated with IVIG. The less common types due to increased antibodies thickening the blood are being treated with a very expensive potentially toxic drug:
Rituxan. So if one has one of these PNs getting it identified is important. Autoimmune illness is treated with immune suppressing drugs in some cases. The secondary benefit then can help that type of PN. Controlling blood sugar helps with diabetic PNs. Control the thyroid disease and the PN improves.

I've just been this month to 2 long seminars on the brain, its chemistry and they both included chronic pain.
Yesterday was a topic included called the "solicitous spouse".. which is a term for placing undo attention on pain and daily management. It is a psychological term to explain that when attention is constantly given either by someone outside of you to your pain, or if YOU yourself pays undo attention to it, then the pain becomes a reinforced behavior in the brain, mediated by dopamine, a neurotransmitter that facilitates learning, and ultimately "addiction" type behaviors in some.

This concept is not going to be greeted with open arms by people with chronic pain, IMO... but it is one step to learning how to live with it and perhaps master it. There is alot of research going on now about the brain and chronic pain, and it is only beginning. Medical change is pretty slow when it comes to clinical handling of patients.

Diagnosis then is to find a trigger if possible and remove it.
This takes time, patience, money.

Over use of Xrays can be a problem...but I really think all PNers should get Xrays of the feet done, to see what mechanical issues may be present. There are many things that can go wrong in the feet, that are mechanically based, and not metabolic.

This website I think is just about the best for explaining all the issues that can happen with the feet:
http://www.northcoastfootcare.com/

I learned how to tie my shoes a new way from that site, that really helps my high insteps and prevents my toes from going numb.