--an immunofixatin electrophoresis for blood and urine to enumerate immunoglobulin levels and to look for paraproteins/monoclonals, which are rogue antibodies that can cause neuropathy by interacting with the nerve gangliosides, SHOULD be a standrad test for those presenting with neuropathic symptoms.

I say SHOULD because far too many doctors don't think to order it, or order only a serum protein anlysis, which is not specific enough and. while it may reveal large levations in protein overall, cannot analyze small elevations or type.

Take a look at:

http://neuromuscular.wustl.edu/antibody/mprotein.htm