You may be able to go to a specialty neuropathy center that was closer to you than Mayo, such as Jack Miller in Chicago, Cornell-Weill in NYC, Massachusetts General, Jacksonville Shands in Florida, Johns Hopkins in Baltimore, The University Of California at San Francisco Med Center . . .

Also, can you tell us what type of testing you've had? It's been the experience of many of us that unless one is under the care of a really savvy neuro, or at one of these kind of centers, the work-ups for possible causes of neuropathic symptoms can be patchy or incomplete--doctors just don't know--which is why I often recommend the Liza Jane spreadsheets (very good for tracking test results over time and suggesting others to doctors):

www.lizajane.org

As well as the Poncelet protocols:

http://www.aafp.org/afp/980215ap/poncelet.html

And this listing of serological tests for neuropathy causes put together by Dr. Norman Latov at Cornell-Weill and Quest diagnostics:

http://www.questdiagnostics.com/hcp/...eralNeurop.htm