--the Liza Jane spreadsheets are probably the most complete; they've been put together to provide tests to investigate neurological symptoms from many possible causes (not just peripheral ones, but central nervous system ones as well), and to track those results over time for patterns:

www.lizajane.org

Also, up in the Useful sites, look under my name for the links to Dr. Latov's/Quest's serological tests for neuropathy, and the Poncelet protocols for the diagnosis of neuropathy.

It's been my experience that unless one in under the care of a research-oriented neurologist at a tertiary center or teaching hospital, rarely is an extensive enough work-up done (many doctors are just not familiar with the many possible causes of the condition).