--have you seen the Liza Jane spreadsheets?
This was put together by Liza Jane--with considerable input from a number of us--to be as comprehensive a series of possible tests for neurological symptoms as current science allows, and it gets updated periodically:
www.lizajane.org
The Useful Websites "stickies" also has a number of entries at which dignostic protocols for neuropathy can be found--those given by Washington University's Neuromuscular conditions website and by Dr. Latov of Cornell Weill and Dr. Poncelet of University of California/San Francisco most prominently.