--these two sites should help regarding classificiation of neuropathy:

http://neuromuscular.wustl.edu/naltbrain.html

This is the Washington University at St. Louis Neuromuscular database--while written for doctors, it is an excellent overview of neurological conditions. The link above is the neuropathy classification page (we also have it in the Useful Websites "stickies") and it breaks down neuropathy type in several dimensions--cause, patttern of onset, anatomical distribution, functional disruption.

http://neuromuscular.wustl.edu/naltbrain.html

This is the classification page of The Neuropathy Association. (A number of us have commented on the inefficiency of the message boards there, but they do have a good informational database on the condition.)