--can you post results of testing that was done, especially any serological tests for anitbodies?

There are a number of autoimmune neuropathies that do not necessarily involve the anti-nuclear antibodies characteristic of vascular/collagen/connective tissue autoimmune conditions (though those can cause neuropathy too), but involve antibodies to specific components of peripheral nerve, and everyone should be tested for these if cause is not obvious (and it often isn't):

http://www.neuropathy.org/site/DocSe....pdf?docID=944

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