--don't go through as many investigations as they could, so I believe more neuropathies are labelled idiopathic than actually are. It is true, though, that a good third or maybe more of small fiber syndromes turn up no cause even after extensive investigation. In many of these metabolic dysregulation, toxin exposure, or autoimmune mechanisms are suspected, but are as of yet unprovable.

I would suspect, though, the your rheumatologist may not be as familiar with other, non immune causes of neuropathy, and may not even be familiar with some of the autoimmune ones (such as those that involve antibodies to specific antigens of peripheral nerve.

You can take a look at the following two documents and see if you have had many of these possible tests--the Liza Jane site, in particular was designed to be about as comprehensive a list of tests for possible neuropathy causes as the best minds around her could think of:


www.lizajane.org

http://www.questdiagnostics.com/test...ripheralNeurop