--you haven't gotten anywhere near a complete work-up yet, though what you have is a decent start.

Cycelops is correct, but you may want to check out that diabetic possibility more closely. The numbers you report are borderline, and certainly fall into the category of imparied glucose tolerance, which is increasingly being recognized as a cause of neuropathy, especially painful small-fiber neuropathy (the type most typical in diabetics). In fact, it is now referred to in some literature as pre-diabetic neuropathy.

You should take a look also at the Liza Jane spreadhseets for neuro testing at www.lizajane.org. These are excellent not only for suggesting further testing, but for keeping track of test results/patterns over time.

You did mention that your upper spinal MRI's showed no lesions, but are a mess of herniations--is it possible that some pressure is being put on a nerve root or the cord there somewhere from those? You can get neural symptoms from nerve compression anywhere from the dermatome of that spinal level downwards--e.g., cervical cord problems can result in lower limb symtpoms, not just upper limb ones. (What exactly did those MRI's say--which brings up another point: do you have copies of all your test results/reports?)

Some stuff on impaired glucose tolerance as a cause of neuropathy:

http://millercenter.uchicago.edu/lea...diabetes.shtml

http://care.diabetesjournals.org/cgi...full/24/8/1448

http://care.diabetesjournals.org/cgi...full/29/6/1294

http://www.jabfm.org/cgi/content/full/17/2/127