1. It certainly can--there are more and more reports of those who have neuropathy symptoms merely with impaired glucose tolerance without frank diabetes. Your fasting blood sugar, though, wouldn't be as good an indication of this as an extended glucose tolerance test, with both glucose and insulin levels drawn every half hour to see the rise and fall patterns, would be.

2. Yes, and your level is pretty low, no matter what the "standard ranges" say. Supplementation can help, but it may depend on how long your symptoms have been ongoing and the extent of damage. Injections aside, I would take at least 1000mcg/day of methylcobalamin B12 to ensure some is being absorbed regularly. (See our B12 thread in the Useful Websites section up top.)

3. That gabapentin dose may be too low (that's not a big dose at all)--usually the dosage is raised to tolerance and to see the point at which no further relief is noted. And often smaller doses are taken closer together (gabapentin's half-life is somewhere between 5-8 hours, depending on your metabolism and kidney function.) You can experiment with raising it a bit at a time and see how it goes.

4. Many people do use both those--some use the R-lipoic form of alpha lipoic, which had greater effect for smaller dosage (as some have reflux difficulty with the acid component). Some also use coenzyme Q10, and B-complex. Supplement regimens vary considerably individually, and often take a lot of trial and error to maximize.

5. Some people with bad symptoms find some of the antidepressants like Elavil, used in small doses, have a synergistic effect with the anti-seizure meds like gabapentin or lyrica. There are also other anti-seizure meds that can be tried.

6. I'm always a fan of a second opinion at a good major medical center that does research in neuropathy. Hopkins is definitely one; Jack Miller in Chicago, Jacksonville Shands in Florida, Cornell-Weill and Columbia Presbyterian in New York, Massachusetts General in Boston, Washington University Neuromuscular in St. Louis, and University of California at San Francisco medical center are others. Of course, you have to be able to travel and afford them.