Have you tried glucosamine? While it doesn't directly do anything to the nerves, it stimulates regrowth of connective tissue and tendons and has been known to relieve symptoms of RSI and arthritis, which include pins and needles and numb.

I used to take this regularly and it really helped with the tingles, but I was taking the sulphite version, which I think was causing other problems.

There is Glucosamine Hydrochloride which can be used by non-diabetics instead of Glucosamine Sulphate. I haven't tried it because I have PCOS which is thought to be caused by Insulin resistance, so I daren't, but if you have no diabetic-type problem it might be worth a try? Once I've had the fillings out I'll be taking it again as the sulpher then might help detox.