Welcome to the forum AzHiker,
I know of the aggravation of carpal tunnel in one wrist and wearing a splint does help but after the small operation i had to fix it, i wouldn't hesitate to have my other side done, if it started to carry on too.
I was diagnosed as having small fibre damage and some large nerve too, mine was caused by Prediabetes, which was picked up by a 3 hour Glucose Tolerance test and i was low on B12 as well, i am nearly cured these days but it took 3 years to repair the damage which was definatly helped by daily Mult- B & B12 supplements and injections of B12 Hydroxocobalamin, and of course changing my diet to low GI foods & excercise fixed the prediabetic state as well.
There are many reasons why small fibres can be damaged, Diabetes is common but there are many are reasons why this happens to people, if you go to the " Important Links & Stickies ": on the front page up top there is a mountain of info that is well worth reading, & Liza Janes charts are very valuable to keep a record of your progress & they also show the many tests that are available to find the cause of your PN, also i would recommend you read Roses B12 site http://roseannster.googlepages.com/home.
I don't know why your doc said Vitamin B won't help, as a combination of multi B with B12 Methylcobalamin helps repair nerve damage.
I never used A/L acid, but i think there is a newer version of it R - Version thats available now, i only know it can be helpfull for Diabetics, but i am sure others here can give you a lot more info on that supplement than i can.
Others will be along shortly, good luck
Brian