Are key to your finding out what is going on....
Here is an article about skin biopsies...
http://www.bmj.com/content/334/7604/1159.full
That, in combination with blood workups, auto-immune blood workups, and nerve conduction studies are key to any diagnosis.. Don't forget the MRI's and Ct's to rule other spinal problems.
IF you can get copies of all the tests done? Do so! Then 'web' up the key things to look out for about each test.. ask us, about this 'test' for X and I bet we can find you a web-site to 'translate' some of the results.
I didn't have to have biopsies, because all other tests showed, in 2 of 3 specialists' opinions, that, I had what I have. [CIDP-an autoimmune neuropathy] But I think the skin biopsy procedures are super! Like Peanut Butter!- minimally 'invasive' and get results! So it's seeming that between the immune testing of blood work and the biopsy work-up, that your neuro, is at least, not a slaggard. I'd give him gold stars for doing what he's done...NOW? It's up to you and your husband to push the tests a few steps further, shouldn't take too many.....
Get the test result copies.. then ask us where to look so you can learn more about them! A lot of info is up in the top sections of the forum, called 'STICKIES', be cause they are 'things to keep' and learn from.
Do let us all know how things are going, test-wise and living wise. So many of us have 'been there! At times, again, and then again.
Keep faith that your instincts are saying: 'SOMETHING IS WRONG HERE" and push to get the tests that say: YES! Something IS wrong.
Hope, heart and faith...plus a few hugs? !!!!!! - j