There are a number of seronegative spondyloarthropathies you can explore. The other option is obviously some kind of autoimmune issue. There are the hereditary ones. Check out the neurowustl site. It has lots of good info. Finding the cause of your neuropathy starts with one test and keeps going until either the docs or you give up, or you hit it 'lucky' and find an answer.

I assume they are talking about doing some PT for your back pain?? At the MRI says is that no problem they can see is impinging on your spinal cord or no orthopedic problem is causing pain. Intermittently, I get horrible coccyx pain, it lasts for several weeks to months and then goes the same way it came. No clue as to what causes it. And I emphathize with you. It is terribly painful. I have a brace which works pretty well for my thoracic pain....Spinomed. It has to be fitted by an orthotist and it is pricey. A German engineered brace to help women with kyphosis due to osteoporosis. I have neither but due to the pain from the herniation we tried it, and it helps.

I was told that thoracic disc herniation did not cause any pain....bs. It does and did, but the spinal nerve root injections of cortisone to make it better made it worse. The above described brace helps.

I don't know how long you had the back or where your neuropathy is, but finding the cause of neuropathy is a marathon....a voyage....gosh, even an odessey. I hope you find a cause and a treatment.