--a disc that is pressuring the spinal cord could be casuing neurological symptoms, although wouldn't technically be peripheral neuropathy (though it would be if it were impacting the nerve roots--radiculopathy--instead of the cord itself).

You may well need a greater range of tests (such as discograms) to determine what is generating the symptoms. The people at the Spinal Disorders and Back Pain forum here will certainly have some suggestions:

http://neurotalk.psychcentral.com/forum22.html