MRI's are not going to show body wide neuropathy unless maybe there is a structural problems high in the cervical spine...but this would not likely cause sudden symptoms as you described.

BTW, they wouldn't typically order a tilt table for numbness, so what are your other symptoms that prompted docs to order that test? Are you passing out, have low BP or high heart rates?

You'd be surprised at the wide range of symptoms that go with autoimmune disease. We might be of more help if you shared your full list of symtpoms...as they might all be related.