I have had the nerve biopsy and can tell you that numbness is NOT the only gift that comes with it. Because the nerve is severed, it can cause phantom nerve pain. The nerve cannot complete it's path...just like an amputee, so pain occurs beyond the point severed. And let me tell you, it can drop you to the floor in agony. I endured this type of pain for months before it finally eased up and then stopped.

As far as I know, they rarely use this test anymore due to the extreme invasive nature and permanent numbness (and pain) that occurs.

I would ask if there is any other means of ruling out the amyloidosis. According to the Mayo Clinic site, the biopsy they use for testing involve skin, salivary, abdominal fat, gums, and bone marrow...no mention of nerve biopsy. Are you sure they are talking about a sural nerve biopsy and not the skin biopsy to look at small nerve fibers?