--length dependent neuropathy is the most common presentation: the longer fibers are affected first, so symptoms are distal initially--but that's hardly the ONLY presentation.

The length dependent "die-back" is more likely in neuropathies that have a significant ischemic or circulatory componet. The theory here is that microvascular changes, such as happen in diabetes and in many connective tissue autoimmune diseases, will affect smaller fibers, and the ends of these, first, as larger nerves with large blood supplies can still get nutrients/oxygen into the nerves, and wastes out. Moreover, the longer foodstuffs and oxygen have to travel, and the farther waste products have to be transported to the trunk to be eliminated, the more likely this travel can be disrupted.

But, if your neuropathy does not have a major ischemic component, it means you might not have that kind of presentation. Neuropathic symptoms can occur anywhere in the body, and at whatever intensity they like.

Further, it's possible that the relative lack of symptoms in your feet compared to higher up on the legs COULD actually be a distal neuropathy, but the process has progressed enough n your feet that you have more "negative" symptoms (i.e., numbness) than "positive" (added) symptoms (i.e., pain). It could be a sign the process is spreading upwards.

This is why a skin biopsy is so useful. While it generally will not reveal a cause, if they take samples, say at foot, at upper calf, at thigh, it may be determiniable (based on relative intraepidermal fiber densities) whether this is a distal "die-back" process or not.

I'm curious about the ANNA (not ANA, I assume, and not ANCA) finding from your past--you may know that the presence of the antibodies (otherwise referred to as Anti-Hu and Anti-Ri) are associated with paraneoplastic snydromes. I'm glad the extractable test was negative, but that doesn't mean you have no autoimmune issues--there are numerous autoantibodies that react directly with aspects of nerve:

http://www.neuro.wustl.edu/NEUROMUSC...oantibody.html

--and I'd have doubts they've titred you up for all the GM/GQ/GD series ones. Have you ever had tests for anti-MAG or sulfatide antibodies?