--to the Washington University at St. Louis Neuromuscular disorders database, which is excellent and comprehesive when it comes to neuro disorders and their attendant lab accompaniment. It is very good on describing anti-neuronal antibodies, of which you seem to have a bunch; I'm not surprised you have neuropathic symptoms. Their presence may also explain your relatively high IgM, especially in light of the negative IFE (immunofixation electrophoresis, designed to detect rogue antibodies such as monoclonals, which themselves can caue neuropathic symptoms and are often associated with blood diseases).

Did they do an immunofixation of urine as well as of blood?

At least you apparently have a doctor that thought to test for anti-neuronal antibodies--I've met too many rheumies and neurologists who don't seem to know of their existence.

There is often cross reactivity between the Anti-GM1 antibodies and the anti-Gd1 gangliosides (peripheral nerve components); and it may be hard to pull these effects out when people have both sensory and motor symptoms. In general, the GM1 antibodies indicate an attack on components of the actual nerve axon, the anti-GD1 antibodies are more specific to myelin sheathing of nerves. Of course, any time one has damage to one part there can be secondary damage to another part--fraying myelin exposes the axon, and axonal damage can lead to fraying myelin . . .

Both of these, as well as the anti-Asialo GM1 antibodies, are often associated with the more acute/subacute onset widespread neuropathies--Guillain Barre and related syndromes, such as acute motor axonal neuropathy--so it was a logical path to trying IVIg. I'm sorry the numbers did not go down with that; have they thought about plasmapharesis or immunomodulating medications?

There are probably a few other antibodies you should be tested for, such as those to sulfatide, but the test pattern is absolutely consistent with a widespread neuropathy, though I'd suspect it may be more large fiber than small fiber (not that small fibers can't be affected). And, such neuropathies are not necessarily confined to the extremities--small fiber can be body-wide, too (mine certainly was). I'm not impressed with your second neurologist.