--just one comment on your test list--ask if they're going to do quantitiative immunoglobulins with that immunofixation electrophoresis (SPEP). Often they're done together, but not always. (Given your monoclonal history, it may be important to see the amounts of immunoglobulins present as well as their characteristics.)

And kpRN--welcome, and I have similar questions, since "mixed axonal and demyelinating peripheral neuropathy" that is idiopathic is more a description of what's happening, diagnostically speaking, than a cause. You're losing myelin sheathing from your larger nerves and this is also resulting in secondary damage to the underlying nerve fibers, but apparently there's no idea what's causing this. Given that this began in your upper extremities, one wonders about autoimmune possibilites, or mechanical ones, such as some variation of Thoracic Outlet syndrome or a brachial plexopathy (did they do any imaging of your neck and shoulder areas
?).

Tell us what test results you have--if you haven't gotten copies of them from the docs, get them. (We're pretty good with them.) And also, if you want, the Liza Jane spreadsheets are really good for tracking results over time, and suggesting future testing to doctors--these were designed to be as comprehensive a testing protocol for neural symptoms as we could come up with:

www.lizajane.org