--it is possible for the onset of such neuropathies to be gradual, but you're right, rfinney, most often the onset is acute to sub-acute, and progresses relatively quickly.

There seems to be a bit of an age division here; those who are older, or who have ANA titers that are not as elevated, seem to show more likelihood of a slower, chronic development of symptoms. And, the different vasculitic conditions have variable patterns--neuropathy secondary to lupus or polyarteritis nodosa tends to come on quickly and aggressively, whereas that of Wegener's Granulomatosis or peripheral nerve specific vasculitis often comes on more gradually.

See:

http://www.neuro.wustl.edu/neuromusc...tml#vasculitis

Nevertheless, I agree that the patten that is described for Alan doesn't seem much like a vasculitic type neuropathy, and, of course, none of the recent testing for ANA-related conditions has panned out. It will be interesting to see of the immunoglobulin /protein studies show anything.