Oldie, but goodie:
Here are a good handful of mimics.
Of course there are more, but recently I have seen a couple posts where this read is important. What I like
about the article is 1) it's brief, and 2) there are a few strategies provided to try avoid mis-diagnosis.
http://www.unitedspinal.org/msscene/2009/12/08/disorders-that-mimic-multiple-sclerosis/
-Shell