I was tested for Lyme during the illimination process. Actually, the first question the doctors tended to ask when told my symptoms is "Have you been bitten by a tick". Nope, but they tested anyway. Of course, the limitations of testing for lyme means that even if I had had it, it might not have shown up. Here in southern Ontario and other parts of Canada there has been a marked increase in ticks carrying lyme, so many doctors are being more vigilant, but sounds like getting a proper diagnosis if it was ruled out in blood testing is still difficult. Aparently you don't produce antibodies until the disease has gotten bad enough to trigger your immune system, and once it's full blown it can't produce them anymore, so positive testing can only be done in a limited time frame. Also, something about Canada testing for strains found in the US, not the specific strains found in the area. (Been lots of talk about this lately).
Of course, I have a friend who was bitten, found the tick that night, removed it, and went straight to emerg. They gave her a round of antibiotics to prevent infection and she's fine. Sounds like a good way to deal with known bites, and then test later if symptoms show up.
As for the MS thing, yeah, that sounds like a really bad misdiagnosis. I'm pretty sure I heard about this story: basically, you must have MS cause there's no lyme in this area. Testing a treatment has to get better.