I was a bit surprised by their statement in last Friday's conference call, that they would not expect to see disease progression in patients that use Tysabri:

"There have been a few patients who have received plasma exchange in the U.S. in the case before full confirmation. But in a sense that is consistent with our advice which is to suspend TYSABRI dosing unless PML can be ruled out. Any kind of relapse activity or disease progression on TYSABRI is extremely uncommon because the drug is so effective.

So we're advising physicians to be very vigilant. If you suspect PML, stop dosing and some patients have even gone so far as to get plasma exchange, even before full confirmation. Dr. Alfred Sandrock"

http://seekingalpha.com/article/1190...nscript?page=7

Did your neuro happen to mention whether they were "enhancing" (i.e. "active") lesions, or not? If not, like you said, they may very well be from before you got on Tysabri.

Good luck on Thurs.

Cherie