I would give Tysabri a try, but make sure you get checked for that specific virus that can lead to a brain infection (J virus maybe? ask your GI) first. Did you have a resection for your first surgery? If that didn't work I would be cautious about
another surgery. Have you tried adding 6MP to biologics?
A week long liquid diet tends to quiet things down for me - but you do need to get on something to maintain remission. Are you willing to do a pred taper?