IMHO, I would not ever consent to an LP if I had clear and obvious signs of MS on the MRI like Dawson's Fingers. My first neuro would not have ever put me through an LP if my MRI was conclusive.
An LP is an invasive procedure not without risks. For those who said it isn't painful, I would have to disagree. Not everyone has a painless LP. Check out Gazelle's thread entitled "So Not Happy" if you want to see several stories of LP's that weren't easy:
http://neurotalk.psychcentral.com/sh...ad.php?t=38801
My own LP wasn't nearly as bad as a lot of people experienced, but it was bad enough that I will not consent to another one unless there is a darn good reason to do it.
I know that it must be really hard to be blindsided with this dx, but rest assured that, in time, you will adjust to it and things will level off.