Welcome Dalia, nice to meet you..
Isn't mitoxantrone..Navatrone? Yuck, if it were me I'd give my Doc a big NO!!!! I'm not saying that it can't help a little, but at what price.
Have you read the side effect history of "N"? I know a few people w MS, who will never be well again, because of "N"..
I think I would truly give Tysabri a try before considering Navatrone. JMO!!!