MS affects everyone a little differently. It would be impossible to predict the course of your cousin's disease. The figure in this post
is the standard model of disease progression for the average MS patient. Note that this is the average, there will be some people who experience worse progression and some that aren't as bad. Thankfully, there are things that we can do to bias the equation in our favor. I would encourage both you and your cousin to read some of the books that have been recommended in the Reading Nook
forum and well as some of the posts in the Diet
and Natural Approach
forums. My own experience was that I was symptom free for 8 years between my first attack and the second one that led to my diagnosis. It's been 20 years now since my first attack and I have been progressing during the last 2 or 3 years. My walking is now appreciably impaired.