The problem is no one knows what MS is yet. They have created several mouse diseases they think are like MS and they find ways to treat it. So far they have slowed progression in those with MS. I believe in the end they will find out what they call MS is actually several diseases. I have what they call Primary Progressive MS which does not act like Relapsing Remitting.The process of understanding MS is slow. There is a good book. Curing MS by Howard Weiner. He goes through the history of MS research.
Whilst i have a basic understanding, it's not nearly comprehensive enough to explain it to a biomedical student....."Variations can be induced by altering the nature of the antigen and the conditions involving immunization. Whilst it is often described as a demyelinating disease, in strict terms it is not, since the primary pathologic process is not demyelination but rather an encephalomyelitis that is immunologically induced. Rather, the prototype demyelinating disease is multiple sclerosis and its variants."