On a separate point - John said that MS is not fatal. However, I've not seen any studies which confirm that this is the case...I don't think think that one could say that MS "never" kills because the young girl (17) that Drs. Prineas and Barrett did their autopsy on, died after suffering a major exacerbation that affected her respiratory system. I have heard of other similar type cases but they are quite rare.
I spoke about the case of that girl with my neuro and her immediate reaction was to wonder if it was indeed MS that the girl had and not something potentially similar and related, such as Devic's syndrome:
She said Devic's is very aggressive, focuses its attack on the spinal cord and, I believe she said, the lower areas of the brain and can often be fatal.
I personally haven't looked further into it since talking with my doc. Does anyone know definitively what that girl's diagnosis was?