There was an old thread on here somewhere, iirc, that talks about MS and ME. There was a quote from an MS specialist who also treats ME (or did he call it CFS, I can't recall). Apparently some patients have very distinct ME. Some have very distinct MS. However in between those the majority of patients look like having some kind of blend. The implication here was that ME and MS might be two ends of a spectrum of disease, but he didn't know that for sure.