Therefore, injury to the inner sheath with relative preservation of the other myelin lamellae is indicative of primary injury to the myelin-producing cell. virus-induced demyelinating disease resembled human MS (Lipton, 1975; Lipton and Dal Canto, 1976a; 1976b; , and numerous investigators have extended our understanding of MS using a variety of TMEV strains (Brahic 2002; Monteyne et al., 1997) .