[Demyelinating processes of a viral nature]

Demyelination processes due to viral infections (encephalomyelitis induced by mouse hepatitis virus, Theiler's encephalomyelitis, canine distemper, and marek's disease) were simulated in laboratory animals to study the corresponding human diseases (multiple sclerosis, multifocal leucoencephalopathy, Guillain-Barre's syndrome). The following mechanisms of tissue injury are discussed: (1) viral damage of myelin-supporting cells, (2) demyelination occurring as a side effect of specific and non-specific inflammatory reactions to the viruses persisting in the nervous system, (3) autoimmune reaction triggered by virus infection. Special attention is paid to the role of virus agents in the development of these processes.