Abstract
Two important acute demyelinating disorders will be discussed in this chapter; multiple sclerosis (MS) and acute disseminated encephalomyelitis (ADEM). The distinction between the two disorders can be problematic, but in this chapter, a concise summary of these two disorders will be presented. Childhood MS is rare and has different genetic risk factors and similar clinical and MRI findings to adult onset MS. Exposure to extrinsic environmental factors during early childhood in genetically predisposed individuals is believed to trigger MS.