Clinicians suspect demyelination when episodes reflecting damage to white matter tracts within the central nervous system occur in young adults. The paucity of specific biological markers of discrete demyelinating syndromes places an emphasis on clinical phenotype—temporal and spatial patterns—when classifying demyelinating disorders. The diagnosis of multiple sclerosis, the most common demyelinating disorder, becomes probable when these symptoms and signs recur, involving different parts of the brain and spinal cord. Other important demyelinating diseases include post-infectious neurological disorders (acute disseminated encephalomyelitis), demyelination resulting from metabolic derangements (central pontine myelinosis), and inherited leucodystrophies that may present in children or in adults. Accepting differences in mechanism, presentation, and treatment, two observations can usefully be made when classifying demyelinating disorders. These are the presence or absence of inflammation, and the extent of focal vs. diffuse demyelination. Multiple sclerosis is prototypic for the former, whereas dysmyelinating disorders, such as leucodystrophies are representative of the latter....
Acute Disseminated Encephalomyelitis (ADEM): A Demyelinating Disease with Specific Morphological Features
