central pontine myelinolysis
a sporadic disorder characterized by a localized area of demyelination in the center of the basis pontis that, on cross section, can vary substantially in size from one patient to another. In most instances, occurs concurrently with some other serious medical disorder (chronic alcoholism, severe burns, advanced lymphomas); clinically may be asymptomatic or markedly symptomatic, depending on the size of the lesion.
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