Pathology of Multiple Sclerosis

We describe postmortem characteristics of individuals with multiple sclerosis that have spinal cord demyelination, cortical demyelination, and an absence of cerebral white matter demyelination. Despite the paucity of cerebral white matter demyelination, cortical neuronal loss, cortical atrophy, and cerebral white matter MRI abnormalities were similar to those found in multiple sclerosis brains with abundant cerebral white matter demyelination. We identify myelinated axonal swellings as the pathological correlate of the focal white matter MRI abnormalities and establish that degeneration of cortical neurons and cerebral white matter demyelination can be independent events in individuals with “myelocortical multiple sclerosis.”