Myelin in Multiple Sclerosis: Composition of Myelin From Normal-Appearing White Matter

Myelin was isolated from white matter of five normal control brains and from normalappearing white matter of five patients with multiple sclerosis. There was statistically significant reduction of 25% to 30% in yield of myelin from abnormal brains, due probably to inadvertent inclusion of small lesions. No abnormalities were found in distribution of major constituents—chloroform-methanol soluble and insoluble proteins and total lipid. Analysis of individual lipids, and fatty acid composition of sphingolipids likewise did not show any differences between control and multiple sclerosis myelin. Contrary to a previous report, myelin isolated from normal-appearing white matter of multiple sclerosis brains contained normal amounts of myelin basic protein. Chemical composition of the myelin sheath in normal-appearing white matter of multiple sclerosis patients is, therefore, completely normal, at least for analytical factors examined.