Sudanophil leucodystrophy in a pachygyric brain.

Recent classifications of the diffuse cerebral scleroses have recognized the need to subdivide those cases which share in common the feature of sudanophil breakdown products of myelin. In Schilder's disease, as represented by the case he described in 1912, there are large, bilocular, sharply demarcated areas of demyelination in the centrum ovale, often associated with smaller plaques similar to those of multiple sclerosis. In contrast to this condition, there are cases in which the demyelination is much more diffuse and involves the gyral cores, the cerebellar white matter, and often parts of the brain-stem, while the degeneration products, as in Schilder's disease, are neutral fat and cholesterol esters. This group has been given a variety of names: 'neutral fat leucodystrophy' (Poser and van Bogaert, 1956), 'simple degenerative diffuse sclerosis' (Hallervorden, 1957), and 'sudanophil-orthochromatic leucoencephalopathy' (Einarson and Str6mgren, 1961). We prefer the simple name 'sudanophil leucodystrophy' because there are other sudanophil substances present in addition to neutral fat. This generic term also includes in its scope the heterogeneous collection of cases at present classed as Pelizaeus-Merzbacher disease. There is often a genetic background to these sudanophil leucodystrophies which is foreign to the Schilder type, but in sporadic cases it may sometimes be difficult to distinguish the two conditions by purely neuropathological criteria (Einarson and Stromgren, 1961). At the present time few cases of sudanophil leucodystrophy have been chemically analysed but there is some evidence pointing to differences between this group and cases of Schilder's disease. We have thought the present case worth recording not only because of the unusual combination of sudanophil leucodystrophy with a gross malformation of the cortex but because chemical analysis of the brain has shown certain features linking the condition to other types of inherited diseases of the white matter.