A 40-year-old male developed a progressive neuropsychiatric illness and died 14 years later in a state of profound dementia and spastic tetraparesis. Pathologically, a primary dystrophic process of the centrum ovale had resulted in the formation of large periventricular cavities. The cerebellum was also involved. The case is viewed as a form of leucodystrophy of the sudanophil variety, although sudanophil lipids were scanty. Despite the lack of any obvious hereditary character in the case, a Löwenberg-Hill form of Pelizaeus-Merzbacher disease can also be considered a suitable diagnosis, provided one shares the view that Pelizaeus-Merzbacher disease (the classical type and its multiple subtypes as well), is nothing but another variant of sudanophil leucodystrophy. The latter is regarded as a morbid process rather than as a kind of disease entity. Little is thought of current nosologic labels based on crude clinico-pathological observations only infrequently supplemented with an adequate study of the pedigree and a sound chemical and ultrastructural investigation of the diseased tissues. Present-day ignorance of the exact etiopathogenesis makes it advisable to group under the heading ‘sudanophil leucodystrophy’ all such cases of endogenous white matter dystrophy, no matter how discrete the sudanophil character of the myelin breakdown may be and despite a broad spectrum of genetic, clinical and pathological variabi