HISTOLOGICAL AND CHEMICAL FINDINGS IN KRABBE'S LEUCODYSTROPHY

Abstract

Three cases of the familial disease Krabbe''s leucodystrophy are described with the purpose of emphasizing the derivation of the perivascular globoid and mononuclear cells. Histologically, demyelination and degeneration were seen throughout the central nervous system. A fibrous gliosis was seen throughout the white matter and microglial cells with swollen processes were numerous. Globoid and epithelioid cell groups were characteristic of all cases. The cell groups were centred only around the smaller vessels and the reticulin fibrils were confined to the vessel wall. Intense fibrillary and cellular gliosis was noted in the thalamus where the nerve cells had degenerated except in the midline nuclei. Except for degeneration of the inferior olives, the brain stem nuclei were intact. The adventitial fibroblasts of vessels in many parts of the grey matter contained heavily stained P.A.S. granules. Chemically, the neutral hexose of the white matter was high and that of the cerebral cortex showed an absolute increase, when compared with normal tissue. In the white matter lipid hexosamine and neuraminic acid greatly increased, sphingomyelin was reduced by a half and lecithin remained unchanged. Characteristic of Krabbe''s disease are the wide spread demyelination, increased level of lipid hexosamine and the distinctive globoid cell groups. The origin of the globoid and epithelioid cells is considered to be the vascular adventitia in which the passage of cerebroside is hindered and consequently stored. Considering the non-specific neuronal changes and absence of visceral lipid storage, the authors classify Krabbe''s disease not as a lipidosis but as a disease of myelinated axons.