[Ultrastructure of neuronal ceroid-lipofuscinoses]

Abstract

The ultrastructure of autofluorescent residual bodies in the Jansky-Bielschowsky and Spielmeyer-Sjögren types of neuronal ceroid-lipofuscinoses (NCL) is variegated though the curvilinear profiles encompass the basic pattern. The infantile and Kufs' types are marked by granular cytosomes. Deposition of the lipopigments in NCL simulates the distribution of "wear and tear" lipofuscin enabling diagnosis by biopsy and electron microscopy in peripheral organs such as skin, rectum, and especially striated muscle. Pathological findings in the retina of the associated retinopathia pigmentosa entail typical NCL residual bodies in almost every type of retinal cells, a loss of photoreceptors, atrophy of pigment epithelial cells and displacement of melanin into inner layers of the retina. This retinopathia pigmentosa seems to be a regular finding of only the classic late infantile and juvenile human types of NCL since it is mostly absent in the adult human type and the canine NCL. As long as an enzyme deficiency of this autosomal recessive disorder remains unproven, the clinical diagnosis of NCL can only be morphologically confirmed by electron microscopy.