Encephalopathy associated with lamellar residual bodies in astrocytes (Towfighi, Grover and Gonatas 1975):a new observation

Cytoplasmic inclusions in neocortical astrocytes associated with arteriopathic encephalopathy and dementia

We describe what we believe to be the fifth case of a degenerative condition of the brain characterized by unusual intracytoplasmic inclusions in neocortical astrocytes, and we review four previous reports of what appears to be the same condition. Whereas these previous cases were characterized by prolonged clinical mental and psychomotor retardation, our case describes a rapid onset in a previously fit and mentally able patient in whom the astrocytic inclusions showed a close association with fibrohyaline vascular degeneration and changes resembling those of Alzheimer's disease. The inclusions, which were most frequent in the second to fourth layers of the frontal, temporal, and occipital cortices but absent from subcortical regions, consisted of large, irregular hyaline bodies surrounding the nucleus and extending into the proximal parts of cell processes. Ultrastructurally they consisted of free ribosomes in a granular and filamentous matrix. They were not bound by a membrane. Lipofuscin granules were associated with them. It is suggested that the inclusions might result from a disturbance of protein metabolism in protoplasmic astrocytes, but their true significance is unknown.

Electron microscopic features of skin in neurometabolic disorders

Skin biopsy may contribute to the clinical diagnosis of neurometabolic disorders. It is an easy and much less traumatic procedure than brain, rectal, peripheral nerve and skeletal muscle biopsies. The method is informative and not too time-consuming for an experienced examiner. Differential diagnosis is possible in most storage disorders since the ultrastructure of the storage is virtually typical in lysosomal and in nonlysosomal diseases. The storage has a particular distribution with characteristic ultrastructural patterns in the various cell types. Skin biopsy plays a major diagnostic role when clinical features are atypical for a storage disorder, to discover new phenotypic variants of known enzymatic deficiencies or when the biochemical defect has not yet been determined. It can be used as a screening procedure to orientate the investigations, to suggest specific biochemical assays on cultured fibroblasts or other tissues or body fluids. It can be applied to detect "presymptomatic" patients in affected families. Other disorders of the nervous system should be investigated in the future to ascertain whether skin biopsies could possibly be used for diagnostic purposes. Thorough knowledge of the morphological features of these disorders may also improve the understanding of their pathogenesis, shed some light on the underlying basic defects and control the results of therapy.

Morphological study of skin biopsy specimens: a contribution to the diagnosis of metabolic disorders with involvement of the nervous system

Skin biopsies were performed in 71 patients affected by the following disorders: ceroid-lipofuscinoses (17 cases), mucopolysaccharidoses (13 cases) mucolipidoses (seven cases), lipidoses (18 cases), metabolic diseases to be further classified (seven cases), acid maltase deficiency (nine cases). After a survey of semithin sections, the skin specimens were examined with the electron microscope. In most of the cases, epithelial cells, hair follicles, fibroblasts, eccrine sweat glands, smooth muscle cells, sebaceous glands, and nerve bundles were available. In 62 cases (87.3%), positive diagnostic information was obtained while in seven other cases (9.9%) suggestive features were discovered which could support the final diagnosis. In only two cases (2.8%) were the results negative. We conclude that, in association with enzymatic assays in the cultured fibroblasts, a skin biopsy specimen provides a simple opportunity for the combination of both morphological and biochemical diagnosis of storage disorders, precluding major surgical procedures.