Mitochondrial hydroxyapatite deposits in spinocerebellar degeneration

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.

Calcium and phosphorus levels in serum and CSF in dementia

Marked differences in CSF levels of both calcium and phosphorus were observed in patients with dementia and aged controls when compared with adult controls. A significant decrease in both Ca and P in CSF was observed in Alzheimer's type dementia (p less than 0.01) and multi-infarct dementia cases (p less than 0.01). The geriatric controls also showed a significant decrease in both Ca and P. A 60% decrease in diffusible Ca in CSF was noted both in patients and geriatric controls when compared to adult controls (p less than 0.001). Diffusible P was also decreased in all three groups (p less than 0.05). A marginal decrease in serum Ca and slight increase in P was observed in both patients and geriatric controls. The significant decrease in CSF Ca and P in both groups of patients compared with aged controls suggests this lowering of Ca and P is not due to solely to the aging process and indicates a role in the pathology of age-related disorders.