Recently the possible existence of a specific defect in muscle lipid metabolism has been considered and a correlation between disturbance of lipid utilization and myopathic impairment has been proposed. A syndrome of subacute proximal myopathy and abnormal lipid accumulation in Type I muscle fibers was reported by Bradley et al. (1969). They defined this condition as 'Lipid Storage Myopathy' (LSM) and speculated that the lipid accumulation was due to an impaired mitochondrial oxidation of free fatty acids (FFA). An impairment of long chain fatty acid (LCFA) utilization was subsequently demonstrated by Engel et al. (1970). From a morphological point of view muscle biopsies of all cases of Lipid Storage Myopathy so far reported present a quite uniform picture. Histological specimens always reveal a vacuolar myopathy with some fibers more affected than others. Histoenzymatic techniques indicate that the abnormal spaces in the muscle fibers are filled with neutral fat. Histochemically the affected fibers are generally Type I and in some cases the Type I fibers appear to be atrophic. The clinical picture of the Lipid Storage Myopathies fail to appear as a uniform and distinct entity. Difference can be recognized in the age of onset, in progression of the disease and the involvement of the skeletal muscles and other organs. Moreover, one can tentatively classify the cases so far reported into 3 main categories.
|Number of pages||7|
|Journal||Biochemistry and Experimental Biology|
|Publication status||Published - 1977|
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