Lafora's disease. Clinical, histological ultrastructural and biochemical study

Clinical, electroencephalographic, neuropathological and biochemical data from a 16 yr old patient with progressive myoclonus epilepsy (PME) of the Lafora type are reported. Histological data show the presence of neuronal loss and gliosis. Electron microscopic observations show the presence of Lafora bodies in neurons with a dense central core and a more lightly staining rim. They are composed of fibrils and granules. The biochemical studies show a decrease of cholesterol (30.8% of control values), glycolipids (29.8%), and phospholipids (50%). Insoluble glycoprotein NaNa and hexosamines were decreased to 13.28% and 17.39%, respectively; soluble glycoprotein NaNa was unchanged, while hexosamines were increased 155.68%. A marked increase was found for insoluble mucopolysaccharides (348.82%). These changes led to speculations concerning the biochemical basis of this syndrome.