1983 Volume 15 Issue 6 Pages 467-477
Abnormal polysaccharide accumulation was found in the muscle biopsied from a patient of progressive myoclonus epilepsy (PME) (Lafora body form), whose elder brother had died at the age of 16 years and diagnosed as PME (Lafora body form) by autopsy. Muscle biopsy was performed at the age of 13 and 18 years. Light microscopy of the muscle revealed PAS positive stippling and type grouping, while electron micloscopy revealed only an increase of glycogen granules. The second muscle biopsy revealed abundant fibers strongly positive for PAS and phosphorylase activities. Acid phosphatase and DAB peroxidase activitise were negative. In an electron microscopic study, abnormal accumulation of small particles which were demonstrated as polysaccharides because of positive reaction for the methenamine silver stain was found. These particles were finer and smaller than normal glycogen particles, some of which formed a beads like arrangement. No distinct filamentous material like the Lafora body was found. Liver biopsy was also performed at the age of 13 years which showed strongly PAS positive cells by the light microscopy and an increase of glycogen granules and dilatation of smooth endoplasmic reticulum by the electron microscopy. These results might suggest the possibility that PME (Lafora body form) is a systemic metabolic disorder with an error of glycogen synthesis.
