The ultrastructural cytochemical study of a brain biopsy and the biochemical study of a muscle biopsy from a 20-year-old girl with typical familial progressive myoclonic epilepsy of Lafora body type yielded the following findings: No evidence of acid phosphatase activity was observed in the great majority of the Lafora bodies, indicating that they do not undergo a hydrolytic degradative process. Both filamentous and amorphous components of Lafora bodies were stained with silver proteinate, a method to detect polysaccharides, and both were digested after incubation with γ-amylase, suggesting that both components of Lafora bodies are polyglucosans, probably in a different state of aggregation. The biochemical study of the muscle revealed twice the normal concentration of glycogen but no defect was found in the activities of the main enzymes of the glycogenosynthetic and glycogenolytic pathways.
Gambetti P, Di Mauro S, Hirt L, Blume RP. Myoclonic Epilepsy With Lafora Bodies: Some Ultrastructural, Histochemical, and Biochemical Aspects. Arch Neurol. 1971;25(6):483–493. doi:10.1001/archneur.1971.00490060017002
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