The Ultrastructure of Lafora Body

Brain biopsy from 15-year-old girl patient suffering from myoclonus epilepsy (Lafora type) was performed. Biopsied specimen was studied by the light microscope, the phase contrast microscope and the electron microscope. Light microscopic finding revealed many Lafora bodies and was completely consistent with the autopsy finding of siblings, already died of myoclonus epilepsy of Lafora type. Phase contrast microscopic study disclosed the body consisted of two different layers, I. e. the external and the internal ones. Electron micrograph of Lafora body revealed that its basic structure was consisted of lamella which composed of double electron dense lines measured about 5o to 100 A thick and electron lucent interspace of similar thickness. Glycogen-like granules of about 250 to 500 A in diameter were scattered throughout the body. Beside the basic lamellar structure, ribosomes, vacuolated rough surfaced endoplasmic reticulum and Golgi apparatus were also found in the large sized body. 　 Discussions were performed concerning following items． 1) Cortex without Lafora body． 2) Lafora body in the neuronal perikarya． 3) Small sized Lafora body． 4) Structures simulate to Lafora body． The relation of abnormal vesicles and the process or Lafora body formation was especially considered.