Fine Structural Studies in Myasthenia gravis

Abstract

The authors carried out electron microscopic studies on muscle biopsy material from 23 patients suffering from myasthenia gravis, in order to show the fine structural changes occurring in the muscle fibres. Splitting of the central part of the sarcomeres and hyperplasia of Z formations were observed in some cases. Formations of concentrically arranged thin filaments were wide-spread. Pleioconial mitochondria containing various inclusions were noted, the lamellae of the crystalline inclusions being composed of granules of double helix configuration. No succino-dehydrogenase activity could be detected in crystalline-containing mitochondria by enzyme-cytochemical tests using the electron microscope. The nonspecificity of these alterations occurring in the muscle fibre organelles is stressed. The general picture reveals the biochemical nature and extent of the lesions, and gives an explanation of the structural changes associated with them.

Familiäres Vorkommen von Myasthenia gravis und okulo-pharyngealer Myopathie

“…Veränderungen an den Mitochondrien wurden in einigen Fallen beschrieben (11,15,19). Pleiokoniale oder megakoniale Mitochondrien kommen jedoch auch bei der Myasthenie vor (12), sogar auch als senile Muskelalterationen (18). Sic können also kaum als spezifischmorphologische Veranderungen betrachtet werden (12,22).…”