Central core disease

Two cases of central core disease and two cases of multicore disease were presented. They were noted to have slight motor retardation and their clinical courses were non progressive or very slowly progressive. Electromyography demonstrated myopathic abnormalities, however, serum enzyme levels except for one case were not increased. Histological examinations of the muscle biopsies revealed the presence of central “core” regions in most of muscle fibers in the formers. On the other hand, the biopsy findings of the latters showed multifocal myofibrillar degeneration like the core in the cen tral core disease. Target fibers in a muscle biopsy from a patient with peripheral neuropathy were examined by light and electron microscopy. In the histochemical and electron microscopic studies, the target and the central core region were morphologically indistinguishable, and the central core region and the cores in multicore disease showed uniform appearance. The relationships of the central core disease to the multicore disease and the target fiber were discussed. The pathogenesis of the cores remains unknown.