Adult form nemaline myopathy:two cases report with clinicopathological and ultrastructural study / 中华神经科杂志

ABSTRACT

Objective To investigate the clinical and pathological features of adult form nemaline myopathy. Methods Biopsied muscle specimens from two patients were observed using enzymatic histochemical method and electron microscope. Results These two patients were found with an initial onset from neck muscle weakness at the age of 52 and 36 years respectively, followed by trunk and limb muscle involvement to a variant degree. Type Ⅰ fiber atrophy and numerous granules (rod) were found in both patients in light microscopy. In case 1, the centralized nuclei were seen almost in all normal sized muscle fibers. Electron microscopic observation showed marked myofibril disorganization and numerous rod-like formations. Two inclusion-carrying nuclei were detected in case 1. The intranuclear inclusion showed a lattice pattern of Z-disc line or sarcoplasmic rod. Conclusions Adult form nemaline myopathy is clinically nonspecific. Rod-like structures might be found either in sarcoplasma or in nucleus. Centralized nuclei might coexist with rods in adult form nemaline myopathy. As compared to the child form, the adult one might often show a marked muscle fiber atrophy.