[An adult case of congenital myopathy--coexistence of nemaline rods and core-like structures].

A 42-year-old female complained of exertional dyspnea and sleep disturbance. Her face was elongated longitudinally and the hard palate was narrow and high-arched. She has slender musculature and kyphoscoliosis. She was dysphonic and could not walk on her heels. Muscles in the face, upper arm, pelvic girdle and thigh were atrophic. Muscle weakness was detected in the neck, tibialis anterior, ilipsoas and other hip muscles, and ranged between 3- and 4 by the manual muscle testing. Electromyography showed definite myogenic abnormalities in all the muscle examined. No abnormality was found on the routine examination of blood, as was the motor and sensory nerve conduction velocity. Her vital capacity was 0.91 L, i.e., 35% of the expected value, suggesting a severe restrictive respiration. The arterial blood gas analysis revealed hypoxia, hypercapnia and desaturation. The blood gas data worsened when she was asleep, because of increased hypoventilation. Muscle biopsy of the biceps brachii showed a marked variation in the muscle fiber size. The type 1 muscle fiber was predominant. Many fibers contained nemaline rods and/or core-like structures. Some fibers contained both nemaline and core-like structures. This core-like structures were not stained with NADH-TR and ATPase reactions, and about 40-100 microns in the longitudinal extension. In this context, typical central cores have not been observed in the present case. No association of nemaline rods and core-like structures in the same muscle fiber has been reported, although a close relationship of the two structures has been suggested.(ABSTRACT TRUNCATED AT 250 WORDS)