Clinical features of myopathy with tubular aggregates:6 cases / 中华神经科杂志

ABSTRACT

Objectives To report clinical,electrophysiological and pathological features of myopathy with tubular aggregates.Methods The onset of the disease was between 5-50 years old in the 6 sporadic male cases.Skeletal muscle biopsy was performed for all cases.Specimens were examined histochemically,enzymhistochemically and electromicroscopically.Results Case 1 and 2 presented with limb girdle myasthenic syndrome.The case 1 developed exercise-induced cramps in the late stage.Case 3 complained about persistent weakness and Dopa-responsive dystonia.Case 4 and 5 were characterized by periodic paralysis.Case 6 showed exercise-induced cramps.Serum potassium was normal in all patients. Slight elevation of serum creatine kinase appeared in 3 cases.Electromyography showed neurogenic pattern in case 1 and 6,myogenic changes in case 4 and 5,and no abnormality in other 2 cases.Marked decrement of active potential amplitude was noted with low frequency repetitive nerve stimuli in case 1 and 2.Four percent to forty percent of muscle fibers showed focal material accumulation in the fibers,which involved mainly type 2 fibers in all cases.The material was stained bright red material with modified gomori trichrome,intensive staining with nicotinamide adenine dinucleotide-tetrazolium reductase,lack activity of succinate dehydrogenase and ATPase.Electron microscopy confirmed bundles of parallel micro-tubular structure in the muscle fiber.Conclusions Myopathy with tubular aggregates has various clinical subtypes and electromyographic pattern.Dystonia or other systemic symptoms could be noted in this disease.The limb girdle myasthenic syndrome can also be accompanied with exercise-induced cramps.