Clinical and pathological features of 12 cases with nemaline myopathy / 中华神经科杂志

ABSTRACT

Objective To study the clinical and pathological features of nemaline myopathy(NM) in 12 cases.Methods Clinical manifestations and pathological features of muscle-biopsy specimens were summarized and analyzed retrospectively in 12 NM cases.Results In 12 cases,7 patients with typical congenital type exhibited lower or four limbs weakness as the first symptom and benign course.Three patients with childhood onset type exhibited lower limbs weakness and progressive course,and this type of patient might have muscle atrophy.Two patients with adult onset type exhibited four limbs and throat muscle weakness,rapidly progressive course and obvious muscle atrophy,and one patient had already shown acute respiratory failure.High arched feet and elongated face were observed.Creatin kinase value in all patients was normal or mildly elevated,and all electromyography showed myogenic changes.In light microscopy,the nemaline bodies were observed in more than half muscle fibers,especially in type 1 fibers.All patients showed type 1 predominance and atrophy.Modified Gomori trichrome stains showed characteristic purplecolored rods.Muscle electron microscopy showed high electron dense nemaline bodies around nucleus and disorganized myofibrillar apparatus such as broken myofilaments,irregular myofibril and Z lines.Nemaline bodies under electron microscopy may be part of myofibril or high electron-dense bodies with no structure.Conclusions The 12 patients in this study with NM are divided into 3 types,of which adult onset type is the most severe one.The key diagnosis is based on the appearance of nemaline bodies in more than half of the muscle fibers and the muscle electron microscopy observation.