重症肌无力常规针极肌电图表现

目的 研究重症肌无力(MG)患者常规针极肌电图(EMG)表现及其诊断价值.方法 回顾性分析83例完成右侧三角肌针极EMG、腋神经低频重复电刺激(RNS)和伸指总肌单纤维肌电图(SFEMG)检查的MG患者的有关资料,分析针极EMG的表现及其与RNS的相关性.结果 83例中EMG检查结果正常12例(14.5%),异常71例(85.5%).在EMG异常者中,出现平均运动单位电位(MUAP)时限缩短67例(94.4%),多项波增多者37例(52.1%),大力收缩时募集电位呈病理干扰相19例(26.8%),异常自发电位3例(4.2%),结果符合"肌源性损害"表现19例(26.8%).腋神经RNS时三角肌波幅衰减幅度与三角肌平均MUAP时限呈负相关.结论 MG患者常规EMG检查主要异常表现为MUAP时限缩短,少数可见"肌源性损害"的EMG表现.对于临床表现不典型的MG患者应检查EMG并结合RNS和SFEMG检查进行诊断和鉴别诊断.     

Needle electromyography and histopathologic correlation in myopathies

Introduction: The molecular mechanism of immune-mediated necrotizing myopathy (IMNM) remains unknown. Autophagy impairment, described in autoimmune diseases, is a key process in myofiber protein degradation flux and muscle integrity and has not been studied in IMNM. Methods: Muscle biopsies from patients with IMNM (n = 40), dermatomyositis (DM; 24), polymyositis (PM; 8), polymyositis with mitochondrial pathology (4), sporadic inclusion body myositis (8), and controls (6) were compared by immunohistochemistry. Results: The proportions of myofibers containing autophagy markers LC3b and p62 were higher in IMNM than in DM or PM and correlated with creatine kinase levels. In IMNM, compartmentalized LC3b puncta were located in regenerating and degenerating myofibers surrounded by major histocompatibility complex type II⁺ inflammatory cells. Several IMNM myofibers accumulated ubiquitin and misfolded protein. Discussion: The detection of LC3b⁺ or p62⁺ myofibers could be used in differentiating IMNM from PM. The identification of autophagy-modifying molecules potentially could improve patients’ outcomes. Muscle Nerve, 2019     

Electromyography in congenital nemaline myopathy

To clarify the discrepancies between earlier reports of electromyography (EMG) in congenital nemaline myopathy (CNM), conventional electromyography was done on 13 patients with CNM, and results were compared with those of 18 earlier EMG examinations of the same patients. Fiber density was measured in 10 patients with a computerized method and neuromuscular jitter in 3 with single-fiber EMG. With age, the EMG abnormality progressed, and "neuropathic" EMG features developed in distal muscles. In 9 of 10 patients fiber density was higher than normal. In two of three patients jitter was abnormal. Motor (13 of 13 patients) and sensory (3 of 3 patients) nerve conduction velocities were normal. Our results seem to explain the conflicting reports of EMG in CNM. We conclude that active degeneration and regeneration of muscle fibers takes place in CNM and suggest that the "neuropathic" motor unit potentials seen in our patients may be secondary to myopathic disease activity.     

Electromyography in infants and children

Electromyography (EMG) is of proven value in the diagnosis of acute and chronic neuromuscular diseases in infants and children. When this technique is combined with nerve conduction studies, including repetitive nerve stimulation studies, it is often possible upon completion of the studies to identify the disorder as one of nerve, neuromuscular junction, or muscle. The purpose of this article is to review the principles and techniques of EMG in infants and children and to describe the EMG findings in several neuromuscular disorders.     

实验性糖尿病大鼠的单纤维肌电图研究

目的:分析链脲佐菌素(STZ)诱导的糖尿病大鼠坐骨神经的神经传导速度和腓肠肌单纤维肌电图的特点,评价两种检查方法对糖尿病多发性神经病早期诊断的价值.方法:健康雄性SD大鼠经腹腔注射STZ60mg穔g-1诱导成1型糖尿病大鼠模型(糖尿病组),在注射STZ后4、6、8、10和12周进行坐骨神经神经传导检查和腓肠肌单纤维肌电...