神经肌肉接头疾病分型与诊断.pptVIP

教学目的 掌握重症肌无力的临床特点 熟悉MG的临床分型 掌握MG的诊断标准 熟悉MG的治疗措施 Diseases of Neuromuscular Junction 定义：指一组神经-肌肉接头处传递功能障碍疾病。特征表现是波动性无力和肌肉易疲劳。 本组疾病包括： 重症肌无力：体内产生AChR自身抗体使AChR受损或减少 有机磷中毒：胆碱酯酶活力受抑制，使ACh作用过度延长而产生去极化传递障碍 Diseases of Neuromuscular Junction 本组疾病包括： Lambert-Eaton综合征和氨基甙类药物：使ACh合成和释放减少 肉毒杆菌中毒和高镁血症：阻碍钙离子进入神经末梢 美洲箭毒素与AChR结合，阻断了ACh AChR结合 Diseases of Neuromuscular Junction Myasthenia Gravis 定义：乙酰胆碱受体抗体介导的、细胞免疫依赖的及补体参与的一种神经-肌肉接头处传递障碍的自身免疫性疾病，主要累及NMJ突触后膜上乙酰胆碱受体 临床特征：部分或全身骨骼肌易于疲劳；症状的波动性 Myasthenia gravis is characterized by fluctuating weakness and easy fatigability of voluntary muscles. Etiology 实验性自身免疫性重症肌无力(experimental auto-immune myasthenia gravis, EAMG)动物模型的建立，在动物血清中检测到AChR (acetylcholine receptor) 胸腺的异常，MG合并胸腺瘤(thymic tumor)及胸腺肥大，发现肌样细胞(myoid cell)，具有横纹并载有AChR MG患者常合并甲亢(thyrotoxicosis)，SLE (systemic lupus erythematosus)，类风湿性关节炎(rheumatoid arthritis)等自身免疫性疾病 MG患者HLA基因型(B8,DR3,DQB1)频率较高 病理 70%患者胸腺肥大 10%患者有胸腺瘤，好发于年龄较大者 NMJ的病理改变：突触后膜皱褶减少，突触间隙加宽，皱褶中有抗体和免疫复合物存在 Clinical findings MG can occur at any age , and more common in females than males. MG is insidious and follows a slowly progressive course. Exacerbation may occur in infection, pregnancy or before menses. There is a predilection for the external ocular muscles and certain other cranial muscles, including the masticatory, facial, pharyngeal, and laryngeal muscles.Respiratory and limb muscles may also be affected. Clinical findings Presentation: ptosis, diplopia, difficulty in chewing or swallowing, nasal speech, respiratory difficulties, or weakness of the limbs. Clinical findings Myasthenia gravis is characterized by fluctuating weakness and easy fatigability of voluntary muscles. The symptoms often fluctuate in intensity during the day, and this diurnal variation is superimposed on longer-term spontaneous relapses and remissions that may last for weeks. Neurological examination The weakness does not conform to the distribution of any single nerve, root, or level of the central nervous syst