Govindarajan Raghav, Iyadurai Stanley J, Connolly Anne, Zaidman Craig
Division of Neuromuscular Medicine, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
Department of Neurology & Psychiatry, Neuromuscular Medicine, Saint Louis University, Monteleone Hall, 1438 South Grand Blvd., St. Louis, MO 63104, USA.
Neuromuscul Disord. 2015 Aug;25(8):651-2. doi: 10.1016/j.nmd.2015.03.014. Epub 2015 Apr 22.
Neuromuscular junction disorders in children are either genetic, such as congenital myasthenic syndrome, or autoimmune with circulating antibodies most commonly against acetylcholine receptors. There is limited experience recognizing and treating children with myasthenia associated with muscle-specific tyrosine kinase antibodies. We report a seven-year-old child with intermittent esotropia since age 3 months, and two years of progressive and severe diplopia, dysarthria, dysphagia, and facial weakness. Acetylcholine receptor antibodies and genetic testing for congenital myasthenic syndrome were negative. Muscle specific tyrosine kinase antibodies were significantly elevated. Ophthalmoplegia and bulbar weakness were refractory to treatment with acetylcholinesterase inhibitors, corticosteroids and IVIg but completely resolved following treatment with rituximab. Her neurologic examination remained normal at the most recent follow-up, 15 months after initiation of rituximab. Children with MuSK myasthenia, like adults, can respond to rituximab despite long standing disease and failure to improve on other immunosuppressant medications.
儿童神经肌肉接头疾病要么是遗传性的，如先天性肌无力综合征，要么是自身免疫性的，体内循环抗体最常见的是针对乙酰胆碱受体。在识别和治疗与肌肉特异性酪氨酸激酶抗体相关的肌无力儿童方面，经验有限。我们报告一名7岁儿童，自3个月大起出现间歇性内斜视，并有两年进行性严重复视、构音障碍、吞咽困难和面部无力。乙酰胆碱受体抗体检测及先天性肌无力综合征基因检测均为阴性。肌肉特异性酪氨酸激酶抗体显著升高。眼肌麻痹和延髓肌无力对乙酰胆碱酯酶抑制剂、皮质类固醇和静脉注射免疫球蛋白治疗无效，但使用利妥昔单抗治疗后完全缓解。在开始使用利妥昔单抗15个月后的最近一次随访中，她的神经系统检查仍正常。与成人一样，患有肌肉特异性酪氨酸激酶（MuSK）型重症肌无力的儿童，尽管病程较长且对其他免疫抑制药物治疗无效，但仍可能对利妥昔单抗产生反应。
