Abstract:
Achondroplasia is the commonest skeletal dysplasia of autosomal dominant inheritance caused by \"gain of function\" mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. Foramen magnum compression due to accelerated ossification and spinal canal stenosis secondary to reduced interpedicular distance is a hallmark of achondroplasia, driven by G380R nucleotide pair substitution. In severe cases, limb weakness and neurogenic claudication will require surgical decompression. Rarely, a neurological condition may mimic the compressive spinal dysfunction and therefore, non-surgical causes must also be considered in cases of acute neurological deterioration in children with achondroplasia. Myasthenia gravis (MG) is an autoimmune condition resulting in fatigable muscle weakness. There are no reported cases of myasthenia gravis in achondroplasia in the literature.
We report a child with achondroplasia scheduled for decompressive surgery for severe lumbar canal stenosis presenting with neurological claudication and knee weakness. While waiting for surgery during the COVID-19 pandemic, she developed generalized fatigability and severe weakness raising concerns of acute worsening of cord compression. Urgent investigations ruled out spinal cord compression but identified an unexpected concurrent myasthenia gravis with positive antibodies to acetylcholine receptors. The surgical intervention was postponed averting the potential risk of life-threatening anaesthetic complications. She was successfully managed with a combination of pyridostigmine, steroids, azathioprine, and plasma exchange.
We report the first case of myasthenia gravis in achondroplasia and review implications in the management.
摘要:
软骨发育不全是由成纤维细胞生长因子受体3(FGFR3)基因的“功能获得”突变引起的常染色体显性遗传的最常见的骨骼发育不良。由于骨化加速和椎管狭窄继发于椎弓根间距减小而导致的大孔压迫是软骨发育不全的标志。由G380R核苷酸对取代驱动。在严重的情况下,肢体无力和神经源性跛行需要手术减压。很少,神经系统疾病可能模仿压迫性脊柱功能障碍,因此,对于软骨发育不全儿童急性神经系统恶化的情况,也必须考虑非手术原因。重症肌无力(MG)是一种自身免疫性疾病,可导致易疲劳的肌肉无力。文献中没有报道软骨发育不全中的重症肌无力病例。
我们报告了一名患有软骨发育不全的儿童,计划接受严重腰椎管狭窄症的减压手术,表现为神经跛行和膝关节无力。在COVID-19大流行期间等待手术时,她出现了广泛的易疲劳性和严重的虚弱,引起了对脐带压迫急性恶化的担忧。紧急调查排除了脊髓压迫,但发现了意外并发的重症肌无力,并伴有乙酰胆碱受体抗体阳性。手术干预被推迟,避免了危及生命的麻醉并发症的潜在风险。她成功地接受了吡啶斯的明的联合治疗,类固醇,硫唑嘌呤,和血浆置换。
我们报告了第一例软骨发育不全的重症肌无力病例,并回顾了治疗的意义。