Department of Neurology, Brain Centre Rudolf Magnus, University Medical Centre Utrecht, Utrecht University, Utrecht.
Department of Child Development and Exercise Centre, University Medical Centre Utrecht, Utrecht.
Eur J Neurol. 2018 Mar;25(3):512-518. doi: 10.1111/ene.13534. Epub 2018 Feb 2.
Natural history studies in spinal muscular atrophy (SMA) have primarily focused on infants and children. Natural history studies encompassing all age groups and SMA types are important for the interpretation of treatment effects of recently introduced survival motor neuron gene-augmenting therapies.
We conducted a cross-sectional study to investigate muscle strength, Hammersmith Functional Motor Scale (Expanded) score and the patterns of muscle weakness in relation to age and SMA type.
We included 180 patients with SMA types 1-4 in the age range 1-77.5 years with median disease duration of 18 (range 0-65.8) years. With the exception of the early phases of disease in which children with SMA types 2 and 3 may achieve new motor skills and show a temporary increase in muscle strength, cross-sectional data suggested that declining muscle strength and loss of motor skills over time are characteristic of all SMA types. Mean loss of strength was at least 1 point on the Medical Research Council score and 0.5 point on the Hammersmith Functional Motor Scale (Expanded) score per year. Trend lines compatible with deterioration of motor function and muscle strength started in childhood and continued into adulthood. The age at loss of specific motor skills was associated with disease severity. Triceps, deltoid, iliopsoas and quadriceps were the weakest muscles in all patients. Hierarchical cluster analysis did not show a segmental distribution of muscle weakness as suggested previously.
Progressive muscle weakness and loss of motor function are characteristic of all SMA types and all ages.
脊髓性肌萎缩症（SMA）的自然史研究主要集中在婴儿和儿童。涵盖所有年龄组和 SMA 类型的自然史研究对于解释最近引入的生存运动神经元基因增强治疗的治疗效果非常重要。
我们进行了一项横断面研究，以调查肌肉力量、汉密尔顿运动功能量表（扩展）评分以及与年龄和 SMA 类型相关的肌肉无力模式。
我们纳入了 180 名 SMA 类型 1-4 患者，年龄在 1-77.5 岁之间，中位病程为 18 年（范围 0-65.8 年）。除了 SMA 类型 2 和 3 的儿童可能获得新的运动技能并表现出肌肉力量的暂时增加的疾病早期阶段外，横断面数据表明，随着时间的推移，肌肉力量的下降和运动技能的丧失是所有 SMA 类型的特征。每年肌肉力量平均下降至少 1 个医学研究委员会评分和 0.5 个汉密尔顿运动功能量表（扩展）评分。与运动功能和肌肉力量恶化相符的趋势线始于儿童期，并持续到成年期。特定运动技能丧失的年龄与疾病严重程度相关。三头肌、三角肌、髂腰肌和股四头肌是所有患者中最弱的肌肉。层次聚类分析并未显示出以前建议的肌肉无力的节段分布。
进行性肌肉无力和运动功能丧失是所有 SMA 类型和所有年龄段的特征。
