Graduate Program in Medicine: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Radiology Departament, Hospital Moinhos de Vento, Porto Alegre, Brazil.
Neuromuscul Disord. 2022 Sep;32(9):763-768. doi: 10.1016/j.nmd.2022.07.395. Epub 2022 Jul 14.
Diagnosis of later-onset spinal muscular atrophy (SMA) can be challenging. This study aimed to evaluate the diagnostic properties of the detection of muscle fasciculations for SMA diagnosis in adolescents and adults with proximal muscle weakness. A cross-sectional diagnostic accuracy study was performed, in which 10 subjects with SMA (5 with type II and 5 with type III) and 9 subjects with genetic muscle diseases were evaluated by physical examination, muscle ultrasound (MUS) and electromyography (EMG). Inter-rater reliability of MUS was higher than physical examination and in a sensitivity analysis of MUS, all SMA subjects and a single patient with genetic muscle disease presented fasciculations in at least 2 different muscle groups, resulting in a sensitivity of 1 (95% CI: 0.69 to 1) and a specificity of 0.89 (95% CI: 0.52 to 1) for SMA diagnosis. Forty-two percent of evaluated subjects did not agree to perform EMG, limiting this method results. Muscle ultrasound presented the best diagnostic accuracy and physical examination combined with MUS seemed to be a good strategy for screening adolescents and adults with proximal muscle weakness for SMA. These results might improve diagnostic guidelines for later-onset SMA, leading to earlier diagnosis, treatment and specific care.
诊断迟发性脊髓性肌萎缩症（SMA）具有一定挑战性。本研究旨在评估肌束震颤检测对近端肌无力青少年和成人 SMA 诊断的诊断性能。进行了一项横断面诊断准确性研究，其中评估了 10 名 SMA 患者（5 型 II 型和 5 型 III 型）和 9 名遗传性肌肉疾病患者，评估方法包括体格检查、肌肉超声（MUS）和肌电图（EMG）。MUS 的观察者间可靠性高于体格检查，在 MUS 的敏感性分析中，所有 SMA 患者和 1 名遗传性肌肉疾病患者至少在 2 个不同肌肉群中出现肌束震颤，因此 SMA 诊断的敏感性为 1（95%CI：0.69 至 1），特异性为 0.89（95%CI：0.52 至 1）。42%的评估对象不同意进行 EMG，限制了该方法的结果。肌肉超声具有最佳的诊断准确性，体格检查结合 MUS 似乎是筛查近端肌无力青少年和成人 SMA 的良好策略。这些结果可能会改进迟发性 SMA 的诊断指南，从而实现更早的诊断、治疗和特定的护理。
