Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.
Department of Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia.
Muscle Nerve. 2022 Dec;66(6):686-693. doi: 10.1002/mus.27716. Epub 2022 Sep 18.
INTRODUCTIONS/AIMS: Inclusion body myositis (IBM) typically presents with progressive weakness preferentially involving finger flexors and quadriceps. Atypical presentations have been less commonly reported. Here, we aim to describe the clinical characteristics and long-term outcomes of IBM patients with atypical presentations.
We retrospectively searched the Mayo Clinic medical records to identify IBM patients with atypical disease onset, seen between 2015 and 2020.
We identified 357 IBM patients, of whom 50 (14%) had an atypical presentation. Thirty-eight patients were diagnosed with IBM because they fulfilled one of the European Neuromuscular Center diagnostic categories at a later stage, 10 had all IBM histopathological features, and 2 were diagnosed on the basis of clinical and laboratory data. The most common presentation was dysphagia (50%), followed by asymptomatic hyperCKemia (24%; CK, creatine kinase), then foot drop (12%). 6% of patients presented with proximal arm weakness, 4% with axial weakness and 4% with facial diplegia. Median time from symptom onset to diagnosis was 9 y. Median age at diagnosis was 70.5 y. 16% of patients needed a walking aid. When tested, 86.5% of patients had impaired swallowing and 56% had elevated cytosolic nucleotidase-1A antibodies. Only 1/26 patients who received immunotherapy had minimal improvement. Upon follow-up, most patients had generalization of their weakness with a decline in their strength summated score of 0.082/mo.
A significant proportion of IBM patients may have an atypical presentation. Recognition of such heterogeneity could improve early diagnosis, prevent unnecessary immunotherapy, and provide insight for future diagnostic criteria development and clinical trials.
介绍/目的：包涵体肌炎（IBM）通常表现为进行性无力，主要累及手指屈肌和股四头肌。不典型表现较少见。在这里，我们旨在描述具有不典型表现的 IBM 患者的临床特征和长期预后。
我们回顾性搜索了梅奥诊所的病历，以确定在 2015 年至 2020 年间出现不典型起病的 IBM 患者。
我们确定了 357 例 IBM 患者，其中 50 例（14%）表现为不典型。38 例患者因后期符合欧洲神经肌肉中心的一个诊断类别而被诊断为 IBM，10 例具有 IBM 的所有组织病理学特征，2 例根据临床和实验室数据诊断。最常见的表现是吞咽困难（50%），其次是无症状性高肌酸激酶血症（24%；肌酸激酶，CK），然后是足下垂（12%）。6%的患者表现为手臂近端无力，4%的患者表现为轴性无力，4%的患者表现为面肌无力。从症状出现到诊断的中位时间为 9 年。诊断时的中位年龄为 70.5 岁。16%的患者需要助行器。当进行测试时，86.5%的患者存在吞咽困难，56%的患者存在胞浆核苷酸酶-1A 抗体升高。接受免疫治疗的 26 例患者中仅有 1 例有轻微改善。随访时，大多数患者的无力均有进展，其肌力总和评分每月下降 0.082。
相当一部分 IBM 患者可能存在不典型表现。认识到这种异质性可以改善早期诊断，避免不必要的免疫治疗，并为未来的诊断标准制定和临床试验提供见解。
