Department of Neurology, Peking University First Hospital, Beijing 100034, China.
Department of Radiology, Peking University First Hospital, Beijing 100034, China.
Chin Med J (Engl). 2018 Jun 20;131(12):1472-1479. doi: 10.4103/0366-6999.233957.
LMNA-related muscular dystrophy can manifest in a wide variety of disorders, including Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy (LGMD), and LMNA-associated congenital muscular dystrophy (L-CMD). Muscle magnetic resonance imaging (MRI) has become a useful tool in the diagnostic workup of patients with muscle dystrophies. This study aimed to investigate whether there is a consistent pattern of MRI changes in patients with LMNA mutations in various muscle subtypes.
Twenty-two patients with LMNA-related muscular dystrophies were enrolled in this study. MRI of the thigh and/or calf muscles was performed in them. The muscle MRI features of the three subtypes were compared by the Mann-Whitney U-test. The relationship between the clinical and MRI findings was also investigated by Spearman's rank analyses.
The present study included five EDMD, nine LGMD, and eight L-CMD patients. The thigh muscle MRI revealed that the fatty infiltration of the adductor magnus, semimembranosus, long and short heads of the biceps femoris, and vasti muscles, with relative sparing of the rectus femoris, was the predominant change observed in the EDMD, LGMD, and advanced-stage L-CMD phenotypes, although the involvement of the vasti muscles was not prominent in the early stage of L-CMD. At the level of the calf, six patients (one EDMD, four LGMD, and one L-CMD) also showed a similar pattern, in which the soleus and the medial and lateral gastrocnemius muscles were most frequently observed to have fatty infiltration. The fatty infiltration severity demonstrated higher scores associated with disease progression, with a corresponding rate of 1.483 + 0.075 × disease duration (X) (r = 0.444, P = 0.026). It was noteworthy that in six L-CMD patients with massive inflammatory cell infiltration in muscle pathology, no remarkable edema-like signals were observed in muscle MRI.
EDMD, LGMD and advanced-staged L-CMD subtypes showed similar pattern of muscle MRI changes, while early-staged L-CMD showed somewhat different changes. Muscle MRI of L-CMD with a muscular dystrophy pattern in MRI provided important clues for differentiating it from childhood inflammatory myopathy. The fatty infiltration score could be used as a reliable biomarker for outcome measure of disease progression.
LMNA 相关肌营养不良症可表现为多种疾病，包括 Emery-Dreifuss 肌营养不良症（EDMD）、肢带型肌营养不良症（LGMD）和 LMNA 相关先天性肌营养不良症（L-CMD）。肌肉磁共振成像（MRI）已成为肌肉营养不良症患者诊断工作中的有用工具。本研究旨在探讨 LMNA 突变患者在各种肌肉亚型中是否存在一致的 MRI 改变模式。
本研究纳入了 22 例 LMNA 相关肌营养不良症患者。对他们的大腿和/或小腿肌肉进行 MRI 检查。采用 Mann-Whitney U 检验比较三种亚型的肌肉 MRI 特征。还通过 Spearman 秩相关分析研究了临床和 MRI 发现之间的关系。
本研究包括 5 例 EDMD、9 例 LGMD 和 8 例 L-CMD 患者。大腿肌肉 MRI 显示，内收大肌、半膜肌、股二头肌长头和短头以及股四头肌的脂肪浸润，而股直肌相对保留，这是 EDMD、LGMD 和晚期 L-CMD 表型中观察到的主要变化，尽管在 L-CMD 的早期阶段股四头肌的受累并不明显。在小腿水平，6 例患者（1 例 EDMD、4 例 LGMD 和 1 例 L-CMD）也表现出类似的模式，其中比目鱼肌和内侧和外侧腓肠肌最常出现脂肪浸润。脂肪浸润严重程度与疾病进展呈更高评分相关，相应的比率为 1.483+0.075×疾病持续时间（X）（r=0.444，P=0.026）。值得注意的是，在 6 例 L-CMD 患者的肌肉病理学中存在大量炎症细胞浸润，肌肉 MRI 中未观察到明显的水肿样信号。
EDMD、LGMD 和晚期 L-CMD 亚型表现出相似的肌肉 MRI 改变模式，而早期 L-CMD 表现出略有不同的变化。MRI 中具有肌营养不良模式的 L-CMD 的肌肉 MRI 提供了将其与儿童炎性肌病区分开来的重要线索。脂肪浸润评分可作为疾病进展预后的可靠生物标志物。
