Introduction

We performed a pilot study in order to investigate the feasibility of an electromyography (EMG)-scoring protocol for the assessment of disease activity in juvenile idiopathic inflammatory myopathies (JIIM).

Methods

Children with JIIM followed up in a tertiary-level care center underwent standardized clinical, laboratory, and EMG assessment. An EMG-scoring protocol was devised by a consensus panel including a pediatric neurophysiologist and two pediatric rheumatologists, based on a combined score obtained as the sum of (1) the presence of denervation signs (fibrillation potentials) and (2) motor unit remodeling (mixed pattern of short- and long-duration motor unit action potentials). The EMG-scoring protocol was then validated following the Outcome Measures in Rheumatoid Arthritis Clinical Trials filter for outcome measures in rheumatology and the consensus-based standards for the selection of health measurement instruments methodology.

Results

Thirteen children (77% females) were included in the study, with a median age of 10 years (interquartile range: 7-17 years) and median disease duration of 11.8 months (interquartile range: 2.1-44.5). A total of 39 EMG examinations were evaluated. A strong positive association between a standardized tool for muscle strength assessment and the combined score was observed. No significant associations were found with both creatine kinase and erythrocyte sedimentation rate levels.

Discussion

Our EMG-scoring protocol is the first standardized and reproducible tool for the neurophysiologic evaluation and grading of muscle involvement in patients with JIIM and could provide relevant additional information in the assessment and follow-up of these rare conditions.

中文翻译：

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用于评估和分级青少年特发性炎症性肌病患者肌肉参与的肌电图评分方案的开发和初步验证

介绍

我们进行了一项初步研究，以调查肌电图 (EMG) 评分方案在评估青少年特发性炎症性肌病 (JIIM) 疾病活动中的可行性。

方法

在三级护理中心随访的 JIIM 儿童接受了标准化的临床、实验室和 EMG 评估。EMG 评分方案由包括一名儿科神经生理学家和两名儿科风湿病学家在内的共识小组设计，其基础是（1）去神经征（纤颤电位）的存在和（2）运动单位重塑的总和。短期和长期运动单位动作电位的混合模式）。然后，EMG 评分协议在类风湿性关节炎临床试验结果测量过滤器用于风湿病学结果测量和选择健康测量仪器方法的基于共识的标准后得到验证。

结果

该研究包括 13 名儿童（77% 为女性），中位年龄为 10 岁（四分位距：7-17 岁），中位病程为 11.8 个月（四分位距：2.1-44.5）。共评估了 39 项肌电图检查。观察到用于肌肉力量评估的标准化工具与综合评分之间存在强正相关。肌酸激酶和红细胞沉降率水平均未发现显着相关性。

讨论

我们的 EMG 评分方案是第一个标准化和可重复的工具，用于对 JIIM 患者的肌肉受累进行神经生理学评估和分级，并且可以在评估和随访这些罕见疾病时提供相关的附加信息。