Pitt Matthew C, Mchugh John C, Deeb Jacquie, Smith Ralph A
Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, United Kingdom.
Department of Clinical Neurophysiology, Our Lady's Children's Hospital, Crumlin, Dublin 12, Ireland.
Clin Neurophysiol. 2017 Feb;128(2):290-296. doi: 10.1016/j.clinph.2016.11.020. Epub 2016 Dec 3.
We present our 9-year experience of stimulated EMG potential analysis using concentric electrodes (SPACE) to evaluate neuromuscular junction (NMJ) disorders in awake children. The technique uses high frequency filtration of stimulated motor unit potentials and applies peak detection software to estimate mean consecutive difference (MCD).
SPACE was carried out in orbicularis oculi of 878 children (377 girls; median age 47months) between 2007 and 2015, stimulating the facial nerve with a monopolar cathode. Mean MCD-index (MCD-I) was expressed as a ratio of the measured MCD to the upper normal limit. Diagnostic accuracy was calculated for primary NMJ disorders based on the 660 cases with clinical follow-up data.
Primary NMJ disorders were present in 106 children, including 46 with genetically confirmed congenital myasthenic syndrome (CMS). Mean MCD-I was two times higher in children with primary NMJ disorders compared to others (205±108μs vs 94±38μs, p<0.005). After excluding children with neuronopathies, an MCD-I >100% had 84% sensitivity and 74% specificity for the primary NMJ disorders. Receiver operating characteristics (ROC) curve identified an MCD-I >115% as providing best diagnostic accuracy with sensitivity of 77% and specificity of 84%.
SPACE is practicable and safe in unsedated children.
In combination with routine EMG, it has high diagnostic accuracy and can facilitate recognition of paediatric NMJ transmission disorders.
我们展示了使用同心电极进行刺激肌电图电位分析（SPACE）以评估清醒儿童神经肌肉接头（NMJ）疾病的9年经验。该技术对刺激运动单位电位进行高频滤波，并应用峰值检测软件来估计平均连续差值（MCD）。
2007年至2015年间，对878名儿童（377名女孩；中位年龄47个月）的眼轮匝肌进行SPACE检查，使用单极阴极刺激面神经。平均MCD指数（MCD-I）表示为测量的MCD与正常上限的比值。基于660例有临床随访数据的病例计算原发性NMJ疾病的诊断准确性。
106名儿童存在原发性NMJ疾病，其中46名经基因确诊为先天性肌无力综合征（CMS）。原发性NMJ疾病患儿的平均MCD-I是其他患儿的两倍（205±108μs对94±38μs，p<0.005）。排除神经病患儿后，MCD-I>100%对原发性NMJ疾病的敏感性为84%，特异性为74%。受试者操作特征（ROC）曲线确定MCD-I>115%时诊断准确性最佳，敏感性为77%，特异性为84%。
SPACE在未使用镇静剂的儿童中可行且安全。
与常规肌电图相结合，它具有较高的诊断准确性，有助于识别儿童NMJ传递障碍。
