对比冰袋试验与单纤维肌电图在重症肌无力眼睑下垂患者中的诊断准确性。

Comparison of ice pack test and single-fiber EMG diagnostic accuracy in patients referred for myasthenic ptosis.

机构信息

From the Dipartimento di Scienze Biomediche e Neuromotorie (M.P.G., P.A., R.L.), Università di Bologna; IRCCS Istituto delle Scienze Neurologiche di Bologna (M.P.G., C.Z., V.D.S., V.D., P.A., R.L.); UO Neurosonologia e Cefalee (M.P.), Università Campus Bio-Medico, Rome; and UO Neurologia (M.P.), Ospedale M. Bufalini, Cesena, AUSL Romagna, Italy.

出版信息

Neurology. 2020 Sep 29;95(13):e1800-e1806. doi: 10.1212/WNL.0000000000010619. Epub 2020 Aug 11.

DOI:10.1212/WNL.0000000000010619

PMID:32788239

Abstract

OBJECTIVE

To compare the diagnostic accuracy of ice pack test (IPT) and single-fiber EMG (SF-EMG) in patients with suspected ocular myasthenia (OM) presenting with ptosis.

METHODS

We studied consecutive patients referred for the clinical suspicion of OM. Patients underwent IPT and stimulated SF-EMG on the orbicularis oculi muscle. Receiver operating characteristic curve analysis was performed to determine the accuracy of IPT, SF-EMG, and their combination.

RESULTS

We included 155 patients, 102 with OM and 53 with other diagnosis (OD). The IPT had a sensitivity of 86% (95% confidence interval [CI] 79-93) and a specificity of 79% (95% CI 68-90). SF-EMG showed a sensitivity of 94% (95% CI 89-98) and a specificity of 79% (95% CI 68-90). Overall, IPT and SF-EMG showed discordant results in 30 cases, 16 OM and 14 OD. The combination of IPT and SF-EMG, using the positivity of at least one test for OM diagnosis, increased the sensitivity to 98% (95% CI 95-100), reducing the specificity to 66% (95% CI 53-78), whereas using the positivity of both tests, we obtained a sensitivity of 82% (95% CI 75-90) and a specificity of 92% (95% CI 85-99). The negativity of both tests had a 94% (95% CI 87-100) negative predictive value. Comparison of the areas under the curve showed no differences in the diagnostic accuracy of IPT, SF-EMG, and their combinations.

CONCLUSIONS

IPT and SF-EMG have similar diagnostic accuracy in patients with OM presenting with ptosis. The negativity of both tests strongly suggests another diagnosis.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that both the IPT and SF-EMG accurately identify patients with OM.

摘要

目的

比较冰敷试验（IPT）和单纤维肌电图（SF-EMG）在以眼睑下垂为首发症状的疑似眼肌型重症肌无力（OM）患者中的诊断准确性。

方法

我们连续研究了因临床疑似 OM 而就诊的患者。患者接受了眶匝肌的 IPT 和 SF-EMG 刺激。通过受试者工作特征曲线分析确定了 IPT、SF-EMG 及其组合的准确性。

结果

我们纳入了 155 例患者，其中 102 例为 OM，53 例为其他诊断（OD）。IPT 的敏感性为 86%（95%置信区间[CI] 79-93），特异性为 79%（95% CI 68-90）。SF-EMG 的敏感性为 94%（95% CI 89-98），特异性为 79%（95% CI 68-90）。总体而言，IPT 和 SF-EMG 在 30 例患者中结果不一致，其中 16 例为 OM，14 例为 OD。IPT 和 SF-EMG 联合使用，至少一项检测结果阳性用于 OM 诊断，可将敏感性提高到 98%（95% CI 95-100），特异性降低到 66%（95% CI 53-78），而两项检测均阳性时，敏感性为 82%（95% CI 75-90），特异性为 92%（95% CI 85-99）。两项检测均阴性的阴性预测值为 94%（95% CI 87-100）。曲线下面积的比较显示，IPT、SF-EMG 及其组合的诊断准确性没有差异。