TY - JOUR
T1 - Comparison of ice pack test and single-fiber EMG diagnostic accuracy in patients referred for myasthenic ptosis
AU - Giannoccaro, Maria Pia
AU - Paolucci, Matteo
AU - Zenesini, Corrado
AU - Di Stasi, Vitantonio
AU - Donadio, Vincenzo
AU - Avoni, Patrizia
AU - Liguori, Rocco
N1 - Ricercatore distaccato presso IRCCS a seguito Convenzione esclusiva con Università di Bologna (Avoni Patrizia, Liguori Rocco, Giannoccaro Maria Pia)
PY - 2020/9/29
Y1 - 2020/9/29
N2 - 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.
AB - 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.
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U2 - 10.1212/WNL.0000000000010619
DO - 10.1212/WNL.0000000000010619
M3 - Article
C2 - 32788239
AN - SCOPUS:85091890809
VL - 95
SP - e1800-e1806
JO - Neurology
JF - Neurology
SN - 0028-3878
IS - 13
ER -