冰冷试验对上睑下垂重症肌无力患儿的诊断价值

方法 以具有上睑下垂体征的临床确诊的、住院的JMG和非重症肌无力(MG)患儿为研究对象，新斯的明试验后24 h再行冰冷试验，对试验前后睑裂宽度进行测量，睑裂宽度较试验前增加≥2 mm为阳性，计算冰冷试验2 min和5 min的敏感度和特异度。 结果 符合本文纳入和排除标准的JMG和非MG患儿分别为29和6例。JMG组（眼肌型MG 28例）中位年龄5.5岁；非MG组中位年龄6.2岁。JMG组新斯的明试验（30 min）27例阳性,2例至60 min依然阴性，冰冷试验2 min和5 min时分别有18和21例阳性。非MG组新斯的明试验和冰冷试验均阴性。新斯的明试验不良反应有腹痛、恶心、出汗和呕吐，冰冷试验不良反应有上眼睑略红。敏感度：冰冷试验2 min和5 min分别为62.1%和72.4%，新斯的明试验为93.1%；特异度均为100%。冰冷试验2 min和5 min的敏感度均与新斯的明试验差异有统计学意义。结论 冰冷试验操作简单且安全，对疑似JMG的上睑下垂患儿先行冰冷试验（5 min），约70%试验呈阳性的患儿可代替新斯的明试验，冰冷试验（5 min）丰富了JMG辅助诊断手段。

Study on the diagnostic accuracy of palpebral fissure width in ice pack test to juvenile myasthenia gravis patients

Objective To observe changes of palpebral fissure of non-invasive ice pack test in children with juvenile myasthenia gravis （JMG）, and evaluate the diagnostic value of ice pack test in JMG.Methods The patients with ptosis were divided into JMG group and non-myasthenic gravis (MG) group. Palpebral fissures of the patients with ptosis in two groups were measured before and 2 min and 5 min immediately after ice pack test which was performed 24 h after neostigmine test for 60 min at 20℃-25℃. The changes of palpebral fissures relative to baseline great than 2 mm were consideed positive. The sensitivity and specificity of ice pack test (2 min and 5 min) and neostigmine test to the diagnosis of JMG were compared.Results ①There were 29 cases of JMG (1 case of generalised myasthenia gravis and 28 cases of ocular myasthenia gravis) in JMG group and 6 cases of non-MG in control group. The median age of JMG group and non-MG group was 5.5 years old and 6.2 years old, respectively. ②In JMG group, 27 cases were positive at 30 min, and 2 cases were negative at 60 min during neostigmine test. The positive results of ice pack test were abserved in 18 and 21 cases at 2 min and 5 min, respectively. ③In non-MG group, there was only 1 case whose palpebral fissure changes of ice pack test for 2 min, ice pack test for 5 min was 1 mm. There were no palpebral fissure changes in 5 cases.④The sensitivities of ice pack test for 2 min, ice pack test for 5 min and neostigmine test were 62.1%, 72.4% and 93.1%, respectively. All of the specificities of ice pack test and neostigmine test were all 100%. There were significant differences between the ice pack test for 2 min and neostigmine test, the ice pack test for 5 min and neostigmine test respectively. ⑤There were 4 cases with abdominal pain, 3 cases with nausea, 3 cases with sweating and 2 cases with vomiting during the neostigmine test. The skin of the upper eyelid of 6 cases turned red slightly.Conclusion The high sensitivity and specificity of ice pack test for 5 min, as well as the rapid, simple, safe, cheap and woundless characteristics make it benefit to the diagnosis of ptosis of JMG.