神经重复电刺激对重症肌无力眼肌型的诊断价值

Diagnostic utility of repetitive nerve stimulation in ocular myasthenia gravis

目的探讨神经重复电刺激检查在重症肌无力(MG)眼肌型患者的诊断价值。方法对46例临床拟诊的重症肌无力(MG)眼肌型患者进行神经重复电刺激检查,并对结果进行分析。结果共测试46例MG眼肌型患者,单上睑下垂者20例,双眼睑下垂者19例,复视者有3例,吞咽困难者2例,咀嚼无力2例。共对204条神经进行神经电生理检测:MG眼肌型患者在疲劳试验前,单独刺激眼轮匝肌、三角肌和小指展肌RNS的阳性率分别为41.30%(19/46)、15.21%(7/46)、6.52%(3/46),3块肌肉综合统计低频刺激的阳性率为58.69%(27/46),高频刺激的阳性率为5%(6/46)。疲劳试验后眼轮匝肌、三角肌和小指展肌RNS阳性率分别为47.82%(22/46)、21.74%(10/46)、6.52%(3/46)。疲劳试验前后可见低频刺激阳性率均远高于高频刺激,且高频刺激阳性者在低频刺激时全部为阳性。疲劳试验后三角肌的RNS阳性率增加;面肌、小指展肌的RNS阳性率无明显变化;3块肌肉综合统计低频刺激下RNS阳性率增高。结论 MG为神经—肌肉接头传递功能障碍的获得性免疫性疾病,神经重复电刺激检查对MG眼肌型的诊断、鉴别诊断及指导治疗有重要价值。

Objective To evaluate the diagnostic utility of repetitive nerve stimulation in ocular myasthenia gravis. MethodsA total of 46 cases of clinically diagnosed with ocular myasthenia gravis were underwent RNS test, and the results were analyzed.ResultsIn the 46 cases of ocular MG, 20 cases of single ptosis, double ptosis in 19 cases, diplopia in 3 cases; dysphagia in 2 cases and inability to chew in 2 cases. A total of 204 nerve underwent electrophysiological testing： Before ocular fatigue test, RNS positive rate was 41.30% （19/46）, 15.21% （7/46）, 6.52% （3/46）, respectively stimulating alone orbicularis muscle, deltoid and little finger abductor. Three muscles comprehensive statistics of low frequency stimulation positive rate was 58.69% （27/46）, the positive rate was 5% （6/46） of high frequency stimulation. Whileafter the fatigue test orbicularis muscle, deltoid and little finger abductor muscle RNS positive rate was 47.82% （22/46）, 21.74% （10/46 ）, 6.52% （3/46）. Visible low-frequency stimulation before and after fatigue testing positive rate is much higher than the high-frequency stimulation, and high-frequency stimulation positive stimulation at low frequencies are all positive. After fatigue test of the deltoid muscle RNS positive rate increased; Facial muscles, the little finger abductor muscle of RNS positive rate has no obvious change; 3 muscles comprehensive statistical RNS under low frequency stimulation increased positive rate.Conclusion MG is nerve-neuromuscular transmission dysfunction acquired autoimmune disease, repetitive nerve stimulation has significant value in diagnosis, differential diagnosis and guide treatment of ocular myasthenia gravis.