Application value of exercise test of repetitive nerve stimulation in evaluating myasthenia gravis
10.3760/cma.j.issn.1671-8925.2013.02.019
- VernacularTitle:重复神经电刺激疲劳试验在全身型重症肌无力中的应用价值
- Author:
Zhao-Xia WEI
1
;
Qi-Xian MO
;
Feng QI
;
Zu-You LIU
;
Ke YU
Author Information
1. 广州医学院荔湾医院神经内科
- Keywords:
Myasthenia gravis;
Repetitive nerve stimulation;
Exercise test;
Low-frequency;
Diagnosis
- From:
Chinese Journal of Neuromedicine
2013;12(2):191-193
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the diagnostic utility of repetitive nerve stimulation (RNS)and the effect of exercise test in RNS,as well as to find the way to improve the diagnostic sensitivity of RNS in myasthenia gravis (MG).Methods A total of 45 patients with generalized MG,admitted to our hospital from January 2008 to June 2012,were chosen in our study; they,firstly,underwent RNS test in orbiculatis otis,anconeus,deltoid and musculus abductor digiti minimi with low frequency (1,3 and 5Hz) and high frequency (10,20 and 30 Hz) supramaximal current,and then,till the muscle tetanic contraction (fatigue),RNS test at the same frequency was performed again; the diagnostic sensitivity of RNS in MG was compared.Results Before exercise test,the comprehensive positive rate of the four muscles on low-frequency RNS test was 60.0％ (27/45),which was significantly higher than that on high-frequency RNS test (17.78％,8/45) (x2=16.878,P=0.000).As compared with that before exercise test,the RNS positive rate of anconeus and deltoid after exercise was significantly higher (P＜0.05),while no significant difference was noted on orbicularis otis and abductor digiti minimi between before exercise test and after exercise test (P＞0.05).Increased comprehensive positive rate of four muscles in low-frequency RNS test was showed as compared with that in high-frequency RNS test (P＜0.05).Conclusion RNS has important diagnosis value in MG,and low-frequency RNS enjoys high positive rate; different muscles have different positive rate of RNS,and RNS for the four muscles at the same time can obviously increase the positive rate and detection sensitivity; exercise test can significantly improve the diagnostic sensitivity of RNS in anconeus and deltoid,as well as the comprehensive positive rate of four muscles in low-frequency RNS test.
