胸锁乳突肌肌电图在炎性肌病中的诊断价值

The Value of EMG for Sternocleidomastoid Muscle in the Diagnosis of Inflammatory Myopathy

目的探讨胸锁乳突肌肌电图检测在炎性肌病诊断中的价值。方法对97例炎性肌病患者进行常规肢体近端肌肉肌电图检测。部分患者合并检测胸锁乳突肌以及胸段脊旁肌。比较肢体近端肌肉与胸锁乳突肌之间肌电图检测结果的差异。结果肢体近端肌肉肌电图总阳性率为64.9%,增加胸锁乳突肌检测后阳性率增加至84.5%(P<0.01)。胸锁乳突肌的时限以及多相波改变程度明显高于肢体近端肌肉(P<0.01),波幅减低的程度与肢体近端肌肉无明显差异(P>0.05)。胸段脊旁肌自发电位阳性率61.5%,增加胸段脊旁肌检测后将自发电位的总阳性率由48.5%提高为62.9%(P<0.05)。结论有必要增加胸锁乳突肌电生理检测以提高炎性肌病电生理诊断阳性率,而脊旁肌自发电位的检测可以作为一个有效的补充。

Objective To explore the value of EMG for sternocleidomastoid muscle in the diagnosis of inflammatory myopathies.Methods Ninety-seven cases of inflammatory myopathy were subjected to the routine electromyography（EMG）,including the needle EMG in the proximal muscles（deltoid muscles and/or quadriceps femoris） in the extremities,and the nerve conduction velocity and F-wave were analyzed.Some patients had the examinations of sternocleidomastoid muscles and thoracic paraspinal muscles.A comparison of EMG results was made between the proximal muscles in the extremities and the sternocleidomastoid muscles.Results The overall rate of EMG for the proximal muscles in the extremities was 64.9%,and it turned into 84.5%（P〈0.01） after combining EGM for the stercleidomastoid muscles.The appearance of the spontaneous potentials in the stercleidomastoid muscles was notably less than the proximal muscles in the upper and the lower extrimities（P〈0.01）.The changes in latencies and ployphasic waves of the sternocleidomastoid muscles were more significant than the others（P〈0.01）,but there was no significant difference in the amplitudes between the each two of the stercleidomastoid muscles,and the proximal muscles in the upper and the lower extrimities（P〉0.05）.The spontaneous potentials of the thoracic paraspinal muscles presented 61.5% in 26 patients.Addition of EGM for the thoracic paraspinal muscles increased the total rate of the spontaneous potentials from 48.5% into 62.9%（P〈0.05）.Conclusion In order to improve the electromyographic diagnosis of inflammatory myopathies,it is necessary to carry out the routine EGM as well as the sternocleidomatoid muscles,and at the same time the detection of the spontaneous potentials of the thoracic paraspinal muscles is an effective addition.