Chen Shi-Cai, Zheng Hong-Liang, Zhou Shui-Miao, Li Zhao-Ji, Zhang Su-Qin, Huang Yi-Deng, Wen Wu, Cui Yi
Department of Otorhinolaryngology Head and Neck Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.
Zhonghua Er Bi Yan Hou Ke Za Zhi. 2004 Jul;39(7):410-4.
To determine the comprehensive prognostic value of spontaneous and evoked electromyography (EMG) in laryngeal paralysis.
The characteristics of laryngeal EMG of 91 cases with unilateral vocal cord paralysis (VCP) after thyroid surgery were assessed. All cases were divided into four groups according to the interval of laryngeal EMG after onset, which were group one (2 months shorter, n = 13), group two (2 to 4 months, n = 23), group three (4 to 6 months, n = 36), group four (6 months longer, n = 19). The waveform morphology and the amplitude of laryngeal EMG and the highest evoked compound muscular active potential (CMAP) of thyroarytenoid muscles were examined and analyzed during voluntary tasks. The potential amplitude was showed by the percentage of that of the healthy lateral. The criterion of evaluation on evoked potential was attained by calculating statistical confidence interval.
The highest evoked CMAP in group one was significantly lower than that of the others (P < 0.05), but no significant difference was observed between group two and group three (P > 0.05), so group two and group three were analyzed together. There were 2 recovered cases and 11 unrecovered cases in group one. On the basis of this criterion that a positive prognosis for laryngeal recovery was indicated when the evoked CMAP presented and there was no misdirect generated potential, correct prognostic rate was 92% (12/13). There were 11 recovered cases and 48 unrecovered cases in group two and three. The highest evoked CMAP was much higher in the recovered than in the unrecovered, significant difference was observed between them (P < 0.001). On the basis of the criterion that a positive prognosis for laryngeal recovery was indicated when the highest evoked CMAP was higher than 26. 4%, correct prognostic rate was 90% (53/59). On the basis of the criterion that a positive prognosis for laryngeal recovery was indicated when there was no misdirect generated potential and the highest evoked CMAP was higher than 26.4%, correct prognostic rate was 93% (55/59). When the interval from onset to laryngeal EMG recovering was longer than 6 months, none of these patients had return of vocal cord mobility whatever were the outcomes of laryngeal EMG.
Correct prognostic rate can be improved if the prognosis of VCP in different courses is judged respectively by analyzing comprehensively spontaneous and evoked EMG.
确定自发肌电图（EMG）和诱发肌电图在喉麻痹中的综合预后价值。
评估91例甲状腺手术后单侧声带麻痹（VCP）患者的喉肌电图特征。所有病例根据发病后喉肌电图检查的时间间隔分为四组，即一组（发病后2个月以内，n = 13）、二组（发病后2至4个月，n = 23）、三组（发病后4至6个月，n = 36）、四组（发病后6个月以上，n = 19）。在自主任务期间检查并分析喉肌电图的波形形态、振幅以及甲杓肌诱发复合肌肉动作电位（CMAP）的最高值。电位振幅以健侧的百分比表示。通过计算统计置信区间得出诱发电位的评估标准。
一组诱发CMAP最高值显著低于其他组（P < 0.05），而二组和三组之间差异无统计学意义（P > 0.05），故将二组和三组合并分析。一组中有2例恢复，11例未恢复。根据诱发电位出现且无再生误发电位提示喉恢复预后良好的标准，正确预后率为92%（12/13）。二组和三组中有11例恢复，48例未恢复。恢复组诱发CMAP最高值显著高于未恢复组（P < 0.001）。根据诱发CMAP最高值高于26.4%提示喉恢复预后良好的标准，正确预后率为90%（53/59）。根据无再生误发电位且诱发CMAP最高值高于26.4%提示喉恢复预后良好的标准，正确预后率为93%（55/59）。当发病至喉肌电图恢复的间隔时间超过6个月时，无论喉肌电图结果如何，这些患者的声带活动均未恢复。
通过综合分析自发肌电图和诱发肌电图分别判断不同病程VCP的预后，可提高正确预后率。
