神经肌电检测对单侧喉返神经损伤预后的评价

Comprehensive prognostic value of spontaneous and evoked electromyography in laryngeal paralysis

目的 探讨喉神经肌电位综合指标对声带麻痹预后的估价作用。方法 检测91例甲状腺手术单侧声带麻痹患者的喉神经电图及肌电位,按病程分成4组;分析各组恢复与未恢复声带运动的患者喉神经肌电位特征,以“95％可信区间”计算神经肌电位预后评估标准。结果 病程2个月内组最大诱发电位幅度明显低于2个月以上的其他各组,差异具有显著性意义(P<0.05),而2-4个月与4-6个月组的组间差异无显著性(P>0.05),故将病程2-6个月计为一组。2个月内组自然恢复与未恢复患者分别为2、11例,以引出诱发电位且无错向再生电位作为预后良好判断指标,准确率为92％(12/13)。2-6个月组恢复与未恢复患者各为11、48例,恢复者最大诱发电位幅度明显大于未恢复者,差异有显著性意义(P<0.01)。以引出诱发电位且电位幅度大于26.4％作为预后良好的判断标准,准确率90％(53/59);结合无错向再生电位综合判断预后,准确率为93％(55/59)。6个月以上组19例无论神经肌电位检查结果如何,声带运动均无恢复。结论 将神经肌电位进行综合分析,分别判断不同病程的声带麻痹的预后,可提高预后判断的准确率。

Objective To determine the comprehensive prognostic value of spontaneous and evoked electromyography (EMG) in laryngeal paralysis. Methods 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. Results 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. Conclusions Correct prognostic rate can be improved if the prognosis of VCP in different courses is judged respectively by analyzing comprehensively spontaneous and evoked EMG.