延髓型重症肌无力喉肌电指标变化的临床价值

Clinical Value of Laryngeal Electromyographic Indicators in Patients with Bulbar Type Myasthenia Gravis

目的探讨延髓型重症肌无力患者电视胸腔镜下胸腺扩大切除术（video-assisted thoracoscopic extended thymectomy，VATET）后喉肌电指标测定的临床价值。方法回顾分析2002年6月～2011年7月我科36例延髓型重症肌无力（延髓型组）行VATET的临床资料，对术前后喉肌电指标进行分析，选取同期36例健康受试者作为对照组。结果延髓型组术前喉内肌肌电振幅（210．68±75．42）μV，较对照组（309．40±55．33）μV明显缩窄（t=6．332，P=0．000）；时程（7．68±0．57）ms较对照（5．42±0．34）mB明显延长（t=-20．431，P=0．000）；募集相最大电位（1132．18±467．19）μV较对照组（1675．00±532．85）μV明显缩窄（t=4．596，P=0．000），术后2组比较仅时程有明显差异（t=6．375，P=0．000）。延髓型组喉内肌群术后肌电振幅（312．91±69．43）μV，较术前（210．68±75．42）μV明显变宽（t=-5．983，P=0．000）；术后时程（6．19±0．64）m8较术前（7．68±0．57）m8明显缩短（t=10．431，P=0．000）；术后募集相最大电位（1557．67±521．45）斗V较术前（1132．18±467．1）μV明显变宽（t=-3．646，P=0．000）；喉外肌仅肌电振幅差异显著[（139．36±74．26）μV vs．（102．75±63．22）μV，t=-2．252，P=0．027]。术后喉肌电图正常的患者疗效有效率89．3％（25／28），喉肌电图异常的患者疗效有效率37．5％（3／8），2组比较有统计学差异（χ2=6．891，P=0．009）。结论延髓型重症肌无力患者肌电指标异常，VATET可有效改善各项指标，缓解相关的临床症状。

Objective To analyze the clinical value of laryngeal electromyographic indicators in patients with bulbar type myasthenia gravis undergoing video-assisted thoracoscopic extended thymectomy （VATET）. Methods A retrospective analysis of 36 cases of bulbar type of myasthenia gravis who had undergone VATET from June 2002 to July 2011 in our department was made. The changes of indicators of laryngeal electromyography before and after operation were evaluated. Another 36 healthy volunteers were selected as the control group at the same time. Results Preoperatively, as compared with the control group, the electromyographic amplitude [（210.68±75.42） μV vs. （309.40 ±55.33） μV, t=6.332, P=0. 000], duration [（7.68±0.57） ms vs. （5.42± 0.34） ms, t= -20.431, P=0.000], and maximum recruitment charge [（1132.18 ±467.19） μV vs. （1675.00 ±532.85） μV, t =4. 596, P = 0. 000 ] of intrinsic laryngeal muscles in bulbar type patients were significantly different. Postoperatively, there was significant difference between the two groups in electromyographic duration （t = 6. 375, P = 0. 000）. In intrinsic laryngeal muscles of bulbar type patients, the postoperative electromyographic amplitude was significantly higher than preoperative one [ （312.91 ± 69.43 ） μV vs. （210.68 ± 75.42） μV, t = -5. 983, P = 0. 000 ] , the postoperative electromyographic duration was significantly shorter than preoperative one [ （6.19 ± 0.64） ms vs. （7.68 ± 0.57 ） ms, t = 10.431, P = 0. 000 ] , and the postoperative maximum recruitment charge was significantly higher than preoperative one [ （ 1557.67 ± 521.45） μV vs. （ 1132. 18 ± 467. 1 ） μV, t = - 3. 646, P = 0. 000]. In extrinsic laryngeal muscles, however, there was significant difference between the two groups only in electromyographic amplitude postoperatively [ （ 139.36 ± 74.26） μV vs. （ 102.75 ± 63.22） μV, t = - 2. 252, P = 0. 027 ]. In patients with normal postoperative electromyographic indicators, the effective rate was 89.3% （25/28） , while in patients with abnormal indicators, 37.5% （3/8） , with significant difference （χ2 = 6. 891, P = 0. 009）. Conclusions Indicators of laryngeal electromyography are seriously abnormal in patients with bulbar type myasthenia gravis. All the indicators can be effectively improved after VATET, with associated symptoms relieved.