神经肌电检测对单侧喉返神经损伤预后的评价

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。     

肌电图检查对声带麻痹预后的评估

目的 :探讨喉肌电图检查对声带麻痹预后的评估作用。方法 :对 4 6例单侧声带麻痹且固定的患者行甲杓肌的自发肌电图检查 ,分析甲杓肌失神经电位及运动单位波形、时程、电位幅度及运动单位平方根 (RMS)值 ;喉镜观察声带运动恢复情况。结果 :病程在 6个月以内 ,肌电图出现正常的运动单位波形、无电静息 ,提示预后较好 ,判断准确率为 76 % ;RMS值在用力发音时大于 2 6 μV ,提示声带运动可恢复 ,判断准确率为 80 %。综合两者 ,判断准确率为 84 %。声带麻痹 6个月以上者 ,无论肌电图检查结果如何 ,声带运动均无恢复。运动单位时程及电位幅度对判断预后价值不大。结论 :将喉肌电图定性指标与RMS值进行综合分析 ,可提高对声带麻痹预后判断的准确率     

Evoked electromyographic test applied for recurrent laryngeal nerve paralysis

This study was performed to apply the evoked electromyographic (EMG) test to the larynx and to find out whether or not this test is useful for diagnosis of patients with recurrent laryngeal nerve paralysis. As a result, it was considered that the present test was useful for the following:

• 1 Diagnosis of the site of lesion: The decision is easily made whether the recurrent laryngeal nerve is damaged alone or together with the superior laryngeal nerve, and on the site of damages along the recurrent laryngeal nerve in some cases.
• 2 Determination of prognosis: The cases showing no evoked wave may not recover completely. For the cases showing an evoked wave, information on prognosis can be obtained from the degree of changes in latency and evoked wave form.
• 3 Indication of the state of nerve regeneration: The evoked EMG test is able to reveal the state of reinnervation of the paralyzed laryngeal nerve as well as and even earlier than the ordinary EMG test.

     

The role of laryngeal electromyography in vocal fold immobility

AIM OF STUDY: To assess the utility of laryngeal electromyography (EMG) as a diagnostic method for patients with immobile vocal folds and to evaluate its possible role as a prognostic indicator in the management of those cases. METHODOLOGY: The study included 35 patients with unilateral vocal fold immobility (VFI) and 10 normal controls. All patients were subjected to full history taking and thorough clinical examination and radiological investigations. Laryngeal EMG was performed for all the patients and controls. RESULTS: The specificity of EMG was 100%, while the sensitivity was 65.7% in detecting VFI. Seventeen cases (74%) with abnormal EMG data had a combined lesion of recurrent and superior laryngeal nerves and 6 cases (26%) had isolated recurrent laryngeal nerve lesion. In both groups there was no statistical difference as regards the position of the paralyzed vocal fold in either paramedian or lateral positions. Clinical follow-up with indirect laryngoscopy, 6 months later, revealed recovery in 10 of the 25 cases (40%). None of the recovered patients showed abnormal EMG data at presentation, while 13 out of 15 cases of non-recovered patients showed abnormal EMG data, i.e. the specificity of EMG was 100%, while the sensitivity was 86.6% in predicting recovery in patients with VFI. The quantitative analysis of the interference pattern was more sensitive (65.7 and 86.6%) than the conventional methods of analysis (60 and 80%) in detecting and predicting recovery in patients with immobile vocal folds, respectively. CONCLUSION: The clinical use of laryngeal EMG is an efficient and objective test in the study of patients with immobile vocal folds and in predicting recovery of those cases. It is also a useful tool in the diagnostic algorithm in vocal fold paralysis.     

一侧膈神经上根选择性神经再支配环杓后肌的实验研究

目的 探讨一侧膈神经上根选择性神经再支配环杓后肌的可行性和有效性.方法 8只健康雄性青年Beagle犬作为实验动物,全麻下切断Beagle犬左侧膈神经上根与左侧喉返神经,两断端通过游离神经桥接的方式吻合,并将同侧喉返神经内收肌支切断并植入同侧环杓后肌中;右侧不做任何处理,作为正常对照侧.于手术前、神经修复术后即刻、术后6个月分别行电子喉镜和喉肌电图检查,在最后一次检查后处死动物,取双侧环杓后肌和喉内段喉返神经行组织学检查并与对侧比较.结果 术前8只犬的双侧声带运动正常,术后即刻左侧声带固定,术后6个月均恢复了吸气性外展运动.术前8只犬双侧环杓后肌均能记录到自发肌电位,并引出诱发电位;术后即刻左侧环杓后肌呈电静息,未记录到诱发电位;术后6个月均能记录到自发肌电位,并引出诱发电位,而且两种电位幅度分别与术前比较差异均无统计学意义(均为P>0.05).环杓后肌Masson染色示两侧肌肉纤维相对截面积、胶原纤维相对截面积、肌肉/胶原纤维截面积比差异均无统计学意义(均为P>0.05).喉内段喉返神经甲苯胺蓝染色后示神经纤维分布较均匀密集,且左右两侧喉返神经有髓神经纤维数量差异无统计学意义(P>0.05).结论 左侧膈神经上根选择性神经再支配环杓后肌能有效避免神经错向再生,恢复声带的生理性外展运动.     

Intraoperative Electrophysiologic Monitoring of the Recurrent Laryngeal Nerve

Intraoperative electrophysiologic monitoring of the recurrent laryngeal nerve was performed with a commercially available device consisting of an endotracheal tube with integrated stainless-steel-wire surface EMG electrodes positioned at the level of the true vocal cords. Forty-two recurrent laryngeal nerves were successfully monitored with this system in 31 patients undergoing thyroidectomy or parathyroidectomy. In all cases, evoked EMG responses were elicited by direct electrical recurrent laryngeal nerve stimulation. Stimulus thresholds for evoked responses ranged from 0.2 to 0.6 mA (mean 0.3 mA) for the 37 nerves with preoperative ipsilateral normal vocal cord mobility. Mechanically evoked potentials with acoustic signals were also detected during the surgical procedures related to recurrent laryngeal nerve manipulation. It may be concluded that surface electrode monitoring of the recurrent laryngeal nerve with this system provides a simplified, noninvasive technique that is as sensitive as monitoring with intramuscular laryngeal electrodes.     

Dose response of topical anesthetic on laryngeal neuromuscular electrical transmission

OBJECTIVES: Our purpose was to determine the effect of a dose response to decreasing concentrations of topical anesthetic upon laryngeal neuromuscular electrical transmission. METHODS: We performed a prospective study at a neurolaryngology referral center. Forty-three patients were divided into 5 groups. Each patient underwent laryngeal electromyography (EMG) of a thyroarytenoid muscle before and 60 seconds after topical laryngotracheal lidocaine hydrochloride, normal saline solution, or nothing was applied. The pretreatment and posttreatment measurements were recorded with the same indwelling EMG electrode. Group 1 (n = 12) received 4% lidocaine, group 2 (n = 9) received 2% lidocaine, and group 3 (n = 8) received 1% lidocaine. Group 4 (n = 5) received topical normal saline solution instead of lidocaine. A fifth group (group 5, n = 9) had 2 EMG recordings measured, each separated by 60 seconds, without topical anesthetic. RESULTS: Groups 1, 2, and 3 showed significant decreases in the maximum peak-to-peak amplitude of the EMG recording (48.5%, 49.7%, 44.7%, respectively). Groups 4 and 5 failed to show a significant change in peak-to-peak amplitude after 60 seconds. There was no dose response change in EMG with decreasing lidocaine concentrations. CONCLUSIONS: All concentrations of lidocaine administered in this study decreased the laryngeal neuromuscular electrical transmission as measured by laryngeal EMG. This group of patients did not exhibit any dose response to anesthetic concentration. This finding is clinically significant for both diagnostic and therapeutic uses of laryngeal EMG preceded by administration of topical anesthetic.     

Red blood cell distribution width predicts prognosis in idiopathic sudden sensorineural hearing loss

Conclusion: Red cell distribution width (RDW) can predict outcome in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). Further studies are required to clarify the potential pathophysiological explanations for these findings.

Objectives: RDW is one of the parameters reported in a complete blood count, and is elevated in direct proportion to variation in red cell size (anisocytosis). High RDW values are strongly associated with poor clinical outcomes in various diseases, including inflammatory and thrombotic diseases. To identify a prognostic biomarker that better predicts outcomes after ISSNHL, the association between RDW values at hospitalization and prognosis in patients with ISSNHL was assessed.

Method: This study measured RDW and performed hearing assessments in 89 consecutive patients with ISSNHL. Patients were then divided into two groups (‘recovered’ and ‘unrecovered’), according to their response to the treatment, and further analysis undertaken.

Results: Mean RDW was significantly higher in the unrecovered group (13.2%?±?1.0% compared with 12.7%?±?0.7% in the recovered group, p?=?0.031). After adjusting for potentially confounding factors in a binary logistic regression model, only RDW was associated with recovery from ISSNHL (odds ratio =?2.33, 95% confidence interval =?1.20–4.51, p?=?0.012).     

微血管密度在声门上型喉鳞状细胞癌中的分布及其预后

目的 :研究微血管密度 (MVD)在声门上型喉鳞状细胞癌 (SGLSCC)中的分布及对预后的影响。方法 :应用CD31两步系统免疫组织化学染色方法研究 5 9例手术治疗的原发SGLSCC标本 ,并以 19例声带息肉(VCP)标本做良性对照。结果 :SGLSCC的间质中可见大量微血管存在 ,而VCP上皮下结缔组织中微血管数明显减少。Kendall等级相关分析表明 ,在SGLSCC各临床病理参数中 ,MVD仅与淋巴结转移有中等程度的正相关 (P <0 .0 1)。N0 与N 、SGLSCC与VCP间的MVD值差异经独立样本均数 t检验显示均有统计学意义 (均P <0 .0 1)。Kaplan Meier生存分析显示 ,MVD与SGLSCC患者术后累积生存率有统计学意义 (P <0 .0 1)。结论 :血管生成在肿瘤形成、侵袭与转移中有重要作用 ;MVD对颈淋巴结转移有预示作用 ;MVD与SGLSCC患者的预后有关。     

Laryngeal electromyography.

Laryngeal electromyography (EMG) is simultaneously a powerful clinical and investigative tool. EMG may be diagnostic and prognostic in cases of laryngeal or vagus nerve injury and can differentiate between vocal cord fixation and paralysis. EMG also is being used to help unravel complex laryngeal neural and muscle physiology. Basic principles of EMG, techniques of EMG limited to three muscles--the thyroarytenoid, the posterior cricoarytenoid, and the cricothyroid, and pitfalls of this procedure are discussed within this article.