Division of Thyroid and Parathyroid Surgery, Department of Laryngology and Otology, Massachusetts Eye and Ear Infirmarym, Harvard Medical School, Boston, Massachusetts, U.S.A.
Laryngoscope. 2015 Feb;125(2):E84-9. doi: 10.1002/lary.24781. Epub 2014 Jun 19.
OBJECTIVES/HYPOTHESIS: To define normative amplitude and latency of vagus, recurrent laryngeal nerve (RLN), and external branch of superior laryngeal nerve (EBSLN) and to apply them to postoperative neural function documentation. To our knowledge, this is the first study to report electrophysiologic characteristics of all three nerves in a consecutive patient series.
Prospective.
Quantitative analysis of evoked waveform data was performed on both sides in consecutive patients undergoing thyroid surgery by a single surgeon. Mean values, standard error of mean, and standard deviation were calculated for latency (in milliseconds) and amplitude (in microvolts) of the vagus nerves, RLN, and EBSLN. Pre- and postoperative vocal cord function was normal in all patients.
Normative latency analysis showed mean right and left vagal latency of 5.47 ms (±0.73) and 8.14 ms (±0.86), respectively (P < .0001). Pooled RLN latency was 3.96 ms (±0.69), and pooled EBSLN latency was 3.56 ms (±0.49), both significantly shorter than vagal latencies (P < .0001). There was no association between amplitude and latency parameters and tumor-size (> or <5 cm), body mass index (> or <25), age (> or <50 years), gender, or degree of neural dissection.
The unique right vagus, left vagus, and RLN latencies are characteristic of the individual nerves and allow identification (through the characteristic waveform latency) of an intact left or right vagus/RLN system. Timed recording of vagal waveform after thyroid lobectomy consequently documents intact ipsilateral vagal-RLN neural circuit and may be placed into the medical record as electrophysiologic documentation of existence of postresection complete neural integrity.
目的/假设：定义迷走神经、喉返神经（RLN）和上喉返神经外支（EBSLN）的正常幅度和潜伏期，并将其应用于术后神经功能记录。据我们所知，这是第一项报告连续患者系列中所有这三种神经的电生理特征的研究。
前瞻性。
由一位外科医生对连续接受甲状腺手术的患者进行双侧诱发电位波形数据的定量分析。计算迷走神经、RLN 和 EBSLN 的潜伏期（毫秒）和振幅（微伏）的平均值、平均值的标准误差和标准差。所有患者术前和术后声带功能均正常。
正常潜伏期分析显示右侧和左侧迷走神经的平均潜伏期分别为 5.47 毫秒（±0.73）和 8.14 毫秒（±0.86）（P < .0001）。RLN 的平均潜伏期为 3.96 毫秒（±0.69），EBSLN 的平均潜伏期为 3.56 毫秒（±0.49），均明显短于迷走神经潜伏期（P < .0001）。振幅和潜伏期参数与肿瘤大小（>5 厘米或<5 厘米）、体重指数（>25 或<25）、年龄（>50 岁或<50 岁）、性别或神经解剖程度均无相关性。
独特的右侧迷走神经、左侧迷走神经和 RLN 潜伏期是各条神经的特征，可以通过特征性的波形潜伏期来识别完整的左侧或右侧迷走神经/RLN 系统。甲状腺叶切除术后迷走神经波形的定时记录因此记录了同侧迷走神经-RLN 神经回路的完整性，并可作为术后完全神经完整性的电生理记录放入病历中。
4 级。
