Broniatowski M, Vito K J, Shah B, Shields R W, Secic M, Dessoffy R, Strome M
Department of Otolaryngology and Communicative Disorders, Cleveland Clinic Foundation Health Sciences Center, Ohio State University, USA.
Laryngoscope. 1996 Dec;106(12 Pt 1):1510-5. doi: 10.1097/00005537-199612000-00013.
The specific performance of intrinsic laryngeal muscles has been difficult to evaluate, especially in living subjects. To reproduce natural contractions, we artificially induced orderly recruitment of their innervating axons according to the size principle. In 5 dogs, both recurrent laryngeal nerves (RLNs) were stimulated with 50 through 10 Hz, 300 to 1000 microA currents while 600 Hz, 1000 to 0 microA decreasing blocking currents were administered. Surface electromyography electrodes placed on the thyroarytenoid, posterior cricoarytenoid, and lateral cricoarytenoid muscles were used to determine the amplitudes (in mA) of compound muscle action potentials. There was a highly statistically significant difference (P<.004) between the thyroarytenoideus which had the fastest rate of recruitment (8.38%), and posterior cricoarytenoideus, which had the slowest (4.81%). There was an intermediate recruitment rate (6.72%) of the lateral cricoarytenoideus, a divergence attributed to a more equal distribution in fast and slow types of myofibers and a smaller sample. We submit that RLN axons can be recruited in an orderly manner according to their sizes and that the rates are unique to the muscle classes they innervate. The parameters defining these contraction patterns may offer key information for laryngeal pacing.
喉内肌的具体表现一直难以评估，尤其是在活体受试者中。为了再现自然收缩，我们根据大小原则人工诱导其支配轴突的有序募集。在5只狗中，双侧喉返神经（RLNs）分别用50至10Hz、300至1000μA的电流刺激，同时给予600Hz、1000至0μA的递减阻断电流。放置在甲杓肌、环杓后肌和环杓侧肌上的表面肌电图电极用于测定复合肌肉动作电位的幅度（以mA为单位）。募集速度最快的甲杓肌（8.38%）与募集速度最慢的环杓后肌（4.81%）之间存在高度统计学显著差异（P<0.004）。环杓侧肌的募集速度居中（6.72%），这种差异归因于快、慢两种类型肌纤维分布更为均匀以及样本量较小。我们认为，喉返神经轴突可以根据其大小有序募集，且募集速度对于它们所支配的肌肉类型而言是独特的。定义这些收缩模式的参数可能为喉起搏提供关键信息。
