Kawasaki A, Fukuda H, Shiotani A, Kanzaki J
Department of Otolaryngology, School of Medicine, Keio University, Tokyo, Japan.
Auris Nasus Larynx. 2001 Jan;28(1):75-84. doi: 10.1016/s0385-8146(00)00087-0.
The purpose of this study was to reveal movements of individual structures of the larynx during swallowing.
Subjects were 7 healthy adults, aged 24 to 32 years (average 27 years), who had no organic or functional disease of the pharynx and larynx and 2 adults with unilateral recurrent nerve palsy, aged 49 and 60 years, respectively. We used the Toshiba IIDR system, which is composed of an X-ray TV system and a digital image managing circuit. One-fifth diluted Omnipark 300 was used as contrast medium (lohexol), with 15 cc for each swallow. The mask image for subtraction was designated as the frame before laryngeal elevation during swallowing for subtraction. We obtained the images for observation and analysis after subtracting the mask image from continuously obtained images. These images were captured into a personal computer at 30 frames per s and thereafter frame-by-frame observation and analysis were performed by means of NIH image 1.56.
We observed that the vocal folds underwent a series of movements during swallowing. (1) They adduct slowly and do not ascend; (2) then begin to ascend and continue adducting; whereby (3) they abduct for a moment while ascending. (4) Again, they adduct and achieve closure. (5) While maintaining closure, vocal folds elevate further to reach their maximal elevation; and (6) begin to abduct rapidly while maintaining maximal elevation. Finally, (7) they begin to descend and undergo repeated irregular abduction and adduction while descending. In examining the relationship between closure and opening at levels of the vocal fold and false vocal fold, we found that closure at the false vocal fold level precedes that at the vocal fold level and that opening at the vocal fold level precedes that at the level of the false vocal fold.
Closure of the false vocal fold level appears important in the protection of the lower respiratory tract during swallowing.
本研究旨在揭示吞咽过程中喉部各结构的运动情况。
研究对象包括7名健康成年人，年龄在24至32岁之间（平均27岁），无咽喉部器质性或功能性疾病，以及2名分别为49岁和60岁的单侧喉返神经麻痹成年人。我们使用了由X射线电视系统和数字图像管理电路组成的东芝IIDR系统。使用五分之一稀释的欧乃派克300（碘海醇）作为造影剂，每次吞咽使用15毫升。减法运算的蒙片图像指定为吞咽时喉部抬高前的帧用于减法运算。从连续获取的图像中减去蒙片图像后，我们获得了用于观察和分析的图像。这些图像以每秒30帧的速度采集到个人计算机中，然后借助NIH Image 1.56进行逐帧观察和分析。
我们观察到吞咽过程中声带会经历一系列运动。（1）它们缓慢内收且不上升；（2）然后开始上升并继续内收；由此（3）它们在上升时短暂外展。（4）再次，它们内收并实现闭合。（5）在保持闭合的同时，声带进一步抬高至最大高度；并且（6）在保持最大高度的同时开始迅速外展。最后，（7）它们开始下降，并在下降过程中反复进行不规则的外展和内收。在检查声带和假声带水平的闭合与开放之间的关系时，我们发现假声带水平的闭合先于声带水平的闭合，而声带水平的开放先于假声带水平的开放。
假声带水平的闭合在吞咽过程中对下呼吸道的保护似乎很重要。
