Availability of Ultrasongraphic Study in Larynx / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The observation about the movements of laryngopharyngeal or surrounding structures is very important to understand the physiology of phonation or swallowing and to diagnose the disease. Many investigating methods were used but most of them were ineffective because those were invasive or indirect methods. Ultrasonographical examination of larynx can be applied, but the shortcomings of mechanics limits the usage of ultrasonographical study of larynx. Recently, the revolution of computer and videosystem made ultrasonographical study to be applied to the larynx. In this study, authors wanted to find out the availability of the ultrasonographical study of larynx. MATERIALS AND METHODS: 3.5 and 7.5 MHz probes were applied to anterior neck and the ultrasonographical findings were observed according to the various phonation types. RESULTS: In the axial plane, the movements of bilateral vocal folds were observed. Unilateral movement of vocal cord alone was seen in the case of unilateral vocal cord paralysis. In the parasagittal plane, the movements of whole laryngopharyngeal structures were observed simultaneously. A specific tongue shape was seen on each vowel phonation. On phonation with high pitch, hyoid bone and thyroid cartilage were elevated. And thyroid cartilage was elevated and laid upon the hyoid bone moving medially. On phonation with high pitch extremely, the hyoid bone went down. On phonation loudly, echogenicity of surrounding muscles was increased. CONCLUSION: Authors think that the ultrasonographical study can be applied to the physiologic study of phonation as well as diagnostic tools or therapeutic tools.

The Significance of Recording Electrode Placement in Test-Retest of Electroneuronography / 대한이비인후과학회지

ENoG is regarded as a valuable method for quantitatively assessing facial nerve function, however it is occasionally discorrelated with clinical findings. So its utility may be diminished, especially in the serial tests. So, we endeavored to find the suitable position of recording electrode in test-retest variability of ENoG. We performed the test five times individually in 18 healthy adults(all males) volunteers. The recording electrodes were placed at 3 different positions(whole nasolabial fold(A), 2/3 portion of the nasolabial fold(B), 1/2 portion of the nasolabial fold(C)). And then we compared the results between action potentials of 3 different positions. The amplitude was more stable at B or C than A. The mean interside variance(ISV) of individuals was less than 50% except one case at A, and there was no significant difference among them(p>or=0.05) except two persons between A and C(p<0.05). In the test-retest variability, the mean was 20.03%(A:20.66+/-10.72%, B:23.75+/-12.60%, C:15.69+/-10.21%). There was more smaller mean and standard deviation at C than others. So, we recommand the 1/2 of the nasolabial fold as the available position in the serial ENoG recordings.