正常者及び喉頭疾患患者における喉頭機能の空気力学的検討

Abstract

Supraglottic pressure, subglottic pressure, and air flow rate were concurrently measured in normal volunteers and in patients with laryngeal disorders. Subglottic pressure was sensed with a miniaturized pressure transducer transglottally inserted. The subjects consisted of 15 normal volunteers, 20 patients with vocal polyp or nodule, 10 patients with polypoid vocal fold, 10 patients with laryngeal cancer, and 10 patients with recurrent laryngeal nerve paralysis. For phonatory examination, the vowel /a/ was used with changing pitch and loudness. Five Japanese vowels were evaluated. The variables examined included the supra-subglottic pressure difference, the air flow rate, and the glottal resistance at the attack (start of phonation), the stable part, and the end portion of phonation. The values of the supra-subglottic pressure difference, the air flow rate, and the glottal resistance were highest at the stable part of phonations. These values were followed by those at the attack, and at the end portion of phonations in this order. The supra-subglottic pressure difference and the glottal resistance were highest in patients with laryngeal cancer, while the air flow rate was highest in patients with recurrent laryngeal nerve paralysis. The value of each variable increased as loudness of voice increased. The glottal resistance increased as loudness of voice increased, though this increment was smaller in patients with laryngeal disorders than in normal volunteers. The supra-subglottic pressure difference generally showed a high value with low voices, while the air flow rate usually showed a high value with high voices. The glottal resistance was higher with low voices, but showed no change with high voice as compared with easy phonation. The amplitudes of the supra-subglottic pressure difference and the air flow rate were large in patients with vocal polyp or nodule, while these values were small in those with laryngeal cancer or recurrent laryngeal nerve paralysis. No difference in the supra-subglottic pressure difference, the air flow rate and the glottal resistance was observed among five vowels both in normal volunteers and in patients. It was suggested that our method might be useful in further studies to reveal the mechanism of phonatory regulation in patients with laryngeal disorders.