Configuration of the glottis in laryngeal paralysis. I: Clinical study.

It is widely accepted in the American literature that the cricothyroid muscle is responsible for the paramedian position of the vocal fold in recurrent laryngeal nerve paralysis. However, support in the literature for this theory is not conclusive, and the cadaveric vocal fold position expected after lesions of the vagus nerve has also been reported in patients with an intact superior laryngeal nerve. This study compares the configuration of the glottis in patients with unilateral paralysis due to known lesions of either the recurrent laryngeal or vagus nerve. Normal subjects were studied as controls. Results indicate that the alteration of glottic configuration in laryngeal paralysis cannot be adequately characterized by standard terms of vocal fold position. The paralyzed vocal fold is shortened, with anterior rotation of the arytenoid. Patients with vagus nerve lesions had a statistically insignificant tendency for a more lateral vocal fold position, but a discrete difference in position between the two groups was not identified. This study also confirms prior observations that paralyzed vocal folds are frequently not denervated. These findings have significant implications for management of laryngeal paralysis.