Unilateral cricothyroid contraction and glottic configuration

It is frequently stated that unilateral cricothyroid muscle (CT) paralysis can be diagnosed by physical examination, noting rotation of the glottis, and shortening and vertical displacement of the ipsilateral vocal fold. These signs, however, are inconsistently observed, and there is considerable co...

Full description

Saved in:
Bibliographic Details
Published in:Journal of voice 1998-09, Vol.12 (3), p.335-339
Main Authors: Woodson, Gayle E., Murry, Marie-Pierre, Schweizer, Valerie, Hengesteg, Arne, Chen, Nady, Yeung, Daniel
Format: Article
Language:English
Subjects:
Cricoid Cartilage - innervation
Cricothyroid muscle
Culture Techniques
Glottis - anatomy & histology
Humans
Muscle Contraction - physiology
Superior laryngeal nerve paralysis
Thyroid Gland - innervation
Vocal Cords - physiology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:It is frequently stated that unilateral cricothyroid muscle (CT) paralysis can be diagnosed by physical examination, noting rotation of the glottis, and shortening and vertical displacement of the ipsilateral vocal fold. These signs, however, are inconsistently observed, and there is considerable controversy regarding the direction of glottic rotation. To determine the effects of CT contraction on three-dimensional glottic configuration, we performed computerized tomography on cadaver larynges before and after simulated CT contraction. Radiopaque makers were used to compute distances. Unilateral CT contraction equally increased the length of both membranous vocal folds, and rotated the posterior glottis less than 1 mm. CT contraction neither adducted the vocal processes, nor significantly their altered vertical level. These results suggest that unilateral CT paralysis cannot be diagnosed on the basis of any clinically apparent change in glottal configuration.
ISSN:0892-1997
1873-4588
DOI:10.1016/S0892-1997(98)80023-4