1. Muscle fiber type composition and effects of vocal fold immobilization on the two compartments of the human posterior cricoarytenoid: a case study of four patients
- Author
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Clark A. Rosen, Michael J. Horton, Mark P. Mooney, Carla A. Brandon, James J. Sciote, and George Georgelis
- Subjects
Male ,Pathology ,medicine.medical_specialty ,Muscle Fibers, Skeletal ,Laryngectomy ,Article ,Cricoid Cartilage ,Speech and Hearing ,Atrophy ,Cricoid cartilage ,Culture Techniques ,Myosin ,medicine ,Humans ,Vocal cord paralysis ,Muscle fibre ,Aged ,Myosin Heavy Chains ,Chemistry ,Arytenoid cartilage ,Anatomy ,Middle Aged ,LPN and LVN ,medicine.disease ,Immunohistochemistry ,medicine.anatomical_structure ,Otorhinolaryngology ,Vocal folds ,Laryngeal Muscle ,Female ,Laryngeal Muscles ,Vocal Cord Paralysis ,Arytenoid Cartilage - Abstract
Summary: The human posterior cricoarytenoid (PCA) muscle is divided into two compartments, the vertical and horizontal bellies, which contain differences in their myosin heavy chain (MyHC) composition. Using immunohistochemical techniques on whole PCA samples, this study provides a more thorough description of the fiber type composition of entire bellies of the PCA. Four patients provided complete PCA samples containing both compartments of their right and left sides; two with unilaterally immobilized vocal folds. The horizontal belly had 80% slow (type I) fibers and 20% fast (type II) fibers. The vertical belly contained equal amounts of slow and fast fibers (∼55%:45%); clearly distinguishing between two compartments. Atrophy of muscle fibers and fiber type grouping were also present in both normal and affected subjects; providing no clear confirmation of the clinical findings of vocal fold immobilization. Further study of the PCA muscle from patients with unilaterally immobilized vocal folds is needed.
- Published
- 2003