Related Experiment Video
Updated: Aug 16, 2026

A Protocol for Comprehensive Assessment of Bulbar Dysfunction in Amyotrophic Lateral Sclerosis (ALS)
Published on: February 22, 2011
Videoendoscopic assessment of dynamic laryngeal function during exercise in horses with grade-III left laryngeal
E J Hammer1, E P Tulleners, E J Parente
1Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, Kennett Square 19348, USA.
Objective:
To evaluate laryngeal function by means of videoendoscopy during high-speed treadmill exercise in racehorses with grade-III left laryngeal hemiparesis at rest and to determine outcome of treatment.
Design:
Retrospective study.
Animals:
26 racehorses.
Procedure:
Videoendoscopy of the larynx was performed while horses were at rest and exercising on a treadmill. Horses were classified as having grade-IIIA, -IIIB, or -IIIC laryngeal hemiparesis on the basis of the degree of arytenoid cartilage abduction maintained during exercise. Postoperative racing performance was determined by evaluating race records and conducting telephone surveys.
Results:
20 (77%) horses had grade-IIIC laryngeal hemiparesis (i.e., severe dynamic laryngeal collapse during exercise). Eighteen underwent surgery, and racing performance was improved in 9. Five (19%) horses had grade-IIIB laryngeal hemiparesis (i.e., left arytenoid cartilage and vocal fold were maintained in an incompletely abducted position during exercise). Four underwent surgery, and racing performance was improved in 1. One (4%) horse had grade-IIIA laryngeal hemiparesis (i.e., full abduction of arytenoid cartilage during exercise); surgery was not performed.
Clinical Implications:
Videoendoscopy is useful in determining dynamic laryngeal function in racehorses with grade-III laryngeal hemiparesis at rest.
Related Concept Videos
Assessment of Airway, Skin Color, and Use of Accessory Muscles
Introduction
The initial evaluation of a patient's respiratory system...
Larynx
Anatomy of the Larynx
The larynx consists of various components, including cartilage, muscles, and vocal cords. Its structure includes three large unpaired cartilages—the thyroid, cricoid, and epiglottis—and three smaller paired cartilages—the arytenoids, corniculates, and...
Mitral Stenosis II: Clinical features and Diagnostic Tests
Cardiopulmonary Resuscitation V: Advanced Airway Management Techniques

