Laryngeal reinnervation as treatment for unilateral vocal fold paralysis may result in synkinesis. Synkinesis occurs when a severed recurrent laryngeal nerve (RLN) is repaired; the adductor and abductor fibers, which are intermixed within the common nerve trunk, may grow into the wrong endoneural tubules as the nerve heals. The resulting cross- innervation causes a variable amount of laryngeal incoordination and impaired function. This phenomenon has not previously been studied in detail. In this study, an attempt will be made to characterize the process of laryngeal synkinesis in a canine model, from a physiologic and histochemical perspective. The primary physiologic measure will be laryngeal adductory pressure (LAP), which is obtained by measuring the pressure in a balloon cuff placed between the vocal folds while stimulating the RLN electrically. The LAP plotted against the stimulation frequency gives a frequency response curve with a characteristic slope. Changes in this slope can be used as an indirect physiologic measure of synkinesis. The ability of a nerve to induce a histochemical change in the muscle it is cross-innervating (Buller et al.) can be used to further quantify laryngeal synkinesis. A series of nerve injury and repair experiments which are expected to produce varying degrees of laryngeal synkinesis will be performed. After 6 months of healing, the laryngeal muscles will be harvested and the histochemistry studied (using alkali-stable ATPase staining) to determine how much the muscle has been transformed from fast-to slow-twitch, or vice-versa. This is another indirect measure of laryngeal synkinesis.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Small Research Grants (R03)
Project #
5R03DC003859-03
Application #
6176068
Study Section
Special Emphasis Panel (ZDC1-SRB-F (11))
Program Officer
Shekim, Lana O
Project Start
1998-08-01
Project End
2002-07-31
Budget Start
2000-08-01
Budget End
2002-07-31
Support Year
3
Fiscal Year
2000
Total Cost
$44,100
Indirect Cost
Name
Washington University
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Paniello, Randal C; Rich, Jason T; Debnath, Nick L (2015) Laryngeal adductor function in experimental models of recurrent laryngeal nerve injury. Laryngoscope 125:E67-72
Yian, C H; Paniello, R C; Gershon Spector, J (2001) Inhibition of motor nerve regeneration in a rabbit facial nerve model. Laryngoscope 111:786-91
Paydarfar, J A; Paniello, R C (2001) Functional study of four neurotoxins as inhibitors of post-traumatic nerve regeneration. Laryngoscope 111:844-50
Paniello, R C; West, S E (2000) Laryngeal adductory pressure as a measure of post-reinnervation synkinesis. Ann Otol Rhinol Laryngol 109:447-51