Effects of denervation on laryngeal muscles: a canine model.
The purpose of this study was to chronologically evaluate the changes in functional and histomorphometry of denervated laryngeal muscles. In 14 adult mongrel dogs, a 2.5-cm segment of the right recurrent laryngeal nerve was excised. Videolaryngoscopy and electromyography were performed at 1, 2, 3, 4, 5, 6, and 9 months under intravenous sedation. The animals were then killed, and the laryngeal muscles were processed for histochemical reactions. The mean muscle fiber diameter, standard deviation, and muscle fiber type composition were determined. The findings indicate that, following recurrent laryngeal nerve sectioning, the canine intrinsic laryngeal muscles undergo denervation atrophy for approximately 3 months, after which reinnervation occurs. The source of reinnervation appears to be from regenerated nerve fibers of the sectioned recurrent laryngeal nerve. The nerve fibers nonselectively reinnervated the abductor and adductor muscles of the larynx.
Shindo
M L
ML
Department of Otolaryngology-Head and Neck Surgery, Northwestern University Medical School, Chicago.
Herzon
G D
GD
Hanson
D G
DG
Cain
D J
DJ
Sahgal
V
V
D000200:Action Potentials / Q000502:physiology; D000251:Adenosine Triphosphatases / Q000032:analysis; D000818:Animals; D001284:Atrophy; D004285:Dogs; D004576:Electromyography; D005207:Fasciculation / Q000503:physiopathology; D005355:Fibrosis; D006984:Hypertrophy; D007821:Laryngeal Muscles / Q000294:innervation* / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D007828:Laryngoscopy; D009046:Motor Neurons / Q000473:pathology / Q000502:physiology; D009121:Muscle Denervation; D009210:Myofibrils / Q000473:pathology; D009246:NADH Tetrazolium Reductase / Q000032:analysis; D009416:Nerve Regeneration; D012009:Recurrent Laryngeal Nerve / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D014741:Video Recording; D014826:Vocal Cord Paralysis / Q000473:pathology / Q000503:physiopathology
D009246:NADH Tetrazolium Reductase; D000251:Adenosine Triphosphatases