Electromyographic and histologic evolution of the recurrent laryngeal nerve from transection and anastomosis to mature reinnervation

Pitman, Michael J.; Weissbrod, Philip A.; Roark, Rick M.; Sharma, S. C.; Schaefer, Steven David

doi:10.1002/lary.21290

Cited by 37 publications

(49 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the early group, optimal fitting of the time to recovery yielded a mean of 4.2 weeks and standard deviation of 1.4 weeks. It follows that 95% of the early group should recover within about 6 to 7 weeks, which is consistent with studies of synkinesis in a rat model . In a systematic review of idiopathic vocal fold paralysis, five cases out of 717 (0.7%) recovered beyond a year, which is consistent with the model prediction of approximately 1% recovering beyond 12 months.…”

Section: Discussionsupporting

confidence: 82%

“…It follows that 95% of the early group should recover within about 6 to 7 weeks, which is consistent with studies of synkinesis in a rat model. 23 In a systematic review of idiopathic vocal fold paralysis, 2 five cases out of 717 (0.7%) recovered beyond a year, which is consistent with the model prediction of approximately 1% recovering beyond 12 months. Rather than regarding these delayed recoverers as anomalies, they are simply the tail part of the same probability distribution describing the entire population of recoverers.…”

Section: Predictions Of the Model Are Consistent With Published Datasupporting

confidence: 67%

See 1 more Smart Citation

The natural history of recoverable vocal fold paralysis: Implications for kinetics of reinnervation

2017

View full text Add to dashboard Cite

show abstract

Section: Discussionsupporting

confidence: 82%

Section: Predictions Of the Model Are Consistent With Published Datasupporting

confidence: 67%

The natural history of recoverable vocal fold paralysis: Implications for kinetics of reinnervation

2017

View full text Add to dashboard Cite

show abstract

“…Reinnervation after freezing injury induced an increased number of myelinated axons with smaller diameter, as already reported . Considering that axon diameter and degree of myelination depend on the axon maturation, the axonal growth rate seems lower than in other studies where the RLn morphologic appearance was comparable to control nerve 20 weeks after injury . Rate of reinnervation is determined by many factors like species, age, type of nerves, nature of injury, and distance from target organ and neuronal cell body .…”

Section: Discussionmentioning

confidence: 81%

Functional electrical stimulation following nerve injury in a large animal model

et al. 2019

View full text Add to dashboard Cite

Introduction: Controversy exists over the effects of functional electrical stimulation (FES) on reinnervation. We hypothesized that intramuscular FES would not delay reinnervation after recurrent laryngeal nerve (RLn) axonotmesis. Methods: RLn cryo‐injury and electrode implantation in ipsilateral posterior cricoarytenoid muscle (PCA) were performed in horses. PCA was stimulated for 20 weeks in eight animals; seven served as controls. Reinnervation was monitored through muscle response to hypercapnia, electrical stimulation and exercise. Ultimately, muscle fiber type proportions and minimum fiber diameters, and RLn axon number and degree of myelination were determined. Results: Laryngeal function returned to normal in both groups within 22 weeks. FES improved muscle strength and geometry, and induced increased type I:II fiber proportion (p = 0.038) in the stimulated PCA. FES showed no deleterious effects on reinnervation. Discussion: Intramuscular electrical stimulation did not delay PCA reinnervation after axonotmesis. FES can represent a supportive treatment to promote laryngeal functional recovery after RLn injury. Muscle Nerve 59:717–725, 2019

show abstract

“…This recovery is delayed up to 16 wpi when the injury is a transection and anastomosis (Pitman et al. ).…”

Section: Discussionmentioning

confidence: 99%

“…A functional score was assigned to the left vocal fold movements observed, with a score of 0 being assigned to a paralyzed vocal fold; 1 for a slight movement being visible; 2 for normal or near to normal movement. Work by previous authors has shown that the effects of the anesthetic used upon laryngeal fold mobility appear to be minimal (Aoyama et al 2010;Pitman et al 2011).…”

Section: Functional Evaluationmentioning

confidence: 99%

Reorganization of laryngeal motoneurons after crush injury in the recurrent laryngeal nerve of the rat

et al. 2013

View full text Add to dashboard Cite

Motoneurons innervating laryngeal muscles are located in the nucleus ambiguus (Amb), but there is no general agreement on the somatotopic representation and even less is known on how an injury in the recurrent laryngeal nerve (RLN) affects this pattern. This study analyzes the normal somatotopy of those motoneurons and describes its changes over time after a crush injury to the RLN. In the control group (control group 1, n = 9 rats), the posterior cricoarytenoid (PCA) and thyroarytenoid (TA) muscles were injected with cholera toxin-B. In the experimental groups the left RLN of each animal was crushed with a fine tip forceps and, after several survival periods (1, 2, 4, 8, 12 weeks; minimum six rats per time), the PCA and TA muscles were injected as described above. After each surgery, the motility of the vocal folds was evaluated. Additional control experiments were performed; the second control experiment (control group 2, n = 6 rats) was performed labeling the TA and PCA immediately prior to the section of the superior laryngeal nerve (SLN), in order to eliminate the possibility of accidental labeling of the cricothyroid (CT) muscle by spread from the injection site. The third control group (control group 3, n = 5 rats) was included to determine if there is some sprouting from the SLN into the territories of the RLN after a crush of this last nerve. One week after the crush injury of the RLN, the PCA and TA muscles were injected immediately before the section of the SLN. The results show that a single population of neurons represents each muscle with the PCA in the most rostral position followed caudalwards by the TA. One week post-RLN injury, both the somatotopy and the number of labeled motoneurons changed, where the labeled neurons were distributed randomly; in addition, an area of topographical overlap of the two populations was observed and vocal fold mobility was lost. In the rest of the survival periods, the overlapping area is larger, but the movement of the vocal folds tends to recover. After 12 weeks of survival, the disorganization within the Amb is the largest, but the number of motoneurons is similar to control, and all animals recovered the movement of the left vocal fold. Our additional controls indicate that no tracer spread to the CT muscle occurred, and that many of the labeled motoneurons from the PCA after 1 week post-RLN injury correspond to motoneurons whose axons travel in the SLN. Therefore, it seems that after RLN injury there is a collateral sprouting and collateral innervation. Although the somatotopic organization of the Amb is lost after a crush injury of the RLN and does not recover in the times studied here, the movement of the vocal folds as well as the number of neurons that supply the TA and the PCA muscles recovered within 8 weeks, indicating that the central nervous system of the rat has a great capacity of plasticity.

show abstract

Electromyographic and histologic evolution of the recurrent laryngeal nerve from transection and anastomosis to mature reinnervation

Cited by 37 publications

References 22 publications

The natural history of recoverable vocal fold paralysis: Implications for kinetics of reinnervation

The natural history of recoverable vocal fold paralysis: Implications for kinetics of reinnervation

Functional electrical stimulation following nerve injury in a large animal model

Reorganization of laryngeal motoneurons after crush injury in the recurrent laryngeal nerve of the rat

Contact Info

Product

Resources

About