Vocal cord paralysis, synkinesis and vocal fold motion impairment

  title={Vocal cord paralysis, synkinesis and vocal fold motion impairment},
  author={Bruce N. Benjamin},
  journal={ANZ Journal of Surgery},
  • B. Benjamin
  • Published 1 October 2003
  • Medicine
  • ANZ Journal of Surgery
Felix Semon's ‘laws’ of vocal cord paralysis were conceived over a century ago, based on the simple concept that abductor function of the recurrent laryngeal nerve was more vulnerable than adductor function. It is now clear that the neuromuscular pathology of laryngeal innervation is much more complex. Whether the nerve has been cut, crushed, stretched, cauterized or otherwise injured, it is seldom completely transected. There might be no detectable vocal cord movement at laryngoscopy, yet… 

Vocal cord paralysis, synkinesis and vocal fold motion impairment

for a change in terminology to describe the clinical variations in vocal cord paralysis. Crumley differentiates four clinical types of the condition, although has not personally seen a type IV, nor

Vocal fold paresis: evidence and controversies

Vocal fold paresis is probably a significant source of vocal disability, especially among cases that have eluded straightforward diagnosis, and an accurate assessment of its clinical impact, patterns of dysfunction, natural history and relationship to other pathologies depends on diagnostic rigor and accuracy and is still evolving.

Local Neurotoxins for Prevention of Laryngeal Synkinesis after Recurrent Laryngeal Nerve Injury

Low-dose VNC injections appear to be relatively safe and effective in selectively inhibiting spontaneous aberrant reinnervation after RLN injury in an animal model.

Value of Laryngeal Electromyography in Diagnosis of Vocal Fold Immobility

The decreased recruitment activities on LEMG and the decreased evoked L EMG signals with longer latency and lower amplitude reflect the severity of neuropathic laryngeal injury.

Diagnosis and Prognosis of Iatrogenic Injury of the Recurrent Laryngeal Nerve

The results show that laryngeal electromyography is a reliable tool for diagnosing the type of injury within the injured RLN, making it possible to predict the functional outcome in patients with acute postoperative unilateral RLN paralysis.

Recurrent Laryngeal Nerve Reinnervation in Rats Posttransection: Neurotrophic Factor Expression over Time

This study is the first to describe the post-RLN injury expression pattern of LAMA1, a target of particular interest as it has been shown to switch netrin 1–mediated growth cone attraction to repulsion, and suggests that qRT-PCR is possible with single rat laryngeal muscles and is chronologically coordinated with muscle innervation in the LTA and MTA.



Laryngeal Synkinesis Revisited

  • R. Crumley
  • Medicine
    The Annals of otology, rhinology, and laryngology
  • 2000
A functional classification of laryngeal synkinesis facilitates the understanding of larygeal pathophysiology following RLN injuries and promotes a more scientific basis for management.

Semon's Law Revisited: An Electromyographic Analysis of Laryngeal Synkinesis

Patients with persistent vocal fold immobility are studied and electrical activity suggestive of variable reinnervation and synkinesis is found using laryngeal electromyography, suggesting that the medialization and upright position of the arytenoid is due to synkinese.

Configuration of the glottis in laryngeal paralysis. I: Clinical study

Results indicate that the alteration of glottic configuration in laryngeal paralysis cannot be adequately characterized by standard terms of vocal fold position, and confirms prior observations that paralyzed vocal folds are frequently not denervated.

Laryngeal abductor function after recurrent laryngeal nerve injury in cats.

Severity of neural injury to the recurrent laryngeal nerve influences the recovery of larynGEal abductor function and the importance of synkinesis is determined.

Configuration of the glottis in laryngeal paralysis. II: Animal experiments

Experiments indicate that the cricothyroid muscle does not appreciably affect vocal fold position in acute paralysis, and complete denervation of intrinsic laryngeal muscles as well as synkinetic reinnervation appear to be significant factors in determining vocal Fold position in chronic larynGEal paralysis.

The clinical differentiation between vocal cord paralysis and vocal cord fixation using electromyography

Clinical experience in a clinical setting has shown laryngeal electromyography to be efficient in accurately assessing the neuromuscular status of the intrinsic larynGEal musculature.

Intraoperative Pediatric Laryngeal Electromyography: Experience and Caveats with Monopolar Electrodes

It is found that L-EMG objectively supported clinical findings, but provided new objective data relevant toward management recommendations in only a few selected pediatric patients with new-onset vocal fold paralysis or paresis or infiltrative laryngeal tumors, and in selected postsurgical cases involving decannulation decisions.

Limitations of Electromyography and Magnetic Stimulation for Assessing Laryngeal Muscle Control

Given the normal variation in laryngeal electromyography and magnetic stimulation response latencies, these techniques may not yet be reliable or accurate for assessing reinnervation or synkinesis following recurrent larynGEal nerve injury.

Misdirected reinnervation in the feline intrinsic laryngeal muscles after long-term denervation.

Nerve terminals which resembled the autonomic nerve varicosities were found at all neuromuscular junctions of the feline intrinsic laryngeal muscles after 21 months of unilateral laryngeal paralysis.

Effects of denervation on laryngeal muscles: A canine model

The findings indicate that, following recurrent laryngeal nerve sectioning, the canine intrinsic larynx muscles undergo denervation atrophy for approximately 3 months, after which reinnervation occurs.