Nimodipine Improves Reinnervation and Neuromuscular Function after Injury to the Recurrent Laryngeal Nerve in the Rat

2007 ◽  
Vol 116 (8) ◽  
pp. 623-630 ◽  
Author(s):  
Jonas Hydman ◽  
Sten Remahl ◽  
Gunnar Björck ◽  
Mikael Svensson ◽  
Per Mattsson
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Motor Neurons ◽  
Neuromuscular Junctions ◽  
Neuromuscular Function ◽  
Nerve Fibers ◽  
Laryngeal Nerve ◽  
Crush Injury ◽  
Adult Rats ◽  
Somatotopic Organization ◽  
The Impact

Objectives: Injury of the recurrent laryngeal nerve (RLN) is associated with a high degree of neuronal survival, but leads to various levels of vocal fold motion impairment or laryngeal synkinesis, which has been attributed to misdirected reinnervation of the target muscles in the larynx or aberrant, competing reinnervation from adjacent nerve fibers. The aim of the present study was to evaluate the impact of the regeneration-promoting agent nimodipine on reinnervation and neuromuscular function following RLN crush injury. Methods: Sixty adult rats were randomized into nimodipine-treated or untreated groups and then underwent RLN crush injury. Reinnervation of the posterior cricoarytenoid muscle (PCA) was assessed by electrophysiological examination, retrograde tracing of lower motor neurons before and after injury, and quantification of neuromuscular junctions in the PCA muscle. Results: At 6 weeks after injury, the nimodipine-treated animals showed significantly enhanced neuromuscular function and also demonstrated a higher number of motor neurons in the brain stem that had reinnervated the PCA, compared to the untreated animals. The somatotopic organization of ambiguus motor neurons innervating the larynx was similar before injury and after reinnervation. Conclusions: Nimodipine improves regeneration and neuromuscular function following RLN injury in the adult rat, and could be of use in future strategies following RLN injury.

scholarly journals The impact of the recurrent laryngeal nerve injury on prognosis after McKeown esophagectomy for ESCC

2020 ◽  
Author(s):  
Rirong Qu ◽  
Dehao Tu ◽  
Wei Ping ◽  
Qi Wang ◽  
Ni Zhang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Recurrent Laryngeal Nerve ◽  
Recurrent Laryngeal Nerve Injury ◽  
Laryngeal Nerve ◽  
Term Survival ◽  
Laryngeal Nerve Injury ◽  
Independent Risk Factors ◽  
Mckeown Esophagectomy ◽  
The Impact

Abstract Background: The objective of this study was to assess the impact of the recurrent laryngeal nerve injury (RLNI) after esophagectomy on prognosis.Methods: Retrospectively collected data from 297 patients with esophageal squamous cell carcinoma who underwent McKeown esophagectomy at our department from April 2014 to May 2018, were analyzed.Results: RLNI occurred in 31.9% of the patients. Left-side RLNI occurred 2.8 times more often than right-side RLNI. Among the cases in which assessment of the vocal cords was continued, 8.4% involved permanent injury. There were no significant differences among clinicopathological data between patients with RLNI and without. Compared with patients without RLNI,patients with RNLI have longer operation time,more number of bronchoscopy suctions, longer postoperation hospital stay, and higher incidence of postoperative complications. T stage, N stage, RLN LN metastasis were independent risk factors for the prognosis, but RLNI is not independent risk factors for long-term survival. Conclusion: RLNI is a serious complication that will affect the short-term prognosis of patients and reduce the quality of life of patients. It should be avoided as much as possible during surgery, but it may not have negative impact on the long-term survival.

scholarly journals A variant nerve that mimics the left recurrent laryngeal nerve: a case study in human anatomy

2015 ◽  
Author(s):  
Dickran Altounian ◽  
Cathy M Tran ◽  
Christina Tran ◽  
Allison Spencer ◽  
Alexandra Shendrik ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Aortic Arch ◽  
Ductus Arteriosus ◽  
Nerve Fibers ◽  
Laryngeal Nerve ◽  
Human Anatomy ◽  
Ligamentum Arteriosum ◽  
Left Recurrent Laryngeal Nerve ◽  
The One ◽  
Arch Of The Aorta

We describe a variant nerve in a human cadaver patient that parallels the course of the left recurrent laryngeal nerve (RLN). Like the normal left RLN, the variant nerve branches from the vagus nerve and wraps around the arch of the aorta, but it passes anterior and medial to the ligamentum arteriosum (= fetal ductus arteriosus) instead of behind it like the normal RLN. After recurring around the aorta, the variant nerve joins the esophageal plexus and also appears to connect to the cervical sympathetic chain. The bilaterally paired RLNs supply innervation not only to the larynx but also to the upper parts of the trachea and esophagus, in particular those parts derived from the 4th and 6th pharyngeal arches. We hypothesize that in this case, some of the nerve fibers to the trachea and esophagus were pulled down into the torso by the 4th embryonic aortic arch (= the arch of the aorta in adults), but passed cranial to the 6th embryonic aortic arch (= fetal ductus arteriosus). From where it recurs around the aorta to join the esophageal plexus, the variant nerve is very similar to the pararecurrent nerve in dogs, so there is at least a partial precedent in another placental mammal. Understanding the relationships of the embryonic pharyngeal and aortic arches and their adult derivatives is crucial for correctly identifying the RLN, especially when imposter nerves, like the one documented here, are present.

An ALS-associated mutation in human FUS reduces neurotransmission from C. elegans motor neurons to muscles

2019 ◽  
Author(s):  
Sebastian M. Markert ◽  
Michael Skoruppa ◽  
Bin Yu ◽  
Ben Mulcahy ◽  
Mei Zhen ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Neuromuscular Junctions ◽  
Neurodegenerative Disorder ◽  
Electron Tomography ◽  
Light And Electron Microscopy ◽  
Electrophysiological Recording ◽  
C Elegans ◽  
Fused In Sarcoma ◽  
And Function ◽  
The Impact

AbstractAmytrophic lateral sclerosis (ALS) is a neurodegenerative disorder that has been associated with multiple genetic lesions, including mutations in the gene FUS (Fused in Sarcoma), an RNA/DNA-binding protein. Expression of the ALS-associated human FUS in C. elegans results in mislocalization and aggregation of FUS outside the nucleus, and leads to impaired neuromuscular behaviors. However, the mechanisms by which mutant FUS disrupts neuronal health and function remain partially understood. Here we investigated the impact of ALS-associated FUS on motor neuron health using correlative light and electron microscopy, electron tomography, and electrophysiology. Expression of ALS-associated FUS impairs synaptic vesicle docking at neuromuscular junctions, and leads to the emergence of a population of large and electron-dense filament-filled endosomes. Electrophysiological recording of neuromuscular transmission revealed reduced transmission from motor neurons to muscles. Together, these results suggest a potential direct or indirect role of human FUS in the organization of synaptic vesicles, and reduced transmission from motor neurons to muscles.Summary statementAn ALS-associated mutation in a trafficking protein disrupts the organization of the C. elegans neuromuscular junction.

Loupe Magnification Reduces Postoperative Hypocalcemia after Total Thyroidectomy

2010 ◽  
Vol 76 (12) ◽  
pp. 1345-1350 ◽  
Author(s):  
Giacomo Pata ◽  
Claudio Casella ◽  
Francesco Mittempergher ◽  
Laura Cirillo ◽  
Bruno Salerni
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Total Thyroidectomy ◽  
Injury Rate ◽  
Laryngeal Nerve ◽  
Parathyroid Glands ◽  
Postoperative Hypocalcemia ◽  
Surgical Teams ◽  
Pathology Reports ◽  
The Impact ◽  
Loupe Magnification

We aimed to evaluate the impact of loupe magnification (LM) on incidental parathyroid gland removal (from pathology reports), hypocalcemia, and recurrent laryngeal nerve (RLN) injury after total thyroidectomy and answer the question of whether this tool should be always recommended for patient's safety. Between January 2005 and December 2008, 126 patients underwent total thyroidectomy with routine use of 2.5 X galilean loupes; their charts were compared with data on 118 patients operated on between January 1997 and December 2000 without LM (two different equally skilled surgical teams operating in the two periods). LM decreased the rate of inadvertent parathyroid glands removal (3.8 vs 7.8% of total parathyroid glands; P = 0.01), as well as of biochemical (20.6 vs 33.9%; P = 0.028) and clinical (12.7 vs 33%; P = 0.0003) hypocalcemia after thyroidectomy. All cases (16 of 16) of symptomatic hypocalcaemia in the LM group proved to be associated with parathyroidectomy vs 76.9 per cent (30 of 39) without LM ( P = 0.046). A trend toward decreased RLN injury rate, although statistically insignificant, was reported, being unilateral transient, unilateral permanent, and bilateral transient palsy rates 6.8, 2.5, and 1.7 per cent, respectively, without LM vs 4.8, 2.4, and 0.8 per cent, respectively, with LM ( P = 0.69; P = 1, and P = 0.61, respectively). Our results do support the routine use of LM during total thyroidectomy.

scholarly journals Morphometric Differences in the Recurrent Laryngeal Nerve in Patients with Vocal Fold Paralysis

2019 ◽  
Vol 129 (1) ◽  
pp. 32-38
Author(s):  
Melissa R. Chao ◽  
Katherine A. Howe ◽  
Jennifer L. Pierce ◽  
Amanda C. Stark ◽  
Marshall E. Smith ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Vocal Fold ◽  
Fiber Diameter ◽  
Vocal Fold Paralysis ◽  
Nerve Fibers ◽  
Laryngeal Nerve ◽  
Diameter Distribution ◽  
Fiber Density ◽  
G Ratio ◽  
Diameter Distributions

Objectives: Injury to the recurrent laryngeal nerve (RLN), if severe enough, can result in vocal fold paralysis. Reinnervation surgery can improve patient outcomes, but previous studies have reported a negative correlation between time since onset of paralysis and surgical outcomes. The ability of the paralyzed nerve to serve as a conduit for donor nerve fibers may be a factor in the success of reinnervation; however, changes in RLN composition after paralysis have not been well studied. Therefore, we investigated the morphometric composition of explanted RLN sections from patients who had experienced vocal fold paralysis for varying length of times. Methods: Nine nerve sections from unilateral vocal fold paralysis (UVP) patients and seven control nerve sections were analyzed for morphometric parameters including fascicular area, fiber count, fiber density, fiber packing, mean g-ratio, and fiber diameter distribution. Nerves from UVP patients were also compared as a function of time since UVP onset. Results: In comparison to control nerves, paralyzed nerves were found to have significantly lower fiber densities and fiber packing, higher mean g-ratio values, and a shift in diameter distributions toward smaller diameter fibers. With respect to paralysis duration, no significant differences were observed except in fiber diameter distributions, where those with paralysis for >2 years had distributions that were significantly shifted toward smaller diameter fibers. Conclusions: The morphometric data presented here suggest that correlations between the time since onset of vocal fold paralysis and reinnervation outcomes may be due to fiber size changes in the paralyzed nerve over time.

scholarly journals Overexpression of an ALS-associated FUS mutation in C. elegans disrupts NMJ morphology and leads to defective neuromuscular transmission

Biology Open ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. bio055129 ◽  
Author(s):  
Sebastian M. Markert ◽  
Michael Skoruppa ◽  
Bin Yu ◽  
Ben Mulcahy ◽  
Mei Zhen ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Neuromuscular Junctions ◽  
Neurodegenerative Disorder ◽  
Electron Tomography ◽  
Light And Electron Microscopy ◽  
Ectopic Expression ◽  
Electrophysiological Recording ◽  
Pathological Effect ◽  
And Function ◽  
The Impact

ABSTRACTThe amyotrophic lateral sclerosis (ALS) neurodegenerative disorder has been associated with multiple genetic lesions, including mutations in the gene for fused in sarcoma (FUS), a nuclear-localized RNA/DNA-binding protein. Neuronal expression of the pathological form of FUS proteins in Caenorhabditis elegans results in mislocalization and aggregation of FUS in the cytoplasm, and leads to impairment of motility. However, the mechanisms by which the mutant FUS disrupts neuronal health and function remain unclear. Here we investigated the impact of ALS-associated FUS on motor neuron health using correlative light and electron microscopy, electron tomography, and electrophysiology. We show that ectopic expression of wild-type or ALS-associated human FUS impairs synaptic vesicle docking at neuromuscular junctions. ALS-associated FUS led to the emergence of a population of large, electron-dense, and filament-filled endosomes. Electrophysiological recording revealed reduced transmission from motor neurons to muscles. Together, these results suggest a pathological effect of ALS-causing FUS at synaptic structure and function organization.This article has an associated First Person interview with the first author of the paper.

Value of intra-operative neuromonitoring of the recurrent laryngeal nerve in total thyroidectomy for benign goitre

2015 ◽  
Vol 129 (6) ◽  
pp. 553-557 ◽  
Author(s):  
C Page ◽  
P Cuvelier ◽  
A Biet ◽  
V Strunski
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Total Thyroidectomy ◽  
Nerve Palsy ◽  
Recurrent Laryngeal Nerve Palsy ◽  
Laryngeal Nerve ◽  
Control Group ◽  
Laryngeal Nerve Palsy ◽  
Significant Difference ◽  
Patient Groups ◽  
The Impact

AbstractObjective:This study aimed to evaluate the impact of intra-operative neuromonitoring of the recurrent laryngeal nerve during total thyroidectomy for benign goitre.Methods:A single-centre retrospective study using historical controls was conducted for a 10-year period, comprising a series of 767 patients treated by total thyroidectomy for benign goitre. Of these, 306 had intra-operative neuromonitoring of the recurrent laryngeal nerve and 461 did not. Post-operative laryngeal mobility was assessed in all patients by direct laryngoscopy before hospital discharge and at post-operative follow-up visits.Results:In all, 6 out of 461 patients (1.30 per cent) in the control group and 6 out of 306 patients (1.96 per cent) in the intra-operative neuromonitoring group developed permanent recurrent laryngeal nerve palsy. No statistically significant difference was observed between the two patient groups.Conclusion:Intra-operative neuromonitoring does not appear to affect the post-operative recurrent laryngeal nerve palsy rate or to reliably predict post-operative recurrent laryngeal nerve palsy. However, it can accurately predict good nerve function after thyroidectomy.

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