• Korean Journal of Bronchoesophagology
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• v.1 no.1
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• pp.69-74
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• 1995

The anatomic course of recurrent laryngeal nerve, its branch and its function were most significant for laryngeal, thyroid and tracheoesophageal surgery. Furthermore, the vocal cord palsy resulting from multi-etiology was serious complication and resulted in affecting the life quality. So, for the prevention of this complication, the concepts and knowledge about anatomic course and variants are very important. At now, most of anatomic courses and it's function has been identified precisely. But recently, the report about the anastomotic loops of both recurrent laryngeal nerve was published. In this study, we explored three cadevors for identifying the reality of the anastomotic loops between recurrent laryngeal nerves. Finally, we identified the cervicomediastinal anastomosis at tracheoesophageal groove in 2 of 3 cadevors that was confirmed by pathologic finding. This anatomic reliefs related to it's branch are extremely interest, although research is still in its initial phase. Our study will be extended toward histomorphometrical study and progressive electrophysiologic study, and we will be able io gather the largest amount of useful data regarding any possible use of this anatomic entity in future.

• Korean Journal of Head & Neck Oncology
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• v.9 no.2
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• pp.183-192
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• 1993

This study reports a prospective analysis of anatomical variations of recurrent laryngeal nerves during 300 thyroidectomies. During thyroidectomies for variable thyroid diseases. the course of recurrent laryngeal nerve was completely isolated from root of neck to the inferior comus of thyroid cartilage. In left side, nerve(53.7%) predominantly ran posterior to the inferior thyroidal artery(p<0.05) but in right side there was no predominant pattern. There were three nonrecurrent laryngeal nerves in the right side. About half of the cases in both sides(51.2% in right, 50.5% in left side) had one or more branches before terminating at cricothyroidal muscles. The average length of branches from inferior comus of thyroid cartilage to the origination of individual branch were l2.0mm in right side and 13.3mm in left side. In right side, majority(50.7%) of nerves ran though paratracheal space but difference did not reach the statistical but in left side, majority(88.3%) ran through tracheoesophageal groove and it was the dominant pattern(p<0.01), the overall status of passages of the nerve were relatively straight in left side(straight 87.8%, oblique 52.1%).

• Journal of Chest Surgery
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• v.26 no.5
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• pp.409-412
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• 1993

We report a case of subglottic stenosis by blunt neck trauma. Preoperative CT showed a stenosis extending distally from just below the vocal cords for 4cm. Concomittent bilateral vocal cords paralysis and quadriplegia were present. At operation the lesion was severely adhesed and the lumen was nearly obstructed. The recurrent laryngeal nerves were embedded in fibrous tissue and were not identified at ease. The stenosed segment was resected and direct end-to-end anastomosis with preservation of the recurrent laryngeal nerves was performed. Six months latar he discharged with intermediate position of vocal cord paralysis.

• Korean Journal of Veterinary Research
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• v.6 no.1
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• pp.82-91
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• 1966

Studies On the myelinated fibers of the recurrent laryneal nerves were made in five, species of domestic animals namely dog, pig, goat, horse and Korean ox. Throughout the studies, the following characteristics of the myelinated fibers were obtained. 1. The number, size and cross sectional area of the myelinated fibers seemed to be proportionally related to the animal body weights. 2. The highest peak of diameter size frequency distribution of the myelinated fibers, observed at the right cranial level, in dog, goat and horse were 4-6 micron group, while in the case of Korean ox, 10-12 micron group was the highest. 3. The highest peak of diameter size frequency distribution of the myelinated fibers, observed at the right caudal level of Korean ox was 6-8 micron group, and 4-6 micron group was the highest in the other animals. 4. The highest peak of diameter size frequency distribution of the myelinated fibers obsered at the left cranial level was same to that of right cranial level. 5. The highest peak of diameter size frequency distribution of the myelinated fibers, observed at the left caudal levels in dog, goat, horse and Korean ox was 4-6 micron group, while in case of pig, $14-16{\mu}$ group was the highest. 6. The largest cross sectional areas were found in the group of 10-16 micron in all species of animals. 7. The fiber diameter size frequency distribution of recurrent laryngeal nerves of dog, goat, pig and horse were bimodal and Korean ox seemed to be a unimodal.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.20 no.2
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• pp.105-109
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• 2009

The laryngeal peripheral nerve system is presented on the basis of our results in the animal. This present paper forcused on the localization of each laryngeal motoneuron, the myotopical arrangements of motoneurons innervating the pharyngeal and esophageal striated muscles whitin the nucleus ambiguous in the motor nerve supply, and the pathway to the larynx in the sensory and symphathetic nerve supplies. Regarding the parasympathetic nerve supply, the neural ganglia and the ganglionic cells in and around the laryngeal nerves and in the laryngeal framework are demonstrated. Most of this innervations, however, is still unclear. In addition, we presented about external branch of superior laryngeal nerve and inferior laryngeal nerve. Discuss from the literature are also reported.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7457-7461
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• 2015

Some thyroid cancer patients undergone insufficient tumor removal in the primary surgery in China. our aim is to evaluate the impact of dissection of the recurrent laryngeal nerve during a salvage thyroid cancer operation in these patients to prevent nerve injury. Clinical data of 49 enrolled patients who received a salvage thyroid operation were retrospectively reviewed. Primary pathology was thyroid papillary cancer. The initial procedure performed included nodulectomy (20 patients), partial thyroidectomy (19 patients) and subtotal thyroidectomy (10 patients). The effect of dissection and protection of the recurrent laryngeal nerve and the mechanism of nerve injury were studied. The cervical courses of the recurrent laryngeal nerves were successfully dissected in all cases. Nerves were adherent to or involved by scars in 22 cases. Three were ligated near the place where the nerve entered the larynx, while another three were cut near the intersection of inferior thyroid artery with the recurrent laryngeal nerve. Light hoarseness occurred to four patients without a preoperative voice change. In conclusion, accurate primary diagnosis allows for a sufficient primary operation to be performed, avoiding insufficient tumor removal that requires a secondary surgery. The most important cause of nerve damage resulted from not identifying the recurrent laryngeal nerve during first surgery, and meticulous dissection during salvage surgery was the most efficient method to avoid nerve damage.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.2
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• pp.172-177
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• 2000

Background and Objectives : Until now, various attempts have been made fir reinnervating paralyzed vocal cord. Nevertheless, the most cases did not produce satisfactory outcome due to occurrence of synkinesis of larynx secondary to misdirected axonal regeneration. Accordingly, the purpose of this investigation is to learn the effect of chronic electrical stimulation on regeneration of the recurrent laryngeal nerve. Material and Methods : Using 20 healthy male Sprague-Dawley rats(250-300g) with normal vocal functions, transections were made on their left recurrent laryngeal nerves and then primary anastomosis were performed under the operating microscope and they were divided into an experimental group and a control group each having 10 rats. After the procedure, for the experimental group, chronic electrical stimulation was carried out until vocal cord movement was functionally recovered. for the control group, only chronic electrical stimulation was not given. Result : In experimental group, the number of functionally recovered rats was two and in control group, that of functionally recovered rate was same. The reorganization of posterior cricoarytenoid muscle motoneuron in nucleus ambiguus appeared in the case of directed reinnervation of recurrent laryngeal nerve. Conclusion : The chronic electrical stimulation does not a direct beneficial effect on the early functional recovery in rats with injured recurrent laryngeal nerve.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.5 no.1
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• pp.5-10
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• 1994

In vivo canine model was made in two mongrel dogs under the general Ⅰ-Ⅴ anesthesia. A vertical skin incision was made on the neck, the larynx and the trachea were dissected. Two tracheal openings were made : lower one for the insertion of the anesthesia tube and upper one for the delivery of air to the larynx to induce phonation. External branch of the superior laryngeal nerves and recurrent laryngeal nerves bilaterally were identified and stimulated electrically constantly. Subglottic pressure. fundamental frequency, intensity, and open quotient were measured when the air flow rate was varying low, medium and high. Glottic resistence was calculated. As the air flow rate was increased, the subglottic pressure and the sound intensity were increased. However, glottic resistance was decreased as the air flow was increased. In falsetto register, fundamenatal frequency was increased with the increment of air flow, but in modal register fundamental frequency was not increased statistically significant Open quotient by the electroglottography was increased according to the increment of airflow.

• Korean Journal of Bronchoesophagology
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• v.2 no.1
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• pp.97-102
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• 1996

The larynx has three major functions such as protective reflex, respiration and phonation, and is richly innervated by sensory, sympathetic and parasympathetic nerves. The sensory innervation of the laryngeal mucosa, which is involved in the perception of pain, mechanical and chemical irritation, prtects the airway via various laryngeal reflexes. We studied the distribution of Substance P (SP) and Calcitonin Gene-Related Peptide (CGRP) sensory fibers in the rat's larynx using the immuno-histochemical methods. Many SP and CGRP immunoreactive fibers were found in all regions of the laryngeal mucosa except the vocal cords. SP immunoreactive fibers showed a very similar distribution to the CGRP fibers in the epithelium and submucosa. But SP immunoreactive fibers were sparser than CGRP immunoreactive fibers in distribution density. Both reactive fibers were denser in the supraglottic region than subglottic region. Especially, intraepithelial fibers displayed the densest innervation to the laryngeal surface of the epiglottis. h the subepithelium, SP and CGRP immunoreactive fibers were distributed along the wall of vessels and around the glands. The present results suggest that the regional distribution of SP and CGRP immunoreactivity may be responsible for the protective reflex function of the laryngeal inlet.

• Annals of Rehabilitation Medicine
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• v.41 no.6
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• pp.1019-1027
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• 2017

Objective To analyze the clinical characteristics between neurogenic and non-neurogenic cause of vocal cord immobility (VCI). Methods The researchers retrospectively reviewed clinical data of patients who underwent laryngeal electromyography (LEMG). LEMG was performed in the bilateral cricothyroid and thyroarytenoid muscles. A total of 137 patients were enrolled from 2011 to 2016, and they were assigned to either the neurogenic or non-neurogenic VCI group, according to the LEMG results. The clinical characteristics were compared between the two groups and a subgroup analysis was done in the neurogenic group. Results Among the 137 subjects, 94 patients had nerve injury. There were no differences between the neurogenic and non-neurogenic group in terms of demographic data, underlying disease except cancer, and premorbid events. In general characteristics, cancer was significantly higher in the neurogenic group than non-neurogenic group (p=0.001). In the clinical findings, the impaired high pitched 'e' sound and aspiration symptoms were significantly higher in neurogenic group (p=0.039 for impaired high pitched 'e' sound; p=0.021 for aspiration symptoms), and sore throat was more common in the non-neurogenic group (p=0.014). In the subgroup analysis of neurogenic group, hoarseness was more common in recurrent laryngeal neuropathy group than superior laryngeal neuropathy group (p=0.018). Conclusion In patients with suspected vocal cord palsy, impaired high pitched 'e' sound and aspiration symptoms were more common in group with neurogenic cause of VCI. Hoarseness was more frequent in subjects with recurrent laryngeal neuropathy. Thorough clinical evaluation and LEMG are important to differentiate underlying cause of VCI.