• Korean Journal of Head & Neck Oncology
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• v.33 no.1
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• pp.57-59
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• 2017

A non-recurrent laryngeal nerve on the left side is a rare anomaly which is reported in 0.04% and it is associated with abnormal developments of the aortic arch during embryogenesis. Although the possibility is extremely low, it is important to consider the possible existence of a non-recurrent laryngeal nerve to prevent a nerve injury during thyroidectomy. We experienced a 42 year-old male with left thyroid papillary cancer who had right side aortic arch and aberrant left subclavian artery. Even though we found that this patient had a recurrent laryngeal nerve, we present this case of the right aortic arch with an aberrant left subclavian artery variation with a brief review of literature.

• 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.

• Journal of Korean Neurosurgical Society
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• v.56 no.2
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• pp.152-156
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• 2014

Intracisternal accessory nerve schwannomas are very rare; only 18 cases have been reported in the literature. In the majority of cases, the tumor origin was the spinal root of the accessory nerve and the tumors usually presented with symptoms and signs of intracranial hypertension, cerebellar ataxia, and myelopathy. Here, we report a unique case of an intracisternal schwannoma arising from the cranial root of the accessory nerve in a 58-year-old woman. The patient presented with the atypical symptom of hoarseness associated with recurrent laryngeal neuropathy which is noted by needle electromyography, and mild hypesthesia on the left side of her body. The tumor was completely removed with sacrifice of the originating nerve rootlet, but no additional neurological deficits. In this report, we describe the anatomical basis for the patient's unusual clinical symptoms and discuss the feasibility and safety of sacrificing the cranial rootlet of the accessory nerve in an effort to achieve total tumor resection. To our knowledge, this is the first case of schwannoma originating from the cranial root of the accessory nerve that has been associated with the symptoms of recurrent laryngeal neuropathy.

• 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 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.21 no.1
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• pp.37-41
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• 2010

Background and Objectives : Transient minor voice changes after thyroidectomy are not infrequent complaints even in cases without any evidence of recurrent laryngeal nerve damage. However, clinical course, diagnosis and management of such voice changes are not fully understood. This study aimed to evaluate the clinical characteristics of minor voice changes after thyroidectomy. We also tried to assess the significance and feasibility of superior laryngeal nerve monitoring and to find out the optimal evaluation tools for such voice changes after thyroidectomy. Materials and Method : Nine adult patients who received total thyroidectomy without evidence of recurrent laryngeal nerve injury were enrolled for this prospective study. Voice evaluations were performed preoperatively and 3 months postoperatively ; acoustic analyses including voice range profile, aerodynamic study, stroboscopic evaluation and subjective voice assessment with questionnaires. The external branch of superior laryngeal nerve was monitored by nerve stimulator after ligation of superior thyroidal vessels. Results: Four of nine patients complained their voice change at 3 months after the surgery. Three of them reported complete recovery of their voice at 6 months after the surgery. Acoustic analysis revealed significant decrease in their phonatory range especially with high tone loss. Questionnaires related to singing was more sensitive than previously well-known "voice handicap index". Stimulation of the superior laryngeal nerve was feasible in most of the cases (94.4%), but it failed to show any correlation with minor voice changes after thyroidectomy. Conclusion : Minor voice changes were not rare events during the first 6 month after thyroidectomy. Decrease in phonatory range with high tone loss and therefore, discomfort in singing was the most common finding. Superior laryngeal monitoring was feasible but it was not a sensitive tool for the prediction of minor voice change after thyroidectomy.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.1
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• pp.59-65
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• 1998

Instead of brilliant advancement of the organ transplantation in the medical fields, laryngeal transplantation still has couple of problems to be solved before trial on human. Among them functional restoration of the implanted larynx is the most important point. Recent advancement in animal model studies showed possibility of solving the main problem. Eighteen cases of canine laryngeal transplantation in mongrel dogs were done in this department. One cranial artery and two external jugular veins were connected. External and internal branches of the superior layngeal nerve and anterior and posterior branches of the recurrent laryngeal nerve were connected individually. Only two dogs have lived longer than 4 weeks(4weeks, and 10 1/2weeks) and they died unfortunately due to asphixia caused by obstruction of the cannula. Thirteen dogs only lived five days through 15 days. The main causes of the failure were obstruction of the connecting vein, pharyngocutaneous fistula and the wound infection. Although the result was not good enough to evaluate the functional restoration of the implanted larynx, the implanted larynges from the two dogs lived longer than minimum criteria of long term survival(4 weeks) were relatively good in shape at the time of autopsy. This program will be continued after renovation of the animal lab. facilities.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.26 no.1
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• pp.16-20
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• 2015

Post-thyroidectomy dysphonia occurs very frequently. Causes of dysphonia include recurrent laryngeal nerve (RLN) or external branch of superior laryngeal nerve (EBSL) injury, intubation, laryngotracheal fixation and other causes. Patients commonly characterized hoarseness or their voice impairment inability to short or sing and loss of loudness. Although complete recovery can be expected mostly in 3 months without obvious nerve injury, dysphonia lowers patients quality of life. The present review discuss the very kinds of causes of post-thyroidectomy dysphonia.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.1
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• pp.30-36
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• 1999

Background and Objectives : Laryngeal Evoked Electromyography(EEMG) is a objective, quantitative technique to determine innervation status of larynx. The possible applications of this technique are to confirm the etiology of impaired vocal fold motion and monitor perioperative vagus nerve trauma. The purpose of this study is to develop a novel method for determining the amount of reinnervation of recurrent laryngeal nerve with accurate, inexpensive, and minimally invasive technique in human. Materials and Methods : Laryngeal EEMG was performed for 16 adults with intact vocal folds motion and 2 patients diagnosed as unilateral vocal fold paralysis. for the purpose of searching what is the optimal and noninvasive technique for laryngeal EEMG, we used 2 types of stimulation configurations(transcutaneous vs percutaneous) and 2 types of recording configurations(intramuscular vs. surface). Results and Conclusions : Percutaneous needle stimulation and surface recording of laryngeal EEMG was reliable and comparable to standard needle stimulation and invasive intramuscular needle recording. But the laryngeal EEMG by the surface recording and transcutaneous surface stimulation was not reliable and repeatable. Therefore we recommended that laryngeal EEMG by surface recording and percutaneous needle stimulation would be minimally invasive, reliable technique to know the status of reinnervation in e patients with vocal fold paralysis.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.1
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• pp.46-54
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• 2001

Background and Objectives : Nitric oxide(NO) is a short-lived molecule with messenger and cytotoxic functions in nervous, cardiovascular, and immune systems. Among the three distinct NOS isoforms, the neuronal isoform is expressed in small, discrete neuronal populations of CNS and PNS. Axonal injury in adult animals results in a dramatic NOS up-regulation in many types of central and peripheral neurons which normally lack the enzyme or express it only at very low levels. In previous study, we confirmed the efficacy of PEMS on the early functional recovery in rats with surgically transected and reanastomosed recurrent laryngeal nerve. Therefore, after we obtained functionally recovered rats using PEMS in this study, we studied to evaluate the expression of nNOS through the analysis of the difference between functional recovery group and non-recovery group in the recurrent laryngeal nerve. Materials and Method : Using 84 healthy male Sprague-Dawley rats, transections and primary anastomosis were performed on their left recurrent laryngeal nerves. Rats were then randomly assigned to 2 groups. The rats in group A(n=42) received PEMS by placing them in custom cages equipped with Helm-holz coils(3 hr/day, 5 days/wk, for 12 wk). The rats in group B(n=42) were handled the same way as the group A, except that they did not receive PEMS. Laryngovideoendoscopy was performed before and after surgery and followed up weekly. Laryngeal EMG was obtained in both PCA and TA muscles. Immunohistochemisty staining using monoclonal anti-neuronal nitric oxide synthase(nNOS) antibody was performed to detect nNOS in recurrent laryngeal nerve and nodose ganglion. Results : 20 rats(63%) in group A and 5 rats(17%) in the group B showed recovery of vocal fo1d motion. The number of NOS-positive cells was increased in functionally-recovered rats. NOS-staining intensity was reduced 12 weeks after nerve injury. The difference between PEMS group and non-stimulated group was not found. Conclusion : This study shows that nNOS may exert a beneficial effect on nerve regeneration and functional repair.