• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.2
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• pp.126-132
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• 2001

Background and Objectives : Signal traduction through phospholipase C(PLC) participate in the regulation of cell growth and differentiation. Growth factors bind to their receptors and thereby induce tyrosine phophorylation of the phospholipase C-${\gamma}$1(PLC-${\gamma}$1). PLC-${\gamma}$1 is a substrate for several receptor tyrosine kinases and its catalytic activity is increased by tyrosine phosphorylation. Tyrosine kinase phosphorylation of PLC-${\gamma}$1 stimulates PLC activation and cell proliferation. However the signal transduction pathway and the significance of PLC in injured recurrent laryngeal nerve regeneration is unknown. Therefore after we obtained fuctionally recovered rats using PEMF in this study, we attempt to provide some evidence that PLC plays a role in nerve regeneration itself and regeneration related to PEMF through the analysis of the difference between fucntional recovery group and non-recovery group in the recurrent laryngeal nerve. Materials and Method : Using 32 healthy male Sprague-Dawley rats, transections and primary anastomosis were performed on their left recurrent laryngeal nerves. Rats were then randomly assigned to 2 groups. The experimental group(n=16) received PEMS by placing them in custom cages equipped with Helm-holz coils(3hr/day, 5days/wk, for 12wk). The control group(n=16) were handled the same way as the experimental group, except that they did not receive PEMS. Laryngo-videoendoscopy was performed before and after surgery and followed up weekly. Laryngeal EMG was obtained in both PCA and TA muscles. Immunohistochemisty staining and Western blotting analysis using monoclonal antibody was performed to detect PLC-${\gamma}$1 in recurrent laryngeal nerve and nodose ganglion. Results : 10 rats(71%) in experimental group and 4 rats(38%) in the control group showed recovery of vocal fold motion. Functionally-recoverd rats show PLC-${\gamma}$1 positive cells in neuron and ganglion cells after 12 weeks from nerve injury. Conclusion : This study shows that PLC1-${\gamma}$ involved in singnal trasduction pathway in functinal recovery of injured recurrent laryngeal nerve and PEMF enhance the functional recovery by effect on this molecule.

• Journal of Korean Neurosurgical Society
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• v.52 no.3
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• pp.264-266
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• 2012

Injury to the bilateral internal branch of superior laryngeal nerve (ibSLN) brings on an impairment of the laryngeal cough reflex that could potentially result in aspiration pneumonia and other respiratory illnesses. We describe a patient with traumatic cervical injury who underwent bilateral ibSLN palsy after anterior cervical discectomy with fusion (ACDF). An 75-year-old man visited with cervical spine fracture and he underwent ACDF through a right side approach. During the post-operative days, he complained of high pitched tone defect, and occasional coughing during meals. With a suspicion of SLN injury and for the work up for the cause of aspiration, we performed several studies. According to the study results, he was diagnosed as right SLN and left ibSLN palsy. We managed him for protecting from silent aspiration. Swallowing study was repeated and no evidence of aspiration was found. The patient was discharged with incomplete recovery of a high pitched tone and improved state of neurologic status. The SLN is an important structure; therefore, spine surgeons need to be concerned and be cautious about SLN injury during high cervical neck dissection, especially around the level of C3-C4 and a suspicious condition of a contralateral nerve injury.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.27 no.2
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• pp.130-133
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• 2016

Rheumatoid arthritis (RA) is a connective tissue disease involving the larynx in 30 % of the patients. Foreign body sensation, hoarseness, and cough are common symptoms in laryngeal involvement. An urgent tracheostomy is required when acute airway obstruction occurs in case of bilateral vocal fold paralysis. The most common cause of bilateral vocal fold paralysis in RA patients is a cricoarytenoid joint arthritis. Laryngeal nerve degeneration is rare cause of bilateral vocal fold paralysis in RA patients. In this case report, an emergent tracheostomy was performed on a 64-years-old male patient with acute dyspnea, and concurrent involvement of RA on laryngeal nerve and cricoarytenoid joint was revealed by laryngeal electromyography and histopathology. The vocal fold mobility was restored after 3-months medical treatment.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.31 no.1
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• pp.1-6
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• 2020

In unilateral vocal fold paralysis (UVFP) patients, we try to improve their symptoms such as hoarseness or aspiration by restoring nerve functions or medialization laryngoplasty (ML), etc. Until now, ML (thyroplasty and/or arytenoid adduction) is considered as gold standard of treatment for UVFP. However, if recurrent laryngeal nerve (RLN) is damaged and use of RLN is feasible during operation, laryngeal reinnervation (LR) would be a good option. Anastomosis with ansa cervicalis to RLN is most common reinnervation method. Delayed LR may be considered in young patients when the RLN denervation period is not long (less than 2 years) for the treatment of surgery-related UVFP. Injection laryngoplasty and laryngeal framework surgery showed great voice outcomes in UVFP. Combination therapy (neuromuscular pedicle innervation with ML) also showed good post-operative voice outcomes even in longer periods (over 2 years). In pediatric patients, LR would be considered as a good treatment option because all procedures need to general anesthesia.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.17 no.2
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• pp.146-148
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• 2006

Spasmodic dysphonia is a voice disorder characterized by involuntary voice breaks during speech. Adductor spasmodic dysphonia is most common and characterized by strained and strangled voice breaks. The current standard of treatment of therapy for adductor spasmodic dysphonia is chemodenervation of thyroarytenoid muscle with botulinum toxin(Botox). However, Botox is a temporary treatment with each injection lasting approximately 3 months on average and require repeated injections. In this study, we report our experience with surgical treatment for adductor spasmodic dysphonia. In this procedure, the thyroarytenoid branch and lateral cricoarytenoid branch of recurrent laryngeal nerve is selectively denervated unilaterally, and its distal nerve stump of thyroarytenoid branch is reinnervated with branch of the usa cervicalis nerve. And lateral cricoarytenoid muscle partial myotomy was done unilaterally. After 6 months of treatment, voice fluency had improved and no period of breathiness or dysphagia was noted.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.2
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• pp.185-192
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• 1997

Behavior of the intrinsic laryngeal muscles : Thyroarytenoid(TA), cricothyroid(CT), lateral cricoarytenoid(LCA), interarytenoid(IA) and posterior cricoarytenoid(PCA) : were evaluated under the in vivo canine laryngeal model in three individual papers. This is the review of the relating three articles. In vivo preparation of the laryngeal model was summarized. Video-laryngoscopic findings of the individual intrinsic laryngeal muscles were documented by electrical stimulation of the individual muscular branches of the laryngeal nerve. Effects on fundamental frequency, subglottic pressure, intensity and open quotient by the stimulation of the individual intrinsic laryngeal muscles were tested.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.1
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• pp.67-70
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• 2007

Background and Objectives: The nonrecurrent laryngeal nerve(NRLN) is exceedingly rare nerve anomaly that is associated with developmentally aberrant subclavian artery. The presence of NRLN is associated with an increased risk of vocal cord palsy in thyroid surgery. The purpose of this study is to investigate its prevalence, associated vascular anomaly and necessity of recognizing its possibility for prevention of intraoperative nerve damage. Materials and Methods: Between January 2004 and December 2006, 583 thyroidectomy were performed at our hospital. Of these cases, 529 cases(90.7%) were checked preoperative neck CT. Results: Patients with preopreative neck CT, 6 cases show the retroesophageal abberant right subclavian artery that arising directly form the aortic arch. 5 cases of these 6 cases(5/6, 83.3%) and of 583 patients(5/583, 0.8%) performed thyroid surgery were identified NRLN per-operatively. All of them are identified on the right side. There were 4 women and 1 man. In all cases, there were no clinical symptoms. I case was performed only left hemithyroidectomy, so we cannot identified NRLN. No vocal cord palsy was observed. Conclusion: It is possible to predict NRLN from preoperative neck CT. When NRLN is suspected, careful, complete dissection of the nerve is always advocated. These process can reduce the operative morbidity.

• Korean Journal of Head & Neck Oncology
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• v.22 no.1
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• pp.3-7
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• 2006

Purpose: The nonrecurrent laryngeal nerve(NRLN) is a rare anomaly that is associated with the developmentally aberrant subclavian artery. Although rare on the right side and exceptional on the left, an aberrant nonrecurrent pathway for RLN represents a major surgical risk. Three course variations of right NRLN can be distinguished: descending(type I) , horizontal(type II), ascending(type III). This study is performed to characterize the variations of NRLN, associated vascular anomaly, and proper surgical methods for preventing nerve damage. Materials and Methods: Between January 1998 and March 2006 3,381 thyroidectomy were performed at our institution, and during these operations a nonrecurrent laryngeal nerve was observed in 13 cases (0.38%). There were 1 men and 12 women with a median age of 48 years(range 28-57). All of them are identified on the right side. Results: In all cases, there were no clinical symptoms observed preoperatively. The nerve anomaly was diagnosed preoperatively in only one case. There were type I variations of right RLN in 2 cases and type II variations in 11 cases. The retroesophageal aberrant right subcalvian artery; no innominate(brachiocephalic) artery was found and the right common carotic artery was arising directly from the aortic arch, was seen in 12 cases. A vocal cord palaysis caused by NRLN damage during operation was observed in one patient(7.6%) , where the nerve was close to the superior thyroid artery. No other complications were noted. Conclusion: It can be possible to predict NRLN from signs associated with the vascular anomaly; clinical symptoms or imaging studies. When an vascular anomaly is not detected preoperatively, overlooking possibility of NRLN may lead to severe operative morbidity. Hence, It is most important to identify all the thyroid structures carefully during thyroid surgery and to be aware of the possibility of anatomic variations of RLN.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.13 no.2
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• pp.188-192
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• 2002

Unilateral vocal cord palsy which is associated with laryngeal trauma is not uncommon event. In a 42-year-old male, a cricoid cartilage fracure had been developed after blunt trauma. The endoscopic findings showed contusion and diffuse swelling around the left arytenoid and false cord. During phonation, the mobility of left side true vocal cord was decreased. There were no level difference and displacement of the left side arytenoid. We used the laryngeal electromyography (LEMG) to make a differential diagnosis between the cricoarytenoid joint dislocation and the injury of recurrent laryngeal nerve. At the right thyroarytenoid muscle and cricothyroid muscle, the findings of LEMG were normal. But the amplitude and frequency during phonation were decreased (partial denervation) at the left thyroarytenoid muscle. LEMG is a very useful method to predict the diagnosis of vocal cord palsy.

• Korean Journal of Head & Neck Oncology
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• v.36 no.1
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• pp.9-14
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• 2020

Visual identification of recurrent laryngeal nerve (RLN) is considered as a gold standard of RLN preservation during thyroid surgery. Intraoperative neuromonitoring (IONM) is classified into the intermittent type and continuous type and helps surgeons identify the functional integrity of RLN and predict the postoperative vocal cord function. RLN injury during thyroid surgery is associated with tumor factors and surgeon factors. Tumor factors mean such as direct tumor invasion, adhesion of RLN to the tumor, and compression by a large thyroid tumor. Surgeon factors include nerve transection, stretching, thermal injury, and ligation injury. A recent meta-analysis reported that the IONM could reduce the RLN injury. Considering various nerve injury mechanism, we suggest that using both I-ONM and C-IONM together is more effective method in preventing nerve damage than using I-IONM alone.