• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.2
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• pp.178-184
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• 2000

Laryngeal evoked EMG is the objective and quantitative method to measure the innervation of laryngeal muscle. If there is a mobility disorder of vocal cords, the cause and location of neural lesion co be understood by the laryngeal evoked EMG and if there is a vocal cord paralysis, the degree of recovery and the policy of treatment can be determined by it. Recently, the studies of reinnervation after recurrent laryngeal nerve injury have been actively carried out. Laryngeal evoked EMC is useful to these studies. The aim of study is to know whether noninvasive methods for stimulating the recurrent laryngeal nerve and for recording of compound action potential(CAP) using surface electrode are as useful as the invasive method using needle electrode. We obtained EMG of laryngeal muscle by various stimulating and recording methods : 1) Direct nerve stimulation by placing nerve cuff electrode made out of silastic tube and platinum wire and recording by insertion of hook wire electrode into posterior cricoarytenoid(PCA) and thyroarytenoid(TA) muscles, respectively. 2) Recording of compound action potential by surface electrode after stimulation of recurrent laryngeal nerve by the insertion of 27 gauge of needle electrode. 3) Recording of compound action potential by surface electrode after stimulating the recurrent laryngeal nerve by transcutaneous blunt rod electrode at tracheoesophageal groove. The amplitude, duration and latency of the CAP evoked by recurrent laryngeal nerve stimulation were compared among the three groups. The amplitude of CAP was smallest in the group recorded from posterior cricoarytenoid and hyroarytenoid muscle, and that recorded by surface electrode after stimulation by needle electrode was largest. The difference in amplitude between the group by hook wire recording and the two groups by surface electrode recording was significant statistically. There is no significant difference in duration and latency among three groups. Since the waveform of CAP from all three methods has similar duration, latency, we concluded that noninvasive method is a useful as invasive methods.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.1
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• pp.24-29
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• 1999

Extrinsic laryngeal muscles are well known to be important for the classical singers. We tried to elucidate any differences in the function of above muscles between trained and untrained singers by non-invasive surface electromyography(EMG). Four trained sopranos and four untrained singers sang vowel /i/ at different pitch(E3, G3, C4, E4, G4, C5, E5, G5, C6). The EMG activities of the suprahyoid, infrahyoid and omohyoid muscles were measured using surface electrodes. In trained singers, infrahyoid muscle activities increased more than those of suprahyoid in most of pitch. To the contrary, in untrained singers, the pattern of EMG activities were variable among each subjects and the EMG activities of suprahyoid muscles were relatively greater than those of infrahyoid.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.2
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• pp.204-209
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• 1997

In the treatment of spasmodic dysphonia, laryngeal injection of botulinum toxin has been reported to be successful. The treatment of adductor type spasmodic dysphonia with botulinum toxin type A injection using EMG was conducted in 24 patients and it's effect was compared with results from flexible nasopharyngoscopy guided injection(29 patients) and telelaryngoscopy guided injection(31 patients). Sixty two point five percent(62.5%) of patients using EMG and 75.8% of patients using flexible nasopharyngoscope and 90.0% of patients using telelaryngoscope reported that the patient's symptom was improved. The functional status of the patient's disorder was classified into low grades. The mean pre-injection grade for patients using EMG, flexible nasopharyngoscope and telelaryngoscope was 1.7, 1.6 and 2.1 respectively. And it was lowered to 1.0, 0.7 and 1.1 respectively after the injection. Results were similar(p＜0.05). As a self assessment method, patients were asked to rate their voice on a scale of 100. In this study, the mean pre-injection score was 66.3, 44.0 and 40.0 respectively. And it was improved to 74.8, 77.7 and 69.8 respectively after the injection. Among 23 patients who undergone above 3method, 17 patients(73.9%) told that EMG-guided botulinum injection was preferable method in its convenience and effectiveness. In conclusion, EMG guided botulinum toxin injection is an another effective method for the treatment of adductor type spasmodic dysphonia similar to telelaryngoscopy-guided injection and flexible nasopharyngoscopy guided injection.

• Journal of radiological science and technology
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• v.41 no.5
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• pp.505-509
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• 2018

VCP (Vocal Cord Paralysis) is rare but one of most serious complications related to endotracheal intubation. This report is a clinical experience of radiography and laryngeal EMG (Electromyography) assessment for the VCP. A 50-year-old woman with hoarseness, which was occurred after urethral diverticulum excision was examined by laryngoscopy. As a result of laryngoscopy, VCP was observed in left side of her vocal cord, and then recurrent laryngeal nerve damage was detected with additional CT (Computed tomography) scan and laryngeal EMG. After that, the vocal cord movement was recovered as normal state with regular conservative treatment for the 6 months.

• Speech Sciences
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• v.10 no.1
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• pp.3-13
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• 2003

The devoicing vowel is a phonological process whose contrast in sonority is lost or reduces in a particular phonetic environment. Phonetically, the vocal fold vibration originates from the abduction/adduction of the glottis in relation to supraglottal articulatory movements. The purpose of this study is to investigate Korean vowel devoicing by means of experimental instruments. The interrelated laryngeal adjustments and aerodynamic effects for this voicing can clarify the redundant articulatory gestures relevant to the distinctive feature of sonority. Five test words were selected, being composed of the high vowel /i/, between the fricative and strong aspirated or lenis affricated consonants. The subjects uttered the test words successively at a normal or at a faster speed. The EMG, the sensing tube Gaeltec S7b and the High-Speech Analysis system and MSL II were used in these studies. Acoustically, three different types of speech waveforms and spectrograms were classified, based on the voicing variation. The intraoral air pressure curves showed differences, depending on the voicing variations. The activity patterns of the PCA and the CT for devoicing vowels appeared differently from those showing the partially devoicing vowels and the voicing vowels.

• Korean Journal of Head & Neck Oncology
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• v.14 no.1
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• pp.27-34
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• 1998

Objectives, Materials & Methods: To prevent deterioration of postoperative voice due to iatrogenic transection of the recurrent laryngeal nerve during the thyroid surgery, intraoperative medialization of the membranous vocal cord by type I thyroplasty together with direct epineurial neurorraphy was done on 2 cases of benign thyroid lesion. To improve the quality of voice together with complete removal of advanced thyroid carcinoma, intraoperative vocal cord medialization on the lesion side together with total thyroidectomy was done by type I thyroplasty in 2 cases and combined procedure by arytenoid adduction and type I thyroplasty in another 2 cases. Results: The resultant voice of the iatrogenic injury cases was relatively tolerable. The voice of the combined procedure was better than that of type I thyroplasty cases for the intraoperative rehabilitation cases. Not only for the preoperative evaluation of the severity of the nerve lesion but also the prognosis will be expected by use of laryngeal EMG in the cases of thyroid cacer with vocal cord palsy. Conclusion: Intraoperative simultaneous rehabilitation for the vocal cord palsy during thyroid surgery is beneficial for the patients.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.2
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• pp.102-118
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• 1999

In this study, the author developed a new animal model to examine morphological changes and functional recoveries after vertical hemilaryngeal transplantation in the canine. Seven vertical hemilaryngeal transplantations were carried out in the canine. After preparing the host dog removing right sided hemilarynx, hemilarynx of the donor dog was transplanted by hooking up the arteries, veins, nerves and hypopharyngeal mucosa. Especially, recurrent laryngeal nerve was anastomosed at the branch level(anterior and posterior) respectively. After 7 days, for the first evaluation of the transplantation, four out of seven dogs were considered successful. Three dogs survived more than one month, which is the critical period to evaluate the functional recovery after transplantations. After EMG examination, two dogs(#3, #5 dog) showed some functional recoveries. The five-transplanted hemilarynges were sectioned at the arytenoid cartilage region to examine the morphological changes. The results showed that the transplanted hemilarynx appeared normal as control in #5 dog. In addition, #2 dog showed fairly good condition even though died from asphyxia after 9 days out of transplantation. The other. three dogs(#3, #6, #7) showed various levels of atrophy and disappearance of the muscles and cartilages in their larynges. It can be suggested that this model could contribute an advance to preparing human laryngeal transplantation in the future.

• Korean Journal of Bronchoesophagology
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• v.19 no.1
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• pp.5-10
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• 2013

Bilateral vocal cord palsy (BVCP) present a challenging condition which result from various etiologies including iatrogenic recurrent laryngeal nerve injury, progressive neurological disorder, intubation, trauma, tumor and idiopathic cause. Careful history taking, laryngoscopic evaluation, laryngeal EMG, and imaging studies are helpful for providing a precise diagnosis and planning appropriate treatment. BVCP causes airway restriction and not vocal dysfunction. In patients with BVFP, treatment is directed at maximizing the airway, while attempting to limit the negative effects of treatment on vocal function. A variety of surgical procedures are available for mangement of BVCP. The most conservative, limited procedure should be selected initially, and then further surgery and more extensive surgery can be tailored to the patient's airway and voice needs. This review will address the etiology, diagnosis, and managements of BVCP.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.25 no.1
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• pp.20-23
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• 2014

Age-related changes in larynx can have a direct impact on voice quality and general comfort level. Observations of vocal aging have spanned perceptual, acoustic, aerodynamic, physical, electromyographic (EMG) and histological levels. Evidence of differential vocal aging in relation to gender and physical condition has been reported. Perceptual, acoustic, aerodynamic, kinematic, EMG and histological data document age-related changes in laryngeal structure and function with advancing age. These changes contribute to a functional age-related impact of vocal hypofunction or compensatory hyperfunction. This review will focus on the current understanding of the clinical and cellular changes in the larynx that lead to presbyphonia.

• Proceedings of the KSLP Conference
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• 1999.11a
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• pp.186-186
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• 1999

Tracheoesophageal fistulation following total laryngectomy has widely been used for voice restoration, This technique make exhaled air to divert to hypopharynx where phayngoesophageal segment forms the neoglottis. Even through layngectomized patients loss the normal laryngeal adjustment for speaking, it has been known that voiced and voiceless sounds are prodused in TE phonation. Nine TE speakeres were subjected to present study designed to clarity the mechanism of neoglottic adjustment in TE phonation, Fiberoptic examination and radiologic studies were performed at all patients and EMG study was performed at 3 patients during I phonation. Fiberoptic ＆ radiologic studies revealed the location of neoglottis, so called pharyngoesophargeal segment which was vibrated well. EMG activity increased for sound production at retropharyngeal prominence. These results indicated that neoglottic adjustment in TE phonation.