• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.2
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• pp.83-87
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• 2003

Background and Objectives : Sphincteric function of the larynx, essential to lower airway protection, is most efficiently achieved through strong reflex adduction by both vocal cords. We hypothesize that central facilitation is an essential component of a bilateral adductor reflex and that its disturbance could result in weakened sphincteric closure. Materials and Method : Seven adult 20kg dogs underwent evoked response laryngeal electromyoraphy under 0.5 to 1.0 MAC isoflurane anesthesia. The internal branch of superior laryngeal nerve was stimulated through bipolar platinum-iridium electrodes and recording electrodes were positioned in the ipsilateral and contralateral thyroaryteonoid muscles. Results : Consistent threshold responses were obtained ipsilaterally under all anesthetic levels. However, contralateral reflex responses disappeared as anesthetic levels approached 1.0 MAC. Additionally, at 0.5 MAC, late responses (R2) were detected in one animal. Conclusion : Alteration of central facilitation by deepening anesthesia abolishes the crossed adductor reflex, predisposing to a weakened glottic closure response. Precise understanding of this effect may improve the prevention of aspiration in patients emerging from prolonged sedation or under heavy psychotropic control.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.1
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• pp.11-16
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• 2001

Background and Objectives : A burn injury to the glottis differs from a burn injury to the trachea, bronchi, and lung parenchyma, in that thermal injury does not occur to any significant degree below the level of the larynx, due to the effective cooling of air by the upper airway and to reflex closure of the vocal cords from a blast of hot air. Therefore, the laryngeal inhalation injury give rise to airway problem and voice change. The objectives of this study is to assess management of laryngeal inhalation injury and voice change after management. Materials and Methods : Voice choses and laryngeal injuries of eight laryngeal inhalation patients were analyzed through questionnaire, voice dynamic laboratory, and laryngeal stroboscopy. Operative management was performed to five patients for airway patiency and vocal cord movement on laryngeal pathology ind voice therapy was performed to all patients. One-year after, voice changes and laryngeal injuries were reanalyzed with same methods. Results : Vocal breathiness, decreased voice intensity, reduced voice range, and easy fatigability were major complaints of laryngeal inhalation patients. Glottic stenosis were developed to five of eight patients, and vocal cord atrophy, bowing were developed to others. Vocal cord mucosal waves were significantly decreased in all patients. Jitter(%), Shimmer(dB) were increased and Maximal phonation time(MPT) was decreased. One-year after, subjective voice changes and objective voice parameters were improved. And vocal cord mucosal waves were recovered in all patients. Conclusions : Subjective voice quality and objective voice parameters were improved after operative management for laryngeal pathology and voice therapy. And we observed recovery of vocal fold mucosal waves by laryngeal stroboscopy. We think that early preventable tracheotomy is necessary to reduce the laryngeal contact injury in laryngeal inhalation patients.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1991.06a
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• pp.14-14
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• 1991

후두의 생리적 기능은 하기도를 보호하는 방어기능과 호흡기능 그리고 발성기능으로 대별할 수 있는데 이 가운데 계통발생적으로 가장 원시적이지만 중요한 기능은 하기도 방어기능으로 이는 다른 기능과 달리 전적으로 불수의적이고 반사적으로 이루어진다. 이 기능은 후두내 점막에 존재하는 촉각 수용체(tactile receptor)가 자극되면서 후두근육이 수축 반사를 일으켜 성문이 닫히는 성문폐쇄반사(glottic closure reflex)로서 다접합뇌간반사(polysynaptic brain stem response)이다. 현재까지 후두의 신경장애에서 그 부위나 정도 또는 신경재생 상태 등을 검사하는 방법으로 근전도검사가 주로 쓰여져 왔으나 그것이 주는 정보가 극히 제한되어 있다. 그러나 최근 청각뇌간유발반응과 같이 후두뇌간유발반응 이라 명명된 wave가 존재한다는 사실이 밝혀져 이에 대한 연구가 이루어지고 있어 이것이 임상에 쓰여질 수 있다면 현재 성문폐쇄반사의 소실이나 이상이 원인으로 사료되는 idiopathic laryngospasm, gastroesophageal reflux, spastic dysphonia, stuttering, sudden infant death syndrome과 같은 질환의 진단과 치료에 커다란 진전이 있을 것이다. 이에 저자들은 고양이 6마리를 이용하여 상후두신경을 전기적으로 자극하여 유발되는 반응을 far field recording을 이용 평균 가산법으로 그 wave를 측정하여 다음과 같은 결과를 얻었다. 1. 상후두신경자극(2㎃, stimuli frequency 3/s, Band filter 320-1000, 0.2 ㎳ duration)에 의한 반회신경에의 유발 반응을 기록하였고 그 잠복시간은 평균 8.2 ㎳ 였다. 2. 상후두신경을 자극하여 후두뇌간유발반응을 기록하였고 후두뇌간유발반응은 4개의 양 wave와 4개의 음 wave로 구성되었다. 3. 각 wave의 평균 잠복시간은 P1은 0.8㎳, P2는 2.3㎳, P3는 3.6㎳, P4는 4.3㎳였고 N1은 1.5㎳, N2 은 2.7㎳, N3는 3.9㎳, N4는 5.5㎳ 였다.