Videostrobokymographic Analysis of Benign Vocal Fold Lesions

Objectives—Videostrobokymography (VSK) has recently been introduced. The aim of this study was to analyze vibratory patterns and objective parameters in various benign vocal fold lesions using VSK and to examine the efficacy of VSK in clinical applications.

Material and Methods—Using VSK, we analyzed the vibration patterns of normal vocal folds, various benign lesions such as nodules, polyps, cysts and Reinke's edema and cases of unilateral vocal fold paralysis. We also calculated the objective parameters open quotient and asymmetric index and compared them with their mean values in normal controls.

Results—In nodules, polyps and cysts, the open quotient at the site of the lesion was similar to the mean value in the normal controls; however, on the other parts of the vocal folds, it was much larger than the normal mean value. In Reinke's edema, irregular and asymmetric vibrations were observed. The posterior area of the vocal folds showed larger open quotients than the anterior area. In unilateral vocal fold paralysis, irregular vocal fold vibration and incomplete closure of the vocal folds were documented. Much larger asymmetric indices were calculated for unilateral vocal fold paralysis than in normal controls or for other lesions. The asymmetric index may be a good quantitative parameter of vibration in patients with vocal fold paralysis.

Conclusion—This study demonstrated that VSK could generate clear quantitative documentation of fine vibrations of vocal folds in many different types of benign lesion. VSK has the potential to be an effective tool for the quantitative analysis of vibratory patterns of vocal folds in clinical settings.     

动态喉镜图像定量分析技术的应用

目的探索图像定量分析技术在声带振动研究中的应用。方法应用计算机软件、分析６０例正常人和２０例单侧声带麻痹患者的动态喉镜图像。结果正常组声带振动均呈规律性,多数声门闭合完全;麻痹组声带振动均不规律,多数声门闭合不全,发声相声门最小面积（Ａｍｉｎ）麻痹组明显大于正常组,而最大面积（Ａｍａｘ）两组间无显著性差异。结论动态喉镜计算机图像分析技术可用于声带振动功能的定量分析。     

声带息肉和Reinke水肿细胞外基质蛋白mRNA表达

目的探讨声带息肉和Reinke水肿中，声带固有层细胞外基质主要成分mRNA表达的变化，为阐明疾病发病机制提供依据。方法应用逆转录-聚合酶链反应检测手术切除标本（声带息肉12例，Reinke水肿2例，5例行全喉切除而声带未受肿瘤侵犯的声带作为正常对照），细胞外基质中与胶原纤维、弹性纤维和透明质酸有关的9种蛋白的mRNA表达。结果声带息肉与对照声带比较，胶原酶mRNA表达下降，纤连蛋白mRNA表达升高，而纤调蛋白mRNA表达下降，差异均有统计学意义（P值均〈0．05）；赖氨酰氧化酶、透明质酸合成酶在病变和对照组织mRNA表达量差异无统计学意义（P值均〉0．05）；前弹性蛋白原、透明质酸酶、弹性蛋白酶在病变组织mRNA阳性表达率低于对照组织；前胶原Ⅰ在所有组织中均无表达。声带Reinke水肿组纤连蛋白表达量接近息肉组，纤调蛋白表达量接近对照组，因样本量小未做统计学分析。结论纤连蛋白和纤调蛋白是参与声带息肉病理过程的两种细胞外基质成分。反复用声造成损伤以及声带对损伤的修复过程可能在声带息肉发病机制起重要作用。     

Exudative laryngeal diseases of Reinke's space: a clinicohistopathological framing

OBJECTIVE: To establish the relationship between the macroscopic and histologic diagnosis of nodules, polyps, and Reinke's edema of the true vocal folds and to propose a clearer clinical definition of them in the hope of settling the difference of opinion between otolaryngologists and pathologists. DESIGN: Retrospective study SETTING: Otolaryngology Department of "La Sapienza" University of Rome. METHODS: The pathologic reports of 203 patients subjected to direct laryngoscopy were studied. MAIN OUTCOME MEASURES: Examination of the histologic specimen of the epithelium and the chorion. RESULTS: Microscopic examination revealed a high percentage of normal epithelium both for nodules (33.79%) and polyps (40.65%). No dysplasia was observed, whereas dysplasia was present in 10 cases of Reinke's edema (7 laryngeal intraepithelial neoplasia 1 and 3 laryngeal intraepithelial neoplasia II). Five different stages of histologic progression resulted from the examination of the chorion in both nodules and polyps. CONCLUSIONS: Our suggestion is to consider polyps as "older" lesions and nodules as "younger" lesions. A polyp may be defined as an abnormal unilateral growth of vocal folds, a nodule as a bilateral growth situated between the anterior and medium third of the vocal fold, and Reinke's edema as a bilateral wound that extends to the whole of the true vocal fold.     

The study of vocal fold vibratory patterns in patients with unilateral vocal fold paralysis before and after type I thyroplasty with or without arytenoid adduction

Type I thyroplasty and arytenoid adduction have been used for the treatment of symptomatic unilateral vocal fold paralysis since the mid-1970s. To this date, the vibratory patterns of the vocal folds in patients with unilateral vocal fold paralysis undergoing thyroplasty have not been studied in depth. Abnormal vibration of the vocal fold mucosa often contributes to voice problems in persons diagnosed with vocal diseases or disorders. The preoperative and postoperative videostroboscopic vibratory patterns including mucosal wave, amplitude, glottic closure, and symmetry were studied in 12 patients who underwent unilateral type I thyroplasty separately or in combination with an arytenoid adduction. The observed changes and clinical implications are discussed.     

Two‐Dimensional Analysis of Vocal Fold Vibration in Unilaterally Atrophied Larynges

Objective Considerable inconsistencies regarding the vibratory pattern of the vocal fold among patients with unilateral vocal fold paralysis (UVFP) have been reported. These differences are derived from differences in the position, stiffness, and atrophy of the paralyzed vocal fold and other factors among patients. The purpose of this study was to assess the effects of unilateral atrophy of the vocal fold on vocal fold vibration. Methods Seven excised canine larynges were studied. The unilateral recurrent laryngeal nerve was severed to cause vocal fold atrophy in four of the seven. The lateral and vertical displacements were monitored simultaneously with photoglottography and a laser Doppler vibrometer, respectively. Videostroboscopy of each larynx was also performed before and after the experiment to translate photoglottographic output into absolute lengths. Atrophy of the unilateral vocal fold was confirmed histologically. Results The lateral amplitude was significantly greater than the vertical amplitude in all larynges. The Lissajous trajectories in the normal larynges were shaped like a reverse crescent. Vibration in the unilaterally atrophied larynges was periodical and symmetrical in phase when the thyroid ala on the atrophied side was pressed medially. The lateral and vertical amplitudes on the atrophied side were significantly greater than those on the normal side. The Lissajous trajectories differed from those of the normal larynges. Conclusions In the absence of a prephonatory glottal gap, periodical vibration occurs in unilaterally atrophied larynges and the amplitude of vibrations of the atrophied vocal fold is greater in the lateral and vertical directions than that of the normal fold. This implies that phonosurgical procedures aiming at closure of the prephonatory glottal gap may have a beneficial effect on hoarseness in UVFP patients, although displacements of the vocal folds during vibration are not symmetrical.     

单侧神经性声带麻痹患者嗓音分析及动态喉镜记波扫描评估

目的以嗓音学分析方法评估单侧神经性声带麻痹患者的嗓音特征,探讨动态喉镜记波扫描（videostrobokymography,VSK）在评价声带麻痹患者声带振动功能中的应用价值。方法选择22例单侧神经性声带麻痹患者及30例嗓音正常对照者分别进行嗓音学检测,并进行动态喉镜检查生成喉记波图像,分析两种方法在诊断声带麻痹中的应用价值。结果嗓音学分析显示,单侧神经性声带麻痹患者的基频微扰（Jitter）、振幅微扰（Shimmer）均高于正常对照组,差异具有统计学意义（P<0.05）;基频（F0）较对照组低,但差异无统计学意义（P>0.05）;声谱图主要见中频、高频区谐波声能减弱或消失,二、三共振峰（F2、F3）基本消失,噪声成分明显增加;低频区谐波及共振峰（F1）仍存在,呈现不规则、中断现象;最长发声时间（maximun phonation time,MPT）,较对照组明显减小,差异具有统计学意义（P<0.05）。VSK图像中,正常对照组声带相位均基本对侧,黏膜波正常开放商为0.48;声带麻痹组的声带闭合相均未见声门闭合,开放商均为1。结论嗓音学分析可客观评估单侧声带麻痹患者嗓音特征。VSK是一种评价检查声带振动功能的有效方法,与正常组比较,差异具有统计学意义（P<0.05）。     

Videostrobokymography: a new method for the quantitative analysis of vocal fold vibration

OBJECTIVES: To develop a new analysis method for the quantitative assessment of vibration of the vocal folds, using conventional videostroboscopic image data. METHODS: We used prerecorded videostroboscopic images to evaluate quantitatively the vibration of the vocal folds. Successive images were converted as digital images by means of an image-grabbing board, processed for analysis, and reconstructed as kymograms by rearranging the same lines of all processed images along the time axis. RESULTS: We developed a new technique for evaluating the vibration of the vocal folds. The vibrations of multiple vocal fold regions were easily and objectively evaluated by this technique. The objective parameters, such as open quotient and asymmetry index, could be obtained easily using this technique. CONCLUSIONS: Videostrobokymography demonstrated objectively the vibrations of several vocal fold regions at the same time. This technique has the potential to be a new tool to analyze and monitor the pathological changes and treatment results of vocal fold movement in a more refined quantitative fashion, using videostroboscopic images.     

Vibratory characteristics of Teflon-injected and noninjected paralyzed vocal folds

This study compared the vibratory characteristics of normal vocal folds, Teflon-injected paralyzed vocal folds, and noninjected paralyzed vocal folds. Laryngeal videostroboscopy under eight phonatory conditions showed that the Teflon-injected vocal folds were adynamic. The noninjected vocal folds, however, vibrated during each of the phonatory conditions although not necessarily like a normal vocal fold. In terms of vocal fold physiology, it appeared that the noninjected paralyzed vocal folds were too compliant, whereas the Teflon-injected vocal folds were too stiff. Because vocal fold paralysis is often treated in voice therapy with "digital manipulation" and "head turning," the effect of these techniques on vocal fold vibration was also studied. The results showed that digital manipulation was superior to head turning for improving glottal closure but that neither technique appeared to influence the periodicity, amplitude, or extent of vocal fold vibration for either the injected or noninjected vocal folds.     

Quantitative analysis of videokymography in normal and pathological vocal folds: a preliminary study

Videokymography (VKG) captures high-speed images of the vocal folds independently of the periodicity of the acoustic signal. The aim of this study was to preliminarily assess a software package that can objectively measure specific parameters of vocal fold vibration. From August 2009 until December 2010, we prospectively evaluated 40 subjects (Group A, 18 normal subjects; Group B, 14 patients with benign lesions of the middle third of the vocal fold, such as polyps and cysts; Group C, 8 patients treated by endoscopic excision of vocal fold benign lesions) by videoendoscopy, videolaryngostroboscopy, and VKG. A VKG camera was coupled to a 70° telescope and video was recorded during phonation. Images were objectively analyzed by a post-processing software tool (VKG-Analyser) with a user-friendly interface developed by our group. Different parameters were considered, including the ratio between the amplitude of the vibration of one vocal fold with respect to the contralateral (R _amp), the ratio between the period of one vocal fold vibration and the opposite one (R _per), and the ratio between the duration of the open and closed phase within a glottal cycle (R _oc). Mean values for R _amp, R _per, and R _oc in Group A were 1.05, 1.04, and 1.35, respectively; in Group B were 1.63, 0.92, and 0.97, respectively; and in Group C were 1.13, 0.91, and 1.85, respectively. Quantitative analysis of videokymograms by the herein presented tool, named VKG-Analyser, is useful for objective evaluation of the vibratory pattern in normal and pathologic vocal folds. Important future developments of this tool for the study of both physiologic and pathologic patterns of vocal fold vibration can be expected.     

喉良性增生性病变的嗓音学特点及治疗转归

目的 :探讨喉良性增生性病变对发声功能的影响及CO2 激光显微外科术后的转归特点。方法 :对2 92例喉良性增生性病变患者 (声带息肉、任克水肿、声带小结、囊肿、慢性肥厚性喉炎 )的流行病学、嗓音声学、形态及CO2 激光显微外科术后转归进行分析。结果 :声带小结患者均为青年女性 ,2 3.0 8%与职业有关 ;任克水肿为中老年患者。声带息肉及小结病变局限 ,手术仅涉及声带局部 ,术后改善明显 ,术后 1个月达正常状态 ;任克水肿患者术后 1个月改善明显 ,术后 3个月恢复最佳稳定 ;声带囊肿患者术后 1个月声音达最佳状态 ,但由于病变切除术后局部存在缺损 ,一定程度上影响预后 ;慢性肥厚性喉炎患者术后改善不满意。术后声门上代偿纠正均不明显。结论 :喉良性增生性病变主要累及声带被覆层 ,嗓音声障碍的程度及疗效与受累范围有关 ,激光显微外科手术可以保留良好结构及功能。除外科治疗外 ,还应及时矫正不良发声习惯等因素 ,以期获得最佳疗效。     

Glottal area waveform analysis of benign vocal fold lesions before and after surgery

Glottal area waveform (GAW) is the plot of relative glottal area versus time through 1 representative glottal cycle. It is derived from the quantitative analysis of the videostroboscopic image. A GAW analysis was performed on 24 patients before and after microlaryngeal phonosurgery. Patients with vocal fold polyps, polypoid degeneration, cysts, sulcus vocalis, and Reinke's edema were included. From each GAW, 5 parameters were determined and compared: maximum normalized glottal area, maximum opening rate, maximum closing rate, percent open time at 50% glottal opening, and glottal gap size. Statistically significant differences in postoperative states included an increased maximum glottal area, an increased maximum opening rate, and an increased maximum closing rate. Glottal opening and closing rate are objective measures of vocal fold pliability that have clinical relevance. The GAW may be used to quantitate vocal fold vibratory capability.     

Spatiotemporal analysis of normal and pathological human vocal fold vibrations

PurposeFor spatiotemporal analysis to become a relevant clinical tool, it must be applied to human vocal fold vibration. Receiver operating characteristic (ROC) analysis will help assess the ability of spatiotemporal parameters to detect pathological vibration.Materials and MethodsSpatiotemporal parameters of correlation length and entropy were extracted from high-speed videos of 124 subjects, 67 without vocal fold pathology and 57 with either vocal fold polyps or nodules. Mann-Whitney rank sum tests were performed to compare normal vocal fold vibrations to pathological vibrations, and ROC analysis was used to assess the diagnostic value of spatiotemporal analysis.ResultsA statistically significant difference was found between the normal and pathological groups in both correlation length (P < .001) and entropy (P < .001). The ROC analysis showed an area under the curve of 0.85 for correlation length, 0.87 for entropy, and 0.92 when the 2 parameters were combined. A statistically significant difference was not found between the nodules and polyps groups in either correlation length (P = .227) or entropy (P = .943). The ROC analysis showed an area under the curve of 0.63 for correlation length and 0.51 for entropy.ConclusionsAlthough they could not effectively distinguish vibration of vocal folds with nodules from those with polyps, the spatiotemporal parameters correlation length and entropy exhibit the ability to differentiate normal and pathological vocal fold vibration and may represent a diagnostic tool for objectively detecting abnormal vibration in the future, especially in neurological voice disorders and vocal folds without a visible lesion.     

喉记波扫描摄像的临床应用

目的 研究喉记波扫描摄像的临床应用。方法 应用喉记波扫描摄像技术，检测50例发声障碍患者和5例发声正常人。结果 50例发声障碍患者，声带振动的重要参数（对称性、周期性、闭合度、开放商、粘膜波等）均可发现异常。正常人中除1例声带振动轻微不对称外，其余4例未发现异常。结论 喉记波扫描摄像是一种研究不规律声带振动的简单方法，对于发声障碍疾病的诊断为精细，并且，能够对声带振动参数进行量化分析。     

Study of vibratory pattern of the vocal folds in the excised canine larynx.

The effect of simulated thyroarytenoid and cricothyroid muscle contraction on the vibratory pattern of the vocal folds was studied in the excised canine larynx. To simulate the action of the thyroarytenoid muscle, small balloons were inflated in the paraglottic space at the level of the vocal folds. To simulate the action of the cricothyroid muscle, longitudinal tension was applied to the anterior commissure of the vocal folds. The photoglottographic and electroglottographic signals, sound intensity, and airflow rate were measured. This study showed that balloon inflation simulating thyroarytenoid muscle contraction produced an elevation of frequency of vibration with a decrease in open quotient, and that an increase in longitudinal tension simulating cricothyroid muscle contraction produced an elevation of frequency with an increase in open quotient. Vocal resistance decreased with increasing open quotient, amplitude of the photoglottographic waveform, and the frequency of vibration. Vocal efficiency increased with increasing photoglottographic amplitude and decreased with increasing frequency. The vocal efficiency peaked when the open quotient was approximately 0.5. This study suggests that glottographic parameters may be useful in assessing the effect of intrinsic laryngeal muscle activity on vocal efficiency and glottic resistance.     

Configuration of the glottis in laryngeal paralysis. I: Clinical study

It is widely accepted in the American literature that the cricothyroid muscle is responsible for the paramedian position of the vocal fold in recurrent laryngeal nerve paralysis. However, support in the literature for this theory is not conclusive, and the cadaveric vocal fold position expected after lesions of the vagus nerve has also been reported in patients with an intact superior laryngeal nerve. This study compares the configuration of the glottis in patients with unilateral paralysis due to known lesions of either the recurrent laryngeal or vagus nerve. Normal subjects were studied as controls. Results indicate that the alteration of glottic configuration in laryngeal paralysis cannot be adequately characterized by standard terms of vocal fold position. The paralyzed vocal fold is shortened, with anterior rotation of the arytenoid. Patients with vagus nerve lesions had a statistically insignificant tendency for a more lateral vocal fold position, but a discrete difference in position between the two groups was not identified. This study also confirms prior observations that paralyzed vocal folds are frequently not denervated. These findings have significant implications for management of laryngeal paralysis.     

High-speed imaging used to detect vocal fold paresis: a case report

High-speed imaging has been used to study vocal fold vibration and has been shown to provide additional information in aid of our understanding of pathologic vocal fold vibration. This is the first case report of vocal fold paresis diagnosed by high-speed imaging. An 18-year-old girl presented with intermittent voice loss that had been present for 4 years. The patient had been seen by other otolaryngologists and had been given proton pump inhibitors without any improvement in her voice. Her voice was diplophonic. The patient was examined by rigid stroboscopy and was found to have a predominantly open phase pattern but a normal vibratory pattern. High-speed photography showed a distinct vibratory frequency for each vocal fold, suggestive of a paresis pattern. Laryngeal electromyography confirmed the diagnosis of vocal fold paresis. A computed tomographic scan of the larynx and chest showed a thymoma. After thymectomy, the patient recovered full voice function. High-speed imaging is useful for the clinical evaluation of pathologic vocal fold vibration and can detect subtle features of paralysis that may not be detected on fiberoptic endoscopy and rigid stroboscopy. The additional information from high-speed imaging helped to make the diagnosis of vocal fold paresis in this patient.     

声带下方收敛角度在声门闭合不全发声困难中可能的作用机理

目的 探讨喉三维CT重建下声带下方收敛角度的测量方法,探索声门闭合不全对声带下方收敛角度的影响,分析声门闭合不全发声疲劳可能的气流动力学原因.方法 采用双源薄层CT,嘱受试者发/i:/音时扫描10例正常人的20侧声带(声门闭合组),深吸气时扫描8例单侧声带麻痹患者的麻痹侧声带(声门闭合不全组),经深吸气时扫描另10例正常人的20侧声带(声带外展组);导入影像数据于Mimics软件,构建声带及气道的3D模型,联合这两模型测量声带下方收敛角度;采用单因素方差分析,比较3组受试者声带下方收敛角度的差异;并尝试采用材料的斜截面应力分配原理进行声门下压力分析,探讨声门下收敛角度对启动发声时声带振动可能的影响.结果 声门闭合组、声门闭合不全组及声带外展组的声带下方收敛角度分别为33.49°±3.75°、55.03°±2.61°及75.02°±7.32°,三组间差异有统计学意义(P<0.01),声带下方收敛角度随声门闭合不全程度增加而增加.结论 声带下方收敛角度可以通过声带及气道的3D模型进行有效测量,声门闭合不全程度增加会引起该角度增大,可能会导致声门下压力作用于声带下方的剪切力和正应力的分力发生变化,从而引起发声困难.     

An automatic method to quantify mucosal waves via videokymography

Objective/Hypothesis: Vocal fold vibration is associated with four distinct vibratory patterns: those of the right‐upper, right‐lower, left‐upper, and left‐lower vocal fold lips. The purpose of this study was to propose a least squares method to quantify the vibratory properties of each of the four vocal fold lips via videokymography (VKG). Study Design: This was a methodological study designed to examine the impact of subglottal pressure and line‐scan position on mucosal wave parameters. Methods: VKG, a line‐scan imaging technique, has proven to be an effective method for studying vocal fold vibratory patterns. This study used VKG images and an automatic mucosal wave extraction method to examine the vibration of each individual vocal fold lip of 17 excised canine larynges under differing subglottal pressures and line‐scan positions. Results: Varying subglottal pressure led to results consistent with previous studies. Examination of the vocal folds at different line‐scan positions along its length revealed that amplitude is greatest at the midpoint of the vocal fold, followed by the anterior portion of the vocal fold, with the posterior portion having the lowest amplitude (P < .001). Frequency and phase delay did not change significantly throughout the length of the vocal fold. Conclusions: The method used in this study allows for easy determination of four sets of vibratory parameters, and examination of the effect of biomechanical parameters on vocal fold vibrations.