Endoscopic and stroboscopic description of adults with paradoxical vocal fold dysfunction

The purpose of this study was to determine if endoscopic and stroboscopic parameters of voice were normal between attacks of paradoxical vocal fold dysfunction (PVFD). Fifty adults (38 females, 12 males) and 54 adult controls (40 females, 14 males) were examined via endoscopy with and without stroboscopy. Endoscopy indicated paradoxical adduction of the folds during the respiratory cycle of all 50 participants with PVFD, although they were asymptomatic. Atypical laryngeal configurations were observed including abnormality of the anterior-posterior dimension and ventricular fold medialization in both groups of subjects. Stroboscopy demonstrated abnormalities including unstable zero phase, decreased amplitude of vibration, decreased mucosal waves, and phase asymmetry primarily for the PVFD subjects alone. Results indicate that persons with PVFD demonstrate subtle laryngeal abnormality endoscopically and stroboscopically when dyspnea is not reported. This supports the hypothesis that PVFD is not episodic but exists as a continuum of laryngeal instability that may, due to various precipitating factors, be exacerbated to breathing attacks.     

Electroglottographic quasi-open quotient and amplitude in crescendo phonation

Crescendo phonation (swelltone) was used to evaluate the laryngeal tensioning behavior of seven normal speakers and of 12 dysphonic patients. EGG quasi-open quotient (qOq), stroboscopic open quotient, and vocal sound pressure level (SPL) were measured, and EGG amplitude and the mucosal wave were assessed qualitatively. For normal speakers, the qOq decreased greatly as vocal intensity increased. The same tendency was observed, but to a lesser extent, among hyperfunctional dysphonics. In contrast, qOq increased with vocal intensity among the hypofunctional dysphonics. The crescendo task combined with EGG assessment appears to offer a valid approach to the classification of laryngeal dysfunctions.     

Aerodynamic measurements of patients with parkinson''s disease

Patients with Parkinson's disease commonly complain of voice dysfunction. Most of these complaints can be attributed to the known muscular control disorders that occur with Parkinson's disease. However, the manifestations of Parkinson's disease muscular dysfunction on parameters of phonation such as airflow, laryngeal resistance, and subglottal pressure necessary to sustain phonation have not been reported. The purpose of this study was to examine the aerodynamic characteristics of flow, laryngeal resistance, and phonation pressure threshold in a heterogeneous population of patients with Parkinson's disease who had varying voice complaints and to compare the data to similar studies for human subjects who have no voice complaints. The studies used a noninvasive method of detecting flow and acoustic signal from the lips, oral cavity and nose during phonation and used an external flow interruption technique to estimate subglottal pressure and phonation threshold pressure. About one third of the patients could not produce phonation at regular and loud intensities that were comfortable for normal subjects. The mean subglottal pressure (SGP) of patients with Parkinson disease who could produce 3 levels of intensity comparable to normal subjects was significantly higher than the mean SG-Ps for normal subjects for the same intensities of vocal production. The mean flow rates measured from patients with Parkinson's disease at the same 3 intensities of phonation was not significantly greater than in normal subjects. This indicated that the mean laryngeal resistance calculated for patients with Parkinson's disease was notably and significantly greater than mean laryngeal resistance calculated for normal subjects at the same intensity levels. The mean vocal efficiency (VE) for normal subjects was not significantly different than the mean VE for patients with Parkinson's disease, because greater pressure was used to generate similar flow and acoustic energy. These findings correlate with the perception of patients with Parkinson's disease that they are working harder to produce phonation. The observation of notably greater laryngeal resistance and phonation threshold pressure in patients with Parkinson's disease suggests that further studies of the glottic aperture in patients with Parkinson' disease may be useful for understanding how this common motor disorder disturbs phonation.     

Value of flexible videolaryngoscopy in the study of laryngeal morphology and functions

In the past 3 years flexible laryngoscopy was used in the evaluation of 315 patients, ranging in age from 4 months to 86 years (in 136 cases a videorecording was obtained). The technique was especially helpful in cases in which a prolonged visual evaluation of laryngeal motion was required for diagnostic, prognostic, and documentative purposes. The main limitations were lack of image definition and wide angle image distortion. Therefore, accurate evaluation of initial mucosal changes was not possible in some of the cases examined. A stroboscopic light source was used every time the characteristics of the vibratory cycle of the vocal folds had to be studied. This technique was applied mainly to the study of vocal fold vibrations in unilateral laryngeal paralysis.     

Nonspecific laryngeal granuloma: A case study of a professional singer

A professional singer with laryngeal granuloma underwent surgery following failed response to conservative treatments. Two primary findings emerged. First, although a sizable lesion was present initially, presurgical voice measures were largely normal or superior. The exception was elevated phonatory effort during singing. Second, postsurgical voice functions were entirely normal or superior (including phonatory effort), despite demanding singing performances a few weeks following surgery. The results add to the limited corpus of quantitative, normative-referenced data on voice in patients with granulomas and are inconsistent with previous reports of voice abnormalities in such patients and poor functional response to surgery.     

Determination of largest lyapunov exponents of vocal signal: Application to unilateral laryngeal paralysis

It has been shown that voice signal abnormalities, particularly in unilateral laryngeal paralysis (ULP), are not always randomly distributed and that "statistical" indexes of regularity, such as jitter and shimmer, may be unreliable in these cases. The techniques of nonlinear dynamics, particularly phase portraits, have been used to demonstrate that some of the abnormalities observed were the consequence of nonlinearity of glottic function. From a theoretical point of view, determination of Lyapunov exponents allows quantification of the complexity of the phase portraits. The authors studied vocal signals recorded in 12 normal subjects and 26 patients with ULP and calculated the largest Lyapunov exponent (LLE). In normal subjects, LLE mean value was 0.380 (SD = 0.182). In patients with ULP, LLE mean value was 0.570 (SD = 0.337). The difference is significant at P = 0.031. Determination of LLE was compared to more "classical" indexes such as jitter and oral airflow during phonation. A principal component analysis showed that information contained in LLE was not redundant but complementary to the other parameters.     

Objective measures of voice production in patients complaining of laryngeal fatigue

The purpose of this retrospective study is to describe results of acoustic, aerodynamic, and videostroboscopic measures in patients complaining of laryngeal fatigue. Data were collected from 88 patients whose primary complaint was chronic laryngeal fatigue in the absence of visible laryngeal pathologies. The results revealed an abnormally high airflow rate and decreased maximum phonation time. An anterior glottal chink, anterior and posterior glottal chinks, or spindle-shaped glottal closure were found in 61% of the subjects.     

Studying vocal fold vibrations in Parkinson's disease with a nonlinear model

A nonlinear model is applied to study pathologic vocal vibratory characteristics and voice treatments of Parkinson's disease. We find that a number of pathologic vocal characteristics commonly observed in Parkinson's disease, including reduced vibratory intensity, incomplete vocal closure, increased phonation threshold pressure, glottal tremor, subharmonics, and chaotic vocal fold vibrations, can be studied with this nonlinear model. We also find that two kinds of clinical voice treatments for Parkinson's disease, including respiratory effort treatment and Lee Silverman voice treatment can be studied with this computer model. Results suggest that respiratory effort treatment, in which subglottal pressure is increased, might aid in enhancing vibratory intensity, improving glottal closure, and avoiding vibratory irregularity. However, the Lee Silverman voice treatment, in which both subglottal pressure and vocal fold adduction are increased, might be better than respiratory effort treatment. Increasing vocal fold thickness would be further helpful to improve these pathologic characteristics. The model studies show consistencies with clinical observations. Computer models may be of value in understanding the dynamic mechanism of disordered voices and studying voice treatment effects in Parkinson's disease.     

Inhaled Corticosteroids: Hazardous Effects on Voice—An Update

Inhaled corticosteroids (ICS) have become the prevalent treatment in asthmatics. Hazards to voice are under-recognized. A total of 38 patients with voice complaints associated with the use of ICS were assessed by 79 strobovideolaryngoscopy (SVL) examinations, 24 single and 14 multiple SVL. Hoarseness and dysphonia were the primary reasons for referral. The ICS initially used most frequently was Advair Diskus (fluticasone propionate and salmeterol-inhalation powder-[IP]) in 22 patients, followed by Flovent (fluticasone propionate inhalation aerosol-pressurized metered-dose inhaler-[PMDI]) in 11. Duration of ICS usage varied from 2 weeks to 4-5 years. Higher dosage and frequency of use exacerbated problems. Hazards to voice previously unrecognized by real-time indirect mirror or fiberoptic laryngoscopy were identified by meticulous attention to SVL abnormalities. There was essentially no difference in occurrence of abnormalities whether analyzed from the perspective of the initial 38 or all 79 examinations. These included abnormal mucosal wave symmetry/periodicity (76-63%), phase closure (74-63%), glottic closure (63-59%), mucosal wave amplitude/magnitude (50-35%), supraglottic hyperactivity (39-25%), mucosal quality (34-34%), and glottic plane (10-5%).Candidiasis of the larynx was infrequently observed. Fluticasone ICS were a cause of steroid inhaler laryngitis, and the best treatment was their avoidance or cessation. Further prospective studies ideally might include SVL documented as a pretherapy baseline and then repeated in each ICS patient who developed hoarseness/dysphonia.     

Endoscopic microsuture repair of vocal fold defects

The presence of a nonvibratory segment of vocal folds after microlaryngeal surgery is often a cause of poor voice result. The etiology of a nonvibratory segment is due to full thickness epithelial defect followed by secondary wound closure and scar contracture. To reduce scar contracture and nonvibratory segment of the vocal folds, primary repair with a 6-0 chromic endo-knot suture technique was used to close defects and approximate microflaps of the vocal folds. This was done in 18 patients with epithelial defects after resection of benign vocal fold lesions. The pathologic findings included severe polypoid degeneration (n = 7), fusiform laryngeal polyps (n = 5), sulcus vocalis (n = 2), cyst (n = 2), and keratosis (n = 2). Voice was improved in all patients after surgery. Comparison of vocal fold vibration before and after surgery showed improvements in configuration, amplitude, and mucosal wave. Vocal folds that were sutured all had good vibratory characteristics; none had a nonvibrating segment at the site of suture placement. Voice and healing after microsuture technique were near normal by Day 10 and return of mucosal wave was often complete by Day 14. Endoscopic microsuture closure of microflaps of the vocal folds edge is safe and affords the surgeon an opportunity for primary repair with improved functional result.     

Treatment of spasmodic dysphonia (laryngeal dystonia) with local injections of Botulinum toxin

In 1984 the authors performed the first laryngeal injection of Botulinum toxin for laryngeal dystonia via percutaneous, electromyographically guided technique. Since that time we have treated 450 patients with adductor spasmodic dysphonia, abductor spasmodic dysphonia, and adductor breathing dystonia. In general, the adductor patients received bilateral injections of 1.25 U to 3.75 U, obtaining greater than 90% of normal voice. The abductor patients received unilateral or staged bilateral injections of the posterior cricoarytenoid muscles with 0.6 to 3.75 U, obtaining 70% of normal function. We have found laryngeal injections of Botulinum toxin to be safe and effective therapy for the symptoms of laryngeal dystonia (spasmodic dysphonia).     

Mild Vocal Fold Paresis: Understanding Clinical Presentation and Electromyographic Findings

The implications of mild vocal fold hypomobility are incompletely understood. This study describes the clinical, electromyographic, and probable etiologic findings in patients who presented with complaints of dysphonia and whose physical examination revealed vocal fold paresis as a factor possibly contributing to their voice complaints. A retrospective chart review of all patients who presented to a tertiary laryngology referral center over a 13-month period, who had a clinical diagnosis of mild vocal fold hypomobility and who underwent laryngeal electromyography, were included in the study. A total of 22 patients completed the medical evaluation of their voice complaint. Of these patients, 19 (86.4%) were found to have evidence of neuropathy on laryngeal electromyography. The clinical picture indicated the following probable origins for the vocal fold paresis: goiter/thyroiditis (7/22 or 31.8%), idiopathic (4/22 or 18.2%), viral neuritis (4/22 or 18.2%), trauma (3/22 or 13.6%), and Lyme's disease (1/22 or 4.5%). This article describes the clinical entity of mild vocal fold hypomobility and associated flexible laryngoscopic, rigid strobovideolaryngoscopic, and laryngeal electromyographic findings.     

Stroboscopic signs associated with benign lesions of the vocal folds

Stroboscopic signs were systematically rated for a group of 80 patients with benign vocal fold lesions, most of whom had either a nodule or a polyp. Each group revealed a characteristic pattern of ranking of signs and exhibited differences of most predominant signs. The results of the ratings were submitted to a multiple discriminant analysis to determine if post hoc stroboscopic ratings could be used to correctly classify patients into one of four diagnostic groups and into one of two treatment groups. All patients except one were correctly classified into the diagnostic groups, and all were correctly classified into the treatment groups. The important signs for classifying patients into the diagnostic groups were roughness of the edge of the affected vocal fold, phase closure pattern, and phase symmetry. The important signs for classifying patients into the treatment groups were roughness of the edge of the affected vocal fold, glottal closure configuration, and vibration characteristics of the affected (or more affected) vocal fold. The results suggest that objective evaluation of stroboscopic examinations can be valuable in correctly diagnosing patients and in selecting the proper treatment regimen for the patient.     

Effects of Bilateral Subthalamic Nucleus Stimulation and Medication on Parkinsonian Speech Impairment

This study aimed to assess quantitatively the effect of bilateral subthalamic nucleus (STN) stimulation and medication on hypokinetic parkinsonian dysarthria. Twelve Italian patients (11 males and 1 female) with idiopathic Parkinson's disease (mean age 60.29+/-7.50 years) and bilateral STN implantation were studied. Neurological assessments and acoustic recordings were performed in four clinical conditions combining stimulation and medication to assess the degree of motor disabilities and speech impairment. Acoustic analysis was performed by means of the Multidimensional Voice Program and the Advanced Motor Speech Profile (Kay Elemetrics, Lincoln Park, NJ). None of the evaluated parameters deteriorated after STN deep brain stimulation. STN stimulation significantly improved motor performances and vocal tremor and provided a major stability to glottal vibration. Effect of stimulation on these parameters was superior to that of levodopa. No significant variations were observed in perceptual evaluation and in acoustic parameters related to prosody, articulation, and intensity after either stimulation or medication. The improvement of acoustic parameters related to glottal vibration and voice tremor was not accompanied by a substantial effect on speech intelligibility. STN stimulation was more effective on global motor limb dysfunctions than on dysarthria, but we did not report negative consequences on speech.     

Tremor: Is Parkinson's disease a dynamical disease?

Experimental evidence has shown a plethora of short-term fluctuations in patients with Parkinson's disease. We investigate these transitory events using the concept of dynamical disease. Several examples of short-term fluctuations in tremor are analyzed, and in two cases, other systemic variables (i.e., respiration and blood pressure) are examined as well. A model for tremor, based on negative feedback with delays is proposed, and the transient events are simulated. The theoretical implications of the model suggest that interactions between the central and peripheral loops, as well as interactions between the control loops and other systemic signals, can give rise to transitory events in tremor, both in the pathological and in the normal case. (c) 1995 American Institute of Physics.     

Transient dynamics in motor control of patients with Parkinson's disease

Experimental observations of movement disorders including tremor and voluntary microdisplacements recorded in patients with Parkinson's disease (PD) during a simple visuomotor tracking task are analyzed. The performance of patients with PD having a very large amplitude tremor is characterized either by the intermittent appearance of transient dynamics or by the presence of sudden transitions in the amplitude or frequency of the signal. The need to develop new tools to characterize changes in dynamics (i.e., transitions) and to redefine neurological degeneration, such as Parkinson's disease, in terms of qualitative changes in oscillatory behaviors is emphasized.     

Changes in glottal configuration in women after loud talking

The purpose of this investigation was to examine changes in glottal configuration in women under a variety of pitch and loudness conditions after an interval of loud reading. Twelve young adult women with normal laryngeal structures were photographed under stroboscopic light and sustained the vowel /i/ for a minimum of 3 s, at three pitch levels and three loudness levels, before and after a 15-min interval of loud reading. Results indicate that female speakers tend to alter glottic configurations across phonatory conditions after loud reading, particularly during high-pitch phonation. Specifically, five subjects tended to increase glottal closure, one tended to increase glottal opening, two tended to maintain the identical configuration, and four demonstrated no consistent pattern of response.     

Tremor classification and tremor time series analysis

The separation between physiologic tremor (PT) in normal subjects and the pathological tremors of essential tremor (ET) or Parkinson's disease (PD) was investigated on the basis of monoaxial accelerometric recordings of 35 s hand tremor epochs. Frequency and amplitude were insufficient to separate between these conditions, except for the trivial distinction between normal and pathologic tremors that is already defined on the basis of amplitude. We found that waveform analysis revealed highly significant differences between normal and pathologic tremors, and, more importantly, among different forms of pathologic tremors. We found in our group of 25 patients with PT and 15 with ET a reasonable distinction with the third momentum and the time reversal invariance. A nearly complete distinction between these two conditions on the basis of the asymmetric decay of the autocorrelation function. We conclude that time series analysis can probably be developed into a powerful tool for the objective analysis of tremors. (c) 1995 American Institute of Physics.     

A study on the mechanism of functional dysphonia

A total of 333 patients with a diagnosis of functional dysphonia were studied by both laryngeal electromyography (EMG) and spectral analysis. EMG and acoustic analysis revealed that some patients with so-called functional dysphonia diagnosed by physical examination alone in fact suffered from a variable degree of laryngeal nerve paralysis. Laryngeal EMG plays an important role in determining whether patients with a diagnosis of functional dysphonia have organic disease of the laryngeal nerves.