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At least 271 records · Page 15Linked to original sources
PubMed2006

Lidocaine block of the recurrent laryngeal nerve in adductor spasmodic dysphonia: a multidimensional assessment.

OBJECTIVES/HYPOTHESIS: Lidocaine block of the recurrent laryngeal nerve (RLN) has been reported as a procedure for surgical selection of patients with adductor spasmodic dysphonia (ADSD). However, its effects on phonation have not been rigorously assessed in a prospective fashion using strict entry criteria and multiple measures of phonatory function. This investigation assessed the phonatory effects of RLN lidocaine block in ADSD to explore its potential as a diagnostic tool. STUDY DESIGN: Single group, pre/postexperimental trial. METHODS: Twenty-one consecutive patients with suspected ADSD underwent unilateral RLN block, causing temporary ipsilateral vocal fold paralysis. Voices were recorded before and during the block. Patients completed self-ratings of overall level of dysphonia severity, vocal effort, and laryngeal tightness. Blinded listeners completed auditory-perceptual ratings, and the frequency of phonatory breaks was acoustically analyzed. RESULTS: During the block, patients reported significant reductions on overall severity (P = .045), vocal effort (P < .001), and laryngeal tightness (P = .002). Listeners rated the voices during the block as significantly more breathy (P < .001), less strained (P < .001), and less severe (P = .059). Acoustic analysis confirmed significantly fewer phonatory breaks during the block (P < .001). Patient-based ratings of improvement were more consistent than listener ratings, and reduction in overall severity correlated with perceived breathiness. CONCLUSIONS: Although individuals varied in their outcomes, group results suggest that response to RLN lidocaine block warrants further study as a possible diagnostic tool in ADSD.

Anesthetics, Local↗
PubMed2004

Diagnostic tools in laryngology.

PURPOSE OF REVIEW: Laryngology has become recognized as a subspecialty within the field of otolaryngology-head and neck surgery over the course of the past 30 years. The evolution of laryngology stems primarily from our better understanding of the physiology of vocal production, society's increased reliance on oral communication in industry, and the resultant demand for improvements in diagnostic and therapeutic protocols to enhance vocal performance. The purpose of this review is to describe current advances in diagnostic tools in laryngology that contribute to our understanding of vocal physiology and our ability to improve quality of life as it relates to vocal performance. RECENT FINDINGS: Diagnostic tools in laryngology allow the clinician the ability to assess the vibratory function of the vocal folds, evaluate laryngeal structure and airway patency, assess glottal and pulmonary airflow, assess the neurologic integrity of the vocal folds, analyze the quality of the voice signal, and assess the degree of functional disability as it relates to laryngeal pathology. SUMMARY: Primary advances in diagnostic laryngology include improvements in laryngoscopy techniques, imaging, electromyography, aerodynamic testing, acoustic analysis, and functional assessment, each of which is improving our ability to understand, diagnose, and treat a wider spectrum of voice, airway, and swallowing disorders.

Acoustics↗
PubMed2004

Electronic videoendoscopic laryngostroboscopy.

Color images obtained using electronic videoendoscopic laryngostroboscopy (EVLS) were presented and the utility of this technique for the diagnosis of dysphonia was discussed in this paper. Stroboscopic evaluations of laryngeal lesions were performed using a rhinolaryngeal electronic videoendoscope system employing a single-plate simultaneous color charge-coupled device (CCD) chip method. Twenty patients underwent electronic videoendoscopic laryngostroboscopy. A Karl Storz laryngostroboscope Pulsar was connected to this system and laryngeal lesions were assessed. The potentialities of laryngostroboscopy using this system were evaluated. Clear stroboscopic images were obtained in all patients. Multiple still images during vocal fold vibration were acquired using an optional function. The laryngostroboscope is not compatible with conventional systems employing a single-plate red, green, and blue (RGB) surface scanning method. However, the system used was successfully connected to a laryngostroboscope. EVLS appears to be a powerful new tool for the diagnosis of dysphonia.

Adult↗
PubMedDate not supplied

Shortening of the front vibrating part of the vocal folds in phonation.

We have tried to make use of the opportunity of repeated observations through the analysis of the recorded movements of the phonating vocal folds by means of the phonating vocal folds through indirect videolaryngostroboscopic technique. The results of our investigation correspond, among others, with Hála and Sovák's diagrammatic description of continual and gradual changes in the vibration of the vocal folds in an uninterrupted sequence of tones of the human voice. In the initial chapter mention has been made of Hála and Honty's works and of Pressmann's work dealing with the described behaviour of the glottis when phonating high-pitched tones. The conclusions analogous to our findings have also been described by means of stereoscopically measuring the length of the phonating vocal folds. In conclusion, by measuring the distances between the anterior commissure and the junction between the membranous part of the vocal fold and vocal process of the arytenoid and the anterior commissure to the posterior nodal point of the vibrating part of the vocal folds we have verified the correctness of the findings published by Czermak, Hála and Honty, Pressmann, and Sovák, who pointed out the phenomenon of the shortening of the front vibrating part of the vocal folds in phonating high-pitched tones of the human voice.

Adult↗
PubMed2006

The prevalence and risk factors for occupational voice disorders in teachers.

OBJECTIVE: Occupational voice disorders in Poland account for over 25% of all occupational diseases. The aim of the study was to assess the prevalence of voice problems in the general population of Polish teachers, and identify risk factors for developing voice pathology. PATIENTS AND METHODS: The study group comprised 425 female full-time teachers (most of them primary and secondary school, age ranging from 23 to 61 years) and 83 non-teacher women (control) whose jobs did not involve vocal effort, matched for age to the study group. All participants were subjected to a survey using an extensive questionnaire, and to laryngological, phoniatric and videostroboscopic examinations. RESULTS: The overall lifetime vocal symptoms were more frequent in the teachers than in the non-teachers (69 vs. 36%), and in particular it related to permanent and recurrent hoarseness, and dryness in the throat. Mean number of the voice symptoms was 3.21 in teachers and 1.98 in controls (p < 0.001). Abnormal (non-euphonic) voice, neck muscle hypertension during phonation and incorrect resonator function were also significantly more frequent in the teachers. Mean maximum phonation time was shorter in teachers than in the controls (14.3 vs. 15.9 s, p < 0.01). Occupational voice disorders and hyperfunctional dysphonia (that is thought to predispose to such pathology) were found in 32.7% of teachers and 9.6% of control subjects. The probability of developing incomplete glottal closure (odds ratio 13.2x; 95% CI: 1.8-96.8) and hyperfunctional dysphonia (odds ratio 2.7; 95% CI: 1.14-6.44) were significantly higher in the teacher group versus non-teachers. A significant positive relationship was found in teachers between the prevalence of hyperfunctional dysphonia and strained phonation, neck muscle hypertension, instability of voice, self-assessed hyper-arousal, and lifetime vocal effort index (years of employment as a teacher x hours of professional activity/week). The prevalence of vocal nodules and incomplete glottal closure were correlated with incorrect phonation technique parameters, but not with psychological factors. No correlation was found with environmental variables, such as classroom temperature, humidity, airborne dust. CONCLUSION: The prevalence of self-reported symptoms and clinical signs of voice disorders is around 2-3 times more frequent in Polish female teachers than in non-teachers. Lifetime vocal effort, incorrect technique of phonation and psychological predisposition seem to constitute major risk factors for developing occupational voice disorders.

Adult↗
PubMed2005

Chronic cough as a sign of laryngeal sensory neuropathy: diagnosis and treatment.

Chronic cough is often attributed to reflux, postnasal drip, or asthma. We present 28 patients who had chronic cough or throat-clearing as a manifestation of sensory neuropathy involving the superior or recurrent laryngeal nerve. They had been identified as having sudden-onset cough, laryngospasm, or throat-clearing after viral illness, surgery, or an unknown trigger. Cough and laryngospasm were the most common complaints. Seventy-one percent of the patients had concomitant superior laryngeal nerve or recurrent laryngeal nerve motor neuropathy documented by laryngeal electromyography or videostroboscopy. After a negative workup for reflux, asthma, or postnasal drip, these patients were treated with gabapentin at 100 to 900 mg/d. Symptomatic relief was achieved in 68% of the patients. Sensory neuropathy of the recurrent laryngeal nerve or superior laryngeal nerve should be considered in the workup for chronic cough or larynx irritability. Symptomatic management of patients with cough and laryngospasm due to a suspected sensory neuropathy may include the use of antiseizure medications such as gabapentin.

Adolescent↗
PubMed2006

Polydimethylsiloxane particles for permanent injection laryngoplasty.

OBJECTIVES: Polydimethylsiloxane (PDMS) particles are a nonresorbable material that allows for permanent vocal fold augmentation. This study investigated morbidity and voice quality in patients treated for unilateral vocal fold paralysis by injection of PDMS particles. METHODS: Fourteen patients who had neurogenic unilateral vocal fold paralysis of different causes were included in this prospective study. Each patient underwent videostroboscopic assessment before and after operation. Friedrich's dysphonia index (DI), a score system combining subjective and objective parameters, was used to describe voice quality. A DI of 0 reflects a normal voice, and a DI of 3 stands for complete aphonia. The PDMS particles were injected into the paraglottic space by microlaryngoscopy under general anesthesia. RESULTS: The median follow-up was 4.1 months. There was no complication attributable to the injection of PDMS particles. The mean DI was 2.8 before operation. After the operation, voice quality improved significantly in each patient, as reflected by a mean postinjection DI of 1.4. CONCLUSIONS: Particles of PDMS provide a relatively safe and minimally invasive option for permanent vocal fold augmentation. The functional results in terms of voice improvement are comparable to those obtained with other techniques, including thyroplasty. In the European Community, PDMS particles are officially approved for use in the human larynx.

Adult↗
PubMed2006

Blinded evaluation of the effects of high definition and magnification on perceived image quality in laryngeal imaging.

OBJECTIVES: Advances in commercial video technology have improved office-based laryngeal imaging. This study investigates the perceived image quality of a true high-definition (HD) video camera and the effect of magnification on laryngeal videostroboscopy. METHODS: We performed a prospective, dual-armed, single-blinded analysis of a standard laryngeal videostroboscopic examination comparing 3 separate add-on camera systems: a 1-chip charge-coupled device (CCD) camera, a 3-chip CCD camera, and a true 720p (progressive scan) HD camera. Displayed images were controlled for magnification and image size (20-inch [50-cm] display, red-green-blue, and S-video cable for 1-chip and 3-chip cameras; digital visual interface cable and HD monitor for HD camera). Ten blinded observers were then asked to rate the following 5 items on a 0-to-100 visual analog scale: resolution, color, ability to see vocal fold vibration, sense of depth perception, and clarity of blood vessels. Eight unblinded observers were then asked to rate the difference in perceived resolution and clarity of laryngeal examination images when displayed on a 10-inch (25-cm) monitor versus a 42-inch (105-cm) monitor. A visual analog scale was used. These monitors were controlled for actual resolution capacity. RESULTS: For each item evaluated, randomized block design analysis demonstrated that the 3-chip camera scored significantly better than the 1-chip camera (p < .05). For the categories of color and blood vessel discrimination, the 3-chip camera scored significantly better than the HD camera (p < .05). For magnification alone, observers rated the 42-inch monitor statistically better than the 10-inch monitor. CONCLUSIONS: The expense of new medical technology must be judged against its added value. This study suggests that HD laryngeal imaging may not add significant value over currently available video systems, in perceived image quality, when a small monitor is used. Although differences in clarity between standard and HD cameras may not be readily apparent on small displays, a large display size coupled with HD technology may impart improved diagnosis of subtle vocal fold lesions and vibratory anomalies.

Equipment Design↗
PubMed2004

Multidimensional assessment of voice and speech after supracricoid laryngectomy with cricohyoidopexy.

This study was designed: to evaluate the vocal function in the patients with supracricoid laryngectomy (SCL) compared with normal subjects; to determine the factors affecting voice (such as number of arytenoid(s) preserved and movement of larynx and tongue base); and to determine the correlations between videolaryngostroboscopy, acoustic and perceptual parameters. Ten patients who underwent SCL with cricohyoidopexy for primary laryngeal squamous cell carcinoma were included into the study. Vocal function was investigated by means or videolaryngostroboscopy. Voice quality was assessed by means of objective acoustic analysis and subjective perceptual ratings by trained raters. Aberrant, incompetent, and rough mucosal wave was observed in the anterior and superior surfaces of arytenoids(s), the inferior part of tongue base and the lateral walls of the hypopharynx. The acoustic parameters were found to be significantly different from those of normal subjects. The values of perceptual scores were approximately within 50 per cent of normal range. The number of arytenoids spared did not affect acoustic or perceptual measurements. A rough, breathy, unpleasant but intelligible and acceptable voice could be obtained after SCL with cricohyoidopexy.

Acoustics↗
PubMed2006

Technique for measurement of fluorescence lifetime by use of stroboscopic excitation and continuous-wave detection.

A study of the practicality a simple technique for obtaining time-domain information that uses continuous wave detection of fluorescence is presented. We show that this technique has potential for use in assays for which a change in the lifetime of an indicator occurs in reaction to an analyte, in fluorescence resonance energy transfer, for example, and could be particularly important when one is carrying out such measurements in the scaled-down environment of a lab on a chip (biochip). A rate-equation model is presented that allows an objective analysis to be made of the relative importance of the key measurement parameters: optical saturation of the fluorophore and period of the excitation pulse. An experimental demonstration of the technique that uses a cuvette-based analysis of a carbocyanine dye and for which the excitation source is a 650 nm wavelength, self-pulsing AlGaInP laser diode is compared with the model.

Algorithms↗
PubMed2006

Stroboscopic white-light interference microscopy.

The principle of stroboscopic motion freezing of oscillating objects extends directly to interference microscopes that use coherence as part of the measurement principle. Analysis shows, however, that the fringe contrast loss for out-of-plane motion in stroboscopic interferometry is a wavelength-dependent phenomenon, which can alter the apparent nominal center wavelength of the white-light source. As in monochromatic systems, the key adjustable parameter is the duty cycle, equal to the product of the vibrational frequency and the pulse width. This theoretical study provides detailed graphs of expected errors as a function of the duty cycle, including fringe contrast loss, apparent wavelength shift, and measurement error.

Algorithms↗
PubMed2005

Stroboscopic ultrahigh-resolution full-field optical coherence tomography.

We present a new technique that produces en face tomographic images with a 10-micros acquisition time per image. The setup consists of an interference microscope with stroboscopic illumination provided by a xenon arc flash lamp (10-micros flashes at 15 Hz). The tomographic images are obtained from two phase-opposed interferometric images recorded simultaneously by two synchronized CCD cameras. Transverse resolution better than 1.0 microm is achieved by use of high-numerical-aperture microscope objectives. The short coherence length of the source yields an axial resolution of 0.9 microm. 3 x 3 pixel binning leads to a detection sensitivity of 71 dB. Our system is suitable for various applications, particularly in biology for in vivo cellular-level imaging.

Animals↗
PubMed2005

Three-dimensional characterization of tethered microspheres by total internal reflection fluorescence microscopy.

Tethered particle microscopy is a powerful tool to study the dynamics of DNA molecules and DNA-protein complexes in single-molecule experiments. We demonstrate that stroboscopic total internal reflection microscopy can be used to characterize the three-dimensional spatiotemporal motion of DNA-tethered particles. By calculating characteristic measures such as symmetry and time constants of the motion, well-formed tethers can be distinguished from defective ones for which the motion is dominated by aberrant surface effects. This improves the reliability of measurements on tether dynamics. For instance, in observations of protein-mediated DNA looping, loop formation is distinguished from adsorption and other nonspecific events.

DNA↗
PubMed2006

Stroboscopic illumination using light-emitting diodes reduces phototoxicity in fluorescence cell imaging.

Excited fluorophores produce reactive oxygen species that are toxic toward many live cells (phototoxicity) and accelerate bleaching of the fluorophores during the course of extended or repeated measurements (photobleaching). We recently developed an illumination system for fluorescence microscopy using a high power light-emitting diode (LED), which can emit short pulses of light (0.5-2 ms) to excite fluorophores. This system minimizes illumination time, thus reducing phototoxicity and photobleaching artifacts. To demonstrate the usefulness of the new system, we compared images of human sperm loaded with various fluorescent indicators and excited with either a conventional mercury lamp as a continuous excitation light source or the LED as a source of pulsed illumination. We found that sperm motility decreased rapidly and photobleaching was relatively rapid under continuous illumination, whereas under pulsed LED illumination, motility was maintained and photobleaching was much reduced. Therefore, fluorescence microscopy using LED-based pulsed illumination offers significant advantages for long-term live cell imaging, reducing the degree of phototoxicity, and extending the effective lifetime of fluorophores.

Calcium↗