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At least 19 recordsLinked to original sources
PubMed1998

[Stroboscopy and imaging in interdisciplinary diagnosis of early stages of laryngeal carcinoma].

The laryngostroboscopy is regarded to be the most important functional investigation in laryngologic and phoniatric diagnostics. She allows an analysis of vocal fold vibrations during phonation. Stroboscopic evaluations permit to early detect infiltrative processes of the vocal folds. Superficial alterations of the mucous membrane that invade into the muscle cause a phonatory "standstill" of the vocal fold in the stroboscopy, i.e. a complete lack of vibratory motion. If such a phonatory standstill persists for more than 2 or 3 weeks, a biopsy via microlaryngoscopy is indicated for diagnostic purposes. In comparison to stroboscopy, imaging techniques are not of such great significance in early laryngeal cancer. But in case of suspected infiltration of the tumor a further diagnostic evaluation with CT or MRI is necessary to detect possible neoplastic invasion of the laryngeal cartilage or of extralaryngeal structures. In this paper, we present the principle of laryngostroboscopy, the examination procedure and the stroboscopic parameters. Case reports of early laryngeal cancer illustrate the interdisciplinary diagnostic procedure with CT, MRI and stroboscopy.

Adult↗
PubMed1985

Stroboscopy--a pertinent laryngological examination.

When observing the vocal fold movements in their laryngoscopic examination, most laryngologists seem to be trained to consider only the gross respiratory movements of the folds, i.e. abduction and adduction. these movements constitute an essential part of the vitally important valve function of the larynx, preventing aspiration and providing parts of the mechanisms for normal swallowing, coughing, and straining. The second important function of the larynx is to serve as a transducer of aerodynamic to acoustic energy; the voice function. Probably for reasons of tradition, the examination of the voice function is generally left to the speech pathologists, who can make an auditory perceptual evaluation of the voice qualities, possibly supplemented by electro-acoustic analyses. By focussing also on the small vibratory movements of the vocal folds during phonation, using laryngeal stroboscopy, the laryngologist can contribute considerably to the diagnosis of voice disorders. For the laryngeal surgeon stroboscopy should be of particular interest, as it is a useful tool for early detection of (cancerous) invasion and for the evaluation of laryngeal paresis. This paper describes the clinical procedure of laryngeal stroboscopy, based on some introductory remarks on vocal anatomy and function.

Humans↗
PubMed2001

A method for assessing the regional vibratory pattern of vocal folds by analysing the video recording of stroboscopy.

Stroboscopy and kymography have been used to examine the motional abnormality of vocal folds and to visualise their regional vibratory pattern. In a previous study (Laryngoscope, 1999), we introduced the conceptual idea of videostrobokymography, in which we applied the concept of kymography on the pre-recorded video images using stroboscopy, and showed its possible clinical application to various disorders in vocal folds. However, a more detailed description about the software and the mathematical formulation used in this system is needed for the reproduction of similar systems. The composition of hardwares, user-interface and detail procedures including mathematical equations in videostrobokymography software is presented in this study. As an initial clinical trial, videostrobokymography was applied to the preoperative and postoperative videostroboscopic images of 15 patients with Reinke's edema. On preoperative examination, videostrobokymograms showed irregular pattern of mucosal wave and, in some patients, a relatively constant glottic gap during phonation. After the operation, the voice quality of all patients was improved in acoustic and aerodynamic assessments, and videostrobokymography showed clearly improved mucosal waves (change in open quotient: mean +/- SD= 0.11 +/- 0.05).

Female↗
PubMed2002

[Physical and technical elements of short-interval, color-filtered double strobe flash-stroboscopy].

INTRODUCTION: Quantitative measurement of vocal fold movements can be done either with high-speed imaging or with short interval, color-filtered double strobe flash-stroboscopy. The physical and technical elements of this new technique are described. METHODS: Two special strobe units (KAY Elemetrics RLS 9100) are used in a master-slave configuration. In this way an adjustable interval of 0.1-2.0 ms between flashes is introduced. The strobe flashes are color filtered and are separated by a brief interval. By this means a double exposure is created in each video frame.Real-time visualization of opening and closing velocities over the entire length of the vocal fold from anterior to posterior is possible. Quantification is possible off-line after image calibration. CONCLUSION: Short-interval, color-filtered double-strobe flash stroboscopy allows quantitative measurement of the velocity of vocal fold movements during vibration at different pitches and sound pressure levels (SPL). Images gained with this new technique provide information about a dynamic property (velocity) of the vocal fold within a single image.Therefore, its use could be helpful from the aspect of clinical documentation.

Artifacts↗
PubMed1996

The role of stroboscopy in the management of a patient with a unilateral vocal fold paralysis.

Stroboscopy is well established as an essential diagnostic tool in the assessment of the vocal folds during phonation. This paper analyses the stroboscopic findings in 100 patients with a unilateral vocal fold paralysis. Reliable stroboscopic signals were only obtained in patients with the paralysed fold close to the midline. These patients seldom require surgery however, usually responding to speech therapy with laryngeal compensation giving a good voice. Most patients that require surgery have a large glottal deficiency, but in this series these patients did not give an adequate signal for analysis. Although useful in the assessment of the muscle tone of the paralysed fold, the influence of stroboscopy on the surgical treatment in this series was limited.

Evaluation Studies as Topic↗
PubMed1995

Glottal area and vibratory patterns studied with simultaneous stroboscopy, flow glottography, and electroglottography.

The purpose of the present study was to examine the relationship between variations in glottal area and vibratory patterns during phonation studied with stroboscopy and glottographic methods. Two normal speaking male and three female subjects were examined by means of simultaneous stroboscopy, flow glottography, and electroglottography. Estimations were made of the glottal area from pressure and flow data using the formula described by van den Berg. Significant correlations were found for the male phonations between estimations and measurements of the minimum glottal area (glottal insufficiency). Estimations of the peak glottal area were also significantly correlated to measured peak glottal area for values below 25 mm2. The estimated minimum area tended to be higher, whereas the estimated peak area values were lower than the corresponding glottal area measurements. This might be explained by variations in glottal and supraglottal geometry for different modes of phonation and by sub- and supraglottal acoustic interaction. Several glottographic parameters for the male phonations were highly correlated with the measurements of glottal insufficiency and also differed significantly between normal, pressed, and breathy hypofunctional modes of phonation. The presence of a hump in the first part of the closed phase for the flow glottogram seems to indicate that a clearly visible mucosal wave is present during vocal fold vibration.

Electric Stimulation↗
PubMed1991

[The value of indirect microlaryngo-stroboscopy in the follow-up care of patients with vocal cord carcinoma treated with primary irradiation].

On the value of indirect Microlaryngo-stroboscopy in the follow-up of patients with vocal cord tumors having had primary radiotherapy: The technique of stroboscopy is explained, its weight in the evaluation of vocal cords vibration is discussed. Arrest of vibration may be a hint for a malignoma, particularly if this state develops again after radiotherapy.

Humans↗
PubMed2001

Analysis of vocal fold vibration by x-ray stroboscopy with multiple markers.

OBJECTIVE: To derive a more precise description of vocal fold vibration, experimental phonation of excised canine larynxes was studied. STUDY DESIGN AND SETTING: Multiple X-ray-positive markers were inserted, and their vibratory movement was observed with x-ray stroboscopy with change of pitch and intensity. A histologic study was also carried out. RESULT: Regular waves were observed just above the lowest point of the lamina propria of the mucous membrane, which shifted upward at high pitch, but downward in high intensity. CONCLUSIONS: The starting point of the mucosal wave was confirmed on the lower surface of the vocal fold, histologically just above the lowest point of the lamina propria of the mucous membrane and shifted upward at high pitch, but downward in high intensity. SIGNIFICANCE: This is the first study investigating the starting point of mucosal wave in vocal fold vibration in a frontal plane using x-ray stroboscopy, providing the evidence for the body-cover theory.

Animals↗
PubMed2002

Imaging of the larynx--extending the use of stroboscopy-related techniques.

Three methods (I-III) are presented to demonstrate how technical modifications in the use of stroboscopy-related techniques can be applied to further analyze vocal fold vibrations. (I) With double exposure videostroboscopy, dynamic properties of vocal folds can be visualized within one single image. This allows for estimations of horizontal vibratory velocity of the vocal fold margins. (II) Stroboscopic transillumination of the larynx makes it possible to localize initial vocal fold opening in the horizontal glottal plane and to visualize different vibratory opening patterns. Bidirectional color-coded endoscopic imaging of the larynx facilitates a semi-automated, digital measurement of the glottal area. (III) Stroboscopic illumination using four light emitting diodes (LEDs) clipped on a rigid endoscope and triggered by a portable 'pocket-sized', battery-powered electronic control device offers new prospects for performing stroboscopy outside of specialized clinical facilities.

Humans↗
PubMedDate not supplied

The relevance of stroboscopy in functional dysphonias(1).

OBJECTIVES: Functional dysphonias are disorders of the voice characterized by sound and efficiency disturbances of the voice without any organic changes of structures being detectable. At present, functional dysphonias are generally subclassified into hyper- and hypofunctional dysphonias in clinical practice. STUDY DESIGN: The study was designed for a critical evaluation of the relevance of stroboscopy to the diagnostics and classification of functional dysphonias. METHODS: 45 patients were examined (27 hyperfunctional, 15 hypofunctional and 3 mixed type) using videostroboscopy. Several stroboscopic parameters were taken into consideration. Three geometrical and three time-dependent parameters were first analyzed in a uni- and multidimensional way, then cluster analyses were performed. RESULTS: We could not confirm the clinical subdivision into hyper- and hypofunctional dysphonias as based on anamnestic data, perceptual evaluation of voice sound, voice profile measurements and videostroboscopy. Quantitative measurements of selected parameters did not correlate with qualitative subjective stroboscopic assessment. In addition to this, it was not possible to identify separate clusters of stroboscopic findings. CONCLUSIONS: The results do not deny the clinical relevance of stroboscopy to the diagnostics of functional dysphonias as a very useful tool to exclude organic lesions. However, a reliable subclassification into different types of functional dysphonias was not possible.

Adolescent↗
PubMed1998

Larynx synchronised stroboscopy--a new tool for outcome measures in the voice clinic.

Direct vocal fold synchronised stroboscopy is a new technique for obtaining useful images of pathological voice, with reduced requirements for both vocal fold cycle regularity and the duration of sustained phonation. Precise synchronisation of the firing of the stroboscope from the Laryngograph waveform, and the capture of images and waveforms into a computer, allows inspection of short periods of phonation (less than one second) as a continuous replay of the images. Replay can be continued indefinitely, automatically repeating the short period of image capture, eliminating the need to rewind a video-tape repetitively. This in turn avoids the need for the lengthy phonation otherwise required when clinical examination is based on the use of conventional live or video-taped stroboscopy. Since the LxStrobe system is based on digital processing, archiving and retrieval of images is much enhanced. A demonstration of the system, called the LxStrobe, is available on the world-wide-web at www.laryngograph.com.

Electrodiagnosis↗
PubMed1998

A multi-media, computer-based method for stroboscopy rating training.

Methods of training individuals to rate stroboscopic examinations vary widely in rating criteria, viewing times, samples, and length of training. Consequently, problems occur in both inter- and intrajudge agreement. Computer-aided instruction (CAI) provides a means to integrate and control key learning factors that facilitate learning. This study attempted to determine if CAI could train individuals to make accurate and reliable visuo-perceptual judgments of stroboscopy. Experienced and inexperienced subjects rated 45 samples before and after training. Following 4 to 5 hours of CAI training, the subjects with no previous experience demonstrated improved interjudge agreement with a panel of expert raters. The training was not effective for the experienced group. Regardless of the rater's experience, the parameters that required evaluation of movement were more difficult to rate than those requiring only an assessment of structure.

Computer-Assisted Instruction↗
PubMed1999

A new stroboscopy rating form.

A newly developed stroboscopy rating form is presented. The evolution of the new form is discussed by focusing on how problems with another commonly used form led to its development. Interjudge agreement and intrajudge reliability data for the new rating form reveal that the parameters of phase closure, phase symmetry, and phase regularity remain difficult to rate even with the revised rating form.

Documentation↗
PubMed1993

Correlation between stroboscopy and electromyography in laryngeal paralysis.

Twenty patients with vocal fold motion impairment were reviewed to correlate the findings of electromyography (EMG) and stroboscopy. The causes of motion impairment were idiopathic, previous surgery with recurrent laryngeal nerve injury, neck and skull base trauma, and neoplasm. The EMG studies were analyzed to assess the status of innervation of the immobile vocal fold. The presence or absence of the mucosal wave prior to therapeutic intervention was determined with stroboscopic examination. Eight of 10 patients with EMG evidence of reinnervation or partial denervation were found to have mucosal waves, and 3 of 10 patients with EMG evidence of denervation were found to have mucosal waves. Six patients developed mucosal waves after surgical medialization, despite evidence of denervation by EMG criteria. These findings support the premise that tension and subglottic pressure, rather than status of innervation, determine the presence of the mucosal wave.

Adult↗
PubMedDate not supplied

[Video-stroboscopy, a method for exploration of laryngeal pathology].

The authors present the importance of stroboscopy in the larynx examination. They insist to prove the functional modifies of the voice specially at the singers also all patients who use the voice more frequently. This method permits to make a differential diagnosis between the inflammatory and tumoral diseases of the larynx.

Diagnosis, Differential↗