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PubMed1994

Noninvasive measurement of traveling wave velocity in the canine larynx.

Laryngologists have long recognized that assessment of the mucosal wave is an important part of laryngeal evaluation. This is the first report of a noninvasive measurement of vocal fold displacement velocity in an in vivo canine model. A newly developed calibrating endoscopic instrument capable of measuring distances on the vocal fold surface is described. Displacement velocity was determined in three dogs and compared to physiologic measures in the in vivo phonation model. The results indicate that the calculated displacement velocity is linearly proportional to traveling wave velocity and fundamental frequency. Because traveling wave velocity has been shown to reflect vocal fold stiffness, this method may advance the usefulness of stroboscopy for the study of mucosal wave abnormalities.

Animals↗
PubMed1995

Clinical measurement of mucosal wave velocity using simultaneous photoglottography and laryngostroboscopy.

Simultaneous glottal transillumination or photoglottography (PGG), electroglottography (EGG), and video laryngostroboscopy were used to measure the traveling wave velocity of the vibrating vocal folds during phonation in human subjects. The duration of travel was calibrated from the PGG signal, while the displacement of the upper and lower lips of the vibrating vocal folds was calibrated from parallel laser beams projected onto the vocal folds. The mucosal wave velocity varied with the portion of the glottal cycle. The amplitude of displacement correlated positively with the intensity of phonation and negatively with the fundamental frequency and was decreased for breathy and pressed phonation modes. The velocity of the opening phase segment of the PGG signal directly correlated with the top lip displacement of the vibrating vocal fold, and bottom lip displacement correlated with the closing phase of the PGG signal. Therefore, with suitable calibration, the effects of mucosal lateral displacement may be measured from a PGG signal. Simultaneous measures of PGG, EGG, and stroboscopy provide a three-dimensional representation of glottal vibration that can be numerically analyzed.

Adult↗
PubMed1997

Vocal function following vertical hemilaryngectomy: comparison of four reconstruction techniques in the canine.

The goals of laryngeal reconstruction have been prevention of aspiration, production of a functional voice, and maintenance of an adequate airway for decannulation. A number of procedures for partial laryngeal reconstruction have accomplished these objectives. However, few studies have attempted to compare patients' vocal characteristics following different reconstruction procedures. In this study, an in vivo canine model was used to compare acoustic and aerodynamic measures of vocal function for the following vertical hemilaryngectomy reconstruction techniques: 1) a superiorly based sternohyoid muscle flap, 2) a modified epiglottic laryngoplasty, 3) a new procedure using a layered vascularized buccal mucosal flap and a transversely oriented sternohyoid muscle flap, and 4) hemilaryngeal transplantation combined with arytenoid adduction. Hemitransplantation provided the most efficient phonation of the four techniques. The vascularized buccal mucosa flap produced the best phonation of the autologous tissue techniques examined. Both vascularized buccal mucosa flap and hemilaryngeal transplantation subjects demonstrated a mucosal wave on stroboscopy. The results indicate that vocal function will improve as the layered structure of the vocal fold is more accurately replicated in a reconstructed hemilarynx. Endoscopic findings and whole organ sections are presented.

Animals↗
PubMed1999

Ectasias and varices of the vocal fold: clearing the striking zone.

Vascular malformations such as ectasias and varices (Es and Vs) are frequently encountered in patients who present with recurrent vocal fold hemorrhage and/or other traumatic vocal fold lesions. This study examined Es and Vs with regard to their anatomic presentation, phonomicrosurgical management, and treatment outcome. Forty-two patients (39 of them singers) were treated for a total of 87 Es and Vs: 67 of 87 (77%) were on the superior surface of the vocal fold and 20 of 87 (23%) were on the medial surface of the vocal fold. Eighty-three percent were located in the middle musculomembranous region (the striking zone), where the greatest aerodynamically induced shearing stresses occur during phonation. Treatment was performed with carbon dioxide laser cauterization (13 patients), or a new technique utilizing cold instrument excision by means of epithelial cordotomies (23 patients), while a combined approach was employed in 6 patients. Comparisons of preoperative and postoperative stroboscopy revealed improvement or no significant change in all patients in whom the cold instrument technique was used, and increased epithelial stiffness was noted in 4 of 19 patients in whom the carbon dioxide laser was used. Clearing the striking zone appears to have halted further hemorrhages by removing the the fragile Es and Vs from this injury-prone region of the vocal fold. Interpretations of stroboscopic examinations were directed at providing new insights into the biomechanical forces of vocal fold vibration that probably contribute to the genesis of Es and Vs in the vocal folds.

Adolescent↗
PubMed1999

Correcting vocal fold immobility by autologous collagen injection for voice rehabilitation. A short-term study.

We report on a short-term clinical study of injectable autologous collagen (Vocalogen) used to correct dysphonias arising from vocal fold immobility. The collagen is extracted from skin taken from the lower abdominal quadrant area or from just above the bikini line. About 30 cm2 of skin are required to provide 2 mL of injectable collagen. The histologic examination of the preparation before injection disclosed the presence of elastin fibers and some clusters of epithelial cells, beside the collagen fibers. The collagen is naturally reticulated, and the molecule is preserved in its entirety. The technique is exactly the same as that reported for bovine collagen: injection into Reinke's space, under general anesthesia, monitored by direct microlaryngoscopy. The amount injected is also similar: 1.5 mL for correction of glottic insufficiency in which the immobile vocal fold is in the intermediate position. Eight patients were injected, and the average follow-up was 4.5 months. Voice assessments made before and after the treatment included stroboscopy, subjective and perceptual judgments, and aerodynamic and acoustic measurements. The functional results were similar to those obtained with bovine collagen. No complications arose. The probability of any hypersensitivity reaction, always a possibility to be feared with bovine collagen, is negligible with the autologous collagen. Long-term results are as yet unknown, but from the fact that the collagen molecular structure is intact and there is little risk of foreign body response, it would be expected that autologous preparations would be more stable than bovine collagen; this appears to be the case in cosmetic applications. Autologous collagen could be employed for the same indications as bovine collagen, provided that a delay of 45 days (the time required to prepare the injectable collagen) is acceptable. The amount of collagen required is also a limiting factor, since the patient's own skin is the starting donor material.

Aged↗
PubMed1990

Indirect laryngoscopic approach for injection of botulinum toxin in spasmodic dysphonia.

Spasmodic dysphonia is a focal dystonia that causes a loss of the fine control of intrinsic laryngeal muscles and produces a strained staccato voice. Temporary relief from symptoms has been reported in patients treated with botulinum toxin percutaneously injected into the thyroarytenoid muscle. A newly developed method of treatment differs from reported methods by increasing the accuracy of botulinum toxin placement, reducing soft tissue trauma, and applying basic scientific information about the functional histology of intrinsic laryngeal musculature. Sixteen patients with primarily adductor spasmodic dysphonia were treated. Initial assessment included laryngeal examination by indirect laryngoscopy, videoendoscopy, and stroboscopy, neurology examination (including laryngeal EMG), and vocal function studies with acoustic analysis and aerodynamic studies. A device originally designed for collagen injection allowed the precise microdelivery of toxin to the thyroarytenoid muscle. Indirect laryngoscopy was used to direct the needle, in an attempt to cover a broad area of motor end plates. The minimally effective dose was titrated for each patient, to avoid paralysis and preserve laryngeal function. All patients showed improved voices after treatment. There were no major complications. The basic technique can be performed in the otolaryngologist's office and does not require electromyography equipment or expertise.

Adult↗
PubMed2006

Does the timing of tracheal intubation based on neuromuscular monitoring decrease laryngeal injury? A randomized, prospective, controlled trial.

Vocal cord injuries (VCI) and postoperative hoarseness (PH) are common complications after general anesthesia. Poor muscle relaxation at the moment of tracheal intubation may result in VCI. There is a large interindividual variation in neuromuscular depression after administration of neuromuscular blocking drugs. Therefore, the optimal individual timing of tracheal intubation based on neuromuscular monitoring (monitoring) may decrease VCI. In this prospective trial, 60 patients were randomized into 2 groups: Monitoring group: tracheal intubation at maximum block based on monitoring after atracurium 0.5 mg/kg and 2-min group: tracheal intubation 2 min after injection of atracurium 0.5 mg/kg. Intubating conditions were evaluated with the Copenhagen score. VCI were examined by stroboscopy before and 24 and 72 h after surgery. PH was assessed at 24, 48, and 72 h after surgery by a standardized interview. Excellent intubating conditions were significantly increased in the monitoring group compared with the 2-min group: 8 versus 2 patients, respectively (P = 0.036). The incidence of PH between the study groups was comparable: 7 (monitoring) versus 8 patients (2-min) (P = 0.860). Similar findings were observed for VCI: 9 versus 5 patients; respectively (P = 0.268); type of VCI: thickening of the vocal cords: 8 (monitoring) versus 5 (2-min) patients (P = 0.423), hematomas: 2 patients in each group (not significant). The present study demonstrated that neuromuscular monitoring improved endotracheal intubating conditions. However, tracheal intubation at maximum intensity of neuromuscular block was not associated with a decrease in vocal cord injuries.

Adult↗
PubMed2006

Rocuronium is not associated with more vocal cord injuries than succinylcholine after rapid-sequence induction: a randomized, prospective, controlled trial.

Postoperative hoarseness (PH), sore throat (ST), and vocal cord injuries (VCI) are common complications after general anesthesia. Excellent endotracheal intubating conditions are associated with less laryngeal morbidity than good or poor intubating conditions. Thus, we tested the hypothesis that a rapid-sequence induction (RSI) with succinylcholine would lead to less PH and VCI than with rocuronium. In this prospective trial, 160 patients were randomized in 2 groups to receive thiopental 5.0 mg/kg, fentanyl 3.0 microg/kg, succinylcholine 1.0 mg/kg, or rocuronium 0.6 mg/kg during RSI. PH and ST were assessed at 24, 48, and 72 h after surgery, VCI were examined by stroboscopy in those patients who had PH >3 days. Excellent and clinically acceptable intubating conditions were significantly increased in the succinylcholine group compared with the rocuronium group: 57% versus 21% and 89% versus 59%, respectively (P < 0.001). The incidence and severity of PH, and VCI between the succinylcholine and the rocuronium groups did not differ significantly: PH: 50% versus 51% (P = 0.99) and VCI: 3% versus 1% (P = 0.98), respectively. Similar findings were found for ST, 39% versus 28% (P = 0.22), and postoperative myalgia, 39% versus 29% (P = 0.25), respectively. Intubating conditions were significantly better in the succinylcholine group compared with the rocuronium group. The incidence and severity of ST and myalgia were not increased in the patients receiving succinylcholine. However, the rate of PH and VCI was similar to the rocuronium group.

Aged↗
PubMed2004

Botulinum toxin: helpful adjunct to early resolution of laryngeal granulomas.

Treating laryngopharyngeal reflux is the most accepted treatment for laryngeal granulomas. However, response to this treatment is prolonged and in some cases persistent. The authors hypothesize that this is due to the continuous trauma to the mucoperichondrium from adduction of the vocal folds thus preventing regeneration of healthy mucosa. A prospective study was performed on six patients with laryngeal granulomas failing prolonged laryngopharyngeal reflux treatment, speech therapy, and surgical excisions. Botulinum toxin A was injected into the affected thyroarytenoid to reduce adduction trauma. Video-stroboscopy was used to assess response. A 50 per cent reduction in the size of the granulomas was noted within two weeks with a complete and permanent response within two to eight weeks in five out of six patients. One patient had an obstructing pyogenic granuloma that required excision and recurred after excision but responded to a repeated injection. The addition of a single injection of botulinum toxin A to the standard treatment expeditiously eliminated persistent and recurrent laryngeal granulomas.

Aged↗
PubMed1990

Effects of short-term endotracheal intubation on vocal function.

Transient voice change associated with endotracheal intubation has generally been attributed to vocal fold trauma. To assess the role of altered vocal fold function in transient voice change, a study was designed to evaluate the audioacoustic, endoscopic, and laryngostroboscopic characteristics of the postintubation voice. Vocal function of 10 patients undergoing short-term outpatient surgical procedures using general anesthesia and endotracheal intubation were studied preoperatively and postoperatively. A second group of 10 patients that did not have surgery or general anesthesia was used as an age-matched control. Fundamental frequency, frequency perturbation, electroglottography, endoscopy (including laryngeal stroboscopy), and subjective speech analysis by experienced listeners were used to assess vocal function. No consistent differences in fundamental frequency were observed, although patient-to-patient variation was marked. Statistically significant increases in cycle-to-cycle fundamental frequency variation (jitter) were found postoperatively in the majority of the postintubation patients (P less than 0.05). Electroglottography, laryngeal endoscopy, and stroboscopic laryngoscopy did not demonstrate consistent changes in glottic mucosal function. Listener judgments characterized the postintubation voice change by decreased intensity, increased roughness, and lowered affect without consistent changes in pitch. The perception of decreased affect in the voices (characterized by reduction in pitch variation, vocal stress, and increases in pause times) was a strong perceptual marker for change in the post-intubation voice. Objective measures of laryngeal function suggest that the glottic contribution to postintubation voice change is minimal and that this dysphonia is probably multifactorial.

Adolescent↗
PubMed1990

Vocal dysfunction following cricothyroidotomy: a prospective study.

Voice dysfunction is a known consequence of cricothyroidotomy, but few detailed analyses have been published. This study reports an investigation of voice function in 19 patients who underwent cricothyroidotomy during a 12-month period (54 were patients operated on, 29 survived the primary disease or injury, and 19 agreed to participate in the investigation). The patients were interviewed regarding signs of dysfunction of the cricothyroid muscles, or a diminished external tensor effect on the vocal folds. Laryngoscopy with a magnifying-angled endoscope, stroboscopy, phonetography, determination of mean speaking fundamental frequency, perceptual analysis of the voice, and electromyogram of the cricothyroid muscle were all performed. Four patients had signs of diminished external tensor effect on the vocal folds (mild or moderate voice dysfunction), 5 patients had other voice disorders, and 10 were classified as having normal voice. Elective cricothyroidotomy should be avoided in patients with professional or other activities that place heavy demands on the voice.

Adult↗
PubMed1994

Diagnosis and treatment of persistent dysphonia after laryngeal surgery: a retrospective analysis of 62 patients.

Sixty-two patients with persistent or recurrent dysphonia after laryngeal surgery underwent interdisciplinary voice evaluation, laryngostroboscopy, and objective measurements of vocal function. The causes of persistent dysphonia were attributed to vocal fold scarring (n = 22), residual mass lesion (n = 8), residual inflammation (n = 13), recurrent mass (n = 4), and hyperfunctional voice disorder (n = 7). Laryngoscopy often showed excessive ventricular compression and anterior-to-posterior laryngeal compression. Ventricular dysphonia was often a compensatory gesture in response to poorly mobile vocal fold membranes. Stroboscopy was able to document a number of abnormalities which included abnormalities of laryngeal configuration, vibratory asymmetry, reduction of amplitude, and mucosal wave. Using a diversified approach consisting of medical therapy, voice therapy, and repeat surgery, better vocal function was able to be restored in the majority of patients. An interdisciplinary approach to the dysphonic patient after laryngeal surgery was most useful in defining the pathology and refining a treatment rehabilitation program.

Adult↗
PubMed1999

Surgery for voice.

Preoperative assessment in a multidisciplinary voice clinic, using stroboscopy, is essential. In the treatment of benign vocal fold mucosal disorders precise phonosurgical techniques, using high magnification which respects the multilayered structured of the vocal fold, are mandatory. A paralysed vocal fold can be assessed by electromyography and medialization thyroplasty procedures offer excellent 'fine tuning' of the voice.

Contraindications↗
PubMed2002

Mucosal wave asymmetries in the clinical voice laboratory.

OBJECTIVE: Anecdotally, it has been observed that in some healthy middle-aged men, who have neither vocal complaints nor known vocal pathology, asymmetries of the mucosal wave exist when examined videostroboscopically. This may cause concern on the part of the otolaryngologist, who might consider mucosal wave asymmetries to be a forewarning of subclinical pathology and subject the patient to unnecessary, expensive, and anxiety-provoking investigations or interventions. The purpose of this study is to establish the presence of mucosal wave asymmetries in a healthy, asymptomatic subpopulation. Acoustic spectral analysis is also used to determine if the presence of subharmonics might be associated. STUDY DESIGN: A prospective, cohort study design was used. The population was randomly selected, healthy, asymptomatic, nonsmoking men aged 35 to 50 years. Each subject completed acoustic spectral analysis and a medical questionnaire, followed by videostroboscopic laryngeal examination. RESULTS: Thirty-seven percent of the subjects exhibited mucosal wave variations at stroboscopy, characterized as periodic lateral phase asymmetries. There was no association with the acoustic spectral parameters chosen. CONCLUSION: Mucosal wave asymmetries may be a variance of normal. The 37% found here is expected to be very significant. Mucosal wave asymmetries are likely to be far more common in the general population than previously believed. There have been few normative data published for variations of the mucosal wave specifically for epidemiologic purposes. These results establish a starting point and justification for the normative population studies under way at our institution. Clinically, in the absence of such data, otolaryngologists may overinterpret videostroboscopic findings, leading to unnecessary investigations or interventions.

Adult↗
PubMedDate not supplied

Acoustic analysis of pathological voice. Some results of clinical application.

Tape-recorded voices of 30 patients were acoustically analysed: 10 had glottic Tla carcinoma, 10 unilateral vocal fold polyp and 10 unilateral recurrent laryngeal nerve paralysis. The carcinoma cases were treated with laser surgery with/without radiotherapy, the polyp cases with endolaryngeal microsurgery and the paralysis cases with intrafold silicone injection. The acoustic analysis was conducted before and after the treatment for each patient. Three acoustic parameters, viz. pitch perturbation quotient (PPQ), amplitude perturbation quotient (APQ) and normalized noise energy (NNE), were employed. The results were as follows: (1) PPQ and APQ were greater in paralysis cases than in carcinoma and polyp cases; (2) none of the parameters was useful in differentiating the three disease groups investigated; (3) all three parameters proved to be useful in monitoring the effects of treatments; (4) all three parameters were positively correlated to the grade of hoarseness, rough and breathy quality of hoarseness, mean airflow rate and regularity of vocal fold vibration viewed under stroboscopy; (5) PPQ, APQ and NNE were positively related to each other.

Aged↗
PubMed1993

Variability analysis of Fo parameter in the voice of individuals with hearing disturbances.

The material of this investigation comprised a group of 18 patients with deep hypoacousis (over 70 dB) or complete deafness which, depending on the onset of the deafness, was divided into the 3 categories: congenital, early childhood to 3rd year of life, and postlingual. All of them underwent ENT, phoniatric and stroboscopy examinations; in 10, X-ray tomography of the larynx was also performed. The status of hearing ability was assessed by audiometric examinations using pure tones in air and bone conductions. The acoustic examinations comprising spectrographic and tonographic analyses were performed on an appropriate linguistic material including vowels, isolated words, sentences and reading text. The measurement of Fo was performed on isolated vowels. In order to characterise the degree and kind of periodicity disturbances the following parameters were estimated: the medium value of fundamental frequency, the range of Fo variability, the maximal change of period length from cycle to cycle, and its medium value (jitter). The results of the acoustic examinations revealed different degrees and kinds of periodicity disturbances depending on the depth of the hypoacousis and its onset.

Adult↗
PubMed1997

Stroboscopic observation of the larynx after radiation in patients with T1 glottic carcinoma.

We studied laryngeal video stroboscopy (LVS) system for evaluation of patients with glottic carcinoma (T1N0M0) before and after radiotherapy. There were 10 patients with T1 glottic squamous cell carcinoma (9 men and 1 woman) who received radiotherapy at the Hitachi General Hospital. We performed LVS before and after radiotherapy. The presence or absence of mucosal waves (MW) was particularly noted. No MW were present before radiotherapy but at 1-6 months after, MW gradually appeared. One year after radiotherapy all patients showed MW on LVS. In patients with glottic carcinoma MW recovered after radiation therapy. LVS may be useful for the clinical follow-up of post-radiation patients for early detection of recurrence of glottic carcinoma.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Analysis of vocal fold function in the miniswine model.

Correlation of the vocal fold vibratory pattern with the postoperative surgical wound should demonstrate to the laryngologist the critical depth of injury at which the functional voice would be adversely affected. An animal model was selected to study these changes. Twelve adult miniswine were operated on in this prospective study. The right true vocal fold was surgically altered; the left true vocal fold was the control. An interval of 6 weeks was allowed for healing, and then changes in vocal fold function were studied by stroboscopy, photography, voice recording, and electroglottography. Laryngectomy provided tissue for histopathological correlation. The results showed that injury at the junction of the lamina propria and vocalis muscle consistently caused significant vibratory dysfunction resulting in poor phonation.

Animals↗