Investigations of a pressure-sensitive theory of marginal velopharyngeal inadequacy.

PURPOSE: This two-part project was designed to test a pressure-sensitive theory of marginal velopharyngeal inadequacy (MPVI). Specifically, are select subgroups of children with MPVI perceived as hypernasal because they fail to achieve consistent closure during vowels and semivowels while demonstrating adequate closure during pressure consonants? METHODS: In part one, 36 children with cleft palate and other craniofacial anomalies were examined using a clinical assessment protocol that included nasometry and perceived ratings of hypernasal resonance. Children with nasalance percentages above threshold during low-pressure (LP) productions and below threshold for high-pressure (HP) productions were placed in one group (group 1), while children with nasalance percentages below threshold for both LP and HP sentences were placed in another (group 2). Children in the two groups were age- and sex-matched. In part two, endoscopic data were examined for 10 additional children who received nasometry, perceived hypernasal resonance scores, and videoendoscopy on the same day and who received higher mean nasalance measures during production of LP sentences than during production of HP sentences. RESULTS: The results of part one confirmed that children in group 1 were perceived as being significantly more hypernasal than children in group 2 (mean(group 1) = 2.17, mean(group 2) = 1.50; t = 2.75, p =.01). However, results of endoscopic testing failed to demonstrate a consistent observable physiologic pattern of velopharyngeal inadequacy that would confirm the theory that some patients with MVPI are perceived as being hypernasal because of difficulty achieving velopharyngeal closure during vowels and semivowels. CONCLUSIONS; The findings provide partial support for a pressure-sensitive theory of MVPI and demonstrate the value of using both HP and LP sentences to evaluate patients with MVPI.

Arytenoid adduction combined with Gore-Tex medialization thyroplasty.

OBJECTIVE: To describe the technique of combined Gore-Tex medialization thyroplasty with arytenoid adduction and to determine the long-term vocal outcome of patients treated for unilateral vocal cord paralysis with this procedure. STUDY DESIGN: A retrospective chart review and patient reevaluation for patients treated at The University of Iowa Hospitals and Clinics between May 1995 and June 1999. METHODS: The review addressed patient demographics, perioperative and long-term complications, and voice outcomes. Details of the surgical technique are provided within the manuscript. RESULTS: Seventy-two Gore-Tex medialization procedures were completed. Arytenoid adduction was included in 22 of these procedures. This subset of patients was compared with the patients treated with Gore-Tex alone. No major postoperative complications occurred in either group. Preoperative and postoperative voice and videostroboscopy data were available for 19 arytenoid adduction patients and 25 Gore-Tex alone patients. On a seven-point scale (6 [severely abnormal] --> 0 [normal voice]), the average patient rating of voice dysfunction improved from 4.2 to 1.6 (arytenoid adduction) and 4.5 to 2.8 (Gore-Tex alone). Maximum phonation time improved from 6.9 seconds to 16.7 seconds in the arytenoid adduction group. Subjective voice assessment employing the four-point GRBAS scale (3 [severely abnormal] --> 0 [normal]) identified average improvement from an overall grade of 2.1 to 0.8 arytenoid adduction and 2.2 to 1.5 in the Gore-Tex alone group. Improvement was identified in the vocal quality of breathiness from 1.9 to 0.2 (arytenoid adduction) and 1.9 to 0.9 (Gore-Tex alone). CONCLUSIONS: The combined technique of Gore-Tex medialization thyroplasty and arytenoid adduction provide functional results that appear to exceed the improvement attained with medialization alone.

Vocal fold paralysis secondary to cardiac countershock (cardioversion).

Application of electrical energy to the heart is effective in treating many dysrhythmias. There are, however, also disadvantages associated with cardioversion. Employment of external electrical current has been shown to induce epicardial and myocardial damage at the site of electrode application. We present the only case in the English literature of vocal fold paralysis in which the single identified associated event was cardioversion. In this case of temporary vocal fold paralysis, there was no invasive procedure to directly damage the nerve. Echocardiography of the patient revealed a large left atrium, placing the recurrent laryngeal nerve in an abnormal anatomic position where it was vulnerable to the electric current.

A classification scheme for paradoxical vocal cord motion.

Paradoxical vocal cord motion (PVCM) is characterized by the inappropriate adduction of the true vocal cords during inspiration. Multiple causes have been proposed for this group of disorders, which share the common finding of mobile vocal cords that adduct inappropriately during inspiration and cause stridor by approximation. Management of this group of disorders has been complicated by the lack of a classification scheme to include all types of PVCM. We propose that PVCM be classified according to its underlying etiology and recognize the following causes of the disorder: 1. brainstem compression; 2. cortical or upper motor neuron injury; 3. nuclear or lower motor neuron injury; 4. movement disorder; 5. gastroesophageal reflux; 6. factitious or malingering disorder; 7. somatization/conversion disorder. Case reports are presented to illustrate the characteristic features and diagnostic evaluation used in assessing patients with PVCM. Management varies depending on the cause of PVCM and entails speech therapy, pharmacologic therapy, behavioral modification, and/or surgical intervention. Recognition of the multiple causes of PVCM allows otolaryngologists to formulate well-directed diagnostic evaluation and treatment.

Comparison of fundamental frequency and perturbation measurements among three analysis systems.

The need for standardization of procedures in approaches to voice measurement has been recently emphasized. The purpose of this study was to determine the extent to which the acoustic perturbation measurements from three different analysis systems agree when standardized recording and analysis procedures are used. High-quality acoustic voice recordings from 20 patients were analyzed. The results showed that, although fundamental frequency measurements were in strong agreement among the three systems tested, frequency and amplitude perturbation measurements were not in agreement. The underlying approaches to perturbation measurement appeared to be sufficiently different to produce different results. An argument is made for a standardized set of acoustic signals representing normal, dysphonic, and synthesized voices with known characteristics to facilitate testing of new acoustic analysis systems and confirm measurement accuracy and sensitivity.

Nasometric discrimination of hypernasality and turbulent nasal airflow.

Agreement between nasalance measures and perception of nasality during speech is not consistently strong. A possible reason may be the complicating combined effects of nasal turbulent airflow and nasal resonance. The purpose of this preliminary study was to examine nasalance measures obtained during production of a low pressure speech sample designed to minimize or eliminate the effects of turbulent nasal airflow. The results showed that nasalance measures obtained as some of the subjects produced the new speech sample were significantly different from those obtained when the standard high pressure speech sample was used. Use of both the new low pressure samples and the standard high pressure samples may result in improved agreement between nasalance measures and ratings of speech nasality as well as assist in the identification of subgroups of patients with marginal velopharyngeal insufficiency.

Acoustic rhinometric measurements of changes in velar positioning.

Acoustic rhinometry as a means to detect changes in velar position was examined in this study. Videofluoroscopic recordings were made of two normal speakers maintaining velopharyngeal open and velopharyngeal closed (silent /f/) targets. Simultaneous acoustic rhinometric recordings were made during the production of each stimulus. Determinations of changes in velar positioning during the closed samples were made from fluoroscopic recordings and compared to nasal cavity-nasopharynx changes detected by rhinometry. The excellent agreement between the measures from the two procedures (less than 1 cm) indicates that acoustic rhinometry is capable of detecting changes in velar positioning during "silent" speech. Implications for assessment and future research are discussed.

Integrated endoscopic/photodetector evaluation of velopharyngeal function.

A new integrated videoendoscopic/photodetection system, including an endoscope with an internal instrument channel used for photodetection, was applied to the evaluation of velopharyngeal closure in a subject with marginal velopharyngeal insufficiency (VPI) and in a subject with no speech disorder. Acoustic and aerodynamic speech assessments were used to establish the severity of velopharyngeal impairment in the marginal VPI patient. A light-out condition was used to establish the photodetector criterion for closure. The new system was effective for providing detailed phonetic assessment of velopharyngeal closure. Variations in degree of closure during select oral and nasal consonant productions were identified in the VPI subject but not in the normal speaking subject. The data show that important details of velopharyngeal insufficiency can be identified using the integrated endoscopic/photodetection system.

Videoendoscopy and photodetection: linearity of a new integrated system.

Simultaneous videoendoscopy and photodetection has potential for improving the assessment of changes in velopharyngeal (VP) movements and closure over time during speech. The purpose of this project was to examine the linearity of a new system, including a pediatric bronchoscope with an internal instrument channel through which the photodetector fiber was positioned. The results led to the conclusion that the response of the new system was linear. However, further examination indicated that system positioning variables had important effects on the overall level of photodetector light detection. These observations confirm the importance of monitoring and controlling the position of the endoscope-photodetector apparatus in the nasopharynx when using the system to evaluate velopharyngeal movement and closure for speech.

Comparison of acoustic voice perturbation measures among three independent voice laboratories.

The purpose of this study was to compare jitter and shimmer data measured with three different analysis systems, the Visi-Pitch PC system (Pine Brook) and two systems based on minicomputers (Chicago and Denver), as a preliminary step toward establishing recording and analysis standards. The results show that, although similar hardware and software used at independent laboratories can yield similar findings, differences in recording hardware as well as recording and analysis procedures can result in important differences in perturbation findings. Jitter measurements obtained with the Visi-Pitch were not consistently in good agreement with jitter measurements obtained from the minicomputer systems due, in part, to an interaction between the Visi-Pitch internal filter selected during the recording process and the novel method of pitch period determination used in the Visi-Pitch. Magnitude of shimmer measurements differed between the two minicomputer systems, in part because of differences in amplitude resolution of the A/D converters and recording noise. The correlation between the two shimmer data sets was relatively high, however, indicating that relative changes across utterances were comparable in spite of magnitude differences.

Laryngeal perturbation analysis: minimum length of analysis window.

Laryngeal perturbation measures have been applied to the analysis of cycle-to-cycle changes in periodicity and amplitude of the acoustic voice signal for more than 25 years. Although such measures enjoy widespread clinical application, there is little agreement about basic methodology, including the length of signal to be analyzed. The purpose of this study was to examine changes in laryngeal perturbation measures as a function of length of signal analyzed in 18 subjects who complained of symptoms of possible laryngeal dysfunction. The results showed that as many as 190 cycles may be necessary before jitter asymptotes and as many as 130 cycles may be necessary before shimmer asymptotes. Pathological voices may require a longer analysis window for perturbation analysis than do nonpathological voices.

Standardization for the reporting of nasopharyngoscopy and multiview videofluoroscopy: a report from an International Working Group.

A multidisciplinary International Working Group of scientists was assembled to address the question of standardizing reporting techniques for multiview videofluoroscopy and nasopharyngoscopy, the generally accepted standards for direct observation of the velopharyngeal valve. This report is a first attempt to propose standards while seeking feedback from the readership in order to further develop a common methodology.

Variations in velar position over time: a nasal videoendoscopic study.

Changes in velar position during production of nonnasal speech in two adults were measured using field-by-field videoendoscopic tracking procedures. The data suggested that the changes in velar position were coordinated with syllable production. Peak velar displacement occurred during maximum oral closure for oral consonant production and was followed by lowering of velar position during vowel production. This pattern of velar movement was not altered by changes in speaking rate or by jaw fixation. The timing of peak velar elevation relative to peak intraoral air pressure and peak jaw elevation was also examined. Timing of peak velar displacement was statistically associated with timing of peak intraoral air pressure in one subject. The data are discussed with regard to the potential value of studying variations in velar position during nonnasal speech in patients with marginal velopharyngeal incompetence.

A comparison of photodetector and endoscopic evaluations of velopharyngeal function.

Simultaneous videoendoscopic and photodetection analyses were made of specific onset and offset times of velopharyngeal opening and closing in two normal speaking subjects. Both procedures were found to have acceptable measurement repeatability and to agree with each other when used to determine movement changes. It is felt that when used together, these techniques contribute to improved understanding of velopharyngeal activity during speech.

Synchronized videostroboscopic and electroglottographic examination of glottal opening.

Interpretation of electroglottography (EGG) as an index of glottal contact area has been complicated by difficulty obtaining independent validation measures. The purpose of this research was to implement a new simultaneous EGG/videostroboscopic technique for the evaluation of the relationship between a discontinuity in the opening phase of the EGG waveform with the onset of glottal opening viewed via videostroboscopy. The results support previous suggestions that this EGG discontinuity, when observed in nonpathologic individuals, usually marks the onset of glottal opening along the superior surface of the vocal folds.

Nasal videoendoscopy in prosthetic management of palatopharyngeal dysfunction.

Application of nasal videoendoscopic procedures simplifies and objectifies design of an obturator prosthesis. Although oral videoendoscopic techniques are also valuable, the nasal perspective provides valuable information not visible from the oral perspective. Because the primary function of the obturator prosthesis is to eliminate hypernasal speech and perceived nasal emission of air associated with palatopharyngeal insufficiency, nasal videoendoscopy should be considered to verify proper soft tissue-obturator contact during speech.

Longitudinal speech performance in patients with cleft palate: comparisons based on secondary management.

Speech performance of three groups of speakers with cleft palate was analyzed at two-year intervals from age 4 years through age 16 years. The three groups consisted of: Group A--individuals who score below 20 percent correct on the Iowa Pressure Articulation Test (IPAT) at 4 years of age and who received secondary surgery by 8 years of age; Group B--individuals who scored below 20 percent correct on the Iowa Pressure Articulation Test at 4 years of age, but did not receive secondary management by 8 years of age; and Group C--individuals who scored above 20 percent correct on the Iowa Pressure Articulation Test and who did not receive secondary surgery by 8 years of age. The results demonstrated that Group A performed better on several measures of speech performance at 16 years of age than either of the other groups. Also, speech performance appeared to become slightly worse around 12 years of age for Group B. This may be interpreted as evidence that this group may have been negatively affected by the physiologic changes associated with puberty. The other two groups did not appear to show this effect. The results of this study emphasize the need for careful research regarding patients who, in spite of early poor speech performance, are not considered candidates for early secondary management.

Multiview videoendoscopic evaluation of velopharyngeal physiology in 15 normal speakers.

Oral and nasal videoendoscopic procedures, when used in tandem, could provide a more useful analysis of velopharyngeal physiology than either procedure used alone. The purposes of this research were to document observed differences between the two approaches when applied to the examination of velopharyngeal function and to determine the advantages and disadvantages of using oral and nasal endoscopy as tandem diagnostic tools. The results indicated that patterns of velopharyngeal closure as observed from both the oral and nasal views are in approximately 60% agreement. Differences between the two perspectives most frequently involve the relative contributions of the pharyngeal walls. These differences are attributed to important physiologic variations along the vertical plane of the velopharynx. The data indicate that using oral and nasal videoendoscopy as tandem diagnostic procedures can result in improved understanding of velopharyngeal physiology. The issues of interference with speech movements and patient compliance are discussed.

Relationships between the perception of nasalization and speech movements in speakers with cleft palate.

The purpose of this study was to examine the relationships between several temporal measures of speech movements and perceived nasalization in speakers with cleft palate. Four adult subjects with repaired cleft palate were filmed using high-speed (100 frames/s) cinefluorography as they produced target syllables embedded in a carrier phrase. Perceived nasalization of each extracted acoustic target syllable was rated by 18 trained judges. Movements of the tongue tip, tongue dorsum, jaw, velar knee, velar tip, and posterior pharyngeal wall were plotted over time. Time of movement onsets and movement offsets was identified from the plots. Voice onset and offset times were identified from the synchronized acoustic recordings. The findings indicate that normally expected velopharyngeal movements occurred near the time of jaw-lowering onset during nasalized CVC and CVN productions in two subjects who were judged to exhibit high levels of nasalization. The other two subjects showed no velopharyngeal movements during the CVC production. It is speculated that velopharyngeal movements normally expected in CVC utterances may be avoided by some speakers with cleft palate in order to minimize perceptible nasalization.

Reliability of the nasopharyngeal fiberscope (NPF) for assessing velopharyngeal function: analysis by judgment.

The reliability and validity of data about velopharyngeal function obtained with the nasopharyngeal fiberscope was assessed in normal subjects. The experimental design included data reduction procedures that are likely to have clinical utility (clinical ratings). The results indicated that relative velar movement and size of the velopharyngeal port may be reliably and validly estimated using the procedures. However NPF estimates of lateral pharyngeal wall movement were not reliable. Finally, the data indicated that velar movement and size of V-P port were consistent within subjects and tasks across data collection sessions. Data about consistency of lateral wall movement across sessions was inconclusive, however. Additional research involving similar procedures with subjects who have morphologic deficits is indicated.