The role of laryngeal ultrasound in the assessment of pediatric dysphonia and stridor.

OBJECTIVES: Dysphonia and stridor are not infrequent in the pediatric population. Awake nasolaryngoscopy (ANL) is the primary diagnostic procedure used to evaluate a child with stridor and/or dysphonia. The major limitation of this technique is poor cooperation in children, resulting in inadequate visualization of the larynx. Ultrasound is a widely used noninvasive imaging modality that has yet to be applied to the laryngeal examination. Our goal was to investigate the feasibility and diagnostic potential of laryngeal ultrasound (LUS) in cases of pediatric stridor and/or dysphonia. METHODS: Prospective blinded cohort study of infants and children 0-16 years of age referred for ANL due to voice disorders and/or stridor. Prior knowledge of the etiology was considered an exclusion criterion. RESULTS: LUS concurred with the ANL in the diagnosis of abnormal vs normal larynx in 28/32 children that were recruited. LUS had a sensitivity and specificity of 87% (95% CI: 69%-96%) and 100% (95% CI: 16%-100%) respectively, for diagnosing overall laryngeal disorders in comparison to ANL. LUS also had an area under the receiver operating characteristic (ROC) curve (AUC) of 0.93, (P = 0.04, 95% CI: 0.84-1). CONCLUSION: LUS may be applied as an adjuvant diagnostic tool for ruling in laryngeal pathologies in children including dysphonia and stridor. As further experience is acquired the value of LUS in diagnosis will be better understood.

Clinical presentation, assessment, and management of inducible laryngeal obstruction.

PURPOSE OF REVIEW: Many aspects of inducible laryngeal obstruction (ILO) are still poorly understood. However, in recent years there have been advances made and an international consensus has achieved a standardized taxonomy. This review will synthesize recent research; specifically, relating to clinical presentation, assessment, and therapeutic interventions. RECENT FINDINGS: The evidence base is growing but still limited for ILO and mostly comprises retrospective reviews, case studies, and anecdotal reports. The proposed relationship between ILO and other manifestations of laryngeal dysfunction via laryngeal hypersensitivity and hyperresponsiveness warrants further investigation. Progress has been made with guidelines published on laryngoscopy reporting procedures and validated symptom questionnaires produced for clinical use, although diagnostic algorithms are yet to be established. Emerging conservative and surgical interventions show promise, although as yet there are no randomized controlled trials investigating treatment efficacy. SUMMARY: The field is in an embryonic state and key research priorities, acknowledged in the current literature, need to be addressed to positively impact patient care.

Delayed otolaryngology referral for voice disorders increases health care costs.

BACKGROUND: Despite the accepted role of laryngoscopy in assessing patients with laryngeal/voice disorders, controversy surrounds its timing. This study sought to determine how increased time from first primary care to first otolaryngology outpatient visit affected the health care costs of patients with laryngeal/voice disorders. METHODS: Retrospective analysis of a large, national administrative claims database was performed. Patients had an International Classification of Diseases, 9(th) Revision-coded diagnosis of a laryngeal/voice disorder; initially saw a primary care physician and, subsequently, an otolaryngologist as outpatients; and provided 6 months of follow-up data after the first otolaryngology evaluation. The outpatient health care costs accrued from the first primary care outpatient visit through the 6 months after the first otolaryngology outpatient visit were determined. RESULTS: There were 260,095 unique patients who saw a primary care physician as an outpatient for a laryngeal/voice disorder, with 8999 (3.5%) subsequently seeing an otolaryngologist and with 6 months postotolaryngology follow-up data. A generalized linear regression model revealed that, compared with patients who saw an otolaryngologist ≤1 month after the first primary care visit, patients in the >1-month and ≤3-months and >3-months time periods had relative mean cost increases of $271.34 (95% confidence interval $115.95-$426.73) and $711.38 (95% confidence interval $428.43-$993.34), respectively. CONCLUSIONS: Increased time from first primary care to first otolaryngology evaluation is associated with increased outpatient health care costs. Earlier otolaryngology examination may reduce health care expenditures in the evaluation and management of patients with laryngeal/voice disorders.

Assessment of effectiveness of acoustic analysis of voice for monitoring the evolution of vocal nodules after vocal treatment.

In the present study, we report the results of acoustic analysis of voice in 97 patients diagnosed with vocal nodules before and after the vocal logopedic treatment, to evaluate its effectiveness in monitoring the evolution. We analyzed five parameters: the mean fundamental frequency (F0) and its standard deviation, jitter, shimmer, and normalized noise energy (NNE). Our results indicate that most patients showed a reduction of fundamental frequency, an increase of perturbation (jitter and shimmer), and an increase of NNE before the treatment. We did not find any statistically significant relationship between previous values of the five parameters analyzed and the clinical course. We did not find significant differences between the two groups (with and without clinical improvement) in the evolution of any of the five parameters, although these differences were greater in the case of jitter. We conclude that the acoustic analysis of voice can be useful as a complementary tool in the diagnosis of vocal nodules, but the parameter values analyzed before treatment did not correlate with the clinical course and we believe that its usefulness in the evaluation of results after the vocal treatment is limited.

Update on pediatric voice and airway disorders: assessment and care.

PURPOSE OF REVIEW: To investigate the status of the recent literature focused on studying the assessment and treatment of pediatric voice and airway disorders using both established and novel techniques. RECENT FINDINGS: Recent research regarding voice assessment and treatment reveals the use of systematic and innovative approaches when collecting instrumental and perceptual voice data. There are recent advancements in certain surgical interventions designed to minimize complications. Wider use of functional endoscopic imaging of the pediatric larynx is improving our understanding of childhood voice production and airway management. There is also an important emerging focus on quantifying the impact of having a childhood voice disorder through the use of new tools. Although there is an increase in pediatric voice and airway research, many studies tend to be entirely descriptive rather than quantitative. There continues to be little specific research that uses prospective, longer-term and formal voice outcomes before and after behavioral and surgical interventions. SUMMARY: Pediatric voice and airway disorders are an important childhood health problem. Voice assessment in children should include formal perceptual and instrumental evaluations, including sophisticated acoustic, aerodynamic and imaging modalities. The care of these children requires a collaborative approach that includes systematic and innovative treatment methods.

Oscillometric assessment of airway obstruction in a mechanical model of vocal cord dysfunction.

Vocal cord dysfunction (VCD) is characterized by inappropriate adduction of the vocal cords, particularly during inspiration, resulting in obstruction and airflow limitation. Direct visualization of the vocal cords with laryngoscopy is the 'gold standard' for diagnosing VCD. However, it is an invasive technique that may induce airway irritation. The aim of this study was to determine whether the forced oscillation technique (FOT) is useful to estimate the degree of closure of a non-linear orifice under conditions mimicking those found in VCD. The FOT (5 Hz, +/-1 cm H(2)O) was applied to an airway model simultaneously with constant levels of flow in the normal breathing range (0-0.8l/s). Pressure-flow (P(0)-V'(0)) curves, quasi-static resistance (R(eff)) and oscillatory resistance (R(FOT)) were measured in orifices with different areas (0.15-1.12 cm2) and shapes and in an orifice with variable area. Their pressure-flow relationship followed a quadratic model. Changes in R(FOT) normalized by flow (DeltaR(FOT)/V'(0)) were related to changes in the area of the vocal cord model (1/A(VC2)(2)-1/A(VC1)(2)) from maximum aperture (A(VC1)) to different degrees of closure (A(VC2)): DeltaR(FOT)/V'(0)=1.93(1/A(VC2)(2)-1/A(VC1)(2))+2.08 cm H(2)Os(2)/l(2); r(2)=0.99. We conclude that FOT could be a useful tool for non-invasively assessing glottic closure in VCD diagnosis, obviating the need for other invasive techniques.

Results of magnetic resonance imaging assessment, acoustic analysis, phonatory function and perceptual rating of glottic insufficiency before and after fat augmentation: correlated with subjective rating.

Autogenous fat augmentation has been proven effective in the treatment of glottic insufficiency (GI) using both subjective and objective methods of evaluation. However, no information is available in published research regarding the effectiveness and predictability of value parameters with regard to patients' perceptions and concerns. This article retrospectively examines the correlation between subjective and objective examinations and subjective ratings (SRs) in patients with presbylaryngis (n = 14) and sulcus vocalis (n = 2). Acoustic analysis, phonatory function, magnetic resonance imaging (MRI) assessment, and perceptual rating data were evaluated against SRs using pre- and postoperative test results in 16 patients. The mean time over which subjective and objective examinations were performed was 10 months. Twelve patients reported excellent results, while no change was observed in 4 patients. When compared against SR, the kappa value of jitter, shimmer, harmonic to noise ratio, phonation time, grade, roughness, breathiness, and MRI were 0.25, 0, -0.08, -0.11, -0.11, 0.18, 0, and 1, respectively. The agreement between the MRI and SR values was complete, and was the only relationship shown to be significant (p < 0.001). MRI assessment is an effective and reliable examination tool which can be considered for use in assessing the progress of the post-fat injection operation in GI patients during follow-up examinations. Furthermore, due to the excellent agreement between MRI assessment and the patients' subjective feelings, the SR value may serve as a good index of fat survival.

Neonatal upper airway assessment by awake flexible laryngoscopy.

Awake flexible laryngoscopy (AFL) provides simple and quick assessment of both the structure and function of the upper airway. To determine its value in neonates, a prospective study was carried out over 2 years of 110 neonates (80 term, 30 premature) under 6 weeks of age (corrected for prematurity) presenting with symptoms suggestive of upper airway disease who underwent AFL performed by the author. A diagnosis was made in 79 cases, while no cause was found for the symptoms in 31. The commonest diagnoses were vocal cord paralysis (29; bilateral 16, unilateral 13), nasal stenosis (9), laryngomalacia (9), glossoptosis (7), subglottic stenosis (6), and choanal atresia (5; bilateral 2, unilateral 3). The AFL was repeated in 31 neonates and the condition was found to be stable in 16, improved in 8, resolved in 2, and progressed in 1, and an additional diagnosis was made in 4. Endoscopy under general anesthesia with or without corrective surgery was performed in 15 neonates (7 also having repeat AFL). The diagnosis was confirmed in 14 and an additional tracheal abnormality was found in 1. The AFL was complicated by cyanosis in 2 neonates and epistaxis in 1, but all complications resolved with minimal intervention. These data suggest that the neonatal upper airway can be relatively safely and reliably assessed by AFL performed by an experienced clinician.

Incidence and management of airway problems in the CHARGE Association.

The airway problems associated with anaesthesia in patients with the CHARGE Association have been underreported. We undertook a retrospective review of 50 cases, of which anaesthetic records were available for 37 patients. Apart from choanal atresia and cleft lip and palate, 56% of patients has some other upper airway abnormality. There appeared to be greater difficulty in tracheal intubation with increase in age in four patients. The incidence and management of airway abnormalities are discussed.

Objective assessment of vocal hyperfunction: an experimental framework and initial results.

This report describes the experimental design and initial results of an ongoing clinical investigation of voice disorders. Its major focus is the development and use of quantitative measures to provide objective descriptions of conditions referred to as "vocal hyperfunction." The experimental design for this project is based on a descriptive theoretical framework, which holds that there are different types and stages of hyperfunctionally related voice disorders. Data consist of indirect measures derived from noninvasive aerodynamic and acoustic recordings including (a) parameters derived from inverse filtered approximations of the glottal air flow waveform; (b) estimates of transglottal pressure, average glottal air flow, glottal resistance and vocal efficiency; and (c) measures of vocal intensity and fundamental frequency. Initial results (based on comparisons among 15 voice patients and 45 normal speakers) support major assumptions that underlie the theoretical framework, and indicate that the measurement approach being utilized is capable of differentiating hyperfunctional from normal voices and hyperfunctional conditions from one another. Organic manifestations of vocal hyperfunction (nodules, polyps, contact ulcers) are accompanied by abnormally high values for the glottal waveform parameters of AC flow and maximum flow declination rate, suggesting increased potential for vocal fold trauma due to high vocal fold closure velocities and collision forces. In contrast, nonorganic manifestations of hyperfunction (functional disorders) tend to be associated with abnormally high levels of unmodulated DC flow, without high values for AC flow and maximum flow declination rate, suggesting reduced potential for vocal fold trauma. Measures also suggest different underlying mechanisms for nodules and polyps as compared to contact ulcers. Results are discussed relative to predictions based on the theoretical framework for vocal hyperfunction.