An extension of the Jerger classification of tympanograms for ventilation tube patency--specification and evaluation of equivalent ear-canal volume criteria.

OBJECTIVE: To determine ventilation tube (VT) patency, or presence of an eardrum perforation, where otoscopy is not available or corroboration is required, tympanometry may be used, with a firm acoustical rationale. However, published literature shows little evidence that tympanometric criteria for patency have been optimized or are in routine clinical use. A randomized trial of VTs in otitis media with effusion offered large case numbers, assessed by uniform protocol, to define and evaluate a tympanometric patency criterion. DESIGN: Children had been randomized to one of three interventions (VT insertion with or without adjuvant adenoidectomy and nonsurgical observation). The study examines 165 left and 171 right ears with functioning VTs and 103 left and 102 right noninserted ears, in children aged 3 3/4 to 7 1/4 yrs at first postintervention visit. Experienced otolaryngologists judged VT patency otoscopically. Measured equivalent ear-canal volume (Veq) was compared across the VT-inserted and the not-inserted groups, and also within the VT-inserted group between the pre- and postintervention visits. With otoscopy as reference, patency coding errors in both VT-inserted and not-inserted groups were analyzed as a function of Veq. Three methods of determining optimum cutoff were considered: equal error (cross-over point of the errors in each group), equated "cost" of error (maximum summed sensitivity and specificity), and minimum combined error (determined from the minimum of a polynomial fitted to the mean of the errors in each group). Cutoffs were evaluated in terms of classification accuracy against otoscopy after intervention. RESULTS: The between-group comparison gave cutoffs by the three methods at Veq > or = 0.95 mL, Veq > or = 1.10 mL, and Veq > or = 1.33 mL, respectively, pooled to 1.13 mL. The same 1.13 mL was also found for the within-group comparison. The corresponding cutoffs for the pre- and postintervention difference in Veq occurred at 0.23, 0.44, and 0.39 mL, respectively, with a mean of 0.35 mL. Within the range studied, age did not influence Veq, nor the optimum Veq cutoff, but boys had significantly larger Veqs (by 0.09 mL) than girls. Raw Veq, pre- and postintervention Veq difference or a combination of these definitions differed little in accuracy of predicting otoscopic status. CONCLUSION: In 3 3/4 to 7 1/4 years olds, the Veq criteria for VT patency, based on rigorous and transparent derivations, offer a supplementary information source for clinical practice, as well as a sole objective marker in research. We recommend for general use the pooled mean cutoff at Veq > or = 1.13 mL, slightly higher than the 1.00 mL in the literature. The pooled pre- and postintervention difference Veq criterion was slightly lower than the 0.4 mL of Shanks et al. However, the extra effort in its use, alone or in combination with raw Veq, was not justified. Given the wide (flat-bottomed) error functions, users have the option of declaring slightly lower or higher cutoffs, reflecting differing "costs" on the two types of errors, e.g. penalizing false "patent" decisions more heavily.

Evaluation of middle ear function in young children: clinical guidelines for the use of 226- and 1,000-Hz tympanometry.

HYPOTHESIS: The aims of the study were to evaluate tympanometry with regard to age and classification system using two probe-tone frequencies and to provide clinical guidelines. METHODS: Six subject groups were included in the evaluation: (1) neonatal intensive care unit babies, (2) children younger than 3 months, (3) children 3 to 6 months old, (4) children 6 to 9 months old, (5) children 9 to 32 months old, and (6) adults. Hearing of all subjects was screened by means of auditory brainstem responses, transient-evoked otoacoustic emissions, or behavioral audiometry. Tympanograms, recorded with probe-tone frequencies of 226 and 1,000 Hz, were classified according to shape and middle ear pressure. Additionally, 1,000-Hz tympanograms were classified based on the Vanhuyse model of tympanometric shapes. Furthermore, tympanometric parameters equivalent ear canal volume, admittance value at +200 daPa, middle ear admittance, tympanometric peak pressure, and tympanometric width were calculated for each tympanogram. RESULTS: For clinical purposes, the visual admittance classification system was more suitable than the Vanhuyse model. Furthermore, in children younger than the age of 3 months, 1,000-Hz tympanometry was easier to interpret and more reliable than 226-Hz tympanometry. From the age of 9 months, 226-Hz tympanometry was more appropriate. In children between 3 and 9 months, the reliability of tympanometry was independent of probe-tone frequency. A two-stage evaluation with a 1,000- to 226-Hz tympanometry sequence was preferred because this reduced the total number of tests. CONCLUSION: The current study provides normative data and age-related guidelines for the use of tympanometry in clinical practice. These results have led to a successful implementation of 1,000-Hz tympanometry in neonatal hearing assessment.

Hipoacusia en niños evaluación y diagnostico / Hearing loss; in children evaluation and diagnosis

La consulta pediatrica ambulatoria cuenta con una pregunta secundaria a veces motivo de consulta principal, la cual es Dr. Mi hijo no habla todavia o bien, Dr. Mi hijo no habla claro. En muchos casos los pacientes son derivados al neurologo pediatra para satisfacer la pregunta, o directamente a profesionales fonoaudiologos, foniatras o terapistas del lenguaje y en otras oportunidades se aconseja observar y esperar. La hipoacusia es causa importante que dificulta la adquisicion normal del lenguaje en los niños, ademas de disfasias, deficiencia mental, autismo, epilepsias y mutismo selectivo. Se estudiaron en dos escuelas para hipoacusicos 102 casos, en los cuales pudimos ver y demostrar que la sospecha familiar esta por encima del primer año de vida; confirmar el diagnostico tarda de 1 a 3 años y el ingreso a las escuelas para programas de estimulacion temprana se retrasa por los motivos expuestos. Un 66 por ciento de los niños no recibieron ninguna terapia de apoyo extra a la ofrecida por la escuela, inclusive el 40 por ciento que usa audifonos. Tambien investigamos las causas de acuerdo al protocolo de riesgo de hipoacusia.

Middle ear involvement in children with chronic rheumatoid juvenile arthritis.

In a selected sample of patients affected by juvenile rheumatoid arthritis (JRA) little is known about middle ear involvement, even though many synovial joints are affected. Multifrequency tympanometry was used to measure admittance, conductance, susceptance and phase angle at different probe frequencies and resonant frequencies. In all, 35 children with JRA and a control group (30 children) were studied. Findings showed that mean resonant frequency values in all children with JRA were greater than in the control children. The multifrequency tympanometry parameters measured in acute JRA subjects are not different from parameters of remission JRA subjects except for a change in the phase angle. The changes found are due to involvement of the incudomalleolar and incudostapedial joints.

Impedanciometría como examen auxiliar para el diagnóstico topográfico de las hipoacusias en el Servicio de O.R.L. del Hospital Regional Honorio Delgado, 1993 - 1995 Arequipa

El presente fue un estudio de tipo retrospectivo, descriptivo, transversal, el cual se realizó con el objetivo de determinar la utilidad de la Impedanciometría para el diagnóstico topográfico de las hipoacusias para lo cual se consideraron a 90 pacientes de ambos sexos, que consultaron al Servicio de Otorrinolaringología del Hospital Regional Honorio Delgado, durante los años 1993 - 1995, que contaron con estudios impedanciométricos. En cuanto a los resultados obtenidos, se logró determinar que la hipoacusia y los acúfenos fueron los síntomas predominantes en la mayoria de los pacientes, la obstrucción nasal en frecuencia importante, siendo la adenoiditis hipertrófica la patología asociada más frecuentemente encontrada, y al realizar el examen físico se encontró que casi la mitad de oídos eran normales. Así mismo se recoleccionó los diagnósticos audiométricos y los resultados impedanciométricos, determinando la topografía de la hipoacucias a la utilidad de la Impedanciometría como examen auxiliar. En conclusión se logró demostrarla determinación de los diagnósticos topográficos de hipoacusias, además demostró la gran utilidad en pacientes en que por alguna circunstancia no se les pudo hacer audiometría. Esto se debe a que la Impedanciometría es un examen objetivo, no así la audiometría que es un examen subjetivo.

Modified schema for classifying positive-pressure tympanograms.

Tympanograms with peaks located in the high-positive air pressure range (greater than or equal to 50 mm H2O) are infrequently recorded in clinical practice and have been little discussed in the literature. Such tympanograms accounted for 1.2% of a series of 8,011 tympanograms recorded at various times from 1,556 subjects ranging in age from 7 months through 12 years. Correlations between otoscopic diagnoses and tympanometric findings in the case of 65 of the high-positive air pressure tympanograms form the basis of the present report. Of the 65 high-positive air pressure tympanograms, 51 showed relatively high compliance (less than or equal to 5.5 Madsen units), and of these 46 (90%) were associated with ears considered normal otoscopically. Fourteen of the high-positive air pressure tympanograms showed low compliance (greater than 5.5 Madsen units), and of these, six (43%) were associated with ears considered normal, six (43%) with ears showing signs of acute infection, and two (14%) with ears in which the presence of effusion seemed probable. A previously presented zonal schema for classifying tympanograms has been modified on the basis of these findings.

Prospective tympanometry in 3-year-old children. A study of the spontaneous course of tympanometry types in a nonselected population.

For six months we observed all 3-year-old children showing type B or C tympanograms at a prevalence study in a geographically limited area (372 ears or 37.2% of the screened total) to study the spontaneous course of middle ear effusions. A considerable test-retest stability was found only for type B. In type C, such stability was equally rare whether the middle ear pressure was highly or only slightly negative. Conversion to type A was observed in about 70% of cases. Ears having a middle ear pressure from -100 to -199 mm H2O almost always returned to normal. The tendency for a negative middle ear pressure or middle ear effusion to develop was the same for both sexes. Conversely, the prognosis of an effusion, once formed, differed significantly, with only girls showing a brief course. Accordingly, a sex-differentiated evaluation appears to be needed in preschool tympanometric screening, and should be included in all clinical considerations when middle ear effusion is demonstrated in young children.

Impedance screening for preschool children. State of the art.

As a test for detecting middle ear disease among preschool children, tympanometry -- as opposed to audiometry -- has three advantageous attributes: a high degree of sensitivity, minimal need for subject cooperation, and total objectivity. For these reasons interest has arisen in tympanometry as a method for screening, i.e., identifying children with previously undetected middle ear disease. However, uncertainty persists concerning the importance of detecting apparently asymptomatic middle ear effusions, and concerning optimal methods, or even the advisability, of treating them. Further, the sensitivity and specificity of tympanometry depend on how the pass-fail cutoff point is defined. Defining this cutoff point so as to achieve high sensitivity may result in excessively low specificity, with the production of large numbers of false-positives who then become overreferrals. Data are presented to show how the validity of the test may be increased to some extent by attention to the gradient of "negative-pressure" tympanograms. At the present time, given the various aforementioned uncertainties, and with adequate validation as to the presence or absence of disease often lacking in reported studies of impedance screening in preschool populations, the cumulative results of these studies do not warrant embarking on large-scale screening programs. What is needed instead is additional research to explore the issue further.

Tympanometry as a predictor of middle ear effusion.

Tympanometry is often used as a major component of medical referral criteria in both diagnostic audiometry and hearing screening programs. This use is based on an assumption that a relationship exists between the tympanogram type and the presence of middle ear effusion. The present investigation examined this relationship in 142 ears immediately prior to myringotomy. The results suggest that prediction of middle ear effusion on the basis of tympanometric data alone is difficult at best. The only exception is in the case of a flat tympanometric curve (type B), when a 90% occurrence of notable effusion was found. The clinical implications of these data are discussed.

Personal results, trial of classification and standardization in clinical impedancemetry.

The author analyzes the results obtained in clinical impedance testing of 2,799 ears by tympanometry and study of the acoustico-facial reflex. Impedance terminology is discussed and classified in an attempt to bring order to the results. Important findings include the high incidence of negative middle ear pressure in older, profoundly hard-of-hearing children.

[Personal results trial of classification and standardization in clinical impedancemetry (author's transl)]. / Essai de classification et de standardisation en impédancemétrie clinique. Résultats personnels.

The author analyses the results obtained in clinical impedancemetry for 2,799 ears: tympanometry and study of the acoustico-facial reflex. He proposes a trial of classification of the results. The author states the terminology to be used in impedancemetry according to the different probe tone frequencies of the clinical impedancemeters and the different acoustic stimulations systems in order to obtain the acoustico-facial reflex.