Auditory screening of preschool children with impedance audiometry--a comparison with pure tone audiometry. Detecting otologic disease prior to the onset of hearing loss

Otitis Media and Child Development

Otitis media with effusion (OME) is the major cause of auditory dysfunction in preschool and early-grade schoolchildren. At especially high risk are children with cleft palate/lip; some groups of mentally retarded children; children from underprivileged communities and children with severe or profound sensorineural hearing loss. In neonates the major concern is to identify those with severe sensorineural hearing loss but awareness of the likelihood of OME is also vital. The hearing loss associated with OME in its early stages may be as small as 10–15 dB and in consequence conventional hearing tests employing pure tones are inadequate as screening procedures. Acoustic impedance testing has proved to be a practicable, acceptable, sensitive and efficient method of identification of OME in infants and children. Impedance measurement cannot, as yet, provide accurate assessment of hearing loss, but this is probably not a serious drawback. The primary requirement is to detect OME in order that swift and effective treatment can be instituted.

Accuracy of the Welch Allyn AudioScope and traditional hearing screening for children with known hearing loss

The Welch Allyn AudioScope is a new screening instrument that allows both audiometric testing at 500, 1000, 2000, and 4000 Hz at 25 dB hearing level and otoscopic examination. Sixty-eight patients between 3 and 9 years of age with normal hearing or a variety of hearing losses comprised the study population. Immediately after receiving an audiologic evaluation the subjects were screened with a traditional screening audiometer and two examinations with the AudioScope, performed in a clinic examining room by pediatricians and nurse practitioners unaware of the children's hearing status. The AudioScope was as accurate as traditional hearing screening in identifying children with normal hearing and those with hearing loss. Log-linear modeling demonstrated that the results of AudioScope testing were similar to those of traditional hearing screening. However, the false positive rate was higher at 500 Hz for the first AudioScope examination, suggesting the need for two AudioScope tests. The AudioScope was quick and easy to use, nonthreatening to the subjects, less expensive than a pure-tone screening audiometer, and does not require a sound-treated room.

Effect of upper respiratory tract infection on eustachian tube ventilatory function in the preschool child

A prospective tympanometric and microbiologic study of 28 pre-schoolchildren was undertaken to better define the effect of acute URI on induction of eustachian tube dysfunction. Significant negative middle ear pressure was present in 12.7% of tympanograms from well children. However, abnormal tympanograms were detected during 74.7% of acute URIs. The abnormality was present on day 1 or 2 of illness in the majority of cases; 10.1% of illnesses were complicated by OME. Respiratory viruses or Sp were etiologically implicated in 40.5% of illnesses; isolation rates of Pn and HF from well and ill children were similar. Although colonization of the nasopharynx of well children with Pn or HF was associated with a higher incidence of abnormal middle ear pressure, colonization with Pn or HF during URI did not influence the frequency of tympanogram abnormality.

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.

Deafness after bacterial meningitis

Seventeen children with previous bacterial meningitis and 17 sib controls were examined clinically and otoscopically. They were also tested with air-conduction and bone-conduction audiometry and evaluated by tympanometry. There were no major neurological abnormalities and few otoscopical signs of ear disease. 21% of the ears showed abnormalities on air-conduction audiometry but all were normal on bone-conduction audiometry. 30% had abnormal middle-ear pressures (more negative than 100 mm water) on tympanometry and 7% had abnormal compliance of the drum. There were no significant differences on any test between the postmeningitis children and the sib controls. Population studies have confirmed that minor hearing loss due to middle-ear dysfunction is common in children, but is probably temporary in most of them. We have found no excess of middle-ear dysfunction and no sensorineural deafness in these postmeningitis children, but other workers have shown that nerve deafness may occur in association with clinical neurological damage. However, much of the deafness attributed to bacterial meningitis in other studies may well reflect population variability.