Thomas J. Fria

Otitis media with effusion in preschool children.

The incidence, prevalence, and natural history of otitis media with effusion (OME) and middle ear high negative pressure (HNP) were investigated in a group of 2 to 6 year old preschool children. The children were examined monthly over a two year period from September 1981 to August 1983. The middle ear status was assessed using a decision‐tree algorithm which combined the findings of pneumatic otoscopy, tympanometry, and acoustic reflex measurements. Fifty‐three percent of the children in the first year and 61% in the second year developed OME; also during the two years, HNP was documented in 66% of the children. Eighty percent of OME episodes lasted only two months. The prevalence of OME and HNP showed a seasonal variation and a strong association with the presence of upper respiratory infections (URIs). The incidence of OME was independent of age. These data indicate that OME and HNP are prevalent conditions with a high spontaneous recovery in the preschool population.

Identification of otitis media with effusion in children.

In an effort to establish the diagnostic value of otoscopy, tympanometry, and the middle ear (ME) muscle reflex in the identification of otitis media with effusion (OME), the diagnostic findings by these three methods were compared with the findings at myringotomy in 333 children (599 ears). The study showed that even experienced clinicians had some difficulty in identifying those ears with effusion (sensitivity) and had even greater difficulty in making a diagnosis of those ears without an effusion (specificity). However, tympanometry, employing patterns that have been validated with myringotomy findings, was found to be more accurate. On the other hand, assessment of the ME muscle reflex as a diagnostic method was unacceptable due to an extremely low specificity (52%). An algorithm derived from the combination of the three methods had highest sensitivity (97%) and specificity (90%).

Maturation of the Auditory Brain Stem Response (abr): Additional Perspectives

A retrospective, cross-sectional analysis of component latencies of the auditory brain stem response (ABR) was performed on 466 patients ranging in age from 30 weeks postconception to adulthood. The ontogeny of ABR component wave latencies was adequately described by two exponential curves having different slopes; the steeper curve represented an early, rapid maturation ending by 8 to 10 weeks post partum, and the ensuing, more gradual curve corresponded to developmental events which were completed by the beginning of the third year of extrauterine life. These observations conform to previous maturational concepts of peripheral versus central segments of the auditory pathway and to the gradual decrease in interwave latencies with increasing age. Unlike interwave latency, however, the ratio of the latencies of selected component waves was constant with increasing age. This was especially apparent in developing newborns less than 50 weeks postconception. The nonlinear bases of this phenomenon are outlined, and the insights which stem from this perspective are discussed.

Validation of an Automatic Otoadmittance Middle Ear Analyzer

Tympanometry and acoustic reflex measurements were performed with an automatic otoadmittance middle ear analyzer (MEA) on 40 otologically normal children and 172 children with a history of recurrent acute otitis media or otoscopic evidence of persistent otitis media with effusion (OME), or both. For children with OME, the measurements were taken within a one-hour period prior to myringotomy. Myringotomy findings were used to validate predictive schema aimed at determining admittance values associated with OME. Predictive accuracy was quantified with percent sensitivity and specificity values. The results show that the MEA demonstrated suitable diagnostic predictability, but this was significantly influenced by the schema chosen to interpret obtained admittance measures. The simple presence or absence of a tympanometric peak (regardless of gradient) yielded the highest sensitivity and specificity values, whereas the manufacturers suggested approach, with or without the acoustic reflex, was not as successful. The implications of these results are discussed.