Anita Bylander

Upper Respiratory Tract Infection and Eustachian Tube Function in Children

The Eustachian tube function was studied in 11 children (3-9 years of age) with and without upper respiratory tract infection ( URTI ). During URTI the active muscular opening function deteriorated and middle ear pressure weakened, whereas the passive pressure opening and closing levels, reflecting tubal closing forces, increased. These findings may explain the high frequency of transient episodes of middle ear underpressure and middle ear effusion (MEE) in children. In children with a primary tubal hypofunction due to poor muscular opening function, URTI may contribute to recurrent or persistent MEE.

Eustachian Tube Function in Normal Children and Adults

Eustachian tubal function was studied in 85 otologically healthy children, 3-12 years of age. Middle ear pressure and muscular opening function was measured by tympanometry performed in a pressure chamber, and the results were compared with those obtained from 92 normal adults. Children were found to have a less good muscular opening function and more negative middle ear pressures within wider ranges, compared with adults. Improvement was also seen in children with increasing age. The results seemed to indicate a relation between muscular opening function and middle ear pressure. Even if it were possible to grade the muscular opening function by means of the test procedure, it would still not be possible to define what should be regarded as normal or abnormal tubal function. This report is the first in a series of tubal function studies in normal children.

Changes in Eustachian Tube Function with Age in Children with Normal Ears: A Longiudinal Study

A longitudinal study of the Eustachian tube function by different pressure equilibration tests was performed during 11/2-3 years in 44 otologically healthy children, 3-12 years of age. The muscular opening function improved significantly with increasing age. The improvement was most frequent during pre-school ages (3-7 years). Also the tympanometrically measured middle ear pressure, related to the muscular opening function, tended to normalize during the follow-up study. The pressure opening and closing functions, reflecting the tubal closing forces, did not, however, change during the observation time. All the children with poorest muscular opening function at the initial test improved; none developed persistent middle ear disease during the follow-up. Using this standardized exhalation/inhalation test of the pressure equilibrating function of the tube it seems possible to grade the muscular opening function in a valid way. It is argued that the main cause of poor muscular opening function in children is not only due to anatomical differences of the skull base, the tube and peritubal structures but also to the immaturity of the neuromuscular system during childhood.

PRESSURE OPENING AND CLOSING FUNCTIONS OF THE EUSTACHIAN TUBE BY INFLATION AND DEFLATION IN CHILDREN AND ADULTS WITH NORMAL EARS

Different inflationary (e.g. Valsalvas) and deflationary (e.g. sniffing) manoeuvres were studied in 58 children and 61 adults, all otologically healthy, in order to evaluate qualitatively and quantitatively the pressure opening and closing functions of the Eustachian tube. Only 71% of the normal children could voluntarily increase the middle ear pressure compared with 100% of the adults. The corresponding figures for evacuating the middle ear by deflation were 24% and 34%, respectively. The rhinopharyngeal pressure levels during the manoeuvres were age-dependent and decided the response rate in children. Tubal factors also determined the response rate since low pressure opening and closing levels were related to successful deflation. Negative middle ear pressures found in the normal children were due to poor muscular opening function of the tube rather than successful deflation. The pressure closing level seems to be a reliable tool in grading tubal closing ability.

High Speed Tympanometry and Ipsilateral Middle Ear Reflex Measurements Using a Computerized Impedance Meter: A Comparison with the Results Obtained by a Conventional Impedance Meter

By means of a new computerized impedance meter, middle ear pressure, tympanograms and ipsilaterally elicited middle ear reflex can be recorded and presented in 3 sec. Owing to the fast rate of air pressure change in the external ear canal it is not necessary to have a completely airtight seal around the ear probe when recording middle ear pressure, which saves time. Results obtained using the new device and those obtained by a conventional impedance bridge are compared.