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Pro Otology
Balkan Journal of Otology & Neuro-Otology, Vol. 2, No 2:66-68 © 2002
All rights reserved. Published by Pro Otology Association

The Feasibility and the Value of Transient Evoked
Otoacoustic Emissions in Otitis Media with Effusion

F. Cicek, R. Yagiz, A. Tas, M. Koten, M. Adali,
C. Uzun, A. Karasalihoglu

Department of Otorhinolaryngology, Faculty of Medicine, Trakya University, Edirne, Turkey

ABSTRACT

Objective: To investigate the feasibility and the value of transient evoked otoacoustic emissions in otitis media with effusion.
Study Design: This study was designed as a prospective clinical study.
Setting: The study was performed in the Department of Otorhinolaryngology, Faculty of Medicine, Trakya University, Edirne, Turkey.
Patients: This study involved 76 ears of 40 patients with otitis media with effusion.
Intervention: Otoscopic examination, tympanometry, pure tone audiometry and TEOAE measurements were performed.
Main outcome measures: These included preoperative tympanometry and TEOAE measurements, peroperative middle ear findings (presence or absence of effusion and type of effusion) and postoperative TEOAE measurements of the ears with ventilation tube insertion.
Results: Between type of tympanogram and result of TEOAE test were found a significantly difference. It was found that the type of middle ear effusion could effect the presence or absence of preoperative TEOAE responses. Positive TEOAEs at the posteperative 1st day were obtained in 50% of ears after ventilation tube insertion. At the between 4-8 weeks following the procedure, positive TEOAEs were obtained in 90% of ears with ventilation tubes.
Conclusions: TEOAE test may have value both in evaluating the presence or absence of effusion in the middle ear, and also in evaluating type of effusion, in the follow-up procedures of patients, who have been performed ventilation tube insertion. So, TEOAE test can be offered for diagnose and follow-up of patients who are recommended to be performed or have been performed ventilation tube insertion.
Key words: Otitis media with effusion, Otoacoustic emissions, Spontaneous, Middle ear ventilation.
Pro Otology 2: 66-68, 2002

INTRODUCTION

Otitis media with effusion (OME) is a very common childhood disease (1). Ventilation tube insertion for OME is the most common surgical procedure in most ENT departments. Testing the hearing of patients, whom we recommend to perform ventilation tube, or in whom ventilation tube have already been performed for OME, is quite difficult. Because most of these patients are children and their cooperations for classical audiometric tests are problematic as well as the subjectivity of the results of these tests (2). Also, another possible problem could be difference between preoperative tympanometry findings and peroperative middle ear findings. Transient Evoked Otoacoustic Emissions (TEOAEs) is a quick, non-invasive and objective test that can be used easily without requiring patients cooperation (3).

The aims of this study were to assess the effects of the presence or absence of effusion in the middle ear on the TEOAEs, to evaluate the presence of abnormal tympanograms and their correlation with the results of TEOAEs, to determine the influence of types of middle ear effusion on the TEOAEs, and to demonstrate that TEOAEs are measurable in ears following myringotomy with ventilatory tube placement.

MATERIAL AND METHODS

This study was done between November 1999 and December 2001 at the department of Otorhinolaryngology, Faculty of Medicine, Trakya University, Edirne, Turkey. This study involved 76 ears of 40 patients with otitis media with effusion (OME). Diagnosis of OME was done according to the findings depending on otoscopy, pure tone audiometry and tympanometry. Each subject had received conservative therapy prior to referral for myringotomy with ventilatory tube insertion. Otoscopic examination, tympanometry, pure tone audiometry and TEOAE measurements were performed 24 hours before surgery. All surgical procedures were performed under general anaesthesia. In 3 patients general anaesthesia was maintained by mask, and the 37 patients were intubated. Ventilatory tube insertion was either performed alone, or with adenoidectomy or adeno-tonsillectomy. Myringotomy was performed in the anterior-inferior quadrant, using a radial incision. After the myringotomy, the type of middle ear effusion was assessed by the surgeon's visual inspection as serous, seromucoid and mucoid. Depending on the type of the effusion and coexisting abnormality of the tympanic membrane, myringotomy alone (16 ears) or the ventilatory tube insertion (60 ears) was performed. Each of the subjects, in whom ventilatory tube insertion was performed, was assessed again at the 1st day and at the between 4-8 weeks after surgery. Otoscopic examination was performed to check for the position and patency of the ventilatory tubes. After the otoscopy, pure tone audiometry and TEOAE measurements were performed.

TEOAE screening was performed using the Otodynamic Analyser ILO 88 (Ver.4.20B). Click stimuli of 80 dB rectangular pulses were used with a peak intensity of 80±5 dB SPL (Sound Pressure Level) and stability was more than 80%. The tests were applied in the quiet environment, the rejection threshold was under 50 dB and quite/noise rate was over 50%. An adult size ear probe, fitted with an expandable foam cuff was placed in the external ear canal and non-linear stimulus was used. Transient responses were averaged 260 times and analysed during the first 2.5- 20 ms interval after the stimulus onset. A "positive" emissions was assumed when the reproducibility was 50% or greater, and the signal-to-noise ratio was greater than, or equal to +3dB at three frequency bands (4). If these levels of reproducibility and signal-to-noise ratio was not obtained after the acquisition of 260 subset, this constituted a "negative"emission.

Audiometric thresholds were obtained with a digital clinical audiometer model AC3-Interacoustics in patients, An impedance audiometer model AZ7-Interacoustics and its XYT recorder were used to obtain tympanometric measures. Tympanograms were categorized according to the Jerger classification (type A, B and C) (5).

The results were analysed by the Fisher's exact c2 and Mc Nemar statistical methods.

RESULTS

This study includes 76 ears (40 left and 36 right) of 40 the patients. The patients comprised of 25 (37.5%) males and 15 (62.5%) females. The average age of the patients was 7 years and five months (range 30 months to 17 years).

Comparison of the results of preoperative tympanometry and TEOAE measurements are summarized in Table 1.

The results of preoperative TEOAE test and peroperative middle ear findings (presence or absence of effusion) are shown in Table 2.

FIG. 1. The Results of TEOAE Test of Ears with Ventilation Tube Insertion.

Table 3 shows preoperative TEOAE test results and type of the middle ear effusion. After myringotomy, the ventilatory tube insertion was performed bilaterally in the 20 patients and unilaterally in the 20 patients. Postoperative TEOAE test results of the ears with ventilation tube insertion are presented in Figure 1.

DISCUSSION

In the literature, the studies (6,7) have shown different results between tympanometry findings and TEOAE test results. In the study of Owens et al. (6) ears with either type B or type C tympanogram patterns showed absent or markedly reduced TEOAE amplitudes. In the study by Amedee (7), tympanogram type does not seem to be a significant contributor to the presence or absence of emissions in all subjects with type B or type C tympanograms. In the present study, we found a significantly difference between type of tympanogram and result of TEOAE test.

Whether or not the type of middle ear effusion is a factor affecting the presence or absence of emissions is controversial (3,7). Richardson et al. (3) stated that there was not a significant difference between the quantity and consistency of middle ear fluid and TEOAE responses. Amedee (7) found that the type of the middle ear effusion affected the presence or absence of preoperative TEOAE responses. In the present study, we found that the type of middle ear effusion could effect the presence or absence of preoperative TEOAE responses.

Tilanus et al. (8) and Richardson et al. (3) have performed TEOAE measurements immediately following the grommet insertion while the child is still under general anaesthesia. They have found 20% and 10% positive emission respectively. In our study, positive TEOAEs at the posteperative 1st day were obtained in 50% of ears after ventilation tube insertion. In a similar study by Cullington et al. (2), this rate was found 43%. These results suggest that the time elapsed between surgery and testing have significantly increased the positive emission rate. Previous authors (3,8) have postulated that the effects of temporary threshold shift following suctioning or mechanical trauma to the middle ear may explain the low otoacoustic emissions pass rate.

In our study, at the between 4-8 weeks following the procedure, we obtained positive emissions in 90% of ears with ventilation tubes. Tilanus et al. (8), at follow up visits, found normal emissions in 80% of ears tested. In the study by Daya et al. (9) was found of 76% positive TEOAE rate at the following procedure. It is likely that if more time elapsed between surgery and the otoacoustic emissions screen, the positive emission rate would increase. But, persisting negative emission at the follow-up procedures, may depend on persisting effusion or underlying sensorineural impairment.

As a result, TEOAE test may have value both in evaluating the presence or absence of effusion in the middle ear, and also in evaluating type of effusion, in the follow-up procedures of patients, who have been performed ventilation tube insertion. So, TEOAE test can be offered for diagnose and follow-up of patients who are recommended to be performed or have been performed ventilation tube insertion.

REFERENCES

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2. Cullington HE, Kumar BU, Flood IM. Feasibility of otoacoustic emission as a hearing screen following grommet insertion. Br J Audiol 1998;32:57-62.

3. Richardson HC, Elliott C, Hill J. The feasibility of recording transiently evoked otoacoustic emissions immediately following grommet insertion. Clin Otolaryngol 1996;21:445-8.

4. Maxon AB, White KR, Vohr BR, Behrens TR. Using transient evoked otoacoustic emissions for neonatal hearing screening. Br J Audiol 1993;27:149-53.

5. Jerger J. Clinical experience with impedance audiometry. Arch Otolaryngol 1970;92:311-24.

6. Owens JJ, McCoy MJ, Lonsbury-Martin BL, Martin GK. Otoacoustic emissions in children with normal ears, middle ear dysfunction and ventilating tubes. Am J Otol 1993;14:34-40.

7. Amedee RG. The effects of chronic otitis media with effusion on the measurement of transiently evoked otoacoustic emissions. Laryngoscope 1995;105:589-95.

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9. Daya H, Hinton AE, Radomskiej P, Huchzermeyer P. Otoacoustic emissions: assessment of hearing after tympanostomy tube insertion. Clin Otolarygol 1996;21:492-4.