Tapani Rahko

Diagnostic value of tympanometry in infants in clinical practice

One hundred and twenty-one visits of 58 infants (2-11 months of age) were evaluated in the Finnish Otitis Media Vaccine Trial. Infants were examined with tympanometry (Grason-Stadler GSI 38 Autotymp) and pneumatic otoscopy by one study doctor. Diagnosis of otitis media was verified by myringotomy in 74% of cases. Tympanometry was technically successful in 94% of ears. The success rate was statistically significantly higher (P < 0.05) among infants less than 7 months of age than those above 7 months. The sensitivity of tympanometry (type B) to detect ears with middle ear fluid was 0.70 and the specificity 0.98 with a positive predictive value of 0.93 and negative predictive value of 0.94. The sensitivity was somewhat lower in the younger age group (0.61); specificity and positive and negative predictive values were good in both age groups. The high success rate and high negative and positive predictive values of tympanometry make it a useful aid for assuring the correct diagnosis of otitis media in infants in routine clinical practice.

Institutional Logics, ICT and Stability of Management Accounting

The purpose of this paper is to study the institutional logics of how and why two case units in the Finnish Defence Forces have reacted differently to external pressures originating from the State Audit Office to change their management accounting systems. The situation is made complex due to the fact that in military organisations, accountants’ tasks have traditionally consisted of bookkeeping and financial reporting, while management accounting tasks especially (e.g. planning and control) have been performed predominantly by military personnel, who can be called hybrid accountants. The data for this study consists of project memos and interviews with people involved in designing and implementing enterprise-resource-planning (ERP)-linked cost accounting and reporting systems. In the case unit where management accounting and control had become institutionalised as a part of the uniformed officers professional sphere, various resistance strategies (i.e. compromise strategy/pacifying tactics, avoidance strategy/buffering tactics and defiance strategy/dismissing tactics) were adopted. However, where this was not the case, the response was acquiescence. Despite the differences in responses to institutional pressure, the outcome for management accounting was the same. In the first case, demands for change were resisted, and in the second case, the old management accounting system was transferred into new information and communication technology (ICT) infrastructure without any significant change in content.

Predicting the development and outcome of otitis media by tympanometry.

OBJECTIVE Identification of children with high risk of development or prolongation of otitis media would be highly useful in clinical practice. In this study, tympanometry was assessed for its capability in predicting development and resolution of acute otitis media (AOM). METHODS Visits of 329 children followed in the Finnish Otitis Media Cohort Study from 2 to 24 months of age were evaluated for this report. Tympanometry was routinely performed on all children during their visits to a special study clinic. Adjacent consecutive visits were used for analysis of development and resolution of middle ear fluid (MEF) between the visits. Descriptive analysis utilized all data obtained during the longitudinal follow-up; confirmatory statistical analysis was performed on data of one randomly selected visit per subject to ensure independence of observations. Presence of MEF at the second visit was used as the outcome. RESULTS Negative tympanometric peak pressure (<-100 daPa) was found to predict the development of otitis media when observed during respiratory infection with no concomitant ear disease. Otitis media developed within 20 days to 40% of children with negative pressure compared with 20% of children without negative pressure. The observed association was confirmed statistically (odds ratio 4.8, 95% confidence interval 2.4-9.6). Poor outcome of AOM at the subsequent follow-up visit 3-5 weeks later was found in 9% of ears with negative pressure tympanogram compared with 24% with initial type B or normal pressure tympanogram during AOM. However, we could not confirm the finding in statistical analysis (odds ratio 0.6, 95% confidence interval 0.2-2.0). CONCLUSIONS Profound negative tympanometric peak pressure is a significant marker of increased risk for development of otitis media. Children with negative pressure have to be thoroughly followed for subsequent progress of the respiratory disease and development of otitis media. For the prediction of resolution of AOM, the findings remained inconclusive.

Negative pressure tympanograms in children less than 2 years of age-different bacterial findings in otitis media by tympanometric results

OBJECTIVE The interpretation of negative pressure tympanograms as indicators of the presence of middle ear fluid has been ambiguous. Our purpose was to assess the occurrence and implications of negative pressure tympanograms and to study their association with bacterial pathogens in otitis media. METHODS Altogether 329 infants were enrolled at a well-baby clinic for the Finnish Otitis Media Cohort Study, a longitudinal prospective cohort study. The children were closely followed in a special study clinic from 2 to 24 months of age for respiratory diseases, especially acute otitis media. Children were examined at the study clinic with tympanometry and pneumatic otoscopy whenever visiting the study clinic for respiratory disease. Myringotomy with aspiration was performed if middle ear fluid was suspected in otoscopy. Occurrence of middle ear fluid in ears with negative pressure tympanograms (less than -100 daPa) was assessed. Nested case control design matched by visit type (acute or follow-up visit) and month of visit was used for analysis of association of bacterial pathogens and tympanometric results. RESULTS Middle ear fluid was encountered in 15% of ears with negative tympanometric peak pressure, a lower proportion than described previously. In otitis media with a negative tympanometric peak pressure, 71% of bacterial cultures remained negative for the main pathogens, compared to 36% in matched controls (P<0.001). Especially Streptococcus pneumoniae but also Haemophilus influenzae were rarely found in samples from negative pressure ears. Moraxella catarrhalis was equally often found. CONCLUSIONS Negative pressure tympanogram is a poor indicator for the presence of middle ear fluid. Furthermore, if otitis media is diagnosed with negative tympanometric peak pressure negative middle ear bacterial culture for the main pathogens is highly probable. Expectant follow-up might be more appropriate than routine antibiotic treatment.

New clinical finding in vestibular neuritis: High-frequency audiometry hearing loss in the affected ear

Twenty‐one patients with established vestibular neuronitis were examined otoneurologically and audiologically. High‐frequency audiometry up to 20,000 Hz was performed on all the patients. In 17 cases a high‐frequency hearing loss was greater in the ear with vestibular neuritis. The mean hearing loss difference varied from 14 dB to 24 dB, depending on the frequency. Our results reveal that in most cases of vestibular neuritis there are no isolated vestibular lesions, but most cases also involve an auditory end‐organ lesion. This finding is in unison with the anatomic conditions of the cochlea and the vestibular end‐organ.

Normative values for tympanometry in 4-5-year-old children.

The objective of this study was to determine normative values for tympanometric variables for 4—5-year-old children. Tympanometry was performed at a pre-scheduled visit at the age of 49—68 months on children recruited to a follow-up visit in a vaccine efficacy trial (n = 756 children). Tympanograms obtained successfully from healthy ears were analysed. At the time of the visit, mean static acoustical admittance (SAA) was 0.52 cm3, mean tympanometric peak pressure (TPP) was-48 daPa, and mean tympanometric width (TW) was 101. Compared to results obtained for the same study population at 24 months of age, the SAA had increased significantly with age, while the values for TPP and TW had decreased with age. A history of previous tympanostomy tubes increased the admittance of the tympanic membrane by producing atrophic scars. Thus, the tympanograms obtained from ears with previous tubes were considerably higher and narrower (high SAA and low TW). In conclusion, this study further emphasizes the need for age-specific normative values for interpretation of SAA and TW. Sumario El objetivo de este estudio fue determinar los valores normativos para las variables timpanométricas en niños de 4–5 años de edad. La timpanometria se realizó en niños reclutados en una visita pre-establecida de seguimiento, de un estudio de eficacia de vacunas, a las edades de 49–68 meses (n=756 niños). Se analizaron los timpanogramas obtenidos de oídos sanos. En ef momento de la visita, la admitancia acústica estática promedio (SAA) fue 0.52 cm3, la presión del pico timpanométrico (TPP) fue-48 daPa, y el ancho timpanométrico promedio (TW) fue 101. Comparados con los resultados obtenidos en la misma población de estudio a los 24 meses de edad, la SAA había aumentado significativamente con la edad, mientras que los valores de TPP y TW habían disminuido con la edad. La historia previa de colocación de tubos de timpanostomía aumentó la admitancia de la membrana timpánica como resultado de cicatrices atróficas. Así, los timpanogramas obtenidos de oídos en los que previamente se habían colocado dichos tubos fueron considerablemente más altos y más angostos (alta SAA y bajo TW). En conclusión, este estudio enfatizó aún más la necesidad de contar con valores normativos, para ser utilizados en la interpretación de la SAA y del TW, para cada grupo de edad.

Walk-rotate-walk test identifies patients responding to Lempert’s maneuver, with benign paroxysmal positional vertigo of the horizontal canal

Abstract Two hundred and fifteen patients were diagnosed and treated for benign paroxysmal positional vertigo of the horizontal canal (BPPV-HC). All patients were tested with conventional positional nystagmus tests lying supine and rotating head for geotropic nystagmus, registered with Frenzels glasses, and in 109 cases with ENG. The walk-rotate-walk (WRW) test, developed by one of us (T.R.) and described in the text, was applied to all patients. The immediate good treatment results with Lempert’s maneuver verify the correct diagnosis of BPPV-HC. The WRW test is a more sensitive test for BPPV-HC than earlier positional tests. The unhabituated acute phase of vestibular neuritis shows positive test results and must be eliminated with caloric tests. The WRW test identifies as a dynamic test patients with symptoms of even lesser magnitude, where the compensatory capacity of the equilibrium system suppresses the diagnostic findings with earlier positional horizontal canal tests.

The Cochlear Component in Operated Otosclerosis after a Mean Period of 16 Years: A Follow-Up Study

107 patients operated on for otosclerosis were studied after an average of 16 years after the operation. The mean age-corrected bone thresholds measured after the postoperative stabilization period and at the follow-up examination did not differ significantly. Our results support the opinion that, in cases of operated otosclerosis, the sensorineural component follows the clinical course of presbyacusis.

Interrater agreement on tympanometry in infants.

Two-hundred and forty-two tympanograms of infants were interpreted according to a standard operating procedure independently by an audiologist and ten study doctors from the Finnish Otitis Media Vaccine Trial. The interrater agreement among the study doctors according to Kappa index was excellent (K = 0.80). The agreement was significantly better on curves taken during pre-scheduled healthy visits than during sick visits due to respiratory infection ( p < 0.001). In addition concurrent knowledge of the clinical ear status significantly improved the agreement on abnormal curves (flat B-curves and failed F-curves, p < 0.001). The clinical differences between the groups were minor. The age of the infant had no effect on interpretation. The agreement between the audiologist and the study doctors was also excellent (K = 0.77). Excellent agreement can be achieved in infant tympanometry through adequate instruction and training.

Audiological and vestibular findings in 219 cases of meningitis.

SummaryThe audiological and electronystagmographic follow-up results of 219 children with different forms of meningitis are presented. The findings for hearing loss are roughly comparable with those of earlier reports. There have been no previous systematic studies on children with meningitis. Our electronystagmographic results show continuous nystagmus, evenly distributed in different aetiological groups, in 26 patients (12%), directional preponderance in 11 patients (5%) and canal paresis in three patients (1.5%). Disconjugate eye movements indicating a possible brain-stem lesion were observed in seven patients (3%). Eye movements were registered individually for both eyes. None of our patients had clinically significant vertigo. The electronystagmographic findings did not appear with hearing loss, indicating that vestibular disorders may develop independently. Our results support the view that electronystagmography should be performed routinely on every child who has had meningitis.