The etiological evaluation of sensorineural hearing loss in children.

This study aims to evaluate the etiology of pediatric sensorineural hearing loss (SNHL). A total of 423 children with SNHL were evaluated, with the focus on the determination of causative genetic and acquired etiologies of uni- and bilateral SNHL in relation to age at diagnosis and severity of the hearing loss. We found that a stepwise diagnostic approach comprising of imaging, genetic, and/or pediatric evaluation identified a cause for SNHL in 67% of the children. The most common causative finding in children with bilateral SNHL was causative gene variants (26%), and in children with unilateral SNHL, a structural anomaly of the temporal bone (27%). The probability of finding an etiologic diagnosis is significantly higher in children under the age of 1 year and children with profound SNHL.Conclusions: With our stepwise diagnostic approach, we found a diagnostic yield of 67%. Bilateral SNHL often has a genetic cause, whereas in unilateral SNHL structural abnormalities of the labyrinth are the dominant etiologic factor. The diagnostic yield is associated with the age at detection and severity of hearing loss: the highest proportion of causative abnormalities is found in children with a young age at detection or a profound hearing loss. What is Known: • Congenital sensorineural hearing loss is one of the most common congenital disorders • Determination of the cause is important for adequate management and prognosis and may include radiology, serology, and DNA analysis What is New: • Using a stepwise diagnostic approach, causative abnormalities are found in 67% both in uni- and bilateral SNHL, with the highest diagnostic yield in very young children and those suffering from profound hearing loss • Bilateral SNHL often has a genetic cause, whereas in unilateral SNHL structural abnormalities of the labyrinth are the dominant etiologic factor.

Evaluation of the outcome of CT and MR imaging in pediatric patients with bilateral sensorineural hearing loss.

OBJECTIVE: To evaluate the clinically relevant abnormalities as visualized on CT and MR imaging in children with symmetric and asymmetric bilateral sensorineural hearing loss (SNHL), in relation to age and the severity of hearing loss. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral otology and audiology center. PATIENTS AND DIAGNOSTIC INTERVENTIONS: From January 2006 until January 2016, a total of 207 children diagnosed with symmetric and asymmetric bilateral SNHL were included. They underwent CT and/or MR imaging for the evaluation of the etiology of their hearing loss. MAIN OUTCOME MEASURES: Radiologic abnormalities associated with SNHL. RESULTS: 302 scans were performed in 207 children (median age of 0.8 years old) with bilateral SNHL. The most frequently identified cause of bilateral SNHL was a malformation of the labyrinth. The combined diagnostic yield of CT and MR imaging was 32%. The diagnostic yield of MR (34%) was considerably higher than that of CT (20%). We found a higher rate of abnormalities in children with profound hearing loss (41%) compared to milder hearing loss (8-29%), and in asymmetric SNHL (52%) compared to symmetric SNHL (30%). CONCLUSION: Imaging is essential in the etiologic evaluation of children with bilateral SNHL. The highest diagnostic yield is found in children with bilateral asymmetric SNHL or profound SNHL. Based on our findings, MR is the primary imaging modality of choice in the etiological evaluation of children with bilateral SNHL because of its high diagnostic yield.

High prevalence of abnormalities on CT and MR imaging in children with unilateral sensorineural hearing loss irrespective of age or degree of hearing loss.

OBJECTIVE: Evaluation of causal abnormalities identified on CT and MR imaging in children with unilateral sensorineural hearing loss (USNHL), and the association with age and severity of hearing loss. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral otology/audiology center. PATIENTS AND DIAGNOSTIC INTERVENTIONS: 102 children diagnosed with USNHL between 2006 and 2016 were included. They underwent CT and/or MR imaging for the evaluation of the etiology of their hearing loss. MAIN OUTCOME MEASURES: Radiologic abnormalities of the inner ear and brain associated with USNHL. RESULTS: Using CT and/or MR imaging, causal abnormalities were identified in 49%, which is higher than previously reported (25-40%). The most frequently affected site was the labyrinth (29%), followed by the cochlear nerve (9%) and brain (7%). No significant difference in the number or type of abnormalities was found for the degree of hearing loss or age categories. CONCLUSIONS: Imaging is essential in the etiologic analysis of USNHL because of the high prevalence of causative abnormalities that can be identified with radiology, irrespective of the patients' age or degree of hearing loss. CT and MR imaging are complementary imaging options. The ideal imaging algorithm is controversial. Based on our findings, we conclude that there is limited additional diagnostic value of simultaneous dual modality imaging over sequential diagnostics. We therefore perform a stepwise radiological workup in order to maximize the diagnostic yield while minimizing impact and costs. If the primary imaging modality does not identify a cause for USNHL, performing the alternative imaging modality should be considered. LEVEL OF EVIDENCE: Retrospective cohort study 2b.

[Working with hearing impairment: an integrated approach]. / Werken met gehoorverlies: een gespecialiseerde aanpak.

Patients with hearing impairment are more likely to encounter health problems and difficulties at work than their colleagues with normal hearing. This is often not realised by either patients or professionals. In this article we describe three cases that illustrate how working conditions can influence the health of workers with hearing loss. We have implemented a vocational enablement protocol that follows a multidisciplinary approach in order to meet these patients' needs. Due to a mismatch between the demands of a job and an individual's auditory capacities, even a mild hearing impairment can cause serious problems if a patient works in adverse conditions. In addition, in many workplaces the ability to hear well is a safety issue. Professionals have to be aware of both possibilities. Specialized centres offer good facilities and ensure the optimal transfer of insight into the working environment by involving an occupational physician in their team.

Cochlear implantation after bacterial meningitis in infants younger than 9 months.

Objective. To describe the audiological, anesthesiological, and surgical key points of cochlear implantation after bacterial meningitis in very young infants. Material and Methods. Between 2005 and 2010, 4 patients received 7 cochlear implants before the age of 9 months (range 4-8 months) because of profound hearing loss after pneumococcal meningitis. Results. Full electrode insertions were achieved in all operated ears. The audiological and linguistic outcome varied considerably, with categories of auditory performance (CAP) scores between 3 and 6, and speech intelligibility rating (SIR) scores between 0 and 5. The audiological, anesthesiological, and surgical issues that apply in this patient group are discussed. Conclusion. Cochlear implantation in very young postmeningitic infants is challenging due to their young age, sequelae of meningitis, and the risk of cochlear obliteration. A swift diagnostic workup is essential, specific audiological, anesthesiological, and surgical considerations apply, and the outcome is variable even in successful implantations.

[Postmeningitis deafness in young children: action warranted before obliteration of the cochlea]. / Doofheid na bacteriële meningitis bij jonge kinderen: ingrijpen vóór de cochlea is geoblitereerd.

Meningitis may cause inflammation of the cochlea, which may result in deafness and also in rapid obliteration ofthe cochlea with fibrous tissue or even ossification, conditions that obstruct the placement ofa cochlear implant. In the first of two cases of postmeningitis deafness, in a boy aged 6 months and a girl aged 1 year and 9 months, ignorance about the time of audiological follow-up threatened the options for restoration of hearing. In the other case, a long diagnostic programme and an unsuccessful attempt at cochlear implantation caused a long delay in optimal restoration of hearing. Both cases illustrate the difficulties in connection with postmeningitis deafness in relation to the option of a cochlear implant operation. To increase the chances of a successful implantation, the time span between meningitis and audiological and radiological follow-up must be short. Auditory brain stem responses (ABR) and MRI are the keystones of the work-up.

The precedence effect for lateralization at low sensation levels.

Using dichotic signals presented by headphone, stimulus onset dominance (the precedence effect) for lateralization at low sensation levels was investigated for five normal hearing subjects. Stimuli were based on 2400-Hz low pass filtered 5-ms noise bursts. We used the paradigm, as described by Aoki and Houtgast (Hear. Res., 59 (1992) 25-30) and Houtgast and Aoki (Hear. Res., 72 (1994) 29-36), in which the stimulus is divided into a leading and a lagging part with opposite lateralization cues (i.e. an interaural time delay of 0.2 ms). The occurrence of onset dominance was investigated by measuring lateral perception of the stimulus, with fixed equal duration of leading and lagging part, while decreasing absolute signal level or adding a filtered white noise with the signal level set at 65 dBA. The dominance of the leading part was quantified by measuring the perceived lateral position of the stimulus as a function of the relative duration of the leading (and thus the lagging) part. This was done at about 45 dB SL without masking noise and also at a signal-to-noise ratio resulting in a sensation level of 10 dB. The occurrence and strength of the precedence effect was found to depend on sensation level, which was decreased either by lowering the signal level or by adding noise. With the present paradigm, besides a decreased lateralization accuracy, a decrease in the precedence effect was found for sensation levels below about 30-40 dB. In daily-life conditions, with a sensation level in noise of typically 10 dB, the onset dominance was still manifest, albeit degraded to some extent.

Evaluation of fitting rules with a programmable hearing aid.

A study was performed with the 3M 8200 multi-programmable hearing aid in order to try to identify an optimal frequency-gain response, based on the standard calculation rules: NAL, POGO, Berger and Half gain. Furthermore, we examined to what extent multiple programs are used and appreciated. The 3M hearing aid was presented to 126 hearing-impaired patients for a trial period. The participants undertook several tests of speech intelligibility and sound quality. In comparison to the final settings after the trial period, it transpired that the NAL rule came f1p4est to the most used program and gave the best prediction of the gain at 1000 Hz. The attempt to optimize standard calculation rules according to indications made by the patients failed. The SRT-in-noise test showed improvements of the S/N ratio of 2.5 dB. The results of this study point towards separate processing of low- and high-frequency sounds as a useful concept.