Inside implant criteria or not? - Detection of non-organic hearing loss during cochlear implant assessment.

OBJECTIVES: The diagnosis of non-organic hearing loss (NOHL) is a difficult but important issue during the assessment process for cochlear implantation (CI). We aim to identify the key factors in identifying patients with NOHL during CI assessment and present our local screening protocol for NOHL. METHODS: A retrospective review of patients referred to the Yorkshire Auditory Implant Service (YAIS) between 2003 and 2015 who were subsequently diagnosed with NOHL during the assessment. Patient demographic data, audiological and functional assessments were assessed. RESULTS: Thirty-two patients were included in the study. Mean age was 43 years (range 14-82 years). Male to female ratio was 1:1.7. Indicators of possible NOHL included a sudden deterioration in hearing (n = 21; 66%), mismatches in observed behaviour and either pure-tone audiogram (PTA) (n = 27; 84%) or functional testing (n = 20; 80%) and stapedial reflexes below reported audiological thresholds (n = 12; 46%). A mismatch in functional hearing and PTA was seen in 72% of patients. Patients with suspected NOHL were referred for further objective testing. All 23 patients who underwent objective testing had better hearing levels compared to reported hearing thresholds thus placing them outside of implant criteria. Five candidates were found to have normal hearing thresholds. DISCUSSION: NOHL can present a significant challenge to the implant team, particularly in the subgroup with a pre-existing organic hearing loss with non-organic overlay. We discuss the common features in this cohort of patients. CONCLUSIONS: To facilitate the identification of patients with NOHL, the YAIS has developed a screening protocol.

Assessment of the latest NGS enrichment capture methods in clinical context.

Enrichment capture methods for NGS are widely used, however, they evolve rapidly and it is necessary to periodically measure their strengths and weaknesses before transfer to diagnostic services. We assessed two recently released custom DNA solution-capture enrichment methods for NGS, namely Illumina NRCCE and Agilent SureSelect(QXT), against a reference method NimbleGen SeqCap EZ Choice on a similar gene panel, sharing 678 kb and 110 genes. Two Illumina MiSeq runs of 12 samples each have been performed, for each of the three methods, using the same 24 patients (affected with sensorineural disorders). Technical outcomes have been computed and compared, including depth and evenness of coverage, enrichment in targeted regions, performance in GC-rich regions and ability to generate consistent variant datasets. While we show that the three methods resulted in suitable datasets for standard DNA variant discovery, we describe significant differences between the results for the above parameters. NimbleGen offered the best depth of coverage and evenness, while NRCCE showed the highest on target levels but high duplicate rates. SureSelect(QXT) showed an overall quality close to that of NimbleGen. The new methods exhibit reduced preparation time but behave differently. These findings will guide laboratories in their choice of library enrichment approach.

[Objective audiologic assessment of children treated with amikacin]. / Amikacinnal kezelt gyermekek objektív audiológiai vizsgálata.

Hearing assessment of 14 children suffered from urinary tract infection and treated by amikacin is reported. The dosage of amikacin was 7.5 mg/kg/daily for 10 days and the serum level of amikacin not exceeded the 35 mcg/ml. The aim of the study was on the one hand to determine the hearing damaging side effect of amikacin and on the other to assess the usefulness of objective methods for detection of hearing loss in this population. Authors used for screening a transient otoacoustic emission (TEOAE) during and after (2-4 weeks) therapy. If subjective and objective (TEOAE) methods gave a good result, no further checkup has considered as necessary, but if there were no evoked emission, acoustic brainstem response audiometry has been carried out for verification. It result no hearing loss could be detected in the measured specimen. In conclusion it has been stated that by proper dosage and serum level screening amikacin may no lead to hearing loss in children, and objective methods are valuable for hearing screening and monitoring of such population of children.

Auditory brain stem response measurement in the assessment of pseudohypoacusis.

In the evaluation of patients with pseudohypoacusis, a test that gives at least a suggestion of the patient's true auditory sensitivity is of great value. This report is an evaluation of the application and contribution of auditory brain stem response (ABR) measurement in pseudohypoacusis through a case study approach. Four patients suspected of having pseudohypoacusis on the basis of their histories and initial audiometric results were tested with the ABR procedure. In all cases the auditory sensitivity suggested by ABR was considerably better than the voluntary thresholds obtained on the initial audiograms. Following ABR measurement, all four patients showed marked improvement in voluntary threshold responses, and two gave responses that were within normal limits. Although auditory brain stem response measurement is not a test of hearing, it can be a powerful tool in the identification and quantification of nonorganic hearing loss.