Maximum acceptable level for the determination of ECAP and ESRT in a paediatric population.

OBJECTIVES: Two of the most used objective measures are electrically evoked action potentials (ECAPs) and electrically evoked stapedius reflex thresholds (ESRTs). Although stimuli used for these measures differ considerably, both measures are influenced by subjective loudness percept. We focus on the subjective maximum acceptable loudness (MAL) to investigate if loudness sensitivity varied along the electrode array during ECAP recordings. In addition, we explored how the MAL reached during an ECAP recording related to the postoperative ESRT. METHODS: Uni- and bilaterally implanted young CI users (n = 15, average age = 9 y, age range 3-18 y) underwent ECAP and ESR recordings using the clinical software MAESTRO (MED-EL, Innsbruck, Austria) and a commercially available immittance instrument (PATH MEDICAL GmbH, Germering, Germany). RESULTS: Loudness tolerance during ECAP recordings was lowest at the two apical-most electrode contacts (number 1 and 2). There was a moderate correlation between the MAL achieved during ECAP recordings and ESR maximum stimulation amplitudes. (r: 0.44344). CONCLUSIONS: ECAP recordings should commence at basal or medial contacts to increase the users' comfort and loudness tolerance, especially in young CI users. A higher maximum stimulation appears to increase the chance of the automatic determination of ECAP thresholds for all electrode contacts.

Poly-D,L-lactic acid polymer and cochlear implantation.

This case report describes a peculiar and innovative fixing procedure with a Poly-D,L-lactic acid (PDLLA) polymer in the unusual case of magnet dislodgment and rupture of the cochlear implant (CI) silicone sheath holding the magnet.

Impact of Cochlear Implant Array Placement on Speech Perception.

PURPOSE: To assess the role of flat panel computed tomography (FPCT) in the evaluation of cochlear implant (CI) electrode position and its relation to speech perception. METHODS: From March 2015 to March 2019, we retrospectively enrolled deaf subjects ≥ 18 years who underwent unilateral CI by one surgeon, imaged with FPCT and assessed with disyllabic words score before CI and at 6 months of follow-up. We calculated the disyllabic score difference before CI and after CI (ΔSDS) and divided the subjects in favorable and unfavorable outcome groups using the median ΔSDS as a cutoff. We compared the demographic, clinical, electrode characteristics, and the CI positioning variables scalar position, surgical insertion depth (SID), linear insertion depth (LID), angular insertion depth (AID) and wrapping factor (WF). RESULTS: We studied 50 subjects (F/M = 27/23; median age = 60.5 years, IQR: 50-70 years). The median ΔSDS was 80% (interquartile range [IQR]: 60-100%) in quiet and 80% (IQR: 47.5-100%) in noise. Of the subjects 23 demonstrated a favorable outcome and had earlier age at CI (median 52 years; IQR 45-67 years versus median 62 years; IQR: 56-71 years p = 0.032) and a significantly higher SID (median: 4.02 mm IQR: 3.00-5.35 mm versus median: 2.94 mm IQR: 2.06-3.90 mm; p = 0.029). No difference was found for LID (p = 0.977), AID (p = 0.302), and WF (p = 0.224). A logistic regression model built with the age at CI, number of CI electrodes, and the SID was significant χ2 ((df = 3, N = 50) = 14.517, p = 0.002). The model explained 33.7% (Nagelkerke R2) of ΔSDS variance and correctly classified 76% of the cases. CONCLUSION: The SID measured by FPCT predicts the ΔSDS at 6 months follow-up, alongside with age at implantation and number of CI electrodes.

Assessment of Frequency-Place Mismatch by Flat-Panel CT and Correlation With Cochlear Implant Performance.

OBJECTIVE: To calculate the frequency allocation mismatch in a group of very selected cochlear implant (CI) recipients and to contrast it with the speech perception performances. STUDY DESIGN: Cross-sectional observational prospective study. SETTINGS: Tertiary Audiological Department, University hospital. PATIENTS: Fifteen adults receiving the same CI array by the same surgeon through a posterior tympanotomy, round window approach. MAIN OUTCOME MEASURES: 1) High definition flat panel computed tomography (FPCT) control of the intracochlear position of each electrode contact, and computation of the relative frequency allocation mismatch; 2) analysis of speech perception outcomes in relation with the mismatch. RESULTS: Despite a consistent and reproducible surgical procedure with the same intracochlear array, significant deviations from the frequency allocation tables (FAT) assigned by default by the manufacturer were observed in this study.Their influences on speech perception performances were negligible in the simple tasks of words or sentences recognition in quiet (and, to a lesser extent also in noise). The greatest effect of a significant mismatch was observed for the vocal-consonant-vocal (VCV) sequences recognition under noise masking, the emotional and the linguistic prosody recognition, and the phonemes discrimination of the Auditory Speech Sound Evaluation (A§E) test. CONCLUSIONS: The greatest frequency-to-place occurred at the high frequencies. The effect was rather irrelevant on simple words and sentences recognition, while it negatively impacted on the more complex perceptual tasks.

Irony Comprehension in Children With Cochlear Implants: The Role of Language Competence, Theory of Mind, and Prosody Recognition.

Purpose Aims of this research were (a) to investigate higher order linguistic and cognitive skills of Italian children with cochlear implants (CIs); (b) to correlate them with the comprehension of irony, which has never been systematically studied in this population; and (c) to identify the factors that facilitate the development of this competence. Method We tested 28 Italian children with CI (mean chronological age = 101 [SD = 25.60] months, age range: 60-144 months), and two control groups of normal-hearing (NH) peers matched for chronological age and for hearing age, on a series of tests assessing their cognitive abilities (nonverbal intelligence and theory of mind), linguistic skills (morphosyntax and prosody recognition), and irony comprehension. Results Despite having grammatical abilities in line with the group of NH children matched for hearing age, children with CI lag behind both groups of NH peers on the recognition of emotions through prosody and on the comprehension of ironic stories, even if these two abilities were not related. Conclusions This is the first study that targeted irony comprehension in children with CI, and we found that this competence, which is crucial for maintaining good social relationships with peers, is impaired in this population. In line with other studies, we found a correlation between this ability and advanced theory of mind skills, but at the same time, a deeper investigation is needed, to account for the high variability of performance in children with CI.

Cochlear implantation in children with Autism Spectrum Disorder (ASD): Outcomes and implant fitting characteristics.

BACKGROUND: Little is known regarding fitting parameters and receptive and expressive language development in cochlear-implanted children (CCI) with profound sensorineural hearing loss (SHL) who are diagnosed with Autism Spectrum Disorder (ASD). The aim of the study was to evaluate a group of ASD CCI users in order to describe their ASD clinical features and CCI outcomes; report on the average electrical charge requirements; and evaluate the possible correlations between electrical and psychophysical outcomes with ASD characteristics. MATERIALS AND METHODS: A multicentre observational study of 22 ASD children implanted in four cochlear implant (CI) centers. Data concerning profound SHL diagnosis, ASD diagnosis, CI timing and CI compliance were collected. Sound Field (SF) was assessed through repeated behavioural measurements. Categories of Auditory Perception (CAP) and Categories of Language (CL) were used to evaluate speech perception and language skills at short (≤2 yrs), medium (5 yrs) and long term (>10 yrs) follow-up. Fitting parameters such as comfortable thresholds, pulse-width (pw, µsec) and clinical units converted into units of charge/phase were collected. The diagnosis of ASD was acquired by the referral neuropsychiatric department and severity was assessed through the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) and the Childhood Autism Rating Scale (CARS). RESULTS: At the final follow-up session the median SF threshold for CI outcomes was 30 dB HL (min 15 - max 60). CAP score was extremely variable: 45.5% showed no improvement over time and only 22% of children reached CAP scores of 5-7. CL 45.5% showed no improvement over time and score was 1-2 in the majority of ASD children (72.7%), while only 18.2% reached the highest level of language skills. There were no statistically significant differences at each follow-up between subjects with or without comorbidities. CAP and CL were inversely correlated with DSM-V A and B domains, corresponding to lower speech and language scores in children with more severe ASD symptoms, and maintained their correlation at mid and long follow-ups whilst controlling for age at CI. Electrical charge requirements did not correlate with SF or age at implant but did inversely correlate with ASD severity. With regards to CI compliance: only 13.6% children (3) with severe DSM-V A/B levels and CARS score were partial/intermittent users. CONCLUSION: The present study is a targeted contribution to the current literature to support clinical procedures for CI fitting and audiological follow-up in children with ASD. The findings indicate that the outcomes of CI use and the fitting procedures are both influenced by the severity of the ASD symptoms rather than the demographic variables or associated disorders.