Don't look at it as a miracle cure: Contested notions of success and failure in family narratives of pediatric cochlear implantation.

Cochlear implants (CIs) are a routine treatment for children identified with a qualifying hearing loss. The CI, however, must be accompanied by a long-term and intense auditory training regimen in order to possibly acquire spoken language with the device. This research investigates families' experiences when they opted for the CI and undertook the task of auditory training, but the child failed to achieve what might be clinically considered "success" - the ability to function solely using spoken language. Using a science and technology studies informed approach that places the CI within a complex sociotechnical system, this research shows the uncertain trajectory of the CI, as well as the contingency of the very notions of success and failure. To do so, data from in-depth interviews with a diverse sample of parents (n = 11) were collected. Results show the shifting definitions of failure and success within families, as well as suggest areas for further exploration regarding clinical practice and pediatric CIs. First, professionals' messaging often conveyed to parents a belief in the infallibility of the CI, this potentially caused "soft failure" to go undetected and unmitigated. Second, speech assessments used in clinical measurements of outcomes did not capture a holistic understanding of a child's identity and social integration, leaving out an important component for consideration of what a 'good outcome' is. Third, minority parents experience structural racism and clinical attitudes that may render "failure" more likely to be identified and expected in these children, an individualizing process that allows structural failures to go uncritiqued.

Independent component analysis for cochlear implant artifacts attenuation from electrically evoked auditory steady-state response measurements.

OBJECTIVE: Electrically evoked auditory steady-state responses (EASSRs) are potentially useful for objective cochlear implant (CI) fitting and follow-up of the auditory maturation in infants and children with a CI. EASSRs are recorded in the electro-encephalogram (EEG) in response to electrical stimulation with continuous pulse trains, and are distorted by significant CI artifacts related to this electrical stimulation. The aim of this study is to evaluate a CI artifacts attenuation method based on independent component analysis (ICA) for three EASSR datasets. APPROACH: ICA has often been used to remove CI artifacts from the EEG to record transient auditory responses, such as cortical evoked auditory potentials. Independent components (ICs) corresponding to CI artifacts are then often manually identified. In this study, an ICA based CI artifacts attenuation method was developed and evaluated for EASSR measurements with varying CI artifacts and EASSR characteristics. Artifactual ICs were automatically identified based on their spectrum. MAIN RESULTS: For 40 Hz amplitude modulation (AM) stimulation at comfort level, in high SNR recordings, ICA succeeded in removing CI artifacts from all recording channels, without distorting the EASSR. For lower SNR recordings, with 40 Hz AM stimulation at lower levels, or 90 Hz AM stimulation, ICA either distorted the EASSR or could not remove all CI artifacts in most subjects, except for two of the seven subjects tested with low level 40 Hz AM stimulation. Noise levels were reduced after ICA was applied, and up to 29 ICs were rejected, suggesting poor ICA separation quality. SIGNIFICANCE: We hypothesize that ICA is capable of separating CI artifacts and EASSR in case the contralateral hemisphere is EASSR dominated. For small EASSRs or large CI artifact amplitudes, ICA separation quality is insufficient to ensure complete CI artifacts attenuation without EASSR distortion.

Criteria versus guidelines: Are we doing the best for our paediatric patients?

The National Institute for Health and Care Excellence guidance for the provision of cochlear implants (NICE Technology Appraisal Guidance 166. Cochlear implants for children and adults with severe to profound deafness. 2009. National Health Service National Institute for Health and Clinical Excellence.) are used to develop candidacy criteria by public health funding bodies within the UK. Often the guidance is interpreted as strict 'criteria' whereby clinicians adhere to specific audiometric thresholds without accounting for the acceptable range of performance on individual tests or a child's functional development. In this paper four clinical paediatric case studies are described from two cochlear implant centres which serve to illustrate difficulties in applying NICE guidance as strict criteria. These are presented in the context of recommending more flexible interpretation based on the content of the current guidance along with considerations of circumstances where NICE guidance might be adapted to optimise use of cochlear implant technology within a national framework.

Evaluation of focused multipolar stimulation for cochlear implants in acutely deafened cats.

OBJECTIVE: The conductive nature of the fluids and tissues of the cochlea can lead to broad activation of spiral ganglion neurons using contemporary cochlear implant stimulation configurations such as monopolar (MP) stimulation. The relatively poor spatial selectivity is thought to limit implant performance, particularly in noisy environments. Several current focusing techniques have been proposed to reduce the spread of activation with the aim towards achieving improved clinical performance. APPROACH: The present research evaluated the efficacy of focused multipolar (FMP) stimulation, a relatively new focusing technique in the cochlea, and compared its efficacy to both MP stimulation and tripolar (TP) stimulation. The spread of neural activity across the inferior colliculus (IC), measured by recording the spatial tuning curve, was used as a measure of spatial selectivity. Adult cats (n = 6) were acutely deafened and implanted with an intracochlear electrode array before multi-unit responses were recorded across the cochleotopic gradient of the contralateral IC. Recordings were made in response to acoustic and electrical stimulation using the MP, TP and FMP configurations. MAIN RESULTS: FMP and TP stimulation resulted in greater spatial selectivity than MP stimulation. However, thresholds were significantly higher (p < 0.001) for FMP and TP stimulation compared to MP stimulation. There were no differences found in spatial selectivity and threshold between FMP and TP stimulation. SIGNIFICANCE: The greater spatial selectivity of FMP and TP stimulation would be expected to result in improved clinical performance. However, further research will be required to demonstrate the efficacy of these modes of stimulation after longer durations of deafness.