Keratoacanthoma in the External Auditory Canal.

A 63-year-old male presented with a prolonged history of bilateral ear discharge, otalgia, and hearing loss. The patient required a significant number of investigations prior to obtaining a diagnosis. Subsequent investigations identified keratoacanthoma affecting the external ear canal (EAC). There has been no case report of keratoacanthoma within the EAC till now. The only risk factor identified for the development of keratoacanthoma, in this case, was the frequent use of earbuds and subsequent long-term trauma associated with a retained bud. The histology of keratoacanthoma is difficult to differentiate from that of squamous cell carcinoma but this is essential for the ear, nose, throat (ENT) multi-disciplinary team.

Total endoscopic stapes surgery: Systematic review and pooled analysis of audiological outcomes.

OBJECTIVE: This study evaluates the current evidence base for total endoscopic stapes surgery, specifically to establish current efficacy and safety of the technique within clinical practice. DATA SOURCES: A systematic review of the literature on endoscopic stapes surgery was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis checklist. A comprehensive search of PubMed, Embase, and the Cochrane Central Register of Controlled Trials database for relevant publications for all available dates with appropriate Medical Subject Headings search criteria in January 2018. STUDY SELECTION: Out of the 160 articles identified in the search, 14 met the inclusion criteria for further analysis. Four of these were level III and 10 level IV evidence. DATA EXTRACTION: A pooled patient population of 314 individuals was analyzed. DATA SYNTHESIS: Documented postoperative air bone gap closure to within 20 dB was found in 95.3% of individuals (285 patients). Facial nerve palsy (temporary) occurred in three patients (0.6%), with all recovering. No total sensorineural hearing losses were recorded, but two moderate sensorineural hearing losses occurred (0.6%). Perilymph fistula was noted on four occasions (1.3%). Chorda tympani trauma was documented in 3.5% of cases, with taste disturbance documented in 13 patients (5%). CONCLUSIONS: Our pooled analysis uses the current published evidence to establish the complication rate and audiological outcome for the endoscopic approach to stapes surgery. These outcomes are comparable to those documented in traditional use of the microscope for stapedectomy. Laryngoscope, 130:1282-1286, 2020.

Initial surgical and clinical experience with the Nucleus CI532 slim modiolar electrode in the UK.

OBJECTIVE: The goal of this work is to describe the first experience in the UK with the slim pre-curved perimodiolar electrode Nucleus CI532 in a continuous series of patients in terms of surgical and clinical reliability and early performance outcomes. METHOD: In this retrospective review we describe the complication rate (including electrode array tip fold-over), NRT thresholds, hearing preservation, power efficiency and CI performance outcomes in a continuous series of 40 cochlear implants CI532 performed between October 2016 and November 2017 in 17 adults and 13 children with severe to profound hearing loss. RESULTS: Preliminary data from these groups reveals some low-frequency hearing preservation in the CI532 group although none of the patients were conventional hearing preservation candidates. NRT thresholds, power efficiency, and BKB sentences in quiet were measured at 3 and 6 months post activation. There were no significant differences in these results. The average BKB score in quiet increases from 22% pre-operatively to 58% at 3 months and 70% at 6 months. In addition, although hearing preservation was not an objective, low-frequency thresholds were preserved in 20% of cases at 3 and 6 months post-operatively. Complications were observed in 5 cases, one case with non-device related aerocoele and four related to the device array: two cases of tip roll over, one case of the electrode array being placed extra-cochlea, and one case with the electrode buckling into the middle ear. The last 2 cases were dealt with per-operatively. DISCUSSION: Our preliminary results with the CI532 implant indicate that it may be reliably placed with standard surgical techniques but care is needed during the deployment of the electrode. Further initial data suggest that switch on and early electrophysiological measures are comparable to the existing CI 512 device. However whilst preliminary, our data suggest that it may be possible to use this electrode for hearing preservation. However, further studies are required to determine its definitive advantage over other electrode designs. CONCLUSION: CI532 is a reliable device offering good initial results and could be an option for hearing preservation although further studies are required.

Development of electrophysiological and behavioural measures of electrode discrimination in adult cochlear implant users.

The plasticity of the auditory system enables it to adjust to electrical stimulation from cochlear implants (CI). Whilst speech perception may develop for many years after implant activation, very little is known about the changes in auditory processing that underpin these improvements. Such an understanding could help guide interventions that improve hearing performance. In this longitudinal study, we examine how electrode discrimination ability changes over time in newly implanted adult CI users. Electrode discrimination was measured with a behavioural task as well as the spatial auditory change complex (ACC), which is a cortical response to a change in place of stimulation. We show that there was significant improvement in electrode discrimination ability over time, though in certain individuals the process of accommodation was slower and more limited. We found a strong relationship between objective and behavioural measures of electrode discrimination using pass-fail rules. In several cases, the development of the spatial ACC preceded accurate behavioural discrimination. These data provide evidence for plasticity of auditory processing in adult CI users. Behavioural electrode discrimination score but not spatial ACC amplitude was found to be a significant predictor of speech perception. We suggest that it would be beneficial to measure electrode discrimination in CI users and that interventions that exploit the plastic capacity of the auditory system to improve basic auditory processing, could be used to optimize performance in CI users.

Objective assessment of electrode discrimination with the auditory change complex in adult cochlear implant users.

The spatial auditory change complex (ACC) is a cortical response elicited by a change in place of stimulation. There is growing evidence that it provides a useful objective measure of electrode discrimination in cochlear implant (CI) users. To date, the spatial ACC has only been measured in relatively experienced CI users with one type of device. Early assessment of electrode discrimination could allow auditory stimulation to be optimized during a potentially sensitive period of auditory rehabilitation. In this study we used a direct stimulation paradigm to measure the spatial ACC in both pre- and post-lingually deafened adults. We show that it is feasible to measure the spatial ACC in different CI devices and as early as 1 week after CI switch-on. The spatial ACC has a strong relationship with performance on a behavioural discrimination task and in some cases provides information over and above behavioural testing. We suggest that it may be useful to measure the spatial ACC to guide auditory rehabilitation and improve hearing performance in CI users.

The use of cone-beam computed tomography to determine cochlear implant electrode position in human temporal bones.

OBJECTIVE: To assess the utility of cone-beam computed tomography (CBCT) imaging in the estimation of cochlear implant (CI) electrode position in implanted temporal bones. STUDY DESIGN: Eight fresh frozen temporal bones were mounted and oriented as for standard surgery and were implanted with Cochlear Slim-Straight (SS) or Contour Advance electrode arrays by 2 CI surgeons. The bones were then imaged using an Accuitomo F170 CBCT scanner (isometric 250 µm voxel size) and were then processed for histologic sectioning (500 µm sections). MAIN OUTCOME MEASURES: The CBCT images and the histologic micrographs (providing the "gold standard") were examined independently by several observers who assessed the scalar position (tympani or vestibuli) of each electrode in each temporal bone specimen. RESULTS: Examination of the histologic micrographs confirmed that all electrodes were positioned within the scala tympani in all 8 bones. Similar judgments were made by the observers rating the CBCT images, except that one of the 2 observers estimated some of the apical electrodes to be located in the scala vestibuli in two of the bones implanted with the SS electrode. CONCLUSION: Cone-beam CT imaging is able to provide a good indication of the scalar position of implanted electrodes, although estimation may be slightly less reliable for apical electrodes and for straight electrode designs. Additional advantages of using CBCT for this purpose are shorter acquisition time and reduction of radiation dose as compared with conventional CT.

Cochlear implantation in a patient with combined renal and liver transplantation.

OBJECTIVE AND IMPORTANCE: Patients who have undergone solid organ transplantation and continuing immunosuppressant medication are at a higher risk of wound problems and infections following cochlear implantation. This risk is theoretically even further increased in multi-organ transplant recipients due to the increased doses of immunosuppressive medications that these patients are administered. CLINICAL PRESENTATION AND INTERVENTION: Here, we present the first reported case of successful cochlear implantation in a patient who had previously undergone successful combined liver and kidney transplant. She had no significant complications from the surgery and had good audiological outcomes 3 months post-operatively. CONCLUSION: As we continue our advances in the use of cochlear implant technology, our report adds to the growing evidence of its benefits in transplant recipients. However, there are important pre- and peri-operative considerations in this group of patients which can improve safety and outcome.

The use of cone beam imaging to determine cochlear implant electrode position in human temporal bones.

This paper describes the outcomes of cochlear implantation in eight cadaveric temporal bones using cone-beam CT imaging and histological examination with respect to scalar position of the electrode array.

Optimizing pneumococcal vaccination for paediatric cochlear implant recipients using the cochlear implant pneumococcal vaccination flowchart.

INTRODUCTION: Cochlear implant recipients are known to be at an increased risk of meningitis. It is routine practice to check that pneumococcal vaccinations have been received prior to surgery. Recent changes in United Kingdom national guidelines mean that children who were previously thought to be fully immunized may in fact not be optimally protected. We present a simple, robust audit tool that can be used in both primary care and tertiary centres to identify those children at risk. METHODS: The pneumococcal immunization status of 63 paediatric cochlear implant recipients was assessed using a unique and comprehensive flowchart-style audit tool. The data collected included age at implantation, details of previous immunizations, and whether or not further vaccinations were required. RESULTS: Fifty-four per cent of children were not optimally immunized prior to implantation. Seventy per cent of children required further vaccinations following surgery. The commonest reason for an incomplete immunization history was failure to administer the 23-valent vaccine after the second birthday. CONCLUSION: The pneumococcal immunization schedule for high-risk children is complicated and nationally available guidance can be difficult to interpret. There are multiple types of vaccines and their use is not standardized across the UK. Cochlear implant programmes may find that a large proportion of their patients are in fact not optimally vaccinated, particularly in light of recent changes in the national guidelines. Our audit tool allows health professionals, in both primary care and implant centres, to accurately assess the status and immunization requirements for both new and old patients.

A practical, single-view alternative to Stenver's for plain radiographic unilateral and bilateral post-cochlear implant position check.

INTRODUCTION: 'Stenver's' is the standard plain radiograph view to check the electrode position after cochlear implantation. However, a reproducible alignment for intra-individual comparison of electrode position using a true Stenver's alignment is not always straightforward to achieve, particularly for inexperienced radiographers, or on non-compliant children. In addition, two ionizing exposures in two different positions are required for bilateral cochlear implants. AIMS: To assess the efficacy of other, more simple, single-exposure radiographs for the assessment of electrode position. METHODS: Dummy electrodes and receiver units were bilaterally implanted into a cadaver. Plain radiographs in Stenver's views, and plain antero-posterior (AP) midline radiographic single views incorporating both implants were obtained with the tube at a range of angles tilted caudal and cranial to the perpendicular. Five internationally renowned cochlear implant surgeons were each asked if each radiograph gave adequate information for unilateral and for bilateral implants and they were asked to list in order of their favoured top three views. RESULTS: No surgeon thought that a single-exposure Stenver's view was adequate for assessment of the contra-lateral side. Consensus was that all AP views were fit for the purpose, with no preference given between each of the AP views. The ipsi-lateral Stenver's was considered to give better depth of insertion information. CONCLUSION: There is no apparent advantage of caudal and cranial tilt angles over a straight perpendicular AP. A single-view AP radiograph is an alternative to Stenver's view for a post-unilateral and post-simultaneous bilateral cochlear implant check.