Latest Publications

Adv Sci (Weinh). 2023 Jul 23:e2301756. doi: 10.1002/advs.202301756. Online ahead of print.

ABSTRACT

Astrocytes are diverse brain cells that form large networks communicating via gap junctions and chemical transmitters. Despite recent advances, the functions of astrocytic networks in information processing in the brain are not fully understood. In culture, brain slices, and in vivo, astrocytes, and neurons grow in tight association, making it challenging to establish whether signals that spread within astrocytic networks communicate with neuronal groups at distant sites, or whether astrocytes solely respond to their local environments. A multi-electrode array (MEA)-based device called AstroMEA is designed to separate neuronal and astrocytic networks, thus allowing to study the transfer of chemical and/or electrical signals transmitted via astrocytic networks capable of changing neuronal electrical behavior. AstroMEA demonstrates that cortical astrocytic networks can induce a significant upregulation in the firing frequency of neurons in response to a theta-burst charge-balanced biphasic current stimulation (5 pulses of 100 Hz × 10 with 200 ms intervals, 2 s total duration) of a separate neuronal-astrocytic group in the absence of direct neuronal contact. This result corroborates the view of astrocytic networks as a parallel mechanism of signal transmission in the brain that is separate from the neuronal connectome. Translationally, it highlights the importance of astrocytic network protection as a treatment target.

PMID:37485646 | DOI:10.1002/advs.202301756

Otol Neurotol. 2023 Jun 15. doi: 10.1097/MAO.0000000000003913. Online ahead of print.

ABSTRACT

OBJECTIVE: The objective of this study is to determine the rate of postoperative meningitis after cochlear implantation in those with inner ear malformations (IEMs) via meta-analysis.

DATA SOURCES: Medline, EMBASE, and the Cochrane Library.

METHODS: This study was reported following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist. Proportion meta-analysis was conducted through an inverse variance random-effect model based on arcsin transformation and presented as forest plots. Quality assessment of the included studies was performed through the National Institutes of Health Quality Assessment Tool.

RESULTS: Overall, 38 of 2966 studies met the inclusion criteria and were included in the analysis. There were 10 cases of meningitis after cochlear implantation in 1300 malformed ears. The overall rate of meningitis after cochlear implantation in IEMs was 0.12% (95% confidence interval, 0.006-0.380%; I2 = 0%). Cases occurred in incomplete partition (n = 5), Mondini deformity (n = 2), common cavity (n = 2), and enlarged internal auditory canal (n = 1). Six of 10 cases of postoperative meningitis occurred with an intraoperative cerebrospinal fluid leak.

CONCLUSION: In those with IEMs, the risk of meningitis after cochlear implantation is very low.

PMID:37317518 | DOI:10.1097/MAO.0000000000003913

Adv Healthc Mater. 2023 Jun 13:e2300732. doi: 10.1002/adhm.202300732. Online ahead of print.

ABSTRACT

Cochlear implants are a life-changing technology for those with severe sensorineural hearing loss, partially restoring hearing through direct electrical stimulation of the auditory nerve. However, they are known to elicit an immune response resulting in fibrotic tissue formation in the cochlea which is linked to residual hearing loss and suboptimal outcomes. Intracochlear fibrosis is difficult to track without post-mortem histology, and no specific electrical marker for fibrosis exists. In this study, we developed a tissue-engineered model of cochlear fibrosis following implant placement to examine the electrical characteristics associated with fibrotic tissue formation around electrodes. We characterized the model using electrochemical impedance spectroscopy and found an increase in the resistance and a decrease in capacitance of the tissue using a representative circuit. This result informed a new marker of fibrosis progression over time that is extractable from voltage waveform responses, which can be directly measured in cochlear implant patients. This marker was tested in a small sample size of recently implanted cochlear implant patients, showing a significant increase over two post-operative timepoints. Using this system, we demonstrated complex impedance as a marker of fibrosis progression that is directly measurable from cochlear implants to enable real-time tracking of fibrosis formation in patients, creating opportunities for earlier treatment intervention to improve cochlear implant efficacy. This article is protected by copyright. All rights reserved.

PMID:37310792 | DOI:10.1002/adhm.202300732

Ann Biomed Eng. 2023 Apr 22. doi: 10.1007/s10439-023-03192-3. Online ahead of print.

ABSTRACT

As the first clinically translated machine-neural interface, cochlear implants (CI) have demonstrated much success in providing hearing to those with severe to profound hearing loss. Despite their clinical effectiveness, key drawbacks such as hearing damage, partly from insertion forces that arise during implantation, and current spread, which limits focussing ability, prevent wider CI eligibility. In this review, we provide an overview of the anatomical and physical properties of the cochlea as a resource to aid the development of accurate models to improve future CI treatments. We highlight the advancements in the development of various physical, animal, tissue engineering, and computational models of the cochlea and the need for such models, challenges in their use, and a perspective on their future directions.

PMID:37087541 | DOI:10.1007/s10439-023-03192-3

Clin Otolaryngol. 2023 Apr 13. doi: 10.1111/coa.14062. Online ahead of print.

ABSTRACT

OBJECTIVES: To estimate the prevalence of, and risk factors associated with electrode migration (EM) in cochlear implant (CI) recipients.

DESIGN: Historical cohort study of all CIs performed between 1 January 2018 and 1 August 2021 in a single tertiary adult and paediatric CI centre in the UK.

MAIN OUTCOME MEASURES: The primary aim is to determine the prevalence of electrode migration, comparing intraoperative surgeon report and examination of a routine plain radiograph performed 2 weeks after surgery. EM is defined as the detection of movement of two or more electrodes out of the cochlea from the time of surgery. Multivariate analysis was performed to investigate preoperative and intraoperative risk factors that might predispose to migration.

RESULTS: Four hundred and sixty-five patients, having 516 distinct surgeries, with 628 implants were analysed. EM occurred following 11.5% of implant operations. Pre-existing cochlear abnormality was an independent associated risk factor for EM (OR: 3.40 ⟨1.20-9.62⟩ p = .021). Demographics, surgical technique, usage of a precurved electrode, CSF leak, surgeon seniority and intraoperative telemetry did not influence risk of migration. There were 5 implants (0.8%) which migrated later than 2 weeks, with a median date of imaging diagnosis (x-ray or CT scan) of 263 days ⟨IQR:198⟩, for which head injury was a common precipitating factor. There were differences in the risk of migration between different lateral wall electrodes.

CONCLUSION: EM in the early postoperative period is a common occurrence and is more likely in implant recipients with obstructed or malformed cochleae.

PMID:37051731 | DOI:10.1111/coa.14062

Eur Arch Otorhinolaryngol. 2023 Apr 3. doi: 10.1007/s00405-023-07928-8. Online ahead of print.

NO ABSTRACT

PMID:37010599 | DOI:10.1007/s00405-023-07928-8

Otolaryngol Head Neck Surg. 2023 Mar 2. doi: 10.1002/ohn.309. Online ahead of print.

ABSTRACT

OBJECTIVE: This study aims to estimate the rate of postoperative meningitis (both immediate and long-term) in patients following cochlear implants (CIs). It aims to do so through a systematic review and meta-analysis of published studies tracking complications after CIs.

DATA SOURCES: MEDLINE, Embase, and Cochrane Library.

REVIEW METHODS: This review was performed in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies tracking complications following CIs in patients were included. Exclusion criteria included non-English language studies and case series reporting <10 patients. Bias risk was evaluated using the Newcastle-Ottawa Scale. Meta-analysis was performed through DerSimonian and Laird random-effects models.

RESULTS: A total of 116/1931 studies met the inclusion criteria and were included in the meta-analysis. Overall, there were 112 cases of meningitis in 58,940 patients after CIs. Meta-analysis estimated an overall rate of postoperative meningitis of 0.07% (95% confidence interval [CIs], 0.03%-0.1%; I2 = 55%). Subgroup meta-analysis showed this rate had 95% CIs crossing 0% in implanted patients who received the pneumococcal vaccine, antibiotic prophylaxis, those with postoperative acute otitis media (AOM), and those implanted less than 5 years.

CONCLUSION: Meningitis is a rare complication following CIs. Our estimated rates of meningitis after CIs appear lower than prior estimates based on epidemiological studies in the early 2000s. However, the rate still appears higher than the baseline rate in the general population. The risk was very low in implanted patients who received the pneumococcal vaccine, antibiotic prophylaxis, received unilateral or bilateral implantations, developed AOM, those implanted with a round window or cochleostomy techniques, and those under 5 years.

PMID:36864717 | DOI:10.1002/ohn.309

BMJ Open. 2023 Feb 20;13(2):e061349. doi: 10.1136/bmjopen-2022-061349.

ABSTRACT

OBJECTIVE: To establish consensus definitions for necrotising otitis externa (NOE) to facilitate the diagnosis and exclusion of NOE in clinical practice and expedite future high-quality study of this neglected condition.

DESIGN: The work comprised of a systematic review of the literature, five iterative rounds of consultation via a Delphi process and open discussion within the collaborative. An expert panel analysed the results to produce the final outputs which were shared with and endorsed by national specialty bodies.

SETTING: Secondary care in the UK.

PARTICIPANTS: UK clinical specialists practising in infection, ear nose and throat (ENT) surgery or radiology.

MAIN OUTCOME MEASURES: Definitions and statements meeting the following criteria were accepted: (a) minimum of 70% of respondents in agreement or strong agreement with a definition/statement AND (b) <15% of respondents in disagreement or strong disagreement with a definition/statement.

RESULTS: Seventy-four UK clinicians specialising in ENT, Infection and Radiology with a special interest in NOE took part in the work which was undertaken between 2019 and 2021. The minimum response rate for a Round was 76%. Consensus criteria for all proposed case definitions, outcome definitions and consensus statements were met in the fifth round.

CONCLUSIONS: This work distills the clinical opinion of a large group of multidisciplinary specialists from across the UK to create practical definitions and statements to support clinical practice and research for NOE. This is the first step in an iterative process. Further work will seek to validate and test these definitions and inform their evolution.

PMID:36806133 | PMC:PMC9945308 | DOI:10.1136/bmjopen-2022-061349

Clin Otolaryngol. 2023 Jan 16. doi: 10.1111/coa.14037. Online ahead of print.

ABSTRACT

OBJECTIVE: There is a paucity of research examining patient experiences of cochlear implants. We sought to use natural language processing methods to explore patient experiences and concerns in the online cochlear implant (CI) community.

MATERIALS AND METHODS: Cross-sectional study of posts on the online Reddit r/CochlearImplants forum from 1 March 2015 to 11 November 2021. Natural language processing using the BERTopic automated topic modelling technique was employed to cluster posts into semantically similar topics. Topic categorisation was manually validated by two independent reviewers and Cohen's kappa calculated to determine inter-rater reliability between machine vs human and human vs human categorisation.

RESULTS: We retrieved 987 posts from 588 unique Reddit users on the r/CochlearImplants forum. Posts were initially categorised by BERTopic into 16 different Topics, which were increased to 23 Topics following manual inspection. The most popular topics related to CI connectivity (n = 112), adults considering getting a CI (n=107), surgery-related posts (n = 89) and day-to-day living with a CI (n = 85). Cohen's kappa among all posts was 0.62 (machine vs human) and 0.72 (human vs human), and among categorised posts was 0.85 (machine vs human) and 0.84 (human vs human).

CONCLUSIONS: This cross-sectional study of social media discussions amongst the online cochlear implant community identified common attitudes, experiences and concerns of patients living with, or seeking, a cochlear implant. Our validation of natural language processing methods to categorise topics shows that automated analysis of similar Otolaryngology-related content is a viable and accurate alternative to manual qualitative approaches. This article is protected by copyright. All rights reserved.

PMID:36645237 | DOI:10.1111/coa.14037

Ear Hear. 2022 Dec 8. doi: 10.1097/AUD.0000000000001305. Online ahead of print.

NO ABSTRACT

PMID:36477611 | DOI:10.1097/AUD.0000000000001305

Biosensors (Basel). 2022 Nov 10;12(11):999. doi: 10.3390/bios12110999.

ABSTRACT

(1) Background: During a cochlear implant insertion, the mechanical trauma can cause residual hearing loss in up to half of implantations. The forces on the cochlea during the insertion can lead to this mechanical trauma but can be highly variable between subjects which is thought to be due to differing anatomy, namely of the scala tympani. This study presents a systematic investigation of the influence of different geometrical parameters of the scala tympani on the cochlear implant insertion force. The influence of these parameters on the insertion forces were determined by testing the forces within 3D-printed, optically transparent models of the scala tympani with geometric alterations. (2) Methods: Three-dimensional segmentations of the cochlea were characterised using a custom MATLAB script which parametrised the scala tympani model, procedurally altered the key shape parameters (e.g., the volume, vertical trajectory, curvature, and cross-sectional area), and generated 3D printable models that were printed using a digital light processing 3D printer. The printed models were then attached to a custom insertion setup that measured the insertion forces on the cochlear implant and the scala tympani model during a controlled robotic insertion. (3) Results: It was determined that the insertion force is largely unaffected by the overall size, curvature, vertical trajectory, and cross-sectional area once the forces were normalised to an angular insertion depth. A Capstan-based model of the CI insertion forces was developed and matched well to the data acquired. (4) Conclusion: By using accurate 3D-printed models of the scala tympani with geometrical alterations, it was possible to demonstrate the insensitivity of the insertion forces to the size and shape of the scala tympani, after controlling for the angular insertion depth. This supports the Capstan model of the cochlear implant insertion force which predicts an exponential growth of the frictional force with an angular insertion depth. This concludes that the angular insertion depth, rather than the length of the CI inserted, should be the major consideration when evaluating the insertion force and associated mechanical trauma caused by cochlear implant insertion.

PMID:36354508 | DOI:10.3390/bios12110999

Eur Arch Otorhinolaryngol. 2022 Sep 26. doi: 10.1007/s00405-022-07638-7. Online ahead of print.

ABSTRACT

OBJECTIVES OF REVIEW: To review the literature for the evidence base for the aetiology and management of referred otalgia, looking particularly at non-malignant, neuralgic, structural and functional issues.

TYPE OF REVIEW: Systematic review.

SEARCH STRATEGY: A systematic literature search was undertaken from the databases of EMBASE, CINAHL, MEDLINE®, BNI, and Cochrane Library according to predefined inclusion and exclusion criteria.

EVALUATION METHOD: All relevant titles, abstracts and full text articles were reviewed by three authors who resolved any differences by discussion and consultation with senior author.

RESULTS: 44 articles were included in our review. The overall quality of evidence was low, with the vast majority of the studies being case-series with three cohort and four randomised-controlled trials included. The prime causes and management strategies were focussed on temporomandibular joint dysfunction (TMJD), Eagle syndrome and neuralgia. Our meta-analyses found no difference on the management strategies for the interventions found.

CONCLUSIONS: Referred otalgia is common and treatment should be aimed at the underlying pathology. Potential aetiologies are vast given the extensive sensory innervation of the ear. An understanding of this and a structured approach to patient assessment is important for optimal patient management.

PMID:36163556 | DOI:10.1007/s00405-022-07638-7

Curr Opin Otolaryngol Head Neck Surg. 2022 Aug 25. doi: 10.1097/MOO.0000000000000839. Online ahead of print.

ABSTRACT

PURPOSE OF REVIEW: Autoimmune inner ear disease (AIED) is a rare, but likely underrecognized cause of hearing loss. However, hearing loss is common in systemic autoimmune disease and it is important for the clinician to be familiar with the spectrum of disease. In this article, we will review the developments in diagnosis and management of AIED, with a focus on the outcomes and potential pitfalls of cochlear implantation.

RECENT FINDINGS: Hearing loss in AIED tends to be progressive and bilateral, but up to 40% can present as sudden hearing loss and one-third can present unilaterally. HSP-70 serology may help with diagnosis and may predict steroid response. Cochlear implantation provides excellent hearing and quality of life outcomes in patients deafened by AIED. Intracochlear fibrosis/ossification is found intraoperatively in the majority (54%) of patients undergoing cochlear implantation. A large percentage (32%) of patients has fluctuating impedances postimplantation, which may interfere with implant performance and mapping.

SUMMARY: Diagnosis of AIED is largely clinical, and a strong index of suspicion is required. Multidisciplinary care is crucial for optimal management. Cochlear implant outcomes are generally excellent, but the clinician needs to be cognizant of the pitfalls of encountering intracochlear fibrosis intraoperatively and likelihood of implant performance fluctuation related to ongoing inflammation in the cochlea.

PMID:36004773 | DOI:10.1097/MOO.0000000000000839

Otol Neurotol. 2022 Aug 1;43(7):734-741. doi: 10.1097/MAO.0000000000003574. Epub 2022 Jul 19.

ABSTRACT

OBJECTIVE: This study aimed to establish hearing outcomes after cochlear implantation in patients with otosclerosis.

MATERIALS AND METHODS: We conducted a systematic review and narrative synthesis. Databases searched were as follows: MEDLINE, PubMed, Embase, Web of Science, Cochrane Collection, and ClinicalTrials.gov . No limits were placed on language or year of publication. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

RESULTS: Searches identified 474 abstracts and 180 full texts, with 68 studies meeting the inclusion criteria and reporting outcomes in a minimum of 481 patients with at least 516 implants. Patient-reported outcome measures (PROMs) were reported in five studies involving 51 patients. Intraoperative adverse events/surgical approach details and preoperative radiological assessment were reported in 46 and 38 studies, respectively. The methodological quality of included studies was modest, predominantly consisting of case reports and noncontrolled case series with small numbers of patients. Most studies were Oxford Centre for Evidence Based Medicine grade IV.

DISCUSSION: Access to good rehabilitation support is essential to achieving the good hearing outcomes and PROMs that can be expected by 12 months after implantation in most cases. There was a significant association between the radiological severity of otosclerosis and an increase in surgical and postoperative complications. Postoperative facial nerve stimulation can occur and may require deactivation of electrodes and subsequent hearing detriment.

CONCLUSIONS: Hearing outcomes are typically good, but patients should be counseled on associated surgical complications that may compromise hearing. Modern diagnostic techniques may help to identify potentially difficult cases to aid operative planning and patient counseling. Further work is needed to characterize PROMs in this population.

PMID:35861644 | DOI:10.1097/MAO.0000000000003574

Clin Otolaryngol. 2022 Jul 14. doi: 10.1111/coa.13963. Online ahead of print.

ABSTRACT

OBJECTIVE: To investigate the value of scalp surface potentials to identify and manage partial short circuits to ground in cochlear implant electrodes.

DESIGN: A retrospective review of patients with suspected partial short circuits.

MAIN OUTCOME MEASURE: Electrical output of individual electrodes was measured using scalp surface potentials for patients reporting a change in hearing function. Electrical output was compared to functional performance and impedance measurements to determine if devices with suspected partial short circuits were experiencing a decrease in performance as a result of reduced electrical output. Electrical output was checked in an artificial cochlea for two implants following explant surgery to confirm scalp surface potential results.

RESULTS: All patients with suspected partial short circuits (n=49) had reduced electrical output, a drop in impedances to approximately ½ of previously stable measurements or to below 2 kOhms, an atypical electrical field measurement (EFI) and a decline in hearing function. Only devices with an atypical EFI showed reduced electrical output. Results of scalp based surface potentials could be replicated in an artificial cochlea following explantation of the device. All explant reports received to date (n=42) have confirmed partial short circuits, with an additional 4 devices failing integrity tests.

CONCLUSION: Surface potential measurements can detect partial shorts and had 100% correlation with atypical EFI measurements, which are characteristic of a partial short to ground in this device. Surface potentials can help determine the degree to which the electrode array is affected, particularly when behavioural testing is limited or not possible.

PMID:35833359 | DOI:10.1111/coa.13963

Otol Neurotol. 2022 Jul 1;43(6):702-708. doi: 10.1097/MAO.0000000000003536.

ABSTRACT

OBJECTIVE: To analyse the 2 and 5-year outcomes of a cohort of patients with newly diagnosed vestibular schwannoma patients.

STUDY DESIGN: Longitudinal cohort study.

SETTING: Tertiary skull base referral unit.

PATIENTS: Six hundred and seventy-one consecutive patients referred to the Cambridge Skull Base Unit between 2005 and 2010.

MAIN OUTCOME MEASURES: 1) Treatment outcomes, 2) hearing preservation, 3) facial nerve function, and 4) gross tumor control.

RESULTS: At initial diagnosis, 440/671(65.6%) of patients entered a watch, wait and rescan (WWR) pathway, 208/671 (31%) underwent primary microsurgical excision and 23/671 (3.4%) primary radiotherapy. Of patients who entered WWR, 144/440 (32.7%) exhibited tumor growth necessitating secondary intervention at a mean of 22.7 months; 67.4% had radiotherapy and 32.6% surgery. Radiotherapy was successful at achieving tumor control in 95% of cases. Primary surgery via the translabyrinthine route was performed in the majority of cases allowing for a radiologically clear surgical resection in 93% of cases.

CONCLUSION: The Cambridge philosophy of treating the newly diagnosed vestibular schwannoma aims at preserving functional status where possible. In patients with small tumors it is recommended that they are placed on to a WWR pathway, of which 67.3% will not exhibit any growth by 5 years. If small tumors grow more than 2 mm by serial scanning, radiotherapy offers a high rate of tumor control. In patients with larger tumors more than 20 mm we would advocate microsurgical excision by the translabyrinthine route which offers excellent functional outcomes and gross tumor control.

PMID:35709433 | DOI:10.1097/MAO.0000000000003536

Otol Neurotol. 2022 Jun 1;43(5):e548-e557. doi: 10.1097/MAO.0000000000003512. Epub 2022 Feb 15.

ABSTRACT

HYPOTHESIS: Stimulation-Current-Induced Non-Stimulating Electrode Voltage Recordings (SCINSEVs) can help detect extracochlear electrodes for a variety of Cochlear Implant (CI) devices.

BACKGROUND: Extracochlear electrodes (EEs) occur in 9 to 13% of cochlear implantations and commonly go unnoticed without imaging. Electrodes on the electrode array located extracochlearly are associated with non-auditory stimulation and a decrease in speech outcomes. We have previously shown that SCINSEVs, with hardware and software from one manufacturer, could detect EEs. Here, we test the generalizability to other manufacturers.

METHODS: Fresh-frozen human cadaveric heads were implanted with Cochlear Ltd. CI522 (CI-A) and MED-EL's FLEX24 (CI-B) electrodes. Contact impedances and SCIN- SEVs were measured, with Cochlear Ltd. research Custom Sound software (Transimpedance Matrix) and MED-EL's clinical MAESTRO (Impedance Field Telemetry), for full insertion and EEs in air, saline and soft tissue. An automated detection tool was optimized and tested for these implants. Intra-operative SCINSEVs with EEs were collected for clinical purposes for six patients.

RESULTS: The pattern of SCINSEVs changed in the transition zone from intracochlear to extracochlear electrodes, even with low contact impedances on EEs. Automated detection in the cadaveric specimens, with two or more EEs in saline or soft tissue, showed a mean 91% sensitivity and specificity for CI-A and 100% sensitivity and specificity for CI-B. Quantification of EEs showed significant correlations of r = 0.69 between estimated and actual EEs for CI-A and r = 0.76 for CI-B.

CONCLUSION: The applicability of SCINSEVs to detect extra- cochlear electrodes could be expanded to other cochlear implant companies despite differences in electrode array design and measurement software.

PMID:35617005 | DOI:10.1097/MAO.0000000000003512

Eur Arch Otorhinolaryngol. 2022 May 13. doi: 10.1007/s00405-022-07399-3. Online ahead of print.

ABSTRACT

PURPOSE: Primary: To determine the rate of occult cervical metastases in primary temporal bone squamous cell carcinomas (TBSSC). Secondary: to perform a subgroup meta-analysis of the risk of occult metastases based on the clinical stage of the tumour and its risk based on corresponding levels of the neck.

METHODS: A systematic review and meta-analysis of papers searched through Medline, Cochrane, Embase, Scopus and Web of Science up to November 2021 to determine the pooled rate of occult lymph node/parotid metastases. Quality assessment of the included studies was assessed through the Newcastle-Ottawa scale.

RESULTS: Overall, 13 out of 3301 screened studies met the inclusion criteria, for a total of 1120 patients of which 550 had TBSCC. Out of the 267 patients who underwent a neck dissection, 33 had positive lymph nodes giving a pooled rate of occult metastases of 14% (95% CI 10-19%). Occult metastases rate varied according to Modified Pittsburg staging system, being 0% (0-16%) among 12 pT1, 7% (2-20%) among 43 pT2 cases, 21% (11-38%) among 45 pT3, and 18% (11-27%) among 102 pT4 cases. Data available showed that most of the positive nodes were in Level II.

CONCLUSION: The rate of occult cervical metastases in TBSCC increases with pathological T category with majority of nodal disease found in level II of the neck.

PMID:35562514 | DOI:10.1007/s00405-022-07399-3

Laryngoscope Investig Otolaryngol. 2022 Feb 8;7(2):540-563. doi: 10.1002/lio2.749. eCollection 2022 Apr.

ABSTRACT

OBJECTIVE: Establish anatomical considerations, audiological outcomes, and optimal management in patients with branchiootic/branchiootorenal syndrome (BO/BOR).

METHODS: Databases reviewed: Medline, Pubmed, Embase, Web of Science, Cochrane Collection, and ClinicalTrials.gov. Clinical or radiological studies of patients with BOR syndrome describing either the audiological profile or anatomical changes were included. Articles in which BOR syndrome was associated with other syndromes, and those that were focused only on general and genetic aspects of BOR syndrome were excluded. Articles were assessed using Oxford Centre for Evidence-Based Medicine (OCEBM) grading system and the Brazzelli risk of bias tool for nonrandomized studies.

RESULTS: Searches identified 379 articles. Of these, 64 studies met the inclusion criteria, reporting outcomes in 482 patients from at least 95 families. In 308 patients, hearing loss was categorized as sensorineural (29%), conductive (20%), and mixed (51%). Hearing outcomes were variable in terms of onset, pattern, and severity; ranging from mild to profound deafness. One hundred sixty-nine patients presented with inner ear anomalies, 145 had middle, and 151 had external ear abnormalities. In 44 studies, 58 ear operations were described. Mixed outcomes were reported in patients managed with hearing aids or middle ear surgery; however, successful cochlear implantation was described in all five cases.

CONCLUSION: The anatomical and audiological profiles of patients with BO/BOR are variable. A range of surgical procedures were described, however lacked objective outcome measures. Given the range of anatomical variants, management decisions should be made on an individual basis including full audiological and radiological assessment.

LEVEL OF EVIDENCE: NA.

PMID:35434312 | PMC:PMC9008175 | DOI:10.1002/lio2.749

IEEE Trans Biomed Eng. 2022 Apr 13;PP. doi: 10.1109/TBME.2022.3167113. Online ahead of print.

ABSTRACT

GOAL: Advances in computational models of biological systems and artificial neural networks enable rapid virtual prototyping of neuroprosthetics, accelerating innovation in the field. Here, we present an end-to-end computational model for predicting speech perception with cochlear implants (CI), the most widely-used neuroprosthetic.

METHODS: The model integrates CI signal processing, a finite element model of the electrically-stimulated cochlea, and an auditory nerve model to predict neural responses to speech stimuli. An automatic speech recognition neural network is then used to extract phoneme-level speech perception from these neural response patterns.

RESULTS: Compared to human CI listener data, the model predicts similar patterns of speech perception and misperception, captures between-phoneme differences in perceptibility, and replicates effects of stimulation parameters and noise on speech recognition. Information transmission analysis at different stages along the CI processing chain indicates that the bottleneck of information flow occurs at the electrode-neural interface, corroborating studies in CI listeners.

CONCLUSION: An end-to-end model of CI speech perception replicated phoneme-level CI speech perception patterns, and was used to quantify information degradation through the CI processing chain.

SIGNIFICANCE: This type of model shows great promise for developing and optimizing new and existing neuroprosthetics.

PMID:35417340 | DOI:10.1109/TBME.2022.3167113