Cochlear implant positioning:development and validation of an automatic method using computed tomography image analysis

The aim of this study was to preoperatively asses the feasibility of drilling a bony recess for the fixation of a cochlear implant in the temporal bone. Even though complications are rare with cochlear implantations, drilling at the site of implantation have resulted in hematoma or cerebrospinal fluid leakage. Mainly in cases with a reduced temporal bone thickness, the risk for complications has increased, such as in paediatric patients.Methods An in-house designed semi-automatic algorithm was developed to analyse a 3D model of the skull. The feasibility of drilling the recess was determined by a gradient descent method to search for the thickest part of the temporal bone. Feasibility was determined by the residual bone thickness which was calculated after a simulated drilling of the recess at the thickest position. An initial validation of the algorithm was performed by measuring the accuracy of the algorithm on five 3D models with known thickest locations for the recess. The accuracy was determined by a part comparison between the known position and algorithm provided position.Results In four of the five validation models a standard deviation for accuracy below the predetermined cut-off value of 4.2 mm was achieved between the actual thickest position and the position determined by the algorithm. Furthermore, the residual thickness calculated by the algorithm showed a high agreement (max. 0.02 mm difference) with the actual thickness.Conclusion With the developed algorithm, a semi-automatic method was created to analyse the temporal bone thickness within a specified region of interest on the skull. Thereby, providing indications for surgical feasibility, potential risks for anatomical structures and impact on procedure time of cochlear implantation. This method could be a valuable research tool to objectively assess feasibility of drilling a recess in patients with thin temporal bones preoperatively

The impact of injury of the chorda tympani nerve during primary stapes surgery or cochlear implantation on taste function, quality of life and food preferences:A study protocol for a double-blind prospective prognostic association study

BACKGROUND: The chorda tympani nerve (CTN) is a mixed nerve, which carries sensory and parasympathetic fibres. The sensory component supplies the taste sensation of the anterior two-thirds of the ipsilateral side of the tongue. During middle ear surgery the CTN is exposed and frequently stretched or sacrificed, because it lacks a bony covering as it passes through the middle ear. Injury may cause hypogeusia, ageusia or altered taste sensation of the ipsilateral side of the tongue. To date, there is no consensus regarding which type of CTN injury (sacrificing or stretching), during middle ear surgery, leads to the least burden for the patient.METHODS: A double-blind prospective prognostic association study was designed in a single medical centre in the Netherlands to determine the effect of CTN injury on postoperative taste disturbance and quality of life. 154 patients, who will undergo primary stapes surgery or cochlear implantation will be included. The taste sensation, food preferences and quality of life of these patients will be evaluated preoperatively and at one week, six weeks and six months postoperatively using the Taste Strip Test, Electrogustometry, supplementary questionnaire on taste disturbance, Macronutrient and Taste Preference Ranking Task, Appetite, Hunger and Sensory Perception questionnaire and Questionnaire of Olfactory Disorders to assess the association of these outcomes with CTN injury. Evaluation of olfactory function will only take place preoperatively and at one week postoperatively using the Sniffin' Sticks. The patient and outcome assessor are blinded to the presence or absence of CTN injury.DISCUSSION: This study is the first to validate and quantify the effect of chorda tympani nerve injury on taste function. The findings of this study may lead to evidence-based proof of the effect of chorda tympani injury on taste function with consequences for surgical strategies.TRIAL REGISTRATION: Netherlands Trial Register NL9791. Registered on 10 October 2021.</p

Systematic review:Validity, reliability, and diagnostic accuracy of the electrogustometer

OBJECTIVE: What are the electrogustometer's (EGM) validity, reliability, and diagnostic accuracy in assessing taste sensation in adults compared to other taste tests?DATA SOURCES: PubMed Medline, Elseviers's Embase, and the six databases of Cochrane Library.METHODS: We conducted a systematic search on December 20, 2022, consisting of synonyms for EGM. We considered randomized controlled trials and observational studies with original data for inclusion if they included adults who underwent electrogustometry. Articles were excluded if no analysis regarding validity, reliability, or diagnostic accuracy had been performed or if these analyses could not be performed with the published data.RESULTS: Nineteen articles discussing 18 studies were included for data extraction. The included studies carry a high risk of bias. Overall, the association between a variety of reference taste tests and EGM was moderate or weak with correlation coefficients ranging from -0.51 to 0.40 with one outlier of -0.74 found in one study correlating EGM and taste solutions. Test-retest reliability was good with reported correlation coefficients between 0.78 and 1.0. The sensitivity, specificity, PPV, and NPV of EGM in identifying abnormal taste function varied widely between the four studies on diagnostic accuracy.CONCLUSION: The included studies in this review lack the required standards regarding study design to draw firm conclusions about the validity, reliability, and diagnostic accuracy of the EGM. Future research is needed to assess these measurement properties. Based on the reported results, we would not recommend using the EGM as a screening test for taste disturbance in clinical practice.LEVEL OF EVIDENCE: NA.</p

Systematic review:Validity, reliability, and diagnostic accuracy of the electrogustometer

OBJECTIVE: What are the electrogustometer's (EGM) validity, reliability, and diagnostic accuracy in assessing taste sensation in adults compared to other taste tests?DATA SOURCES: PubMed Medline, Elseviers's Embase, and the six databases of Cochrane Library.METHODS: We conducted a systematic search on December 20, 2022, consisting of synonyms for EGM. We considered randomized controlled trials and observational studies with original data for inclusion if they included adults who underwent electrogustometry. Articles were excluded if no analysis regarding validity, reliability, or diagnostic accuracy had been performed or if these analyses could not be performed with the published data.RESULTS: Nineteen articles discussing 18 studies were included for data extraction. The included studies carry a high risk of bias. Overall, the association between a variety of reference taste tests and EGM was moderate or weak with correlation coefficients ranging from -0.51 to 0.40 with one outlier of -0.74 found in one study correlating EGM and taste solutions. Test-retest reliability was good with reported correlation coefficients between 0.78 and 1.0. The sensitivity, specificity, PPV, and NPV of EGM in identifying abnormal taste function varied widely between the four studies on diagnostic accuracy.CONCLUSION: The included studies in this review lack the required standards regarding study design to draw firm conclusions about the validity, reliability, and diagnostic accuracy of the EGM. Future research is needed to assess these measurement properties. Based on the reported results, we would not recommend using the EGM as a screening test for taste disturbance in clinical practice.LEVEL OF EVIDENCE: NA.</p

Cochlear Implant Awareness: Development and Validation of a Patient Reported Outcome Measure

BACKGROUND: Surgical success of cochlear implantation is usually measured through speech perception and quality of life questionnaires. Although these questionnaires cover a broad spectrum of domains, they do not evaluate the consciousness of wearing a cochlear implant (CI) and how this impacts the daily life of patients. To evaluate this concept we aimed to develop and validate a standardized patient reported outcome measure (PROM) for use in cochlear implant users. METHODS: Development and evaluation of the COchlear iMPlant AwareneSS (COMPASS) questionnaire was realized following the COSMIN guidelines in three phases: (1) item generation, (2) qualitative pilot study to ensure relevance, comprehensiveness, comprehensibility, and face validity, and (3) quantitative survey study for the assessment of reliability (test-retest) with 54 participants. RESULTS: Nine domains of CI awareness were identified through literature research and interviews with experts and patients. These resulted in the formulation of 18 items which were tested with a pilot study, after which 3 items were deleted. The final 15-item COMPASS questionnaire proved to have good validity and satisfactory reliability. The intraclass correlation coefficient calculated for items with continuous variables ranged from 0.66 to 0.89 with seven out of eight items scoring above the acceptable level of 0.7. The Cohen's kappa calculated for items with nominal variables ranged from -0.4 to 0.78 with 11 (sub)items out of 15 scoring above fair to good agreement. Measurement error analysis for items with continuous variables showed a mean difference of -2.18 to 0.22. The calculated 95% limits of agreement for these items revealed no statistically significant difference between the two administered questionnaires. For items with nominal variables, the percentages of agreement calculated, ranged between 0 and 95%, and 83.3 and 96.6% for positive and negative agreement, respectively. CONCLUSION: The COMPASS questionnaire is a valid and reliable PROM for evaluating the cochlear implant awareness, and it can be easily used in routine clinical practice

Adhesion and proliferation of human schwann cells on adhesive coatings

Attachment to and proliferation on the substrate are deemed important considerations when Schwann cells (SCs) are to be seeded in synthetic nerve grafts. Attachment is a prerequisite for the SCs to survive and fast proliferation will yield large numbers of SCs in a short time, which appears promising for stimulation of peripheral nerve regeneration. The aim of the present study was to compare the adhesion and proliferation of human Schwann cells (HSCs) on different substrates. The following were selected for their suitability as an internal coating of synthetic nerve grafts; the extracellular matrix proteins fibronectin, laminin and collagen type I and the poly-electrolytes poly( -lysine) (PDL) and poly(ethylene-imine) (PEI). On all coatings, attachment of HSCs was satisfactory and comparable, indicating that this factor is not a major consideration in choosing a suitable coating.\ud \ud Proliferation was best on fibronectin, laminin and PDL, and worst on collagen type I and PEI. Since nerve regeneration is enhanced by laminin and/or fibronectin, these are preferred as coatings for synthetic nerve grafts seeded with SCs

Engaging Long-Term Care Workers in Research: Recruitment Approaches and Participant Characteristics From a Randomized Controlled Trial to Improve COVID-19 Vaccine Confidence.

To describe and compare the recruitment methods employed in a randomized controlled trial targeting long-term care workers, and resulting participant baseline characteristics. We used a multifaceted recruitment process to enroll long-term care workers in our 3-arm randomized controlled trial comparing 2 interventions to enhanced usual practice, for improving COVID-19 vaccine confidence and other outcomes. Adult long-term care workers living in the United States employed within the last 2 years were invited to join the study. Participants also had to meet specific screening criteria related to their degree of worry about the vaccine and/or their vaccination status. We used a participatory approach to engage our long-term care stakeholders in codesigning and executing a combination of recruitment methods, including targeted e-recruitment, paid e-recruitment, and in-person recruitment. Participants were screened, consented, and enrolled online. We implemented a participant verification process to ensure the integrity of our study data, and used a tailored participant management platform to manage enrollment. We enrolled 1930 long-term care workers between May 2022 and January 2023. We met our enrollment target, despite each recruitment method having limitations. Total variable costs of approximately $102,700 were incurred and differed on a per-enrolled participant basis across methods:$25.73 for targeted e-recruitment, $57.12 for paid e-recruitment, and$64.92 for in-person methods. Our sample differed from the national population in age, gender, race/ethnicity, education, and role in long-term care. Differences were also observed between online and in-person recruitment methods. Our results support the feasibility of enrolling a large number of long-term care workers in a randomized controlled trial to increase COVID-19 vaccine confidence. Findings build upon the evidence base for engaging this important population in research, a critical step to improving long-term care resident health and well-being. Results from our trial are anticipated in 2024