The Effect of Electrode Placement on Cochlear Implant Function and Outcomes

Cochlear implants have been an effective treatment for restoring profound sensorineural hearing loss to those who do not benefit from traditional hearing aids. Advances in surgical technique and electrode design allow for preservation of residual hearing. This allows cochlear implant candidacy criteria to expand to those with good low frequency hearing and severe high frequency hearing loss above 1000 Hz with poor speech discrimination. With a less traumatic surgical approach, low frequency hearing can be preserved resulting in combined low frequency auditory perception and mid- to high-frequency electric perception resulting in electro-acoustic stimulation (EAS). Despite the improvements in cochlear implantation, outcomes continue to vary significantly from one user to another. The variance in performance may potentially be due to the placement of the electrode within in the cochlea. This study focused on performance of patients compared to insertion depth, age, pitch perception and electrophysiologic measures. Patients with residual hearing were included and outcome measures were measured via speech perception tests. Radiographic imaging confirmed insertion depth, and the change in pure tone average was compared to this depth. Hearing preservation was further accomplished with two patients who presented with residual mid and high frequency hearing. Custom atraumatic electrodes were inserted, and hearing was preserved across all frequencies. These cases allowed for electric and acoustic pitch matching experiments to be conducted in the same ear providing information on where in the cochlear the implant is actually stimulating. Several pairs along the cochlea were run between electric and acoustic pitches at varying rates of stimulation. Place to pitch mismatch varied depending on the area within the cochlea. Lastly, objective measures were used in attempt to determine the variance in outcomes. Two main contributing factors govern implant performance, 1) the ability of the processor to effectively deliver the electrical signal to the ear, and 2) the patient's ability to process the information. Peripheral mechanisms were analyzed with the electric compound action potential and its amplitude growth function. The slope of the amplitude growth function was measured at the corresponding electrodes and compared to speech discrimination scores. Steeper slopes correlated with increased word understanding abilities. For further insight into the health of the cochlea, age effects were compared to hearing preservation. The pure tone averages were calculated before and after surgery. Pure tone averages following surgery elevated with increased age suggesting that the elderly may be at more risk for loss of residual hearing as compared to the general population

The Impact of a Post-Prescription Review and Feedback Antimicrobial Stewardship Program in Lebanon

Antimicrobial stewardship programs (ASPs) are effective means to optimize prescribing practices. They are under-utilized in the Middle East where many challenges exist for ASP implementation. We assessed the effectiveness of infectious disease physician-driven post-prescription review and feedback as an ASP in Lebanon. This prospective cohort study was conducted over an 18-month period in the medical, surgical, and intensive care units of a tertiary care hospital. It consisted of three phases: the baseline, intervention, and follow-up. There was a washout period of two months between each phase. Patients aged ≥16 years receiving 48 h of antibiotics were included. During the intervention phase, the AMS team reviewed antimicrobial use within 72 h post-prescription and gave alternate recommendations based on the guidelines for use. The acceptance of the recommendations was measured at 72 h. The primary outcome of the study was days of therapy per 1000 study patient days. A total of 328 patients were recruited in the baseline phase (August-October 2020), 467 patients in the intervention phase (January-June 2021), and 301 patients in the post-intervention phase (September-December 2021). The total days of therapy decreased from 11.46 during the baseline phase to 8.64 during the intervention phase (p \u3c 0.001). Intervention acceptance occurred 88.5% of the time. The infectious disease physician-driven implementation of an ASP was successful in reducing antibiotic utilization in an acute care setting in Lebanon

Cochlear implant programming: a global survey on the state of the art

The programming of CIs is essential for good performance. However, no Good Clinical Practice guidelines exist. This paper reports on the results of an inventory of the current practice worldwide. A questionnaire was distributed to 47 CI centers. They follow 47600 recipients in 17 countries and 5 continents. The results were discussed during a debate. Sixty-two percent of the results were verified through individual interviews during the following months. Most centers (72%) participated in a cross-sectional study logging 5 consecutive fitting sessions in 5 different recipients. Data indicate that general practice starts with a single switch-on session, followed by three monthly sessions, three quarterly sessions, and then annual sessions, all containing one hour of programming and testing. The main focus lies on setting maximum and, to a lesser extent, minimum current levels per electrode. These levels are often determined on a few electrodes and then extrapolated. They are mainly based on subjective loudness perception by the CI user and, to a lesser extent, on pure tone and speech audiometry. Objective measures play a small role as indication of the global MAP profile. Other MAP parameters are rarely modified. Measurable targets are only defined for pure tone audiometry. Huge variation exists between centers on all aspects of the fitting practice

Cochlear Implant Programming: A Global Survey on the State of the Art

The programming of CIs is essential for good performance. However, no Good Clinical Practice guidelines exist. This paper reports on the results of an inventory of the current practice worldwide. A questionnaire was distributed to 47 CI centers. They follow 47600 recipients in 17 countries and 5 continents. The results were discussed during a debate. Sixty-two percent of the results were verified through individual interviews during the following months. Most centers (72%) participated in a cross-sectional study logging 5 consecutive fitting sessions in 5 different recipients. Data indicate that general practice starts with a single switch-on session, followed by three monthly sessions, three quarterly sessions, and then annual sessions, all containing one hour of programming and testing. The main focus lies on setting maximum and, to a lesser extent, minimum current levels per electrode. These levels are often determined on a few electrodes and then extrapolated. They are mainly based on subjective loudness perception by the CI user and, to a lesser extent, on pure tone and speech audiometry. Objective measures play a small role as indication of the global MAP profile. Other MAP parameters are rarely modified. Measurable targets are only defined for pure tone audiometry. Huge variation exists between centers on all aspects of the fitting practice

Cochlear Implant Programming: A Global Survey on the State of the Art

The programming of CIs is essential for good performance. However, no Good Clinical Practice guidelines exist. This paper reports on the results of an inventory of the current practice worldwide. A questionnaire was distributed to 47 CI centers. They follow 47600 recipients in 17 countries and 5 continents. The results were discussed during a debate. Sixty-two percent of the results were verified through individual interviews during the following months. Most centers (72%) participated in a cross-sectional study logging 5 consecutive fitting sessions in 5 different recipients. Data indicate that general practice starts with a single switch-on session, followed by three monthly sessions, three quarterly sessions, and then annual sessions, all containing one hour of programming and testing. The main focus lies on setting maximum and, to a lesser extent, minimum current levels per electrode. These levels are often determined on a few electrodes and then extrapolated. They are mainly based on subjective loudness perception by the CI user and, to a lesser extent, on pure tone and speech audiometry. Objective measures play a small role as indication of the global MAP profile. Other MAP parameters are rarely modified. Measurable targets are only defined for pure tone audiometry. Huge variation exists between centers on all aspects of the fitting practice

Audiology Practices in the Preoperative Evaluation and Management of Adult Cochlear Implant Candidates

Currently, no clear guidelines exist regarding clinical testing methods for identifying adult cochlear implant (CI) candidates. Indications provided by the US Food and Drug Administration, Medicare, and private insurers are ambiguous concerning test materials and the level and mode of test presentation. This could lead to wide variability in clinical assessment and, potentially, unequal access to CIs for individuals with clinically significant hearing loss. To examine the preoperative testing methods used by audiologists in evaluating adult CI candidates across the United States. A survey assessing audiology practice patterns was created using a Research Electronic Data Capture system hosted at the University of Miami. A link to a survey (65 questions in multiple-choice or rank-order format was distributed electronically along with a request for completion to members of the American Cochlear Implant Alliance and to the Institute for Cochlear Implant Training forum. Responses were collected from January 17 to June 4, 2018. Participation was limited to audiologists who evaluate adult CI candidates, and respondents who do not provide adult CI care were excluded. Collected demographic information included work setting, years of experience, and highest level of education attained. Percentages, medians, and interquartile ranges were from aggregated responses concerning hearing aid verification methods; testing methods, materials, and practices; nonauditory factors that might affect CI candidacy; audiology practice patterns; and expanded indications for CIs. Anonymized surveys were returned by 99 respondents; because surveys were available electronically, the number of audiologists who viewed the survey but did not respond was not available. Seven respondents identified themselves as pediatric specialists and were excluded, resulting in a total of 92 surveys available for analysis (denominators vary because respondents could complete the survey without answering all questions). Seventy percent of respondents (51 of 72) were doctors of audiology, and nearly 50% (33 of 74) were employed at universities and academic centers performing more than 50 CIs per year. When assessing adult candidacy for implant, most respondents reported using test materials from the Minimum Speech Test Battery: 96% (51 of 53), using AzBio sentences in quiet; 89% (47 of 53), AzBio sentences in noise; and 100% (53 of 53), the consonant-vowel nucleus-consonant, monosyllabic words test. However, these tests were applied inconsistently, with 39 of 53 respondents (74%) reporting use of a sound pressure level scale and the other 14 (26%) a hearing level scale at various decibel levels, and with some using a single signal-to-noise ratio and others using multiple ratios for sound-in-noise tests. Respondents' definitions of the best aided listening condition for assessing implant candidates also varied widely. Among the nonauditory factors ranked most important for assessing CI candidacy were patient's level of cognition and expectations of CI; yet, few respondents reported including cognitive or psychological tests in the assessment protocol. Findings of this study reveal considerable variability in preoperative testing methods and practices across health care professionals assessing adult candidates for CI. This lack of standardization in the delivery of care may increase the risk for health care inequities, specifically in access to care for adults with clinically significant hearing loss

Ipsilateral acoustic electric pitch matching: A case study of cochlear implantation in an up-sloping hearing loss with preserved hearing across multiple frequencies

Objectives Determine ipsilateral acoustic electric pitch place match in a patient with preserved residual hearing across a broad frequency range. Methods Case report. Patient with up-sloping sensorineural hearing loss underwent implantation with a 680° insertion angle with preserved residual hearing. Pitch matching with variance of pulse rate was carried out. Results Electrical pitch percepts closely approximated the Greenwood map when compared to the acoustical pitch percepts and electrode position as determined by post-operative computed tomographic scan. The pitch matching results achieved from the deeply inserted electrodes, in the apical portion of the cochlea, suggest that the electrical stimulation may activate the dendritic extensions from the ganglion cell bodies that radiate from the terminal bulb. Stimulation rate influenced pitch perception in the apical turn but not in the mid- and basilar regions. Discussion Frequency to pitch allocation can potentially be improved by cochlear implants that access the apical third of the spiral ganglion. The ultimate goal of stimulating the apical third of the cochlea is to provide the maximum amount of spectral information to the user. We had the unique opportunity to work with a patient who presented with a severe sensorineural hearing loss rising to within normal limits and poor speech discrimination scores. Data from this study may aid our ability to give patients a broader spectrum of sound perception

Partial Deafness Cochlear Implantation at the University of Kansas: Techniques and Outcomes

One of the most significant recent advances in cochlear implantation is the implantation of patients with residual hearing. These patients have a downsloping sensorineural hearing loss with poor speech discrimination and perform poorly with standard amplification. Studies using a variety of different electrode designs have demonstrated that it is possible to implant an inner ear and preserve residual hearing. Initial studies have demonstrated that a combination of residual acoustic hearing in the low frequencies with electrical stimulation in the mid- to high frequencies resulted in superior hearing performance in background noise. The objective of this study was to determine the effect of electrode insertion depth on hearing preservation. Eighteen patients with mild to severe hearing loss in the low frequencies combined with poor word recognition were recruited for the study. Cochlear implantation. Pre- and postoperative hearing test, Hearing in Noise Test, and consonant-nucleus-consonant testing. Data analysis was performed with Kruskal Wallis and Mann-Whitney testing. In our study of 18 patients implanted with a Med-El PulsarCI100 we demonstrated the ability to preserve residual hearing with implant insertion depths ranging from 20 to 28 mm, giving us the possibility of near complete cochlear frequency coverage with an implant array while preserving residual hearing. These patients performed well both in quiet and in 10 dB signal-to-noise ratio conditions. Hearing preservation was achievable even with deep implant insertion. Patients performed well in combined acoustic and electric conditions