Selection of patients for multiple-channel cochlear implantation

The Journal of Laryngology & Otology, 1977

1991

Cochlear implantation is indicated in patients with severe to profound hearing loss that cannot be adequately treated by other auditory rehabilitation measures. The definitive indication of cochlear implantation is made on the basis of an extensive interdisciplinary clinical, audiological, radiological, and psychological diagnostic work-up. There are numerous changes are happening in cochlear implant candidacy. These have been associated with concomitant changes in surgical techniques, which enhanced the utility and safety of cochlear implantation. Currently, cochlear implants are approved for individuals with severe to profound unilateral hearing loss rather than previously needed for bilateral profound hearing loss. Studies have begun using the short electrode arrays for shallow insertion in patients with low-frequency residual hearing loss. The advancement in designs of the cochlear implant along with improvements in surgical techniques reduce the complications and result in the safety and efficacy of the cochlear implant which further encourages the use of these devices. This review article aims to discuss the new concepts in the candidacy of the cochlear implant, cochlear implant in younger children and hearing preservation, a cochlear implant for unilateral deafness, bilateral cochlear implant, and cochlear implant with neural plasticity and selection of patients for the cochlear implant.

Owing to technological progress and a growing body of clinical experience, indication criteria for cochlear implants (CI) are being extended to less severe hearing impairments. It is, therefore, worth reconsidering these indication criteria by introducing novel testing procedures. The diagnostic evidence collected will be evaluated. The investigation includes postlingually deafened adults seeking a CI. Prior to surgery, speech perception tests [Freiburg Speech Test and Oldenburg sentence (OLSA) test] were performed unaided and aided using the Oldenburg Master Hearing Aid (MHA) system. Linguistic skills were assessed with the visual Text Reception Threshold (TRT) test, and general state of health, socioeconomic status (SES) and subjective hearing were evaluated through questionnaires. After surgery, the speech tests were repeated aided with a CI. To date, 97 complete data sets are available for evaluation. Statistical analyses showed significant correlations between postsurgical speech reception threshold (SRT) measured with the adaptive OLSA test and pre-surgical data such as the TRT test (r=-0.29), SES (r=-0.22) and (if available) aided SRT (r=0.53). The results suggest that new measures and setups such as the TRT test, SES and speech perception with the MHA provide valuable extra information regarding indication for CI.

Perspectives in Pragmatics, Philosophy & Psychology, 2017

The aim of this study is to detect the variations in cochlear size which may help in selection of the best cochlear implant electrode length and may also influence the insertion depth angles of the electrode arrays. To achieve this goal, 40 patients (21 females and 19 male) were included, their age ranged from 4 to 57 years (mean 24.63±17.30 years), pre-and postoperative non-contrast CT examination of the petrous bone was performed. It showed that, the cochlear distance (diameter A) ranged between 7.10-10.10mm (mean 8.53 ± 0.56mm) ,The cochlear duct length ranged between 25.50-38.0mm (mean 31.45 ± 2.33mm), postoperative, insertion depth angles ranged between 405 to 500o (mean 450.17±36.77), for advanced bionics, 211.0-420.0o (mean 367.56 ± 71.81o) for cochlear nucleus, 371.0-520.0o (mean 456.14 ± 61.33o) for Flex 28, and 475.0-598.0o (mean 513.06 ± 31.76 o) for Med-El standard electrode, a non-significant correlation was found between the insertion depth angles and the cochlear distance. A statistically significant positive correlation was found between the insertion depth angle and length of the electrode array. Therefore, it is concluded that assessing the cochlear parameters helps to choose the optimal electrode to provide proper cochlear coverage while avoiding insertional trauma.

Journal of International Advanced Otology, 2012

Background: the preoperative assessment, the surgical procedure and the postoperative evaluation of cochlear implantation (CI) are evolving fast to improve effectiveness and to reduce complications. Objective: to disclose the current trends in CI and the customs of practice of CI teams worldwide. Methods: a survey on CI had been conducted through an online questionnaire posted on the Global Otology Online Discussion Forum of the Politzer Society-The International Society for Otologic Surgery and Science. Questions were grouped into general informations, preoperative issues, surgical procedure, postoperative issues and free comments. A preliminary statistical analysis was performed. Results: one-hundred and twenty-one responses were recorded, coming from 43 nations in the 5 continents. CI in single sided deafness (SSD), CI at extreme ages, the relationship between electrode array technology and outcome, minimally invasive CI techniques, quality of life after CI were investigated. Conclusion: some facets of CI are still a controversial topic, resulting in very different standards of practice among CI teams.

European Archives of Oto-Rhino-Laryngology, 2014

The goal of this work was to review the pre-and postsurgical auditory thresholds of two surgical implantation techniques, namely the mastoidectomy with posterior tympanotomy approach (MPTA) and suprameatal approach (SMA), to determine whether there is a difference in the degree of preservation of residual hearing. In a series of 430 consecutive implanted patients 227 patients had measurable pre-operative hearing thresholds at 250, 500, and 1,000 Hz. These patients were divided into two groups according to the surgical technique that was used for implantation. The SMA approach was followed for 84 patients in Amsterdam, whereas the MPTA technique was adhered to 143 patients in Maastricht. The outcome variables of interest were alteration of pre-and postoperative auditory thresholds after cochlear implantation. Complete or partial preservation of residual hearing was obtained in 21.4 and 21.7 % in the SMA and MPTA group, respectively. No statistical differences could be found between the SMA and MPTA group (p = 0.96; Chi-square test). The SMA technique is correlated with a similar degree of hearing loss after cochlear implantation compared to the MPTA technique. However, both techniques were not able to conserve a measurable amount of hearing in patients with a substantial degree of residual hearing. Therefore, both surgical techniques need to be refined for patients in which residual acoustical hearing is pursued.

2014

analysis of several factors was performed to reveal any significant effect of the outcome of the procedure. RESULTS: The duration of deafness in adults showed a significant linear yet non-monotonic correlation with the postoperative average auditory thresholds as revealed by Pearson’s correlation coefficient (r=0.839, p=0.009) and a linear regression model (f=14.211, p=0.009), which showed that the increase in the duration of deafness led to an increase in hearing thresholds and accounted for 70.3% of the variance in the outcome (β=0.839, t=3.770, and p=0.009). Age at implantation in children showed a positive linear, monotonic relation with the postoperative receptive (r=0.725, p<0.001, r S =0.354, p=0.010) and was a significant predictor of outcome (β=0.440, t=2.961; p=0.005) according to multiple linear regression. Mann-Whitney U-test was performed to evaluate the difference in medians of outcomes in relation to the regularity of attendance to speech rehabilitation. We found a...

Brazilian Journal of Otorhinolaryngology, 2014

Introduction: Knowledge of the characteristics related to profound hearing loss is a matter of great importance, as it allows for the etiological and prognostic identification and strategic planning for public health interventions. Objective: To assess the different etiologies of hearing loss, age at diagnosis of the hearing loss, its relation to language acquisition, and the age at the first consultation in this service for cochlear implant assessment. Methods: This was a historical cohort, cross-sectional study, using retrospective analysis of the records of 115 patients with confirmed sensorineural hearing loss, who were followed in a university hospital, based on gender, age of hearing loss, age at the first consultation, language, and hearing loss etiology. Results and conclusion: The majority of patients assessed for cochlear implants attend the first consultation when they are older than one year (an alarming mean of 3.8 years in the prelingual group) in spite of the early diagnosis of hearing loss. This reflects an already deficient health care system, in terms of referral. The idiopathic cause remains the most frequently identified. Among the known causes, the most prevalent are perinatal causes and meningitis. Implante coclear; Perfil de saúde; Perda auditiva bilateral

Cochlear Implants International, 2009

The objective of this study was to determine if intra-operative auditory monitoring is feasible during cochlear implantation and whether this can be used as feedback to the surgeon to improve the preservation of residual hearing. This prospective non-randomised study was set in a paediatric tertiary referral hospital. Thirty eight consecutive paediatric patients undergoing cochlear implantation who had measurable auditory thresholds pre-operatively were divided into two cohorts. The unmonitored cohort included the fi rst 22 patients and the monitored cohort included the last 16 patients. The main outcome measure(s) were pre-operative, intra-operative and more than one month post-operative average auditory thresholds at 500, 1000 and 2000 Hz measured using auditory steady-state response audiometry. The average pre-operative thresholds were 103.5 dB HL and 99.7 dB HL in the unmonitored and monitored cohorts, respectively. These were not statistically different (p > 0.3). In the monitored cohort, we measured auditory thresholds to assess cochlear function at multiple time points during the operation. Compared to baseline, thresholds were increased 0.7 dB after drilling the mastoidectomy and well, 0.2 dB after opening the cochlea and 4.6 dB after inserting the electrode array. One month post-operatively, the average thresholds were 114.0 dB HL in the unmonitored cohort but only 98.8 dB HL in the monitored cohort (p < 0.001). Both the use of JS Oghalai et al. 2 intra-operative auditory monitoring and higher pre-operative thresholds were associated with improved preservation of residual hearing (p < = 0.001). Intra-operative auditory monitoring is a viable tool that can provide real-time feedback to the surgeon during cochlear implant surgery. These data suggest that this can lead the surgeon to modify his or her surgical technique in ways that can improve the rate of long-term hearing preservation. The majority of the patients had minimal changes in their ASSR thresholds during the procedure. The average thresholds at each time point confi rm this (baseline: 108.1 dB HL; before opening cochlea: 108.8 dB HL; after opening cochlea: 108.3 dB Figure 2: Predictors of hearing preservation. (A) Scatter plot of the pre-operative average threshold versus the threshold shift (post-operative minus pre-operative threshold). A regression line is also plotted (R 2 = 0.167, p = 0.02). (B) Box plot showing the average threshold shift in the unmonitored and monitored cohorts. These were statistically different (p = 0.006). The boxes contain the 25-75 per cent values and the error bars contain the ten to 90 per cent values. The line within the box is the median value.