Michal Luntz

Objective measurements of auditory nerve recovery function in nucleus CI 24 implantees in relation to subjective preference of stimulation rate

Objective Setting the optimal rate of stimulation for individual cochlear implant recipients is critical to the successful functional outcome of cochlear implantation. In the absence of an objective methodology, cochlear implants are currently fitted by means of a time-consuming (and therefore expensive) trial-and-error process of limited accuracy. The aim of this study was to evaluate a possible relationship between the patients subjectively preferred stimulation rate and an objective measurement of auditory nerve recovery time. Material and Methods Eleven recipients of Nucleus CI 24 implants initially fitted with a speech processor using the ACE speech-coding strategy at a rate of 900 Hz were introduced to 2 other stimulation rate options, 1200 and 1800 Hz, at 2 different fitting sessions and asked to choose their preferred rate. Preferences were compared with objective measurements of auditory nerve recovery time obtained using the refractory recovery function of neural response telemetry. Results The auditory nerve recovery time for individuals with a subjective preference for a slow stimulation rate was longer than that for individuals who preferred a fast stimulation rate, with significant differences between the 2 groups for 3 tested electrodes (7, 11 and 15): p=0.024, 0.009 and 0.03, respectively (Mann–Whitney test). Conclusion The association observed between the subjective stimulation rate preference and measurements of auditory nerve recovery time indicates that the measured auditory nerve recovery time can be used as a reliable predictor for setting up a basic stimulation rate of a particular individuals map, thus reducing the cost of the technology and significantly increasing its effectiveness.

Risk factors for sensorineural hearing loss in chronic otitis media

Abstract Conclusions: Risk factors for sensorineural hearing loss (SNHL) development in patients with chronic otitis media (COM) are longer duration of disease, older age and the presence of cholesteatoma. To prevent the expected development of SNHL, it is imperative to treat COM actively. Objectives: To assess the severity of SNHL in patients with unilateral COM and to define risk factors for its development. Methods: The study included 317 patients with unilateral COM. Mean age was 28.7 ± 16.7 years (range 7–78 years) and mean duration of disease was 12.2 ± 11.3 years (range 0.25–60 years). In all patients, air conduction (AC) and bone conduction (BC) thresholds in both ears were measured at 500, 1000, 2000 and 4000 Hz. The parameters evaluated were demographics, duration of disease, presence and location of cholesteatoma and otologic history. Results: The difference in mean BC thresholds between the diseased ears and the healthy ears was statistically significant, ranging from 4.55 ± 10.89 dB to 12.55 ± 19.09 dB across the measured frequency range (p < 0.0001). Multivariate regression analysis revealed statistically significant correlations between advanced age, longer duration of disease and presence of cholesteatoma, and the BC threshold differences between the affected and healthy ears.

Risk factors for sensorineural hearing loss in pediatric chronic otitis media

OBJECTIVES To assess the clinical significance of sensorineural hearing loss (SNHL) in a group of pediatric patients suffering from unilateral chronic otitis media (COM) with or without cholesteatoma, using the contralateral healthy ear as a control, and to define risk factors for the development of SNHL in such patients. METHODS The subjects of this retrospective study were 124 pediatric patients with unilateral COM admitted for surgery. Mean age at surgery was 13.3±3.2 years (range, 7-18) and mean duration of the disease was 88.4±45.0 months (range, 6-192 months). The preoperative pure-tone average value (PTA) for bone conduction (BC) was calculated in each ear (BC-PTA) as the average of BC thresholds at 500, 1000, 2000, and 4000Hz. Potential risk factors for SNHL that we evaluated were demographics, duration of disease, presence of cholesteatoma, and previous otologic history. RESULTS Mean BC-PTA values in the diseased ears prior to surgery differed significantly from those in the healthy ears (12.74±8.75dB and 9.36±6.33dB, respectively; P<0.01). The degree of SNHL in the diseased ear at 2000Hz was found to be significantly correlated with the presence of cholesteatoma and with age above 10 years. CONCLUSIONS One of the complications of COM, with or without cholesteatoma, in addition to the conductive hearing loss, is the development of clinically significant SNHL. It is therefore imperative to actively treat pediatric patients diagnosed with COM, with the aim of preventing the possible development of SNHL.

Sound localization in patients with cochlear implant-preliminary results

OBJECTIVES To evaluate sound localization ability in patients with unilateral cochlear implant, who do not wear a hearing aid on the contralateral ear, and to try to improve this ability by training. SETTING Tertiary academic referral center. METHODS In the initial test, patients were exposed to sound stimuli from different directions and were asked to localize them. Following a training period the patients were re-evaluated by the same test. For each test, the percentage of correct answers and the final test score were calculated. RESULTS In the initial test, the mean score of the study group of four cochlear implant users was 42.8 (out of a maximal score of 100), the mean rate of correct responses was 27.5%. Following a training period (6.5 sessions on the average), on the final test the mean score of the group was 74.3, while the mean rate of correct responses was 66.5%. CONCLUSIONS The results demonstrated that patients with unilateral cochlear implant have some ability to localize sound, and that this ability may be improved by regular training.

Sound localization in patients with unilateral cochlear implants

Objectives To evaluate sound localization ability in totally deaf patients with unilateral cochlear implants and to estimate the ability to improve this function by training. Design A controlled case series. Materials and methods Nine patients with monaural cochlear implants were asked to identify the source of 50 randomly distributed sound stimuli coming from five different directions anteriorly or laterally. After some training, patients were retested. There were two control groups. One comprised nine adults with normal hearing, and the other comprised nine adults with normal hearing but one ear plugged. Results The mean initial score of the study group (maximal score 100) was 41.5 (range 23-63). Patients who had used cochlear implants longer had better sound localization ability (Spearmans correlation coefficient = 0.92). On retesting, after an average of 6.3 training sessions, their mean score improved to 66 (range 32-95), (p=0.008). The improvement was more pronounced in postlinguals than in prelinguals (p=0.016). Conclusions Spontaneous development of sound localization ability in totally deaf patients with unilateral cochlear implants is proprtional to the time interbal between implantation and initial testing. Improvement appears to be influenced by training, and to be greater in postlingual than prelingual implantees.

Natural history of contralateral residual hearing in unilateral cochlear implant users - long-term findings.

Abstract Conclusion: The long-term stability of low-frequency residual hearing found in a significant number of bilateral-bimodal users (cochlear implant (CI) in one ear and a hearing aid (HA) on the other ear; CI/HA) with severe-to-profound or profound hearing loss in the non-implanted ear justifies bilateral-bimodal fitting efforts in this group. Since low-frequency residual hearing tends to deteriorate in some of these CI/HA users, periodic evaluation, which includes pure-tone thresholds and speech perception tests, is mandatory for determining the point in time at which CI/HA hearing is no longer effective, and the patient should accordingly be considered as a candidate for contralateral cochlear implantation. Objective: To determine, in bilateral-bimodal (CI/HA) users with severe-to-profound or profound hearing loss in the non-implanted ear, the rate of residual hearing deterioration in the non-implanted ear after cochlear implantation. Methods: Pure-tone aided and unaided thresholds in the non-implanted ears of 39 CI/HA users at 0.25–4.0 kHz were recorded prospectively up to 6 years after implantation. Results: Group mean threshold values in the non-implanted ears remained stable over 3, 4, 5 and 6 years post-implantation, except for significant deterioration at 4.0 kHz of both unaided (4.2, 5.2, 9.0 and 8.2 dB, respectively) and aided thresholds (8.1, 4.6, 6.1 and 8.3 dB, respectively).

Impact of Imaging in Management of Otosclerosis

The use of imaging in otosclerosis for diagnosis, preoperative assessment, and follow-up has the potential to give the clinician an additional tier of patient evaluation and validation of diagnosis. Before stapes surgery, imaging may help avoid unnecessary middle ear explorations in nonotosclerotic cases, prevent potential complications, and assist in appropriate patient counseling regarding management expectations. Postoperatively, following unsuccessful air-bone gap closure in stapes surgery or conductive hearing deterioration following initial successful closure of the air bone gap, imaging can be used to determine the prosthesis position in the middle ear.

Clinical Significance of Sensorineural Hearing Loss in Pediatric Chronic Otitis Media: Presenting Author: Noam Yehudai

Introduction: Hearing loss is considered a common complication and sequela of chronic otitis media (COM). The loss is usually conductive, but sensorineural involvement also occurs. Clinically significant sensorineural hearing loss (SNHL) has been reported in adults with COM; however its significance in children is still unclear. The aim of the study is to assess the severity of SNHL in single sided COM, in a group of children, using the contra-lateral healthy ear as a control and to define risk factors for the development of SNHL in COM. Characterizing these risk factors will assist in better defining treatment indications for COM and thus reduce the occurrence of SNHL.