Sound Exposure Promotes Intratympanic Drug Delivery to the Inner Ear.

OBJECTIVE: To investigate the impact of sound exposure, with the resultant windows vibration on perilymphatic concentrations following intratympanic (IT) dexamethasone and gentamicin in an animal model. STUDY DESIGN: Animal model blinded study. SETTING: Animal facility of a tertiary medical center. METHODS: Bilateral IT dexamethasone or gentamicin was applied to 15 tested rats. Following injections, each rat was exposed for 3 minutes to free field 30 dB sound pressure level (SPL), 512 vHz noise, with 1 external auditory canal plugged (contralateral control). Following noise exposure, perilymph was obtained from both ears. Drug concentrations were measured using ultrahigh-performance liquid chromatography-mass spectrometer. RESULTS: For dexamethasone, the average (±SD) perilymphatic steroidal concentration was 0.417 µg/mL (±0.549) in the control ears versus 0.487 µg/mL (±0.636) in the sound-exposed ears (P = .008). The average (±SD) gentamicin perilymphatic concentration was 8.628 µg/mL (±2.549) in the sound-exposed ears, compared to 4.930 µg/mL (±0.668) in the contralateral control (nonsound exposed) ears. Sound exposure promoted steroidal and gentamicin diffusion to the inner ear by an averaged (±SD) factor of 1.431 and 1.730 (±0.291 and 0.339), respectively. CONCLUSION: Low-intensity noise (30 dB SPL) was found to enhance dexamethasone phosphate and gentamicin diffusion to the inner ear (by an averaged factor of ∼1.4 and 1.7, respectively) in a murine model.

Balloon dilation of the eustachian tube using endovascular balloon under local anesthesia-a case series and systematic literature review.

Objective: To report a novel technique in Balloon Dilation of Eustachian Tube (BDET) using an endovascular balloon (EVB), in a prospective cohort. The results are compared with reported outcomes using standard balloons. Methods: Demographic information and clinical parameters were collected prospectively fora series of patients with obstructive eustachian tube dysfunction (OETD). Balloon dilation Eustachian tuboplasty was performed under local anesthesia in a tertiary referral center, using the EVB. Systematic literature review was used for comparison, using Medline via "PubMed", "Embase", and "Web of Science". Results: Eight OETD candidates (12 ears) were enrolled; 5 males and 3 females. Average age was 48 (range -23 to 63) years. The most common presenting symptom was aural fullness (9/12), followed by ear pressure (7/12), hearing loss (5/12) and tinnitus (4/12). Otoscopically, tympanic membrane retraction was evident in 10/12 ears, the majority of which was class II-Sade classification. Pre-operative tympanogram was type B and C in 7 and 5 ears, respectively. All BDETs were performed without complications. Post-operative tympanometry was A in 8/12 ears. Post-operatively, Eustachian Tube Dysfunction Questionnaire-7 results reduced to within normal limits (average score ≤3) in 11/12 ears (p = 0.0014). The systematic literature review included 6 papers (193 patients, 262 ETs) with comparable results, most also with little adverse effects. Conclusion: BDET using an EVB is a safe and effective option for OETD. It is well tolerated under local anesthesia in properly selected individuals. The reduced procedural cost may be an important factor in certain healthcare jurisdictions.

Hidden hearing loss: current concepts.

PURPOSE OF REVIEW: The purpose of this review is to offer a concise summary of current knowledge regarding hidden hearing loss (HHL) and to describe the variety of mechanisms that contribute to its development. We will also discuss the various diagnostic tools that are available as well as future directions. RECENT FINDINGS: Hidden hearing loss often also called cochlear synaptopathy affects afferent synapses of the inner hair cells. This description is in contrast to traditional models of hearing loss, which predominantly affects auditory hair cells. In HHL, the synapses of nerve fibres with a slow spontaneous firing rate, which are crucial for locating sound in background noise, are severely impaired. In addition, recent research suggests that HHL may also be related to cochlear nerve demyelination. Noise exposure causes loss of myelin sheath thickness. Auditory brainstem response, envelope-following response and middle-ear muscle reflex are promising diagnostic tests, but they have yet to be validated in humans. SUMMARY: Establishing diagnostic tools for cochlear synaptopathy in humans is important to better understand this patient population, predict the long-term outcomes and allow patients to take the necessary protective precautions.

Is otologic surgery contributing to the opioid epidemic?

BACKGROUND: The opioid epidemic is a significant public health crisis challenging the lives of North Americans. Interestingly, this problem does not exist to the same extent in Europe. Surgeons play a significant role in prescribing opioids, especially in the context of post-operative pain management. The aim of this study was to compare the post-surgical prescribing patterns of otologists comparing Canada and Austria. METHODS: An online questionnaire was sent to 33 Canadian and 32 Austrian surgeons, who perform otologic surgery on a regular basis. Surgeons were asked to answer some questions about their background as well as typical prescribing patterns for postoperative pain medication for different ear surgeries (cochlear implant, stapedotomy, tympanoplasty). In addition, surgeons were asked about the typical use of local anesthetics for pain control at the end of a procedure. Otologists gave an estimate how confident they were that their therapy and prescriptions provide sufficient pain control to their patients. RESULTS: Analysis of the returned questionnaires showed that opioids are more commonly prescribed in Canada than in Austria. Nonsteroidal anti-inflammatory drugs are used for postoperative pain more regularly after ear surgery in Austria, as opposed to Canada. Some of the prescribed drugs by European otologists are not available in North America. The use of local anesthetics at the end of surgery is not common in Austria. Surgeons´ confidence that the prescribed pain medication was sufficient to control postoperative symptoms was higher in the group not prescribing opioids than in the group that did routinely prescribe opioids. CONCLUSION: Prescribing patterns differ substantially between the two evaluated countries. This data suggests an opportunity to reduce opioid prescriptions after otologic surgeries. Studies to evaluate pain after these operations as well as efficacy of analgesics following ear surgery are an important next step.

The Benefit of a Wireless Contralateral Routing of Signals (CROS) Microphone in Unilateral Cochlear Implant Recipients.

OBJECTIVE: Assess speech outcomes in unilateral cochlear implant (CI) recipients after addition of a wireless contralateral routing of signals (CROS) microphone. STUDY DESIGN: Prospective cohort study. SETTING: Ambulatory. PATIENTS: Sixteen adult unilateral CI users with nonserviceable hearing on the contralateral side were recruited. Those with AzBio sentence scores of 40 to 80% or Hearing in Noise Test - Quiet (HINT-Q) scores of 60 to 90% with a CI alone were eligible participants. INTERVENTION: Speech testing was carried out with the CROS on and off. MAIN OUTCOME MEASURE: Speech recognition. RESULTS: In the consonant-nucleus-consonant test presented in quiet from the front, word scores were 64.4 (CI) and 63.8% (CI + CROS) (p = 0.72), and phoneme scores were 80.2 (CI) and 80.8% (CI + CROS) (p = 0.65). In AzBio sentence testing in quiet, with the signals projected from the contralateral, front, or ipsilateral to the CI, speech perception with the CI alone was 60.8, 75.9, and 79.1%. With the addition of the CROS microphone, using the same speaker arrangement, speech perception was 69.8 (p < 0.05), 71.8 (p = 0.05), and 71.8 (p < 0.05). In AzBio sentence testing in noise, speech perception with the CI alone was 18.6, 45.3, and 56.3% when signals were projected from contralateral, front, and ipsilateral sides to the CI. The addition of the CROS microphone led to speech perception of 45.3 (p < 0.05), 45.3 (p = 0.86), and 51.4% (p = 0.27) in the same paradigm. CONCLUSIONS: Addition of a wireless CROS microphone to a unilateral CI recipient can improve users' perception of speech in both quiet and noise if speech signals come from the deaf ear, mitigating the head shadow effect.

Noise exposure while commuting in Toronto - a study of personal and public transportation in Toronto.

BACKGROUND: With an increasing proportion of the population living in cities, mass transportation has been rapidly expanding to facilitate the demand, yet there is a concern that mass transit has the potential to result in excessive exposure to noise, and subsequently noise-induced hearing loss. METHODS: Noise dosimetry was used to measure time-integrated noise levels in a representative sample of the Toronto Mass Transit system (subway, streetcar, and buses) both aboard moving transit vehicles and on boarding platforms from April - August 2016. 210 measurements were conducted with multiple measurements approximating 2 min on platforms, 4 min within a vehicle in motion, and 10 min while in a car, on a bike or on foot. Descriptive statistics for each type of transportation, and measurement location (platform vs. vehicle) was computed, with measurement locations compared using 1-way analysis of variance. RESULTS: On average, there are 1.69 million riders per day, who are serviced by 69 subway stations, and 154 streetcar or subway routes. Average noise level was greater in the subway and bus than in the streetcar (79.8 +/- 4.0 dBA, 78.1 +/- 4.9 dBA, vs 71.5 +/-1.8 dBA, p < 0.0001). Furthermore, average noise measured on subway platforms were higher than within vehicles (80.9 +/- 3.9 dBA vs 76.8 +/- 2.6 dBA, p < 0.0001). Peak noise exposures on subway, bus and streetcar routes had an average of 109.8 +/- 4.9 dBA and range of 90.4-123.4 dBA, 112.3 +/- 6.0 dBA and 89.4-128.1 dBA, and 108.6 +/- 8.1 dBA and 103.5-125.2 dBA respectively. Peak noise exposures exceeded 115 dBA on 19.9%, 85.0%, and 20.0% of measurements in the subway, bus and streetcar respectively. CONCLUSIONS: Although the mean average noise levels on the Toronto transit system are within the recommended level of safe noise exposure, cumulative intermittent bursts of impulse noise (peak noise exposures) particularly on bus routes have the potential to place individuals at risk for noise induced hearing loss.

Linking Deafness and Dementia: Challenges and Opportunities.

: The rising incidence of dementia locally and worldwide has now reached a critical level. The associated costs associated with these individuals will ultimately be untenable to most societies. Furthermore there is a paucity of highly effective treatments. However, the recent discovery of the association of hearing loss and dementia may open many potential opportunities. Although we still are acquiring knowledge on the pathophysiology of this association, clinicians are hopeful that our current highly effective treatments of hearing loss may ultimately be shown to have a positive effect on those with dementia.

Development of cognitive screening test for the severely hearing impaired: Hearing-impaired MoCA.

OBJECTIVES: To develop a version of the Montreal Cognitive Assessment (MoCA) to be administered to the severely hearing impaired (HI-MoCA), and to assess its performance in two groups of cognitively intact adults over the age of 60. STUDY TYPE: Test development followed by prospective subject recruitment. METHODS: The MoCA was converted into a timed PowerPoint (Microsoft Corp., Redmond, WA) presentation, and verbal instructions were converted into visual instructions. Two groups of subjects over the age of 60 were recruited. All subjects passed screening questionnaires to eliminate those with undiagnosed mild cognitive impairment. The first group had normal hearing (group 1). The second group was severely hearing impaired (group 2). Group 1 received either the MoCA or HI-MoCA test (T1). Six months later (T2), subjects were administered the test (MoCA or HI-MoCA) they had not received previously to determine equivalency. Group 2 received the HI-MoCA at T1 and again at T2 to determine test-retest reliability. RESULTS: One hundred and three subjects were recruited into group 1, with a score of 26.66 (HI-MoCA) versus 27.14 (MoCA). This was significant (P < 0.05), but scoring uses whole numerals and the 0.48 difference was found not clinically significant using post hoc sensitivity analyses. Forty-nine subjects were recruited into group 2. They scored 26.18 and 26.49 (HI-MoCA at T1 and T2). No significance was noted (P > 0.05), with a test-retest coefficient of 0.66. CONCLUSION: The HI-MoCA is easy to administer and reliable for screening cognitive impairment in the severely hearing impaired. No conversion factor is required in our prospectively tested cohort of cognitively intact subjects. LEVEL OF EVIDENCE: 1b. Laryngoscope, 127:S4-S11, 2017.

Depth of Cochlear Implant Array Within the Cochlea and Performance Outcome.

OBJECTIVE: To evaluate whether the depth of cochlear implant array within the cochlea affects performance outcomes 1 year following cochlear implantation. METHODS: A retrospective case review of 120 patients who were implanted with the Advanced Bionics HiFocus 1J. Post-implantation plain-radiographs were retrospectively reviewed, and the depth of insertion was measured in degrees from the round window to the electrode tip. Correlation between the depth of insertion and 1-year post-activation Hearing in Noise Test (HINT) scores was analyzed. Intrascala position was not assessed. RESULTS: Depth of electrode insertion ranged from 180° to 720°, and HINT scores ranged from 0% to 100%. A Mann-Whitney U test demonstrated significantly improved 1-year post-activation HINT scores in patients with an insertion depth of 360° or more in comparison with patients with insertion depth of less than 360° (81% vs 61%, P = .048). Patients with 13 to 15 contacts within cochlear turns performed as well as patients with full insertion of all 16 contacts, while patients with only 12 contacts performed poorly. CONCLUSIONS: Insertion depth of the AB HiFocus 1J electrode of less than 360° is associated with reduced 1-year post-activation HINT scores when compared with deeper insertions. Partial insertion of 13 active contacts or more led to similar results as full insertion.

Comprehensive Expression of Wnt Signaling Pathway Genes during Development and Maturation of the Mouse Cochlea.

BACKGROUND: In the inner ear Wnt signaling is necessary for proliferation, cell fate determination, growth of the cochlear duct, polarized orientation of stereociliary bundles, differentiation of the periotic mesenchyme, and homeostasis of the stria vascularis. In neonatal tissue Wnt signaling can drive proliferation of cells in the sensory region, suggesting that Wnt signaling could be used to regenerate the sensory epithelium in the damaged adult inner ear. Manipulation of Wnt signaling for regeneration will require an understanding of the dynamics of Wnt pathway gene expression in the ear. We present a comprehensive screen for 84 Wnt signaling related genes across four developmental and postnatal time points. RESULTS: We identified 72 Wnt related genes expressed in the inner ear on embryonic day (E) 12.5, postnatal day (P) 0, P6 and P30. These genes included secreted Wnts, Wnt antagonists, intracellular components of canonical signaling and components of non-canonical signaling/planar cell polarity. CONCLUSION: A large number of Wnt signaling molecules were dynamically expressed during cochlear development and in the early postnatal period, suggesting complex regulation of Wnt transduction. The data revealed several potential key regulators for further study.

Diffusion Tensor Imaging Tractography of the Facial Nerve in Patients With Cerebellopontine Angle Tumors.

OBJECTIVE: To demonstrate the utility of diffusion tensor imaging (DTI) fiber tractography of the facial nerve in patients with cerebellopontine angle (CPA) tumors. STUDY DESIGN: Prospective. SETTING: Tertiary referral center. PATIENTS: DTI technique was established in 113 patients without tumors and in 28 patients with CPA tumors. Subsequently, DTI results were compared with intraoperative findings in 21 patients with medium and large-sized tumors, treated surgically via a translabyrinthine approach. INTERVENTION: Three Tesla magnetic resonance (MR) was used for DTI tractography. For patients without CPA tumors, the scanning protocol was 32 directions with a 3 × 3 × 3 mm voxel size. For CPA tumor patients, scanning protocol was 32 directions with a 2 × 2 × 2 mm voxel size. DTI data were used to track the facial nerve. MAIN OUTCOME MEASURES: Facial nerve identification rate. RESULTS: Facial nerve identification rate in MR-DTI was 97% and 100% in patients without tumors and in patients with tumors of the CPA of the internal auditory canal that were not treated surgically, respectively. MR-DTI identification of the facial nerve was successful in 20 patients who were treated surgically (95%). Good agreement between surgical findings and MR-DTI results was found in 19 patients (90%). CONCLUSION: MR DTI tractography is an effective technique in positively identifying the position of the facial nerve in patients with CPA tumors.

Predictors of round window accessibility for adult cochlear implantation based on pre-operative CT scan: a prospective observational study.

BACKGROUND: Cochlear implantation has become a mainstream treatment option for patients with severe to profound sensorineural hearing loss. During cochlear implant, there are key surgical steps which are influenced by anatomical variations between each patient. The aim of this study is to determine if there are potential predictors of difficulties that may be encountered during the cortical mastoidectomy, facial recess approach and round window access in cochlear implant surgery based upon pre-operative temporal bone CT scan. METHODS: Fifty seven patients undergoing unilateral cochlear implantation were analyzed. Difficulty with 1) cortical mastoidectomy, 2) facial recess approach, and 3) round window access were scored intra-operatively by the surgeon in a blinded fashion (1 = "easy", 2 = "moderate", 3 = "difficult"). Pre-operative temporal bone CT scans were analyzed for 1) degree of mastoid aeration; 2) location of the sigmoid sinus; 3) height of the tegmen; 4) the presence of air cells in the facial recess, and 5) degree of round window bony overhang. RESULTS: Poor mastoid aeration and lower tegmen position, but not the location of sigmoid sinus, are associated with greater difficulty with the cortical mastoidectomy. Presence of an air cell around the facial nerve was predictive of easier facial recess access. However, the degree of round window bony overhang was not predictive of difficulty associated with round window access. CONCLUSION: Certain parameters on the pre-operative temporal bone CT scan may be useful in predicting potential difficulties encountered during the key steps involved in cochlear implant surgery.

The role of a new contralateral routing of signal microphone in established unilateral cochlear implant recipients.

OBJECTIVES/HYPOTHESIS: To investigate whether a contralateral routing of signal (CROS) microphone combined with a unilateral cochlear implant (CI) results in hearing improvement after a prolonged trial period. STUDY DESIGN: A prospective experimental trial was undertaken on a group of 10 postlingually deafened adults who are experienced CI users. METHODS: Participants completed audiometric testing and validated questionnaires with their unilateral CI alone, followed by addition of a CROS microphone (CI-CROS). This was worn daily for the 2-week trial, after which hearing performance was reevaluated using the same measures. Objective tests included AzBio sentences in quiet and noise and consonant-vowel nucleus-consonant (CNC) words. Subjective measures included the Abbreviated Profile of Hearing Aid Benefit (APHAB); Speech, Spatial, Qualities of Hearing Index (SSQ); Hearing Implant Sound Quality Index; an institutional questionnaire; and a daily log sheet. RESULTS: There is statistically significant enhanced speech discrimination with the CI-CROS when speech is presented on the CROS side. However, scores are markedly diminished when background noise is introduced, particularly to the CROS side. Subjective results indicate lower satisfaction scores for the global and ease of communication subdomains of the APHAB with the CI-CROS, but increased scores on the spatial hearing subdomain of the SSQ (P < 0.05). CONCLUSION: The CI-CROS provides significant benefit in certain situations, particularly speech recognition in quiet. CI-CROS performance with background noise is poor, leading to low satisfaction scores. Further refinement of the device may yield a useful tool for unilateral CI users in the future.

Development of an ototoxicity model in the adult CBA/CaJ mouse and determination of a golden window of corticosteroid intervention for otoprotection.

OBJECTIVE: To investigate the effect of timing of dexamethasone administration on auditory hair cell survival following an ototoxic insult with kanamycin and furosemide. STUDY DESIGN: Controlled experimental study. SETTING: Translational science experimental laboratory. METHODS: 5-6 week old CBA/CaJ mice, divided into 6 groups, were injected with kanamycin (1 mg/g SC) followed by furosemide (0.5 mg/g IP). Dexamethasone (0.1 mg/g IP) was injected at either 1 hour prior to insult, +1 hr, +6 hr, +12 hr, or +72 hr post insult. Temporal bones harvested on day 7 underwent Organ of Corti dissection. Immunohistochemical staining was performed using antibodies to myosin 7a, phalloidin, and TO-PRO. RESULTS: Hair cell counts demonstrate a uniform ototoxicity model with total loss of outer hair cells (OHCs) and near-total loss of inner hair cells (IHCs). The group pre-treated with dexamethasone showed a statistically significant improvement in counts compared to controls (p = 0.004). Counts from the other experimental groups given dexamethasone after the insult were highly variable but demonstrated some apical and middle turn inner hair cell survival. CONCLUSION: Treatment of systemic dexamethasone prior to ototoxic insult attenuates hair cell loss in a reliable, novel, ototoxicity model using kanamycin and furosemide in CBA/CaJ mice. Dosing with dexamethasone following ototoxic insult shows promising yet variable response in hair cell survival.

Cochlear implantation in patients with chronic suppurative otitis media.

OBJECTIVE: To determine the safety, efficacy, and outcomes of cochlear implantation in patients with chronic suppurative otitis media (CSOM). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center with large cochlear implant program. PATIENTS: Nineteen patients with CSOM who underwent cochlear implantation were identified. Case history, timing of surgical procedures, complications, infections, and postimplant audiometric scores (Hearing in Noise Test [HINT], City University of New York Sentences [CUNY], and Central Institute for the Deaf Sentences [CID]) were evaluated. MAIN OUTCOME MEASURES: Rates of postoperative infections and complications as well as postimplant auditory performance. RESULTS: Twelve patients underwent a staged procedure involving canal wall down mastoidectomy or radical revision mastoidectomy with middle ear and mastoid obliteration and closure of the external auditory canal followed by cochlear implantation approximately 5 months later. Seven patients were implanted in a single procedure. There were no infections or medical complications after implantation. On average, patients had excellent audiometric scores at 1 year postimplantation (mean sentence test, 79%; SD, 14), and these scores were comparable to our general population (mean sentence test, 71%; SD, 32). CONCLUSION: Cochlear implant patients with CSOM have no increased risk of postoperative infections or complications. These patients have excellent outcomes with audiometric scores comparable to the general cochlear implant population. Cochlear implantation is a safe and effective treatment for patients with profound hearing loss secondary to CSOM.

Changes in the cochlear vasculature and vascular endothelial growth factor and its receptors in the aging c57 mouse cochlea.

Introduction. Previous work has shown a strong association between alterations in cochlear vasculature, aging, and the development of presbycusis. The important role of vascular endothelial growth factor (VEGF) and its receptors Flt-1 and Flk-1 in angiogenesis suggests a potential role for involvement in this process. The aim of this study was to characterize vascular structure and VEGF and its' receptors in young and old C57 Mice. Methods. Young (4 weeks, n = 14) and aged (32-36 weeks, n = 14) C57BL/6 mice were used. Hearing was evaluated using auditory brainstem response. Cochleas were characterized with qRT-PCR, immunohistochemistry, and gross histological quantification. Results. Old C57 mice demonstrated significantly decreased strial area, blood vessel number, luminal size, and luminal area normalized to strial area (vascularity). qRT-PCR showed a significant upregulation of Flt-1, a VEGF receptor, in older animals. No differences were found in VEGF-A or Flk-1. Immunohistochemistry did not show any differences in staining intensity or area with age or cochlear turn location. Conclusion. The marked deafness of aged C57 mice could be in part meditated by loss of vascular development and alterations in VEGF signaling.

Attenuating Cardiac Pulsations within the Cochlea: Structure and Function of Tortuous Vessels Feeding Stria Vascularis.

The mammalian ear has an extraordinary capacity to detect very low-level acoustic signals from the environment. Sound pressures as low as a few µ Pa (-10 dB SPL) can activate cochlear hair cells. To achieve this sensitivity, biological noise has to be minimized including that generated by cardiovascular pulsation. Generally, cardiac pressure changes are transmitted to most peripheral capillary beds; however, such signals within the stria vascularis of the cochlea would be highly disruptive. Not least, it would result in a constant auditory sensation of heartbeat. We investigate special adaptations in cochlear vasculature that serve to attenuate cardiac pulse signals. We describe the structure of tortuous arterioles that feed stria vascularis as seen in corrosion casts of the cochlea. We provide a mathematical model to explain the role of this unique vascular anatomy in dampening pulsatile blood flow to the stria vascularis.

Dexamethasone uptake in the murine organ of Corti with transtympanic versus systemic administration.

OBJECTIVE: To investigate glucocorticoid uptake in auditory hair cells following transtympanic versus systemic administration of dexamethasone. STUDY DESIGN: Controlled experimental study. SETTING: Translational science experimental laboratory. METHODS: Swiss-Webster mice were injected with dexamethasone via transtympanic or systemic administration. At 1, 6, or 12 hours post-injection the temporal bones were harvested. After cryosectioning, immunohistochemical staining was performed using an antibody for dexamethasone. RESULTS: Dexamethasone labelling was greatest at 1 hour. Inner hair cells demonstrated much higher steroid uptake than outer hair cells. Both transtympanic injection and high-dose systemic administration resulted in strong dexamethasone labelling of hair cells, and a decreasing basal-to-apical gradient of hair cell fluorescence intensity was observed. Systemically delivered dexamethasone was rapidly eliminated from the inner ear, demonstrating mild labelling after 6 hours and none after 12 hours. In contrast, the mice receiving transtympanic injection had persistent moderate intensity fluorescence at 6 and 12 hours post-injection. CONCLUSION: There is similar uptake of dexamethasone by auditory hair cells after transtympanic and high-dose systemic delivery. Novel findings include the presence of a decreasing basal-apical gradient of steroid uptake, and demonstration of greater affinity of inner hair cells for dexamethasone compared to outer hair cells. In this animal model transtympanic injection resulted in prolonged steroid uptake. These findings help further our understanding of the pharmacokinetics of steroids in the cochlea, with a focus on auditory hair cells.

Expanded selection criteria in adult cochlear implantation.

Cochlear implantation has become the standard procedure for restoring substantial hearing in the profoundly deaf. The excellent performance of most of the CI recipients coupled with the rapid evolution of implant technology lead to a distinct expansion in selection criteria for CI. These changes in candidacy primarily include patients with (1) moderate preoperative speech recognition with hearing aids, (2) significant residual hearing, (3) single-sided deafness, and (4) geriatric patients. Many of these patients' conditions were regarded as a clear contraindication to CI only a few years ago. In this article an overview of the current and new aspects of candidacy for cochlear implantation is provided.