Long-Term Results of Cochlear Implantation in Single-Sided Deaf Patients: Influence of Duration of Deafness and Age at Onset of Deafness.

Objective: The aim of the current study was to investigate the influence of duration, time point, and etiology of deafness on cochlear implant user rates, and to investigate the long-term hearing performance in single-sided deaf patients.

Study Design: Retrospective study.

Setting: Tertiary care hospital.

Silicone-based AC102-loaded cochlear implant coatings protect residual hearing in an animal model of cochlear implantation.

Cochlear implant users with residual hearing benefit synergistically from combined electrical stimulation via the cochlear implant and preserved residual hearing after surgery. However, direct mechanical trauma and subsequent inflammation may deteriorate hearing function. AC102, a novel otoprotective pyridoindole with anti-apoptotic and anti-oxidative properties significantly improved hearing recovery following cochlear implantation when administered intratympanically prior to surgery.

A Single Intratympanic Triamcinolone Acetonide Administration Elicits Long-Term Reduction in Impedances Following Cochlear Implantation.

Background: Intracochlear fibrosis and inflammation remain important limitations in cochlear implantation (CI). Glucocorticoids are routinely used to ameliorate the inflammatory response following CI. This study investigates the long-term effects of an intratympanically-applied triamcinolone-acetonide suspension on intracochlear impedance changes in CI recipients and investigates differences in drug concentrations and timepoints of injection.

A preoperative dose of the pyridoindole AC102 improves the recovery of residual hearing in a gerbil animal model of cochlear implantation.

Sensorineural hearing loss (SNHL) is the most common sensory deficit worldwide. Due to the heterogeneity of causes for SNHL, effective treatment options remain scarce, creating an unmet need for novel drugs in the field of otology. Cochlear implantation (CI) currently is the only established method to restore hearing function in profound SNHL and deaf patients.

Insertion trauma of a novel inner ear catheter for intracochlear drug delivery.

Introduction: Even with recent research advances, effective delivery of a compound to its target cells inside the inner ear remains a challenging endeavor due to anatomical and physiological barriers. Direct intracochlear drug administration with an inner ear catheter (IEC) aims to overcome this obstacle and strives to provide a safe and efficient way for inner ear pharmacotherapy. The goal of this study was to histologically and audiologically evaluate the traumatic properties of a novel IEC for intracochlear drug delivery in a large animal model.

Establishment of an optimized guinea pig model of cisplatin-induced ototoxicity.

Background: Cisplatin is among the most effective antineoplastic agents and has revolutionized the treatment of many cancer diseases. However, one of its serious side effects is a progressive and irreversible hearing loss, occurring in both adults and children. For the development of otoprotective therapies that prevent this side effect, cisplatin-induced hearing loss animal models are indispensable.

A Novel Preparation Technique for Human Nasal Respiratory Mucosa to Disclose Its Glycosylation Pattern for Bioadhesive Drug Delivery.

To shed some light on glycotargeting as a potential strategy for nasal drug delivery, a reliable preparation method for human nasal mucosa samples and a tool to investigate the carbohydrate building blocks of the glycocalyx of the respiratory epithelium are required. Applying a simple experimental setup in a 96-well plate format together with a panel of six fluorescein-labeled lectins with different carbohydrate specificities allowed for the detection and quantification of accessible carbohydrates in the mucosa. As confirmed by binding experiments at 4 °C, both quantitatively by fluorimetry and qualitatively by microscopy, the binding of wheat germ agglutinin exceeded that of the others by 150% on average, indicating a high content of N-acetyl-D-glucosamine and sialic acid.

Investigation of inner ear drug delivery with a cochlear catheter in piglets as a representative model for human cochlear pharmacokinetics.

Hearing impairment is the most common sensory disorder in humans, and yet hardly any medications are licensed for the treatment of inner ear pathologies. Intricate pharmacokinetic examinations to better understand drug distribution within this complex organ could facilitate the development of novel therapeutics. For such translational research projects, animal models are indispensable, but differences in inner ear dimensions and other anatomical features complicate the transfer of experimental results to the clinic.

Multicentric study on surgical information and early safety and performance results with the Bonebridge BCI 602: an active transcutaneous bone conduction hearing implant.

Aim: This European multicentric study aimed to prove safety and performance of the Bonebridge BCI 602 in children and adults suffering from either conductive hearing loss (CHL), mixed hearing loss (MHL), or single-sided sensorineural deafness (SSD).

Methods: 33 patients (13 adults and 10 children with either CHL or MHL and 10 patients with SSD) in three study groups were included. Patients were their own controls (single-subject repeated measures), comparing the unaided or pre-operative to the 3-month post-operative outcomes.

Intratympanic Substance Distribution After Injection of Liquid and Thermosensitive Drug Carriers: An Endoscopic Study.

Objective: In the treatment of inner ear conditions, intratympanic injection emerges as an important drug delivery method. Novel compounds designed for intratympanic injection are routinely loaded in viscous drug carriers. To date, it is unclear if they can freely distribute in the middle ear.

Single-incision cochlear implantation and hearing evaluation in piglets and minipigs.

Objectives: Various animal models have been established and applied in hearing research. In the exploration of novel cochlear implant developments, mainly rodents have been used. Despite their important contribution to the understanding of auditory function, translation of experimental observations from rodents to humans is limited due to the size differences and genetic variability.

The Effect of Pulse Shape and Interphase Gaps on Speech Perception and Perceived Sound Quality in Electrical Hearing.

Background: Stimulation with triphasic pulses has been shown to reduce the occurrence of unwanted facial nerve stimulation (FNS) with cochlear implants (CIs). However, there is little data available on how different pulse shapes affect the hearing outcome with electrical hearing in general. The aim of the study was to evaluate the effects of different stimulation pulse shapes on speech perception in noise, as well as loudness perception and subjective sound quality.

Evaluation of Levels of Triamcinolone Acetonide in Human Perilymph and Plasma After Intratympanic Application in Patients Receiving Cochlear Implants: A Randomized Clinical Trial.

Importance: The use of intratympanically applied steroids is of increasing interest. Consequently, research has focused on finding an ideal drug that diffuses through the round window membrane and can be retained in the perilymph.

Objective: To compare levels of triamcinolone acetonide (TAC) in perilymph and plasma after intratympanic injection.

Simultaneous Vestibular Schwannoma Resection and Cochlear Implantation Using Electrically Evoked Auditory Brainstem Response Audiometry for Decision-making.

Objective: The aim of the study was to evaluate the predictive value regarding postoperative hearing benefit of electrically evoked auditory brainstem response audiometry in sporadic vestibular schwannoma patients undergoing simultaneous tumor resection and cochlear implantation.

Design: Patients were included in a prospective study conducted between October 2016 and January 2019.

Setting: The study was conducted at a tertiary care center.

Intratympanic application of poloxamer 407 hydrogels results in sustained N-acetylcysteine delivery to the inner ear.

N-acetylcysteine is a thiol-containing antioxidant, which has shown otoprotective effects in in vitro as well as in vivo models of cisplatin-induced hearing loss. Systemic administration of antioxidants, however, is associated with the major potential drawback of interference with the tumoricidal effect of cisplatin. This therapeutic limitation can be overcome by local intratympanic injection of the antioxidant N-acetylcysteine, which results in very restricted systemic uptake of the drug, whilst intracochlear drug levels are substantially higher.

Long-term effects and potential limits of intratympanic dexamethasone-loaded hydrogels combined with dexamethasone-eluting cochlear electrodes in a low-insertion trauma Guinea pig model.

Cochlear implantation has become the most effective hearing restoration method and is one of the great advances in modern medicine. Early implants have been continuously developed into more efficient devices, and electro-acoustic stimulation is increasingly expanding the indication criteria for cochlear implants to patients with more residual hearing. Therefore, protecting the cochlear structures and maintaining its intrinsic capacities like residual hearing has become more important than ever before.

Sustained-Release Triamcinolone Acetonide Hydrogels Reduce Hearing Threshold Shifts in a Model for Cochlear Implantation with Hearing Preservation.

Introduction: In recent years, the preservation of residual hearing has become a major factor in patients undergoing cochlear implantation (CI). In studies attempting to pharmaceutically improve hearing preservation rates, glucocorticoids (GCs) applied perioperatively in many institutions have emerged as a promising treatment regimen. Although dexamethasone is most commonly used and has been applied successfully by various research groups, recently pharmacological properties have been reported to be relatively unsuitable for topical delivery to the inner ear.

Intratympanic Triamcinolone Acetonide as Treatment Option for Idiopathic Sudden Sensorineural Hearing Loss.

Introduction: Corticosteroids represent the most commonly used treatment option for patients with idiopathic sudden sensorineural hearing loss. In the past, these compounds were mainly formulated and tested for intravenous or oral administration. Intratympanic application is increasingly being used, often as salvage treatment.

Single Sided Deaf Cochlear Implant Users in the Difficult Listening Situation: Speech Perception and Subjective Benefit.

Objectives: Patients with single-sided deafness (SSD) have great difficulties in listening situations which rely on binaural auditory processing. The purpose of this study was to examine to which extent a cochlear implant (CI) can improve speech perception outcomes in various noisy listening environments. Additionally, the ability to use interaural level differences for sound localization and subjective benefit with the CI were assessed.

Evaluation of Sustained-Release Steroid Hydrogels in a Guinea Pig Model for Noise-Induced Hearing Loss.

The otoprotective effects of thermoreversible poloxamer 407 hydrogels containing dexamethasone or triamcinolone acetonide were evaluated in an animal model of noise-induced hearing loss. Seven days after noise exposure, hearing threshold shifts at 16 kHz were significantly reduced in the 6% dexamethasone group (p < 0.05).

Cochlear Implantation in the Guinea Pig.

Cochlear implants are highly efficient devices that can restore hearing in subjects with profound hearing loss. Due to improved speech perception outcomes, candidacy criteria have been expanded over the last few decades. This includes patients with substantial residual hearing that benefit from electrical and acoustical stimulation of the same ear, which makes hearing preservation during cochlear implantation an important issue.

Fixed and adaptive beamforming improves speech perception in noise in cochlear implant recipients equipped with the MED-EL SONNET audio processor.

Objective: To determine the impact of the fixed and adaptive beamforming technology of the new MED-EL SONNET cochlear implant audio processor on speech perception in noise.

Methods: The study cohort comprises 18 postlingually deafened adult cochlear implant recipients with at least six months of experience. Speech reception thresholds were measured with the Oldenburg Sentence Test in continuous, speech-shaped noise.

Effects of sustained release dexamethasone hydrogels in hearing preservation cochlear implantation.

It has been shown that glucocorticoids reduce the hearing threshold shifts associated with cochlear implantation. Previous studies evaluated the administration of glucocorticoids immediately before surgery or the repeated pre- or perioperative systemic application of glucocorticoids. The aim of this study was to evaluate the effects of a sustained release dexamethasone hydrogel in hearing preservation cochlear implantation.

Noise trauma and systemic application of the selective glucocorticoid receptor modulator compound A.

Background: Selective glucocorticoid receptor modulators (SEGRMs) comprise a novel class of drugs promising both reduced side effects and similar pharmacological potency relative to glucocorticoids, which presently serve as the only clinical treatment for many otologic disorders. In the first otologic SEGRM experiment in an animal model of noise trauma, we compare the effects of Compound A (a SEGRM) and dexamethasone (potent glucocorticoid).

Methods: Forty adult guinea pigs received experimental treatment once daily for ten days.

Determination of the glycosylation-pattern of the middle ear mucosa in guinea pigs.

In the present study the glycosylation pattern of the middle ear mucosa (MEM) of guinea pigs, an approved model for middle ear research, was characterized with the purpose to identify bioadhesive ligands which might prolong the contact time of drug delivery systems with the middle ear mucosa (MEM). To assess the utility of five fluorescein labeled plant lectins with different carbohydrate specificities as bioadhesive ligands, viable MEM specimens were incubated at 4°C and the lectin binding capacities were calculated from the MEM-associated relative fluorescence intensities. Among all lectins under investigation, fluorescein-labeled wheat germ agglutinin (F-WGA) emerged as the highest bioadhesive lectin.