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

2019 ◽  
Vol 24 (5) ◽  
pp. 237-244
Author(s):  
Clemens Honeder ◽  
Chengjing Zhu ◽  
Julia Clara Gausterer ◽  
Hanna Schöpper ◽  
Navid Ahmadi ◽  
...  
Keyword(s):  
Sustained Release ◽  
Triamcinolone Acetonide ◽  
Cochlear Implantation ◽  
Hearing Threshold ◽  
Hearing Preservation ◽  
Poloxamer 407 ◽  
Histological Evaluation ◽  
Control Group ◽  
Spiral Ganglion Cell ◽  
Temporal Bones

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. Consequently other glucocorticoids merit further evaluation. The aim of this study was therefore to evaluate the otoprotective effects of the topical application of a sustained-release triamcinolone acetonide (TAAC) hydrogel in CI with hearing preservation. Methods: Normal-hearing pigmented guinea pigs were randomized into a group receiving a single dose of a 6% TAAC poloxamer 407 hydrogel, a group receiving a 30% TAAC hydrogel and a control group. All hydrogel applications were performed 1 day prior to CI. After a cochleostomy was drilled, a specifically designed silicone electrode was inserted into the scala tympani for 5 mm. Frequency-specific compound action potentials of the auditory nerve (0.5–32 kHz) were measured pre- and directly postoperatively as well as on days 3, 7, 14, 21, and 28. Finally, temporal bones were harvested for histological evaluation. Results: Application of the TAAC hydrogels resulted in significantly reduced hearing threshold shifts in low, middle and high frequencies and improved spiral ganglion cell survival in the second turn of the cochlea. Outer hair cell numbers in the basal and second turn of the cochlea were slightly reduced after TAAC application. Conclusion: In summary, we were able to demonstrate functional benefits of a single preoperative application of a TAAC hydrogel in a guinea pig model for CI, which persisted until the end of the observational period, that is, 28 days after surgery.

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

2018 ◽  
Vol 23 (2) ◽  
pp. 73-81 ◽  
Author(s):  
Chengjing Zhu ◽  
Julia Clara Gausterer ◽  
Hanna Schöpper ◽  
Michael Nieratschker ◽  
Nodir Saidov ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Triamcinolone Acetonide ◽  
Noise Exposure ◽  
Spiral Ganglion ◽  
Hearing Threshold ◽  
Poloxamer 407 ◽  
Noise Induced Hearing Loss ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Guinea Pig Model

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). Even though no significant differences in hair cell counts were found, histological analysis revealed a significantly higher spiral ganglion cell density in the first turn of the cochlea in this group (p < 0.05). No otoprotective effects were observed after the application of the triamcinolone acetonide hydrogels. As the findings of this study indicate potential otoprotective effects of sustained topical dexamethasone delivery in the setting of noise-induced hearing loss, this strategy merits further evaluation.

Dexamethasone Is One of the Factors Minimizing the Inner Ear Damage from Electrode Insertion in Cochlear Implantation

2016 ◽  
Vol 21 (3) ◽  
pp. 178-186 ◽  
Author(s):  
Hyun Soo Cho ◽  
Kyu-Yup Lee ◽  
Hongsoo Choi ◽  
Jeong Hun Jang ◽  
Sang Heun Lee
Keyword(s):  
Inner Ear ◽  
Cochlear Implantation ◽  
Hearing Threshold ◽  
Hearing Preservation ◽  
Control Group ◽  
Hearing Level ◽  
Hearing Thresholds ◽  
The Difference ◽  
Caloric Response ◽  
Inner Ear Damage

The aim of this study was to investigate the efficacy of preoperative and intraoperative steroid administration for inner ear protection in cochlear implantation (CI). Nineteen subjects who underwent CI were included in the study, and 10 subjects were enrolled as controls (steroid-administered group, n = 19; control group, n = 10). Dexamethasone (dexamethasone sodium phosphate, 5 mg/ml) was systemically administered preoperatively (1 ml) and topically applied during CI (0.5 ml). The extent of hearing preservation (HP) after CI and the change in the bithermal caloric response were evaluated. Hearing level was calculated using mean thresholds [(250 Hz + 500 Hz + 1,000 Hz + 2,000 Hz)/4]. Preoperative hearing thresholds were similar in the steroid-administered and control groups (100.92 ± 12.60 vs. 103.29 ± 14.39 dB, p = 0.650). The mean thresholds significantly increased in both groups after surgery (108.46 ± 14.08 dB, p = 0.006, for the steroid-administered group; 117.50 ± 6.34 dB, p = 0.027, for the control group), and the difference between the groups was also significant (p = 0.027). The postoperative shift in the hearing thresholds at frequencies of 500 and 1,000 Hz was significant in the steroid-administered group and that at the frequencies of 500, 1,000 and 2,000 Hz was significant in the control group. However, the extent of the shift in hearing threshold levels at each frequency was not significantly different between the groups. Preservation of hearing thresholds was compared between the groups, and there were significantly more subjects with complete and partial HP in the steroid-administered group than in the control group (p = 0.008). The preoperative caloric response was maintained after CI in the steroid-administered group. This study suggests that the perioperative use of a steroid could minimize the inner ear damage after CI.

scholarly journals Effects of sustained release dexamethasone hydrogels in hearing preservation cochlear implantation

2016 ◽  
Vol 341 ◽  
pp. 43-49 ◽  
Author(s):  
Clemens Honeder ◽  
Chengjing Zhu ◽  
Hanna Schöpper ◽  
Julia Clara Gausterer ◽  
Manuel Walter ◽  
...  
Keyword(s):  
Sustained Release ◽  
Cochlear Implantation ◽  
Hearing Preservation

Histopathology of Cochlear Implants in Humans

2001 ◽  
Vol 110 (9) ◽  
pp. 883-891 ◽  
Author(s):  
Joseph B. Nadol ◽  
Barbara J. Burgess ◽  
Bruce J. Gantz ◽  
Newton J. Coker ◽  
Darlene R. Ketten ◽  
...  
Keyword(s):  
Ganglion Cell ◽  
Cochlear Implantation ◽  
Single Channel ◽  
Spiral Ganglion ◽  
Electrode Array ◽  
Speech Comprehension ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Significant Difference ◽  
Temporal Bones

The insertion of an intrascalar electrode array during cochlear implantation causes immediate damage to the inner ear and may result in delayed onset of additional damage that may interfere with neuronal stimulation. To date, there have been reports on fewer than 50 temporal bone specimens from patients who had undergone implantation during life. The majority of these were single-channel implants, whereas the majority of implants inserted today are multichannel systems. This report presents the histopathologic findings in temporal bones from 8 individuals who in life had undergone multichannel cochlear implantation, with particular attention to the type and location of trauma and to long-term changes within the cochlea. The effect of these changes on spiral ganglion cell counts and the correlation between speech comprehension and spiral ganglion cell counts were calculated. In 4 of the 8 cases, the opposite, unimplanted ear was available for comparison. In 3 of the 4 cases, there was no significant difference between the spiral ganglion cell counts on the implanted and unimplanted sides. In addition, in this series of 8 cases, there was an apparent negative correlation between residual spiral ganglion cell count and hearing performance during life as measured by single-syllable word recognition. This finding suggests that abnormalities in the central auditory pathways are at least as important as spiral ganglion cell loss in limiting the performance of implant users.

The Role of Preoperative Steroids for Hearing Preservation Cochlear Implantation: Results of a Randomized Controlled Trial

2017 ◽  
Vol 22 (4-5) ◽  
pp. 292-302 ◽  
Author(s):  
Jafri Kuthubutheen ◽  
Samidha Joglekar ◽  
Leah Smith ◽  
Lendra Friesen ◽  
Kari Smilsky ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Single Dose ◽  
Cochlear Implantation ◽  
Controlled Trial ◽  
Hearing Preservation ◽  
Oral Steroid ◽  
Control Group ◽  
Randomized Controlled ◽  
Steroid Group ◽  
Better Than

Objectives: To determine whether preoperative steroids can improve hearing outcomes in cochlear implantation (CI). Methods: This is a randomized controlled trial involving 30 postlingual deaf CI patients. Subjects had preoperative thresholds of better than or equal to 80 dB at 125 and 250 Hz, and better than or equal to 90 dB at 500 and 1,000 Hz. The subjects were randomized to a control group, an oral steroid group (receiving 1 mg/kg/day of prednisolone for 6 days prior to surgery), or a transtympanic steroid group (receiving a single dose of 0.5 mL of 10 mg/mL dexamethasone at 24 h prior to surgery). Results: The subjects receiving transtympanic steroids had a significant decrease in the pure tone average over 3 months compared to the control and oral steroid group, which persisted over 12 months (p < 0.05). Conclusion: A single dose of preoperative transtympanic steroids prior to CI appears to have a beneficial effect, at least in the short term, with minimal effects seen in the longer term.

scholarly journals A maradványhallás megőrzésének lehetőségei cochlearis implantáció során Nucleus CI532 Slim Modiolar elektródasorral

2018 ◽  
Vol 159 (41) ◽  
pp. 1680-1688 ◽  
Author(s):  
Roland Nagy ◽  
János András Jarabin ◽  
Balázs Dimák ◽  
Ádám Perényi ◽  
Ferenc Tóth ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Minimally Invasive ◽  
Cochlear Implantation ◽  
Basilar Membrane ◽  
Round Window ◽  
Spiral Ganglion ◽  
Hearing Threshold ◽  
Electrode Array ◽  
Hearing Preservation ◽  
Residual Hearing

Abstract: During the rehabilitation of hearing-impaired patients, the preservation of residual acoustic hearing following cochlear implantation by minimizing the implantation trauma allows for improved hearing performance. To achieve this, minimally invasive, soft surgery methods and thinner, atraumatic electrodes were required. In our present study, we reported a case where Cochlear® Nucleus CI532 Slim Modiolar electrode was implanted in a patient with residual hearing. Our aim was to study the possible preservation of postoperative acoustic residual hearing by audiological monitoring. Since childhood, due to her congenital hearing loss, she has been wearing a conventional, airborne hearing correction device on both ears. Six months before cochlear implantation, we measured the progression on both sides of the hearing loss, so we decided to perform cochlear implantation. The patient had residual hearing on both ears prior to surgery thus the Cochlear® Nucleus CI532 Slim Modiolar Implant was used. The minimally invasive surgery was performed on the patient’s right ear through the round window approach. Compared to the preoperative hearing threshold (average 85 dBHL) in the 4th postoperative week, an initial hearing threshold progression of 20–25 dBHL was observed between 0.25 and 1.0 kHz, while of 5–10 dBHL between 2.0–4.0 kHz. Hearing threshold measured in the 6th month showed a slight progression in the range above 1 kHz, but improved by the 12th month, to the results achieved at the 4th week. The effects of cochlear implantation on residual hearing have been studied in numerous studies, in which several key surgical and technical factors have been identified. Nucleus CI532 is a Slim Modiolar electrode profile that is close to the modiolus, so it is expected to have a lower endocochlear hydrodynamic load since it lies in the covering of the osseus spiral lamina, thus less influencing the dynamics of the basilar membrane. However, the perimodiolar location of the electrode array allows the adjacent nerve elements of the spiral ganglion to be stimulated with a lower electrical intensity and a reduced surface that may be neuroprotective. Preservation of acoustic residual hearing following cochlear implantation improves the patient’s speech perception and the sound localization skills, particularly in difficult circumstances. Long-term residual hearing preservation may also be of great importance in the subsequent feasibility for regenerative procedures and drug treatments. Orv Hetil. 2018; 159(41): 1680–1688.

Analysis of Intracochlear New Bone and Fibrous Tissue Formation in Human Subjects with Cochlear Implants

2007 ◽  
Vol 116 (10) ◽  
pp. 731-738 ◽  
Author(s):  
Peter M. M. C. Li ◽  
Mehmet A. Somdas ◽  
Donald K. Eddington ◽  
Joseph B. Nadol
Keyword(s):  
Word Recognition ◽  
Cochlear Implantation ◽  
Ganglion Cells ◽  
Human Subjects ◽  
Fibrous Tissue ◽  
Spiral Ganglion ◽  
Tissue Formation ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Temporal Bones

Objectives: In this study we aimed to evaluate new bone and new fibrous tissue formation in the inner ear following cochlear implantation. Methods: Twelve temporal bones from patients who underwent cochlear implantation during life were prepared for histologic study. The specimens were reconstructed by both 2-dimensional and 3-dimensional methods. These reconstructions were used to calculate the total volume and distribution of new bone and new fibrous tissue in the cochlea, the number of spiral ganglion cells, and other histopathologic parameters. Clinical data, including the last-recorded word recognition scores, were obtained from the patients' medical records. Results: New bone and new fibrous tissue were found in all 12 specimens, particularly at the site of cochleostomy. There was a significant correlation between overall damage to the lateral cochlear wall and the total volume of intracochlear new tissue (Spearman rho = .853; p = .0004). The total volume of new tissue did not correlate with word recognition scores or spiral ganglion cell counts. Conclusions: These preliminary results suggest that the degree of damage to the lateral cochlear wall may play an important role in influencing the amount of new tissue formation following cochlear implantation. Intracochlear new tissue does not appear to be an important determinant of performance as measured by word recognition scores or the total number of remaining spiral ganglion cells.

scholarly journals Measurement of the Intracochlear Hypothermia Distribution Utilizing Tympanic Cavity Hypothermic Rinsing Technique in a Cochlea Hypothermia Model

2021 ◽  
Vol 11 ◽  
Author(s):  
Werner Bader ◽  
Timo Gottfried ◽  
Gerald Degenhart ◽  
Lejo Johnson Chacko ◽  
Daniel Sieber ◽  
...  
Keyword(s):  
Mild Hypothermia ◽  
Hearing Preservation ◽  
Severe Trauma ◽  
Control Group ◽  
Tympanic Cavity ◽  
Basal Turn ◽  
Posterior Tympanotomy ◽  
Local Hypothermia ◽  
Temperature Levels ◽  
Temporal Bones

Introduction: Cochlea implants can cause severe trauma leading to intracochlear apoptosis, fibrosis, and eventually to loss of residual hearing. Mild hypothermia has been shown to reduce toxic or mechanical noxious effects, which can result in inflammation and subsequent hearing loss. This paper evaluates the usability of standard surgical otologic rinsing as cooling medium during cochlea implantation as a potential hearing preservation technique.Material and Methods: Three human temporal bones were prepared following standard mastoidectomy and posterior tympanotomy. Applying a retrocochlear approach leaving the mastoidectomy side intact, temperature probes were placed into the basal turn (n = 4), the middle turn (n = 2), the helicotrema, and the modiolus. Temperature probe positions were visualized by microcomputed tomography (μCT) imaging and manually segmented using Amira® 7.6. Through the posterior tympanotomy, the tympanic cavity was rinsed at 37°C in the control group, at room temperature (in the range between 22 and 24°C), and at iced water conditions. Temperature changes were measured in the preheated temporal bone. In each temperature model, rinsing was done for 20 min at the pre-specified temperatures measured in 0.5-s intervals. At least five repetitions were performed. Data were statistically analyzed using pairwise t-tests with Bonferroni correction.Results: Steady-state conditions achieved in all three different temperature ranges were compared in periods between 150 and 300 s. Temperature in the inner ear started dropping within the initial 150 s. Temperature probes placed at basal turn, the helicotrema, and middle turn detected statistically significant fall in temperature levels following body temperature rinses. Irrigation at iced conditions lead to the most significant temperature drops. The curves during all measurements remained stable with 37°C rinses.Conclusion: Therapeutic hypothermia is achieved with standard surgical irrigation fluid, and temperature gradients are seen along the cochlea. Rinsing of 120 s duration results in a therapeutic local hypothermia throughout the cochlea. This otoprotective procedure can be easily realized in clinical practice.

Pengaruh bising lalu lintas terhadap penurunan fungsi pendengaran pada juru parkir di kota Denpasar

2013 ◽  
Vol 40 (2) ◽  
Author(s):  
Ni Ketut Susilawati ◽  
Wayan Sudana ◽  
Eka Putra Setiawan
Keyword(s):  
Hearing Impairment ◽  
Noise Exposure ◽  
Traffic Noise ◽  
Hearing Threshold ◽  
Noise Pollution ◽  
Simple Random Sampling ◽  
Cross Sectional Study ◽  
Control Group ◽  
Cross Sectional ◽  
Hearing Function

Background: Noise pollution or noise is an unwanted sound which is disturbing to human beings.However small or soft the sound, if it is undesirable it is considered as noise. Noise induced hearingloss is a sensorineural hearing loss that is commonly encountered second to presbycusis. Purpose: Toknow the effect of traffic noise exposure on hearing impairment to the employees of the Parking DistrictCompany of the Denpasar city and to improve diagnostic detection on hearing impairment caused bynoise. Method: A cross sectional study was conducted at the Parking District Company office. Thepopulations of this study were the employees of the Parking District Company. Samples of this study were the employees who were exposed to traffic noise and control samples were an employee who was unexposed. Samples were selected by simple random sampling. Results: From 40 parking attendants,27 persons (67.5%) aged above 35 years old. The parking attendants who had been working for ten to fifteen years were 36 persons (90%) and no history using ear protection when working. Seven persons(17.5%) had referred DPOAE upon examination with increase hearing threshold on audiogram result.In this study the parking attendants who had hearing deficit induced by noise were 7 persons (17.5%)and only one person (2.5%) in control group. There was a statistically significant effect of traffic noiseto hearing function deficit (p<0.05). Conclusion: Traffic noise has effect in hearing function deficit onthe parking attendants.ORLI Vol. 40 No. 2 Tahun 2010Key words: NIHL, parking attendant, audiometry, DPOAE.

Motor Recovery after Chronic Spinal Cord Transection in Rats: A Proof-of-Concept Study Evaluating a Combined Strategy

2019 ◽  
Vol 18 (1) ◽  
pp. 52-62 ◽  
Author(s):  
Antonio Ibarra ◽  
Erika Mendieta-Arbesú ◽  
Paola Suarez-Meade ◽  
Elisa García-Vences ◽  
Susana Martiñón ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Treatment Strategies ◽  
Chronic Phase ◽  
Motor Recovery ◽  
Neural Regeneration ◽  
Histological Evaluation ◽  
Control Group ◽  
Proof Of Concept ◽  
Sprague Dawley ◽  
Concept Study

Background: The chronic phase of Spinal Cord (SC) injury is characterized by the presence of a hostile microenvironment that causes low activity and a progressive decline in neurological function; this phase is non-compatible with regeneration. Several treatment strategies have been investigated in chronic SC injury with no satisfactory results. OBJECTIVE- In this proof-of-concept study, we designed a combination therapy (Comb Tx) consisting of surgical glial scar removal plus scar inhibition, accompanied with implantation of mesenchymal stem cells (MSC), and immunization with neural-derived peptides (INDP). Methods: This study was divided into three subsets, all in which Sprague Dawley rats were subjected to a complete SC transection. Sixty days after injury, animals were randomly allocated into two groups for therapeutic intervention: control group and animals receiving the Comb-Tx. Sixty-three days after treatment we carried out experiments analyzing motor recovery, presence of somatosensory evoked potentials, neural regeneration-related genes, and histological evaluation of serotoninergic fibers. Results: Comb-Tx induced a significant locomotor and electrophysiological recovery. An increase in the expression of regeneration-associated genes and the percentage of 5-HT+ fibers was noted at the caudal stump of the SC of animals receiving the Comb-Tx. There was a significant correlation of locomotor recovery with positive electrophysiological activity, expression of GAP43, and percentage of 5-HT+ fibers. Conclusion: Comb-Tx promotes motor and electrophysiological recovery in the chronic phase of SC injury subsequent to a complete transection. Likewise, it is capable of inducing the permissive microenvironment to promote axonal regeneration.

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