Tinnitus and Cochlear Functions in Hearing Impaired and Normal Hearing Individuals

Background: In order to determine the pathophysiology of tinnitus and deciding on treatment, the function of peripheral hearing organs is very important. Objective: To evaluate the cochlear functions in tinnitus patients with or without hearing-loss(HL). Methods: Participants with tinnitus were divided into two groups; 16 participants with accompanying HL were included in the first study group (SG-I), and 15 participants without HL were included in the second group (SG-II). 21 normal-hearing subjects without tinnitus included as control group(CG). Tinnitus discomfort levels was determined with Tinnitus Handicap Inventory(THI). Besides pure-tone audiometry, Otoacoustic Emissions, to evaluate cochlear functions and to decide dead regions (DR), Threshold Equalizing Noise-(TEN) was used. Results: The threshold-shift was observed with TEN in subjects in SG-I and these levels were statistically different from SG-II and CG. There were both threshold-shift and DR in SG-II according to TEN. TEOAEs did not differ between SG-II and CG. The DPOAE results for SG-II showed significant decreases in emission amplitudes at 6 & 8 kHz. Conclusion: While Tinnitus patients with HL can be evaluated with conventional tests, evaluating patients with normal hearing tinnitus with additional tests such as OAE and TEN allows us to get more precise results on the functions of peripheral hearing organs

Nanofiber orientation and surface functionalization modulate human mesenchymal stem cell behavior in vitro

Electrospun nanofiber meshes have emerged as a new generation of scaffold membranes possessing a number of features suitable for tissue regeneration. One of these features is the flexibility to modify their structure and composition to orchestrate specific cellular responses. In this study, we investigated the effects of nanofiber orientation and surface functionalization on human mesenchymal stem cell (hMSC) migration and osteogenic differentiation. We used an in vitro model to examine hMSC migration into a cell-free zone on nanofiber meshes and mitomycin C treatment to assess the contribution of proliferation to the observed migration. Poly (ɛ-caprolactone) meshes with oriented topography were created by electrospinning aligned nanofibers on a rotating mandrel, while randomly oriented controls were collected on a stationary collector. Both aligned and random meshes were coated with a triple-helical, type I collagen-mimetic peptide, containing the glycine-phenylalanine-hydroxyproline-glycine-glutamate-arginine (GFOGER) motif. Our results indicate that nanofiber GFOGER peptide functionalization and orientation modulate cellular behavior, individually, and in combination. GFOGER significantly enhanced the migration, proliferation, and osteogenic differentiation of hMSCs on nanofiber meshes. Aligned nanofiber meshes displayed increased cell migration along the direction of fiber orientation compared to random meshes; however, fiber alignment did not influence osteogenic differentiation. Compared to each other, GFOGER coating resulted in a higher proliferation-driven cell migration, whereas fiber orientation appeared to generate a larger direct migratory effect. This study demonstrates that peptide surface modification and topographical cues associated with fiber alignment can be used to direct cellular behavior on nanofiber mesh scaffolds, which may be exploited for tissue regeneration

Simultaneous Cochlear and Auditory Brainstem Implantation in Children With Severe Inner Ear Malformations: Initial Surgical and Audiological Results

Objective: To report the initial surgical and audiological outcomes of three pediatric patients with severe inner ear malformations who were simultaneously implanted with cochlear and brainstem implants in the same surgical session. Study design: Retrospective case review. Setting: Tertiary referral center. Patients: Three pediatric patients with severe inner ear malformations between ages of 1.9 to 2.5 years, who were simultaneously implanted with cochlear implant in one ear and auditory brainstem implant in the other ear. Intervention(s): Simultaneous application of cochlar implant in one ear, auditory brainstem implant in the other ear. Main outcome measures: Free field thresholds with cochlear and brainstem implants. Surgical issues are also discussed. Results: The study is descriptive in nature. Free field thresholds with each device alone and together showed good progress. One of the patients had slower progress possibly due to comorbid CHARGE syndrome. Conclusions: The results showed good progress in terms of audition with both devices. Simultaneous cochlear and brainstem application serves as a remedy for pediatric patients who are candidates for cochlear implant on one side and brainstem implant on the other side. With this simultaneous application precious time for auditory development is not lost.Wo

Bimodal stimulation in children with inner ear malformation: One side cochlear implant and contralateral auditory brainstem implant

Objective: To determine audiological outcomes of children who use a cochlear implant (CI) in one ear and an auditory brainstem implant (ABI) in the contralateral ear. Design: Retrospective case review. Setting: Tertiary referral hospital. Participants: Twelve children followed with CI and contralateral auditory brainstem implant (ABI) by Hacettepe University Department of Otorhinolaryngology and Audiology in Turkey. All children were diagnosed with different inner ear malformations with cochlear nerve aplasia/hypoplasia. CI was planned in the ear with better sound detection during behavioural testing with inserted ear phones and with better CN as seen on MRI. Due to the limited auditory and speech progress with the cochlear implant, ABI was performed on the contralateral ear in all subjects. Main outcome measures: Audiological performance and auditory perception skills of children with cochlear nerve deficiency (CND) who use bimodal electrical stimulation with CI and contralateral ABI. Results: Mean age of the subjects was 84.00 ± 33.94 months. Age at CI surgery and ABI surgery was 25.00 ± 10.98 months and 41.50 ± 16.14 months, respectively. However, hearing thresholds only with CI and only with ABI did not reveal significant difference, and auditory perception scores improved with bimodal stimulation. The MAIS scores were significantly improved from unilateral CI to bimodal stimulation (P = .002). Pattern perception and word recognition scores were significantly higher with the bimodal condition when compared to CI only and ABI only conditions. Conclusion: Children with CND showed better performance with CI and contralateral ABI combined. Depending on the audiological and radiological results, bimodal stimulation should be advised for children with CND.Wo

Transcanal Endoscopic Management of Middle Ear Paragangliomas

ObjectiveTo evaluate the clinical and audiological outcomes of transcanal endoscopic resection of middle ear paragangliomas.Study DesignRetrospective multicenter study.SettingTertiary referral center and private otology clinic.PatientsPatients who underwent transcanal endoscopic surgery between January 2015 and September 2020.Intervention(s)Transcanal endocope-assisted resection of middle ear paragangliomas.Main Outcome Measure(s)Demographic data.ResultsTwenty-three patients (2 men, 21 women) with a mean (standard deviation [SD]) age of 50.5 (11.8) years and stage 1 or 2 disease were included in the study. The mean follow-up time was 2.7 years (range, 1-5 yr). Preoperatively, the mean (SD) air-conduction threshold was 33.8 (17.9) dB, and the mean (SD) air-bone gap was 13.1 (13.9) dB. Postoperatively, the mean (SD) air-conduction threshold was 25.7 (10.2) dB, the mean (SD) air-bone gap was 6.3 (6.1) dB. The mean (SD) hospital stay was 27.7 (9.9) hours. No tumor regrowth was detected on magnetic resonance imaging during postoperative follow-up.ConclusionsEndoscopic transcanal tumor resection is effective and feasible in the treatment of stage 1 and 2 tumors and is associated with short operative time, low risk of perioperative and postoperative complications, and rapid discharge

Spatiotemporal delivery of bone morphogenetic protein enhances functional repair of segmental bone defects

Osteogenic growth factors that promote endogenous repair mechanisms hold considerable potential for repairing challenging bone defects. The local delivery of one such growth factor, bone morphogenetic protein (BMP), has been successfully translated to clinical practice for spinal fusion and bone fractures. However, improvements are needed in the spatial and temporal control of BMP delivery to avoid the currently used supraphysiologic doses and the concomitant adverse effects. We have recently introduced a hybrid protein delivery system comprised of two parts: a perforated nanofibrous mesh that spatially confines the defect region and a functionalized alginate hydrogel that provides temporal growth factor release kinetics. Using this unique spatiotemporal delivery system, we previously demonstrated BMP-mediated functional restoration of challenging 8 mm femoral defects in a rat model. In this study, we compared the efficacy of the hybrid system in repairing segmental bone defects to that of the current clinical standard, collagen sponge, at the same dose of recombinant human BMP-2. In addition, we investigated the specific role of the nanofibrous mesh tube on bone regeneration. Our results indicate that the hybrid delivery system significantly increased bone regeneration and improved biomechanical function compared to collagen sponge delivery. Furthermore, we observed that presence of the nanofiber mesh tube was essential to promote maximal mineralized matrix synthesis, prevent extra-anatomical mineralization, and guide an integrated pattern of bone formation. Together, these results suggest that spatiotemporal strategies for osteogenic protein delivery may enhance clinical outcomes by improving localized protein retention