Morphometric Measurements of the Incomplete Partition Type II (IP-II) Cochlea and Implications on Cochlear Implantation.

Hypothesis: The objective of this study is to obtain comprehensive morphometric measurements of the incomplete partition type II (IP-II) cochlea to provide a better understanding of intracochlear anatomy and important considerations for electrode selection and insertion.

Background: IP-II is the most common bony inner ear malformation that often requires cochlear implantation. Currently, there is significant controversy on electrode selection due to a lack of research that can provide reliable, high-resolution measurements.

New non-contrast MRI of endolymphatic hydrops in Ménière's disease considering inversion time.

Objectives: Three-tesla MRI with gadolinium-based contrast agents is important in diagnosing Ménière's disease. However, contrast agents cannot be used in some patients. By using the compositional difference between the inner ear endolymph and perilymph, we performed basic and clinical research focused on potassium ions and protein to find the optimal parameters for visualizing endolymphatic hydrops on MRI without contrast.

Expression of TGFβ-1 and CTGF in the Implanted Cochlea and its Implication on New Tissue Formation.

Hypothesis: Transforming growth factor beta-1 (TGFβ-1) and connective tissue growth factor (CTGF) are upregulated in the implanted human cochlea.

Background: Cochlear implantation can lead to insertion trauma and intracochlear new tissue formation, which can detrimentally affect implant performance. TGFβ-1 and CTGF are profibrotic proteins implicated in various pathologic conditions, but little is known about their role in the cochlea.

Expression of Brain-Derived Neurotrophic Factor in Human Spiral Ganglia Neurons after Cochlear Implantation.

Background: Brain-derived neurotrophic factor (BDNF) is an important factor in the development and neuroprotection of afferent auditory pathways. In this study, we investigated the expression of BDNF in the afferent auditory pathway after cochlear implantation (CI), hypothesizing that electrical stimulation after CI stimulates BDNF expression in the afferent auditory pathway.

Methods: Archival human temporal bones from eight patients with a history of CI and five patients with normal hearing (ages 65-93 years old) were studied.

Dynamic Molecular Markers of Otosclerosis in the Human Cochlea.

Objective: To investigate the role and distribution of various molecular markers using immunohistochemistry and immunofluorescence to further elucidate and understand the pathogenesis of otosclerosis.

Methods: Archival celloidin formalin-fixed 20-micron thick histologic sections from 7 patients diagnosed with otosclerosis were studied and compared to controls. Sections in the mid-modiolar region were immunoreacted with rabbit polyclonal antibodies against nidogen-1, β2-laminin, collagen-IX, BSP, and monoclonal antibodies against TGF β-1 and ubiquitin.

Temporal bone histopathology in revision cochlear implantation.

An increasing number of young infants, as early as six months of age with congenital hearing loss receive cochlear implantation, and it is probable that many of these patients will require revision surgery later in life. The possibility of explantation of the cochlear electrode and reimplantation may cause damage to the cochlea, compromising the speech perception outcome in revision implant is of concern. There is only one prior temporal bone histopathology study to look at the outcome of revision surgery and no prior study evaluating revision cochlear implantation that used the round window approach.

Temporal Trends in Early Pediatric Cochlear Implantations in California from 2018 to 2020.

Objective: To characterize the demographics of children receiving cochlear implantations, identify factors associated with delayed implantations, and trend these factors over time.

Design: Retrospective cross-sectional study.

Setting: Healthcare Cost and Utilization Project California State Ambulatory Surgery Database for calendar years 2018-2020.

Morphometric Analysis and Linear Measurements of the Scala Tympani and Implications in Cochlear Implant Electrodes.

Hypothesis: The objective of this study was to perform detailed height and cross-sectional area measurements of the scala tympani in histologic sections of nondiseased human temporal bones and correlate them with cochlear implant electrode dimensions.

Background: Previous investigations in scala tympani dimensions have used microcomputed tomography or casting modalities, which cannot be correlated directly with microanatomy visible on histologic specimens.

Methods: Three-dimensional reconstructions of 10 archival human temporal bone specimens with no history of middle or inner ear disease were generated using hematoxylin and eosin histopathologic slides.

Immunohistochemical localization of glucocorticoid receptors in the human cochlea.

In the present study we investigated the localization of glucocorticoid receptors (GCR) in the human inner ear using immunohistochemistry. Celloidin-embedded cochlear sections of patients with normal hearing (n = 5), patients diagnosed with MD (n = 5), and noise induced hearing loss (n = 5) were immunostained using GCR rabbit affinity-purified polyclonal antibodies and secondary fluorescent or HRP labeled antibodies. Digital fluorescent images were acquired using a light sheet laser confocal microscope.

Archival Human Temporal Bone: Anatomical and Histopathological Studies of Cochlear Implantation.

Since being FDA approved in 1984, cochlear implantation has been used successfully to restore hearing in those with severe to profound hearing loss with broader applications including single-sided deafness, the use of hybrid electroacoustic stimulation, and implantation at all extremes of age. Cochlear implants have undergone multiple changes in the design aimed at improving the processing technology, while simultaneously minimizing the surgical trauma and foreign body reaction. The following review examines the human temporal bone studies regarding the anatomy of the human cochlea and how the anatomy relates to cochlear implant design, the factors related to complications after implantation, and the predictors of new tissue formation and osteoneogenesis.

Differential Expression of Na/K-ATPase in the Human Saccule of Patients With and Without Otologic Disease.

Hypothesis: Na + , K + -ATPase (Na/K-ATPase) α1 subunit expression in the saccule of patients diagnosed with otologic disease is different compared with normal controls.

Background: We have recently characterized changes in the expression of Na/K-ATPase α1 subunit in the normal and pathological cochlea; however, no studies have determined the distribution Na/K-ATPase α1 subunit in the human saccule. The present study uses archival temporal bones to study the expression Na/K-ATPase α1 subunit in the human saccule.

Cochlear implants: Causes, effects and mitigation strategies for the foreign body response and inflammation.

Cochlear implants provide effective auditory rehabilitation for patients with severe to profound sensorineural hearing loss. Recent advances in cochlear implant technology and surgical approaches have enabled a greater number of patients to benefit from this technology, including those with significant residual low frequency acoustic hearing. Nearly all cochleae implanted with a cochlear implant electrode array develop an inflammatory and fibrotic response.

Relationship Between the Onset of Ménière's Disease and Sympathetic Hyperactivity.

Objective: The pathogenesis of Ménière's disease is still largely unknown; however, it is known to be strongly associated with stress. Excessive stress can cause hyperactivity of the sympathetic autonomic nervous system. With the aim of understanding changes in sympathetic hyperactivity before and after Ménière's disease, we compared autonomic nervous function in patients in a stable phase of Ménière's disease and that in healthy adults.

Association of Socioeconomic Characteristics With Receipt of Pediatric Cochlear Implantations in California.

Importance: Earlier cochlear implantation among children with bilateral severe to profound sensorineural hearing loss is associated with improved language outcomes. More work is necessary to identify patients at risk for delayed cochlear implantation and understand targets for interventions to improve cochlear implantation rates among children.

Objective: To describe the demographics among children receiving cochlear implantations and variability in implantation rates in California and to investigate sociodemographic and parental factors associated with early pediatric cochlear implantation.

Histopathologic Analysis of Temporal Bones With Otosclerosis Following Cochlear Implantation.

Objective: Analyze changes in osteoneogenesis and fibrosis following cochlear implant (CI) surgery in patients with otosclerosis and compare differences based on insertion technique.

Background: When advanced otosclerotic disease extends to the otic capsule, severe and profound sensorineural hearing loss necessitates consideration of a cochlear implant. Histopathological analysis of the human temporal bone after implantation in the patient with otosclerosis may reveal important variables that predict CI success.

Cisplatin ototoxicity histopathology.

This study investigates the histopathological changes of the cochlea and vestibular end organs of a patient who received cisplatin for Hodgkin's lymphoma. He experienced acute high-frequency sensorineural hearing loss and tinnitus after receiving treatment. Using histopathological analysis of his temporal bones after he unfortunately succumbed to his disease, we found that the ototoxic effect of cisplatin is primarily within the cochlea, with significant damage located at the organ of Corti at the base-hook region, consistent with findings in animal models.

Selected Otologic Disorders Causing Dizziness.

Purpose Of Review: This article details updated clinical presentations and current treatment paradigms of the common otologic disorders that may present to the neurologist for vertigo, including Ménière disease, superior semicircular canal dehiscence syndrome, perilymphatic fistula, barotrauma, cholesteatoma, Ramsay Hunt syndrome, enlarged vestibular aqueduct syndrome, and autoimmune inner ear disease including Cogan syndrome.

Recent Findings: The recent data on modern imaging techniques with three-dimensional delayed IV contrast in Ménière disease, findings on the clinical and testing parameters to diagnose semicircular canal dehiscence and barotrauma, and clinical findings in Ramsay Hunt syndrome, cholesteatoma, and enlarged vestibular aqueduct syndrome are discussed in the article. The most recent findings on the treatment and evaluation of autoimmune inner ear disease and Cogan syndrome are also covered.

Cochlear Meniere's: A Distinct Clinical Entity With Isolated Cochlear Hydrops on High-Resolution MRI?

Describe the clinical characteristics of patients with isolated cochlear endolymphatic hydrops (EH). Clinical case series. Tertiary Neurotology referral clinic.

Predictors of Fibrotic and Bone Tissue Formation With 3-D Reconstructions of Post-implantation Human Temporal Bones.

Hypothesis: Years of implantation, surgical insertion approach, and electrode length will impact the volume of new tissue formation secondary to cochlear implantation.

Background: New tissue formation, fibrosis, and osteoneogenesis after cochlear implantation have been implicated in increasing impedance and affecting performance of the cochlear implant.

Methods: 3-D reconstructions of 15 archival human temporal bones from patients with a history of cochlear implantation (CI) were generated from H&E histopathologic slides to study factors which affect volume of tissue formation.

Isolated Saccular Hydrops on High-resolution MRI Is Associated With Full Spectrum Menière's Disease.

Objective: To describe the clinical presentation of patients with isolated saccular endolymphathic hydrops (EH) detected.

Study Design: Clinical case series.

Setting: University-based tertiary referral center.

Immunohistochemical location of Na, K-ATPase α1 subunit in the human inner ear.

Na, K-ATPase (Na,K-ATPase) is an ubiquitous enzyme in the inner ear and a key factor in the maintenance of the osmotic gradient of the endolymph. This study uses Na,K-ATPase α1 subunit immunoreactivity (IR) to identify cellular structures in the normal and disease human cochlea. Formalin-fixed celloidin-embedded (FFCE) human temporal bone sections were immunoreacted with mouse monoclonal antibodies against Na,K-ATPase α1 subunit.

Immune Response of Macrophage Population to Cochlear Implantation: Cochlea Immune Cells.

Hypothesis: The presence and distribution of ionized calcium binding adaptor 1 and CD68 macrophages in the human cochlea is altered in cochlear implantation (CI) compared with the normative or nonimplanted cochlea.

Background: It has been hypothesized that CI induces an immunological response in macrophages leading to implant failure or reduced hearing. Macrophages are resident immune cells in human cochlea and have been shown to phagocytize implant material.