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Acta Oto-laryngologica Jan 2005The round window membrane is considered the most likely pathway from the middle to the inner ear. Various substances placed in the middle ear have been seen to pass... (Review)
Review
The round window membrane is considered the most likely pathway from the middle to the inner ear. Various substances placed in the middle ear have been seen to pass through the round window membrane. Once toxic substances or inflammatory mediators such as cytokines and nitric oxide enter the inner ear, various inner ear sequelae such as labyrinthitis, endolymphatic hydrops, sensorineural hearing loss or more insidious diseases can occur.
Topics: Bacterial Infections; Basilar Membrane; Cell Membrane Permeability; Cytokines; Humans; Labyrinthitis; Nitric Oxide; Otitis Media; Round Window, Ear
PubMed: 15799567
DOI: 10.1080/00016480410022534 -
Balkan Medical Journal Sep 2017Morphologically congenital sensorineural hearing loss can be investigated under two categories. The majority of congenital hearing loss causes (80%) are membranous...
Morphologically congenital sensorineural hearing loss can be investigated under two categories. The majority of congenital hearing loss causes (80%) are membranous malformations. Here, the pathology involves inner ear hair cells. There is no gross bony abnormality and, therefore, in these cases high-resolution computerized tomography and magnetic resonance imaging of the temporal bone reveal normal findings. The remaining 20% have various malformations involving the bony labyrinth and, therefore, can be radiologically demonstrated by computerized tomography and magnetic resonance imaging. The latter group involves surgical challenges as well as problems in decision-making. Some cases may be managed by a hearing aid, others need cochlear implantation, and some cases are candidates for an auditory brainstem implantation (ABI). During cochlear implantation, there may be facial nerve abnormalities, cerebrospinal fluid leakage, electrode misplacement or difficulty in finding the cochlea itself. During surgery for inner ear malformations, the surgeon must be ready to modify the surgical approach or choose special electrodes for surgery. In the present review article, inner ear malformations are classified according to the differences observed in the cochlea. Hearing and language outcomes after various implantation methods are closely related to the status of the cochlear nerve, and a practical classification of the cochlear nerve deficiency is also provided.
Topics: Classification; Cochlea; Cochlear Nerve; Ear, Inner; Hearing Loss, Sensorineural; Humans; Osteogenesis; Temporal Bone; Tomography, X-Ray Computed
PubMed: 28840850
DOI: 10.4274/balkanmedj.2017.0367 -
Proceedings of the Royal Society of... Aug 1976
Topics: Adolescent; Adult; Aged; Child; Ear, Inner; Female; Fistula; Hearing Disorders; Hearing Loss, Noise-Induced; Humans; Intracranial Pressure; Labyrinth Diseases; Male; Middle Aged; Physical Exertion; Pressure; Rest; Rupture
PubMed: 981244
DOI: No ID Found -
Lin Chuang Er Bi Yan Hou Tou Jing Wai... Apr 2021As isolated anatomical position, limited labyrinthine artery supply, and blood-labyrinth barrier hampers systemic drug delivery to the inner ear. The efficient... (Review)
Review
As isolated anatomical position, limited labyrinthine artery supply, and blood-labyrinth barrier hampers systemic drug delivery to the inner ear. The efficient concentration of drug treatment is unsatisfactory and there's possible side effects after systemic administration. Intratympanic injection of drug can bypass the blood-labyrinth and permeated to the hair cells or synaptic area via the round-or oval window of the cochlea. Efficacy and safety of pharmacotherapy has become increasingly relied on the inner ear delivery carrier system. The goal of this review focus on the anatomical barrier that need to be overcome in the intratympanic applications, the improvement of drug retention and specific targets, and the safety of novel drug carriers, these emerging strategies of local drug delivery promise novel and better guidance for the clinical application.
Topics: Cochlea; Drug Carriers; Drug Delivery Systems; Ear, Inner; Round Window, Ear
PubMed: 33794643
DOI: 10.13201/j.issn.2096-7993.2021.04.022 -
Acta Oto-laryngologica. Supplementum 1992Current research and an overall review of round window membrane studies is presented and the concepts that have evolved from these studies are described. Ultrastructural... (Review)
Review
Current research and an overall review of round window membrane studies is presented and the concepts that have evolved from these studies are described. Ultrastructural studies of the round window membrane of rodents, felines, and primates disclosed three basic layers: an outer epithelium lining the middle ear, a middle core of connective tissue, and an inner epithelium bordering the inner ear. Morphological evidence suggests that the membrane participates in: (a) the release of mechanical energy supplied by the ossicular chain to the labyrinthine fluids; (b) an alternative route for sound energy to enter the cochlea; (c) secretion into and absorption from perilymph; and (d) the defense system of the middle and inner ears. Permeability of the round window is considered an accident and not a function of the membrane. The complications of permeability (potential ototoxicity) and its potential usefulness (drug delivery) are discussed.
Topics: Animals; Anti-Bacterial Agents; Cats; Chinchilla; Cochlear Diseases; Connective Tissue; Ear, Inner; Ear, Middle; Epithelial Cells; Epithelium; Female; Humans; Macaca mulatta; Male; Microscopy, Electron, Scanning; Perilymph; Permeability; Pinocytosis; Round Window, Ear
PubMed: 1636422
DOI: No ID Found -
The Annals of Otology, Rhinology, and... 1977Three cases with postinflammatory inner ear sequelae are presented to illustrate unusual histopathologic changes. Endolymphatic hydrops without changes in the...
Three cases with postinflammatory inner ear sequelae are presented to illustrate unusual histopathologic changes. Endolymphatic hydrops without changes in the perilymphatic system was present in one ear following "influenza" meningitis and labyrinthitis ossificans in the contralateral ear. The characteristic histopathological changes of the temporal bones with hematogenic bacterial infection were an extensive labyrinthine ossification associated with a generalized sclerotic change of the whole periotic bone. Bony fixation of the stapedial footplate occurred with the generalized inflammatory process of the otic capsule. Severe and diffuse labyrinthitis ossificans occurred in one case due to tympanogenic inflammation spreading through the round window membrane in the course of suppurative otitis media. A general immunosuppression leading to fatal termination was the apparent factor predisposing to the inner ear complication.
Topics: Adult; Child; Cochlea; Ear, Inner; Ear, Middle; Female; Humans; Influenza, Human; Labyrinth Diseases; Labyrinthitis; Male; Meningitis, Viral; Middle Aged; Ossification, Heterotopic; Osteomyelitis; Otitis Media; Temporal Bone
PubMed: 402099
DOI: 10.1177/000348947708600105 -
Purinergic Signalling Jun 2022The inner ear comprises the cochlea and vestibular system, which detect sound and acceleration stimulation, respectively. The function of the inner ear is regulated by... (Review)
Review
The inner ear comprises the cochlea and vestibular system, which detect sound and acceleration stimulation, respectively. The function of the inner ear is regulated by ion transport activity among sensory epithelial cells, neuronal cells, non-sensory epithelial cells, and luminal fluid with a unique ionic composition of high [K] and low [Na], which enables normal hearing and balance maintenance. One of the important mechanisms regulating ion transport in the inner ear is purinergic signaling. Various purinergic receptors are distributed throughout inner ear epithelial cells and neuronal cells. To date, most studies have focused on the role of purinergic receptors in the cochlea, and few studies have examined these receptors in the vestibular system. As purinergic receptors play an important role in the cochlea, they would likely do the same in the vestibular system, which is fairly similar to the cochlea in cellular structure and function. Based on available studies performed to date, purinergic signaling is postulated to be involved in the regulation of ion homeostasis, protection of hair cells, otoconia formation, and regulation of electrical signaling from the sensory epithelium to vestibular neurons. In this review, the distribution and roles of purinergic receptors in the peripheral vestibular system are summarized and discussed.
Topics: Cochlea; Ear, Inner; Receptors, Purinergic; Signal Transduction; Vestibular System
PubMed: 35344126
DOI: 10.1007/s11302-022-09855-5 -
The Journal of International Advanced... Mar 2021It has been revealed that the pure-tone audiometry demonstrates large air-bone gaps at low pitches due to the presence of inner ear fistulae. When a third mobile window... (Review)
Review
It has been revealed that the pure-tone audiometry demonstrates large air-bone gaps at low pitches due to the presence of inner ear fistulae. When a third mobile window resulting from an inner ear fistula is present, in addition to the 2 normally present windows consisting of the oval window and the round window, a portion of the air-conducted waves escape from the scala vestibuli through the inner ear fistula. On the other hand, bone-conducted waves traveling to the scala vestibuli are reduced by an inner ear fistula; however, bone-conducted waves traveling to the scala tympani are not affected by an inner ear fistula. This results in a larger gap than usual in compliance between both perilymphatic spaces and leads to a decrease in the bone conduction threshold. This phenomenon, so-called the third mobile window effects, sometimes may lead otology/neuro-otology surgeons to misunderstand the reason why large air-bone gaps still exist after ossicular reconstruction in tympanoplasty. This review article gives good examples regarding the third mobile window effects in otology/neuro-otology diseases and surgeries.
Topics: Bone Conduction; Cochlea; Neurotology; Round Window, Ear; Scala Tympani
PubMed: 33893786
DOI: 10.5152/JIAO.2021.8632 -
Hearing Research Mar 2013
Topics: Animals; Cell Lineage; Ear, Inner; Hair Cells, Auditory; Humans; Nerve Regeneration; Signal Transduction
PubMed: 23276729
DOI: 10.1016/j.heares.2012.12.009 -
The American Journal of Otology Apr 1984General anesthesia is not considered as a potential cause of hearing loss. However, three patients who sustained sensorineural hearing loss due to labyrinthine membrane...
General anesthesia is not considered as a potential cause of hearing loss. However, three patients who sustained sensorineural hearing loss due to labyrinthine membrane rupture following general anesthesia with nitrous oxide have come to the authors' attention. These cases are presented and the mechanism causing labyrinthine membrane rupture is discussed.
Topics: Adult; Anesthesia, General; Audiometry, Pure-Tone; Cochlea; Deafness; Female; Hearing Loss, Sensorineural; Humans; Male; Middle Aged; Nitrous Oxide; Oval Window, Ear; Postoperative Complications; Round Window, Ear; Rupture, Spontaneous; Vestibule, Labyrinth
PubMed: 6609644
DOI: No ID Found