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Cranial Neuropathies I, V, and VII–XII
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Sound waves are transmitted by the pump-like effect of the stapes in the oval window, which creates shock waves that are passed to the round window where the energy dissipates. The pressure wave is transmitted through the perilymph, and leads to vibration of the basilar membrane, depending on the frequency of the sound. When the basilar membrane oscillates, the tectorial membrane has a shearing effect across the hair cells, stimulating the cochlear nerve fibers.
Tailoring Teaching to the Elderly in Home Care
Published in Barbara J. Horn, Facilitating Self Care Practices in the Elderly, 2019
Martha lies Worcester, Ann Loustau, Kathleen O’Connor
Research Findings. Loss of neurons and stiffening of the basilar membrane cause a decreased ability to discriminate speech and increased difficulty in hearing high frequency sounds, particularly soft consonants (e.g., c, ch, f, s, sh, th, and z). Thus, many messages sound garbled and are frequently misunderstood (Corso, 1977; Botwinick, 1984). Hearing loss increases with age. As few as 5 percent are unable to distinguish normal speech at ages 65 to 69. This increases to as many as 30 percent after age 85 (Huntley et al., 1984). The type of hearing deficit makes discrimination of speech from background noises more difficult.
Paediatric Implantation Otology
Published in John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed, Paediatrics, The Ear, Skull Base, 2018
James Ramsden, Payal Mukherjee
The ideal position of the electrode is within the scala tympani where it sits close to the neural elements. Disruption of the basilar membrane by traumatic insertion or displacement into the scala vestibuli causes complete loss of residual hearing and may lead to worse outcomes.4 Electrodes can be modiolar hugging (e.g. Cochlear Contour), Midscala (e.g. Advanced Bionics Midscala electrode) or lateral wall (e.g. MED-EL FLEX electrode).
Effects of basilar-membrane lesions on dynamic responses of the middle ear
Published in Acta Oto-Laryngologica, 2023
Junyi Liang, Wen Xie, Wenjuan Yao, Maoli Duan
Some disorders of metabolism in the cochlear such as mucopolysaccharidosis can cause basilar membrane damage or an increase the sensory cell weight. In addition, the mass of the spiral limbus cells, spiral process, and the spiral ligament increases notably [16]. All these structures are within the organ of Corti, which attaches to the basilar membrane. As a result, added mass of the basilar membrane increases. In addition, some genetic defects can lead to congenital deafness. The main characteristics embody in the hypertrophy of Sertoli cells in cortis device, leads to the increase of the basilar membrane mass. Added mass in the basilar membrane was adopted as the following situation: average thickness increased 0.15 mm, while the added mass is 36 × 10−9 kg. Under 90 dB SPL, compared with the normal human ear, the frequency-response curve of displacement and velocity were respectively obtained, as shown in Figure 7.
The PERK/ATF4/CHOP signaling branch of the unfolded protein response mediates cisplatin-induced ototoxicity in hair cells
Published in Drug and Chemical Toxicology, 2023
Yanji Qu, Shimin Zong, Zhe Wang, Peiyu Du, Yingying Wen, Hao Li, Nan Wu, Hongjun Xiao
The cochlear explants were dissected from SD rats at postnatal day 3 and cultured as previously described (Chen et al.2013, He et al.2017, 2020). Briefly, the animals were kept under specific pathogen-free (SPF) conditions and monitored for health status daily. Neonatal rats (P3, n = 15) were sacrificed by cervical dislocation after euthanasia with pentobarbital solution (50 mg/kg, i.p, Sigma Aldrich, USA). The basilar membrane of the cochlea was dissected out under a microscope. The membrane was then attached to a concretionary drop of PureCol EZ Gel solution (Sigma Aldrich, 5074) in culture media in a 35-mm dish. The explants were cultured in an incubator overnight. Cisplatin was added for 0–48 h to damage the hair cells. This study was approved by the Institutional Animal Care and Use Committee of Tongji Medical College, Huazhong University of Science and Technology, China, and all efforts were made to minimize the number of rats used and their suffering.
Mechanically evoked tinnitus after cochlear implantation with preservation of residual hearing
Published in Cochlear Implants International, 2022
Lenka Vankatova, Julien Wen Hsieh, Dimitrios Daskalou, Pascal Senn
As usual, the round window membrane incision, as well as the posterior tympanotomy, were secured with free soft tissue grafts. During the revision surgery a small amount of fibrosis, which did not contact the ossicular chain, was observed at this level. This would likely have been unable to prevent micro-movements that could then be transmitted to the cochlear structures. We hypothesize that the sound was actually originating within the inner ear, at least in part, through direct mechanical stimulation of the mechano-transducing elements in the cochlea, probably through a contact of the intracochlear electrode array with the basilar membrane. We believe that the occurrence of a mechanically induced tinnitus may be a warning sign for the integrity of intracochlear structures. The hypothesized proximity between the intracochlear array and the basilar membrane may indicate a mechanical stress prior to penetration of the membrane and loss of residual hearing. Again, this concept remains speculative, as the cone-beam CT scan does not offer a sufficient resolution of the intracochlear compartments to formally prove the assumption.